T06b forms selection: checkbox, radio, cards, switch, select, combobox, multi select, cascader, transfer list, list box, chips, rating, sliders, knob, stepper

AGENTS.md

@@ -53,6 +53,8 @@ Ely GPUI Component. A component library for GPUI, in light and dark.
 - The macOS open panel runs out of process too. Escape does not reach it; the harness sends it `cancel:`.
 - gpui's `test-support` swaps its executor: `block` fails on a real dispatcher. It stays behind this crate's `test-support` feature, never on for the gallery.
 - A tracked `FocusHandle` is a Tab stop only when built with `.tab_stop(true)`. `tab_index` on the div reaches only handles gpui makes itself.
+- Floating lists go below their anchor, or above when only above has room (`forms::options::float`). gpui's own switch keeps the anchor point, so a flipped list would cover its trigger.
+- Motion for a value change keys its animation on `motion::changes`, so it replays per change and stays still on first paint.
 - Masks reshape edits inside `TextInput::set_fit`, which sees the replaced range and the typed text. A diff after the fact cannot tell typed characters from kept ones.
 - Ids inside a reusable component carry its owner's id or `EntityId`. Twin ids share focus and click state.
 - Set an explicit line height on any box that clips text. gpui's default leading is taller than a tight box, and the clip eats descenders.

TASKS.md

@@ -23,7 +23,7 @@ Per-component lines live in `tasks/`. Tags there:
 - [x] T04 Window & Shell
 - [x] T05 Buttons & Actions
 - [x] T06a Forms · Text
-- [ ] T06b Forms · Selection
+- [x] T06b Forms · Selection
 - [ ] T06c Forms · Date & Time
 - [ ] T06d Forms · Color
 - [ ] T06e Forms · Files
@@ -122,3 +122,6 @@ Per-component lines live in `tasks/`. Tags there:
 | T06a | 1 | FAIL | twin ids in clear and eye buttons; text fields not Tab stops; IME undo; stepping from a stale value; mask literals re-read as input; undo while disabled; Down past the last line; clamp before rounding; stuck mention dismissal; NaN swallowed by min and max |
 | T06a | 2 | FAIL | float error in rounded bounds; composition commit skipped filter and length; a typed leading literal was eaten; PIN select-all collapsed; stepper state read the old value |
 | T06a | 3 | FAIL | a mask diff misread a select-all replacement; grid tolerance too wide for large numbers; fixed after the cap by fitting masks inside `TextInput` with the exact edit, and a float-error tolerance; verified by tests and capture, no fourth review |
+| T06b | 1 | FAIL | kept highlight and cascade trail went out of bounds; keyboard click reclosed MultiSelect and Cascader; disabled rows committed by keyboard; Combobox hid its owner's value; a disabled chosen radio left no Tab stop; a disabled Rating took arrows |
+| T06b | 2 | FAIL | a free Combobox cleared the text it mounted with |
+| T06b | 3 | PASS | |

examples/gallery/pages/forms/choices.rs

@@ -0,0 +1,214 @@
+use ely_gpui_component::{
+    forms::{
+        CheckState, Checkbox, CheckboxCard, CheckboxGroup, Choice, RadioCard, RadioGroup, Switch,
+    },
+    primitives::IconName,
+};
+use gpui::{App, Entity, IntoElement, ParentElement, SharedString, Styled, Window, div, px};
+
+use crate::{
+    probe::probe,
+    ui::{code, section, specimen},
+};
+
+pub(super) fn keep<T: 'static>(
+    key: &'static str,
+    init: impl FnOnce() -> T,
+    window: &mut Window,
+    cx: &mut App,
+) -> Entity<T> {
+    window.use_keyed_state(key, cx, move |_, _| init())
+}
+
+pub(super) fn set<T: 'static>(state: &Entity<T>, value: T, cx: &mut App) {
+    state.update(cx, |state, cx| {
+        *state = value;
+        cx.notify();
+    });
+}
+
+fn values(list: &[&'static str]) -> Vec<SharedString> {
+    list.iter()
+        .map(|value| SharedString::from(*value))
+        .collect()
+}
+
+pub fn checkboxes(window: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let channels = [
+        Choice::new("email", "Email"),
+        Choice::new("push", "Push"),
+        Choice::new("sms", "Text message").disabled(),
+    ];
+    let open: Vec<SharedString> = channels
+        .iter()
+        .filter(|choice| !choice.disabled)
+        .map(|choice| choice.value.clone())
+        .collect();
+    let on = keep("check-channels", || values(&["email"]), window, cx);
+    let now = on.read(cx).clone();
+    let parent = match now.len() {
+        0 => CheckState::Off,
+        n if n == open.len() => CheckState::On,
+        _ => CheckState::Mixed,
+    };
+    let (all, some) = (on.clone(), on.clone());
+    section(
+        "Checkbox / CheckboxGroup",
+        "On, off, or mixed when a parent's children disagree. The check pops in.",
+        cx,
+    )
+    .child(probe(
+        "checks",
+        div()
+            .flex()
+            .flex_col()
+            .gap_2()
+            .w(px(280.0))
+            .child(
+                Checkbox::new("check-all", parent)
+                    .label("All notifications")
+                    .on_change(move |on, _, cx| {
+                        set(&all, if on { open.clone() } else { Vec::new() }, cx)
+                    }),
+            )
+            .child(
+                div().pl_6().child(
+                    CheckboxGroup::new("check-group", channels)
+                        .selected(now)
+                        .on_change(move |next, _, cx| set(&some, next.to_vec(), cx)),
+                ),
+            ),
+    ))
+    .child(code("Checkbox::new(id, CheckState::Mixed)", cx))
+}
+
+pub fn radios(window: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let plan = keep("radio-plan", || SharedString::from("pro"), window, cx);
+    let density = keep(
+        "radio-density",
+        || SharedString::from("standard"),
+        window,
+        cx,
+    );
+    let (plan_now, density_now) = (plan.read(cx).clone(), density.read(cx).clone());
+    section(
+        "Radio / RadioGroup",
+        "One Tab stop per group; the arrow keys move the choice.",
+        cx,
+    )
+    .child(
+        div()
+            .flex()
+            .flex_col()
+            .gap_6()
+            .child(specimen(
+                "plan",
+                probe(
+                    "radios",
+                    RadioGroup::new(
+                        "radio-plan",
+                        [
+                            Choice::new("free", "Free"),
+                            Choice::new("pro", "Pro"),
+                            Choice::new("team", "Team"),
+                            Choice::new("enterprise", "Enterprise").disabled(),
+                        ],
+                    )
+                    .selected(plan_now)
+                    .on_change(move |value, _, cx| set(&plan, value.clone(), cx)),
+                ),
+                cx,
+            ))
+            .child(specimen(
+                "density, in a row",
+                RadioGroup::new(
+                    "radio-density",
+                    [
+                        Choice::new("compact", "Compact"),
+                        Choice::new("standard", "Standard"),
+                        Choice::new("comfortable", "Comfortable"),
+                    ],
+                )
+                .horizontal()
+                .selected(density_now)
+                .on_change(move |value, _, cx| set(&density, value.clone(), cx)),
+                cx,
+            )),
+    )
+}
+
+pub fn cards(window: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let space = keep("card-space", || SharedString::from("personal"), window, cx);
+    let backup = keep("card-backup", || true, window, cx);
+    let (space_now, backup_now) = (space.read(cx).clone(), *backup.read(cx));
+    let (personal, team) = (space.clone(), space);
+    section(
+        "CheckboxCard / RadioCard",
+        "Larger targets that explain a choice. The chosen border turns to ink.",
+        cx,
+    )
+    .child(probe(
+        "cards",
+        div()
+            .flex()
+            .gap_3()
+            .w(px(640.0))
+            .child(
+                div().flex_1().child(
+                    RadioCard::new("card-personal", space_now == "personal", "Personal")
+                        .description("Just you. Notes stay on this Mac.")
+                        .icon(IconName::User)
+                        .on_select(move |_, cx| set(&personal, "personal".into(), cx)),
+                ),
+            )
+            .child(
+                div().flex_1().child(
+                    RadioCard::new("card-team", space_now == "team", "Team")
+                        .description("Shared with everyone you invite.")
+                        .icon(IconName::Users)
+                        .on_select(move |_, cx| set(&team, "team".into(), cx)),
+                ),
+            ),
+    ))
+    .child(
+        div().w(px(640.0)).child(
+            CheckboxCard::new("card-backup", backup_now, "Back up nightly")
+                .description("Copies change sets to the cloud at 2 AM.")
+                .icon(IconName::Cloud)
+                .on_change(move |on, _, cx| set(&backup, on, cx)),
+        ),
+    )
+}
+
+pub fn switches(window: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let wifi = keep("switch-wifi", || true, window, cx);
+    let sync = keep("switch-sync", || false, window, cx);
+    let (wifi_now, sync_now) = (*wifi.read(cx), *sync.read(cx));
+    section(
+        "Switch / Toggle",
+        "Takes effect at once. The thumb slides with a little overshoot.",
+        cx,
+    )
+    .child(probe(
+        "switches",
+        div()
+            .flex()
+            .flex_col()
+            .gap_3()
+            .child(
+                Switch::new("switch-wifi", wifi_now)
+                    .label("Wi-Fi")
+                    .on_change(move |on, _, cx| set(&wifi, on, cx)),
+            )
+            .child(
+                Switch::new("switch-sync", sync_now)
+                    .label("Sync over cellular")
+                    .on_change(move |on, _, cx| set(&sync, on, cx)),
+            )
+            .child(
+                Switch::new("switch-locked", true)
+                    .label("Managed by your admin")
+                    .disabled(true),
+            ),
+    ))
+}

examples/gallery/pages/forms/mod.rs

@@ -1,7 +1,10 @@
+mod choices;
 mod formats;
 mod numbers;
+mod pickers;
 mod rich;
 mod text;
+mod values;
 
 use gpui::{AnyElement, App, IntoElement, ParentElement, Window, div};
 
@@ -109,6 +112,74 @@ const SCRIPT: &[Step] = &[
     Step::Wait(1200),
     Step::CancelPanel,
     Step::Wait(600),
+    Step::DownAt("checks", 40.0, 66.0),
+    Step::UpAt("checks", 40.0, 66.0),
+    Step::Wait(300),
+    Step::Shot("checks"),
+    Step::DownAt("radios", 30.0, 66.0),
+    Step::UpAt("radios", 30.0, 66.0),
+    Step::Wait(400),
+    Step::Shot("radios"),
+    Step::DownAt("cards", 480.0, 30.0),
+    Step::UpAt("cards", 480.0, 30.0),
+    Step::Wait(400),
+    Step::Shot("cards"),
+    Step::DownAt("switches", 16.0, 39.0),
+    Step::UpAt("switches", 16.0, 39.0),
+    Step::Wait(600),
+    Step::Shot("switches"),
+    Step::Click("select"),
+    Step::Wait(300),
+    Step::Key("down"),
+    Step::Wait(200),
+    Step::Shot("select-open"),
+    Step::Key("enter"),
+    Step::Wait(300),
+    Step::Click("combobox"),
+    Step::Key("secondary-a"),
+    Step::Type("lis"),
+    Step::Wait(300),
+    Step::Shot("combobox"),
+    Step::Key("enter"),
+    Step::Wait(200),
+    Step::Click("multi"),
+    Step::Wait(300),
+    Step::Key("down"),
+    Step::Key("enter"),
+    Step::Wait(300),
+    Step::Shot("multi"),
+    Step::Key("escape"),
+    Step::Click("cascader"),
+    Step::Wait(300),
+    Step::Key("down"),
+    Step::Key("right"),
+    Step::Wait(300),
+    Step::Shot("cascader"),
+    Step::Key("escape"),
+    Step::DownAt("transfer", 60.0, 45.0),
+    Step::UpAt("transfer", 60.0, 45.0),
+    Step::Wait(200),
+    Step::DownAt("transfer", 280.0, 134.0),
+    Step::UpAt("transfer", 280.0, 134.0),
+    Step::Wait(300),
+    Step::Shot("transfer"),
+    Step::DownAt("chips", 120.0, 14.0),
+    Step::UpAt("chips", 120.0, 14.0),
+    Step::DownAt("rating", 79.0, 13.0),
+    Step::UpAt("rating", 79.0, 13.0),
+    Step::Wait(300),
+    Step::Shot("chips-rating"),
+    Step::DownAt("slider", 130.0, 8.0),
+    Step::DragTo("slider", 220.0, 8.0),
+    Step::UpAt("slider", 220.0, 8.0),
+    Step::Wait(200),
+    Step::DownAt("knob", 24.0, 24.0),
+    Step::DragTo("knob", 24.0, -36.0),
+    Step::UpAt("knob", 24.0, -36.0),
+    Step::DownAt("stepper", 76.0, 16.0),
+    Step::UpAt("stepper", 76.0, 16.0),
+    Step::Wait(300),
+    Step::Shot("values"),
     Step::Rest,
 ];
 
@@ -133,5 +204,19 @@ fn render(window: &mut Window, cx: &mut App) -> AnyElement {
         .child(rich::regex(window, cx))
         .child(rich::expression(window, cx))
         .child(rich::hotkey(window, cx))
+        .child(choices::checkboxes(window, cx))
+        .child(choices::radios(window, cx))
+        .child(choices::cards(window, cx))
+        .child(choices::switches(window, cx))
+        .child(pickers::select(window, cx))
+        .child(pickers::list_box(window, cx))
+        .child(pickers::combobox(window, cx))
+        .child(pickers::multi_select(window, cx))
+        .child(pickers::cascader(window, cx))
+        .child(pickers::transfer(window, cx))
+        .child(values::chips(window, cx))
+        .child(values::rating(window, cx))
+        .child(values::sliders(window, cx))
+        .child(values::dials(window, cx))
         .into_any_element()
 }

examples/gallery/pages/forms/pickers.rs

@@ -0,0 +1,235 @@
+use ely_gpui_component::{
+    forms::{Cascade, Cascader, Choice, Combobox, ListBox, MultiSelect, Select, TransferList},
+    primitives::IconName,
+};
+use gpui::{App, IntoElement, ParentElement, SharedString, Styled, Window, div, px};
+
+use super::{
+    choices::{keep, set},
+    text::field,
+};
+use crate::{
+    probe::probe,
+    ui::{blocked, section, specimen, specimens},
+};
+
+fn cities() -> Vec<Choice> {
+    [
+        ("ams", "Amsterdam"),
+        ("ber", "Berlin"),
+        ("cph", "Copenhagen"),
+        ("lis", "Lisbon"),
+        ("lon", "London"),
+        ("osl", "Oslo"),
+        ("par", "Paris"),
+        ("vie", "Vienna"),
+    ]
+    .into_iter()
+    .map(|(value, label)| Choice::new(value, label))
+    .collect()
+}
+
+pub fn select(window: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let view = keep("select-view", || SharedString::from("list"), window, cx);
+    let now = view.read(cx).clone();
+    section(
+        "Select / NativeSelect",
+        "A button that opens its list. Arrows move, Enter picks, Escape closes.",
+        cx,
+    )
+    .child(
+        specimens()
+            .child(specimen(
+                "view",
+                probe(
+                    "select",
+                    div().w(px(240.0)).child(
+                        Select::new(
+                            "select-view",
+                            [
+                                Choice::new("list", "List").icon(IconName::List),
+                                Choice::new("board", "Board").icon(IconName::Kanban),
+                                Choice::new("calendar", "Calendar").icon(IconName::Calendar),
+                                Choice::new("gallery", "Gallery")
+                                    .icon(IconName::LayoutGrid)
+                                    .disabled(),
+                            ],
+                        )
+                        .selected(now)
+                        .on_change(move |value, _, cx| set(&view, value.clone(), cx)),
+                    ),
+                ),
+                cx,
+            ))
+            .child(specimen(
+                "disabled",
+                div().w(px(200.0)).child(
+                    Select::new("select-off", [Choice::new("utc", "UTC")])
+                        .selected("utc")
+                        .disabled(true),
+                ),
+                cx,
+            )),
+    )
+    .child(blocked(
+        "NativeSelect: gpui 0.2.2 has no native popup menu, so Select draws its own.",
+        cx,
+    ))
+}
+
+pub fn list_box(window: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let picked = keep(
+        "listbox-cities",
+        || vec![SharedString::from("lis")],
+        window,
+        cx,
+    );
+    let now = picked.read(cx).clone();
+    section(
+        "ListBox",
+        "A list chosen from in place. Focus it and use the arrows, Space or Enter.",
+        cx,
+    )
+    .child(
+        div().w(px(240.0)).child(
+            ListBox::new("listbox-cities", cities())
+                .selected(now)
+                .on_change(move |next, _, cx| set(&picked, next.to_vec(), cx)),
+        ),
+    )
+}
+
+pub fn combobox(window: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let city = field("input-city", window, cx, |input| {
+        input.placeholder("Search cities")
+    });
+    let tag = field("input-tag", window, cx, |input| {
+        input.placeholder("Any label")
+    });
+    let chosen = keep("combobox-city", || None::<SharedString>, window, cx);
+    let now = chosen.read(cx).clone();
+    let labels: Vec<Choice> = ["design", "docs", "infra", "motion", "release"]
+        .into_iter()
+        .map(|label| Choice::new(label, label))
+        .collect();
+    let mut combo = Combobox::new("combobox-city", &city, cities())
+        .on_change(move |value, _, cx| set(&chosen, Some(value.clone()), cx));
+    if let Some(value) = now {
+        combo = combo.selected(value);
+    }
+    section(
+        "Combobox / Autocomplete",
+        "Type to filter. A combobox keeps a listed value; an autocomplete keeps any text.",
+        cx,
+    )
+    .child(
+        specimens()
+            .child(specimen(
+                "combobox",
+                probe("combobox", div().w(px(260.0)).child(combo)),
+                cx,
+            ))
+            .child(specimen(
+                "autocomplete",
+                div()
+                    .w(px(260.0))
+                    .child(Combobox::new("combobox-tag", &tag, labels).free()),
+                cx,
+            )),
+    )
+}
+
+pub fn multi_select(window: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let picked = keep(
+        "multi-cities",
+        || vec![SharedString::from("ber"), SharedString::from("osl")],
+        window,
+        cx,
+    );
+    let now = picked.read(cx).clone();
+    section(
+        "MultiSelect",
+        "Several values as chips. The list stays open while you pick; Backspace drops the last.",
+        cx,
+    )
+    .child(probe(
+        "multi",
+        div().w(px(360.0)).child(
+            MultiSelect::new("multi-cities", cities())
+                .selected(now)
+                .placeholder("Pick cities")
+                .on_change(move |next, _, cx| set(&picked, next.to_vec(), cx)),
+        ),
+    ))
+}
+
+pub fn cascader(window: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let path = keep(
+        "cascade-office",
+        || {
+            vec![
+                SharedString::from("eu"),
+                SharedString::from("pt"),
+                SharedString::from("lis"),
+            ]
+        },
+        window,
+        cx,
+    );
+    let now = path.read(cx).clone();
+    let world = [
+        Cascade::new("am", "Americas")
+            .child(
+                Cascade::new("us", "United States")
+                    .child(Cascade::new("nyc", "New York"))
+                    .child(Cascade::new("sfo", "San Francisco")),
+            )
+            .child(Cascade::new("br", "Brazil").child(Cascade::new("sao", "São Paulo"))),
+        Cascade::new("eu", "Europe")
+            .child(
+                Cascade::new("pt", "Portugal")
+                    .child(Cascade::new("lis", "Lisbon"))
+                    .child(Cascade::new("opo", "Porto")),
+            )
+            .child(Cascade::new("de", "Germany").child(Cascade::new("ber", "Berlin"))),
+        Cascade::new("as", "Asia")
+            .child(Cascade::new("jp", "Japan").child(Cascade::new("tyo", "Tokyo"))),
+    ];
+    section(
+        "CascadeSelect / Cascader",
+        "Each column opens the next. Right and Left walk the levels; a leaf picks the path.",
+        cx,
+    )
+    .child(probe(
+        "cascader",
+        div().w(px(320.0)).child(
+            Cascader::new("cascade-office", world)
+                .selected(now)
+                .on_change(move |next, _, cx| set(&path, next.to_vec(), cx)),
+        ),
+    ))
+}
+
+pub fn transfer(window: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let chosen = keep(
+        "transfer-cities",
+        || vec![SharedString::from("par")],
+        window,
+        cx,
+    );
+    let now = chosen.read(cx).clone();
+    section(
+        "TransferList",
+        "Mark rows on one side, then move them across.",
+        cx,
+    )
+    .child(probe(
+        "transfer",
+        div().w(px(560.0)).child(
+            TransferList::new("transfer-cities", cities())
+                .chosen(now)
+                .titles("Cities", "On the tour")
+                .on_change(move |next, _, cx| set(&chosen, next.to_vec(), cx)),
+        ),
+    ))
+}

examples/gallery/pages/forms/values.rs

@@ -0,0 +1,176 @@
+use ely_gpui_component::forms::{Choice, ChoiceChips, Knob, RangeSlider, Rating, Slider, Stepper};
+use gpui::{App, IntoElement, ParentElement, SharedString, Styled, Window, div, px};
+
+use super::choices::{keep, set};
+use crate::{
+    probe::probe,
+    ui::{section, specimen, specimens},
+};
+
+pub fn chips(window: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let sort = keep("chips-sort", || vec![SharedString::from("new")], window, cx);
+    let teams = keep(
+        "chips-teams",
+        || vec![SharedString::from("design")],
+        window,
+        cx,
+    );
+    let (sort_now, teams_now) = (sort.read(cx).clone(), teams.read(cx).clone());
+    section(
+        "ChoiceChips / FilterChips",
+        "Pills for a few options. Filter chips toggle and show a check.",
+        cx,
+    )
+    .child(
+        div()
+            .flex()
+            .flex_col()
+            .gap_6()
+            .child(specimen(
+                "choice",
+                probe(
+                    "chips",
+                    ChoiceChips::new(
+                        "chips-sort",
+                        [
+                            Choice::new("new", "Newest"),
+                            Choice::new("top", "Popular"),
+                            Choice::new("old", "Oldest"),
+                        ],
+                    )
+                    .selected(sort_now)
+                    .on_change(move |next, _, cx| set(&sort, next.to_vec(), cx)),
+                ),
+                cx,
+            ))
+            .child(specimen(
+                "filter",
+                ChoiceChips::new(
+                    "chips-teams",
+                    [
+                        Choice::new("design", "Design"),
+                        Choice::new("eng", "Engineering"),
+                        Choice::new("research", "Research"),
+                        Choice::new("ops", "Operations").disabled(),
+                    ],
+                )
+                .multiple()
+                .selected(teams_now)
+                .on_change(move |next, _, cx| set(&teams, next.to_vec(), cx)),
+                cx,
+            )),
+    )
+}
+
+pub fn rating(window: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let stars = keep("rating-stars", || 3u8, window, cx);
+    let now = *stars.read(cx);
+    section(
+        "Rating",
+        "Hover previews, a click sets it, and clicking the same star clears it.",
+        cx,
+    )
+    .child(
+        specimens()
+            .child(specimen(
+                format!("{now} of 5"),
+                probe(
+                    "rating",
+                    Rating::new("rating-stars", now)
+                        .on_change(move |next, _, cx| set(&stars, next, cx)),
+                ),
+                cx,
+            ))
+            .child(specimen(
+                "read only",
+                Rating::new("rating-fixed", 4).disabled(true),
+                cx,
+            )),
+    )
+}
+
+pub fn sliders(window: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let volume = keep("slider-volume", || 40.0, window, cx);
+    let level = keep("slider-level", || 60.0, window, cx);
+    let price = keep("slider-price", || (20.0, 80.0), window, cx);
+    let (volume_now, level_now, (low, high)) = (*volume.read(cx), *level.read(cx), *price.read(cx));
+    section(
+        "Slider / RangeSlider / VerticalSlider",
+        "Drag a thumb, click the track, or use the arrows; Page keys jump ten steps.",
+        cx,
+    )
+    .child(
+        specimens()
+            .child(specimen(
+                format!("volume {volume_now:.0}"),
+                probe(
+                    "slider",
+                    div().w(px(320.0)).child(
+                        Slider::new("slider-volume", volume_now)
+                            .on_change(move |next, _, cx| set(&volume, next, cx)),
+                    ),
+                ),
+                cx,
+            ))
+            .child(specimen(
+                format!("price {low:.0} to {high:.0}"),
+                div().w(px(320.0)).child(
+                    RangeSlider::new("slider-price", low, high)
+                        .step(5.0)
+                        .on_change(move |next, _, cx| set(&price, next, cx)),
+                ),
+                cx,
+            ))
+            .child(specimen(
+                format!("level {level_now:.0}"),
+                div().h(px(140.0)).child(
+                    Slider::new("slider-level", level_now)
+                        .vertical()
+                        .step(5.0)
+                        .on_change(move |next, _, cx| set(&level, next, cx)),
+                ),
+                cx,
+            )),
+    )
+}
+
+pub fn dials(window: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let gain = keep("knob-gain", || 65.0, window, cx);
+    let pan = keep("knob-pan", || 0.0, window, cx);
+    let guests = keep("stepper-guests", || 2.0, window, cx);
+    let (gain_now, pan_now, guests_now) = (*gain.read(cx), *pan.read(cx), *guests.read(cx));
+    section(
+        "Knob / Dial / Stepper",
+        "Drag a knob up or down, or use the arrows. The stepper counts without typing.",
+        cx,
+    )
+    .child(
+        specimens()
+            .child(specimen(
+                format!("gain {gain_now:.0}"),
+                probe(
+                    "knob",
+                    Knob::new("knob-gain", gain_now)
+                        .on_change(move |next, _, cx| set(&gain, next, cx)),
+                ),
+                cx,
+            ))
+            .child(specimen(
+                format!("pan {pan_now:.0}"),
+                Knob::new("knob-pan", pan_now)
+                    .range(-50.0, 50.0)
+                    .on_change(move |next, _, cx| set(&pan, next, cx)),
+                cx,
+            ))
+            .child(specimen(
+                "guests",
+                probe(
+                    "stepper",
+                    Stepper::new("stepper-guests", guests_now)
+                        .range(1.0, 10.0)
+                        .on_change(move |next, _, cx| set(&guests, next, cx)),
+                ),
+                cx,
+            )),
+    )
+}

src/forms/card.rs

@@ -0,0 +1,243 @@
+use std::rc::Rc;
+
+use gpui::{
+    AnyElement, App, Div, ElementId, FocusHandle, FontWeight, InteractiveElement, IntoElement,
+    MouseButton, ParentElement, RenderOnce, SharedString, Stateful, StatefulInteractiveElement,
+    Styled, Window, div, prelude::*,
+};
+
+use super::{
+    CheckState,
+    check::{check_mark, tab_stop},
+    options::{OnFlag, Run},
+    radio::radio_mark,
+};
+use crate::{
+    motion,
+    primitives::{Icon, IconName},
+    theme::{ActiveTheme, IconSize, Radius, TextSize},
+};
+
+/// What a card says: a title, a line under it, and an icon at its end.
+struct Face {
+    title: SharedString,
+    description: Option<SharedString>,
+    icon: Option<IconName>,
+    disabled: bool,
+    on: bool,
+}
+
+impl Face {
+    fn new(title: SharedString, on: bool) -> Self {
+        Self {
+            title,
+            description: None,
+            icon: None,
+            disabled: false,
+            on,
+        }
+    }
+}
+
+/// A bordered choice: the mark, then the words. The border darkens while chosen.
+fn card(
+    id: ElementId,
+    face: Face,
+    mark: AnyElement,
+    focus: &FocusHandle,
+    press: Run,
+    window: &Window,
+    cx: &App,
+) -> Stateful<Div> {
+    let (on, focused) = (face.on, focus.is_focused(window));
+    let theme = cx.theme();
+    let colors = &theme.colors;
+    let border = if focused {
+        colors.focus
+    } else if on {
+        colors.accent
+    } else {
+        colors.border
+    };
+    let strong = colors.border_strong;
+    div()
+        .id(id)
+        .track_focus(focus)
+        .flex()
+        .items_start()
+        .gap_3()
+        .p_4()
+        .rounded(theme.radius(Radius::Lg))
+        .border_1()
+        .border_color(border)
+        .bg(colors.surface)
+        .map(|card| {
+            if face.disabled {
+                return card.opacity(0.5);
+            }
+            card.cursor_pointer()
+                .when(!on && !focused, |card| {
+                    card.hover(|style| style.border_color(strong))
+                })
+                .on_mouse_down(MouseButton::Left, |_, window, _| window.prevent_default())
+                .on_click(move |_, window, cx| press(window, cx))
+        })
+        .child(div().pt_0p5().child(mark))
+        .child(
+            div()
+                .flex_1()
+                .flex()
+                .flex_col()
+                .gap_0p5()
+                .child(
+                    div()
+                        .text_size(theme.text_size(TextSize::Base))
+                        .font_weight(FontWeight::MEDIUM)
+                        .text_color(colors.fg)
+                        .child(face.title),
+                )
+                .when_some(face.description, |words, description| {
+                    words.child(
+                        div()
+                            .text_size(theme.text_size(TextSize::Sm))
+                            .text_color(colors.fg_muted)
+                            .child(description),
+                    )
+                }),
+        )
+        .when_some(face.icon, |card, icon| {
+            card.child(Icon::new(icon).size(IconSize::Md).color(colors.fg_muted))
+        })
+}
+
+/// A card that turns on and off, with a checkbox in its corner.
+#[derive(IntoElement)]
+pub struct CheckboxCard {
+    id: ElementId,
+    checked: bool,
+    face: Face,
+    on_change: Option<OnFlag>,
+}
+
+impl CheckboxCard {
+    pub fn new(id: impl Into<ElementId>, checked: bool, title: impl Into<SharedString>) -> Self {
+        Self {
+            id: id.into(),
+            checked,
+            face: Face::new(title.into(), checked),
+            on_change: None,
+        }
+    }
+
+    pub fn description(mut self, text: impl Into<SharedString>) -> Self {
+        self.face.description = Some(text.into());
+        self
+    }
+
+    pub fn icon(mut self, icon: IconName) -> Self {
+        self.face.icon = Some(icon);
+        self
+    }
+
+    pub fn disabled(mut self, disabled: bool) -> Self {
+        self.face.disabled = disabled;
+        self
+    }
+
+    pub fn on_change(mut self, handler: impl Fn(bool, &mut Window, &mut App) + 'static) -> Self {
+        self.on_change = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for CheckboxCard {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let focus = tab_stop(
+            (self.id.clone(), "focus").into(),
+            !self.face.disabled,
+            window,
+            cx,
+        );
+        let changes = motion::changes((self.id.clone(), "changes"), self.checked, window, cx);
+        let (id, next, on_change) = (self.id.clone(), !self.checked, self.on_change);
+        let mark = check_mark(
+            CheckState::from(self.checked),
+            false,
+            self.face.disabled,
+            changes,
+            cx,
+        );
+        let press: Run = Rc::new(move |window, cx| {
+            log::info!("checkbox card {id:?}: {}", if next { "on" } else { "off" });
+            if let Some(on_change) = &on_change {
+                on_change(next, window, cx);
+            }
+        });
+        card(self.id, self.face, mark, &focus, press, window, cx)
+    }
+}
+
+/// A card chosen from several, with a radio in its corner.
+#[derive(IntoElement)]
+pub struct RadioCard {
+    id: ElementId,
+    selected: bool,
+    face: Face,
+    on_select: Option<Run>,
+}
+
+impl RadioCard {
+    pub fn new(id: impl Into<ElementId>, selected: bool, title: impl Into<SharedString>) -> Self {
+        Self {
+            id: id.into(),
+            selected,
+            face: Face::new(title.into(), selected),
+            on_select: None,
+        }
+    }
+
+    pub fn description(mut self, text: impl Into<SharedString>) -> Self {
+        self.face.description = Some(text.into());
+        self
+    }
+
+    pub fn icon(mut self, icon: IconName) -> Self {
+        self.face.icon = Some(icon);
+        self
+    }
+
+    pub fn disabled(mut self, disabled: bool) -> Self {
+        self.face.disabled = disabled;
+        self
+    }
+
+    /// Runs when chosen while not selected.
+    pub fn on_select(mut self, handler: impl Fn(&mut Window, &mut App) + 'static) -> Self {
+        self.on_select = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for RadioCard {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let focus = tab_stop(
+            (self.id.clone(), "focus").into(),
+            !self.face.disabled,
+            window,
+            cx,
+        );
+        let changes = motion::changes((self.id.clone(), "changes"), self.selected, window, cx);
+        let (id, selected, on_select) = (self.id.clone(), self.selected, self.on_select);
+        let mark = radio_mark(self.selected, false, self.face.disabled, changes, cx);
+        let press: Run = Rc::new(move |window, cx| {
+            if selected {
+                return;
+            }
+            log::info!("radio card {id:?}: chosen");
+            if let Some(on_select) = &on_select {
+                on_select(window, cx);
+            }
+        });
+        card(self.id, self.face, mark, &focus, press, window, cx)
+    }
+}

src/forms/cascade.rs

@@ -0,0 +1,430 @@
+use std::rc::Rc;
+
+use gpui::{
+    App, Bounds, ClickEvent, ElementId, Entity, InteractiveElement, IntoElement, ParentElement,
+    Pixels, RenderOnce, SharedString, StatefulInteractiveElement, Styled, Window, canvas, div,
+    prelude::*,
+};
+
+use super::{
+    Choice,
+    check::tab_stop,
+    input::text_size,
+    options::{OnValues, float, option_row, surface},
+};
+use crate::{
+    primitives::{Icon, IconName},
+    theme::{ActiveTheme, ControlSize, IconSize, Radius},
+};
+
+/// A node of a cascade: a value, its label, and the nodes under it.
+#[derive(Clone, Debug, PartialEq)]
+pub struct Cascade {
+    pub value: SharedString,
+    pub label: SharedString,
+    pub children: Vec<Cascade>,
+}
+
+impl Cascade {
+    pub fn new(value: impl Into<SharedString>, label: impl Into<SharedString>) -> Self {
+        Self {
+            value: value.into(),
+            label: label.into(),
+            children: Vec::new(),
+        }
+    }
+
+    pub fn child(mut self, node: Cascade) -> Self {
+        self.children.push(node);
+        self
+    }
+}
+
+/// The columns a trail opens: the roots, then the children of each step with any.
+fn columns<'a>(roots: &'a [Cascade], trail: &[usize]) -> Vec<&'a [Cascade]> {
+    let mut out = vec![roots];
+    for &ix in trail {
+        let node = &out[out.len() - 1][ix];
+        if node.children.is_empty() {
+            break;
+        }
+        out.push(&node.children);
+    }
+    out
+}
+
+/// Row indices along `path`, as far as it matches.
+fn trail_of(roots: &[Cascade], path: &[SharedString]) -> Vec<usize> {
+    let mut trail = Vec::new();
+    let mut level = roots;
+    for value in path {
+        let Some(ix) = level.iter().position(|node| node.value == *value) else {
+            break;
+        };
+        trail.push(ix);
+        level = &level[ix].children;
+    }
+    trail
+}
+
+/// `trail` cut back to rows that still exist; never empty.
+fn fit_trail(roots: &[Cascade], trail: &[usize]) -> Vec<usize> {
+    let mut fitted = Vec::new();
+    let mut level = roots;
+    for &ix in trail {
+        let Some(node) = level.get(ix) else {
+            break;
+        };
+        fitted.push(ix);
+        level = &node.children;
+    }
+    if fitted.is_empty() {
+        fitted.push(0);
+    }
+    fitted
+}
+
+/// The nodes a trail passes through.
+fn nodes<'a>(roots: &'a [Cascade], trail: &[usize]) -> Vec<&'a Cascade> {
+    let mut level = roots;
+    trail
+        .iter()
+        .map(|&ix| {
+            let node = &level[ix];
+            level = &node.children;
+            node
+        })
+        .collect()
+}
+
+#[derive(Default)]
+struct Trail {
+    open: bool,
+    trail: Vec<usize>,
+    anchor: Bounds<Pixels>,
+}
+
+fn show(state: &Entity<Trail>, open: bool, trail: Vec<usize>, cx: &mut App) {
+    state.update(cx, |state, cx| {
+        state.open = open;
+        state.trail = trail;
+        cx.notify();
+    });
+}
+
+type PickTrail = Rc<dyn Fn(Vec<usize>, &mut Window, &mut App)>;
+
+/// A select over a tree: each column opens the next, and a leaf picks the path.
+#[derive(IntoElement)]
+pub struct Cascader {
+    id: ElementId,
+    roots: Vec<Cascade>,
+    selected: Vec<SharedString>,
+    placeholder: SharedString,
+    size: ControlSize,
+    on_change: Option<OnValues>,
+}
+
+impl Cascader {
+    pub fn new(id: impl Into<ElementId>, roots: impl IntoIterator<Item = Cascade>) -> Self {
+        Self {
+            id: id.into(),
+            roots: roots.into_iter().collect(),
+            selected: Vec::new(),
+            placeholder: SharedString::from("Choose…"),
+            size: ControlSize::default(),
+            on_change: None,
+        }
+    }
+
+    /// The chosen path, root first.
+    pub fn selected(mut self, path: impl IntoIterator<Item = impl Into<SharedString>>) -> Self {
+        self.selected = path.into_iter().map(Into::into).collect();
+        self
+    }
+
+    pub fn placeholder(mut self, text: impl Into<SharedString>) -> Self {
+        self.placeholder = text.into();
+        self
+    }
+
+    pub fn size(mut self, size: ControlSize) -> Self {
+        self.size = size;
+        self
+    }
+
+    pub fn on_change(
+        mut self,
+        handler: impl Fn(&[SharedString], &mut Window, &mut App) + 'static,
+    ) -> Self {
+        self.on_change = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for Cascader {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        assert!(
+            !self.roots.is_empty(),
+            "cascader {:?} has no roots",
+            self.id
+        );
+        let focus = tab_stop((self.id.clone(), "focus").into(), true, window, cx);
+        let focused = focus.is_focused(window);
+        let state = window.use_keyed_state((self.id.clone(), "trail"), cx, |_, _| Trail::default());
+        if state.read(cx).open && !focused {
+            state.update(cx, |state, _| state.open = false);
+        }
+        let roots = Rc::new(self.roots);
+        let start = {
+            let trail = trail_of(&roots, &self.selected);
+            if trail.is_empty() { vec![0] } else { trail }
+        };
+        let kept = state.read(cx).trail.clone();
+        let fitted = fit_trail(&roots, &kept);
+        if fitted != kept {
+            state.update(cx, |state, _| state.trail = fitted);
+        }
+        let (open, trail, anchor) = {
+            let state = state.read(cx);
+            (state.open, state.trail.clone(), state.anchor)
+        };
+        let pick: PickTrail = {
+            let (id, roots, state, on_change) = (
+                self.id.clone(),
+                roots.clone(),
+                state.clone(),
+                self.on_change,
+            );
+            Rc::new(move |trail, window, cx| {
+                let path: Vec<SharedString> = nodes(&roots, &trail)
+                    .iter()
+                    .map(|node| node.value.clone())
+                    .collect();
+                log::info!("cascader {id:?}: {path:?}");
+                show(&state, false, trail, cx);
+                if let Some(on_change) = &on_change {
+                    on_change(&path, window, cx);
+                }
+            })
+        };
+        let theme = cx.theme();
+        let colors = &theme.colors;
+        let shown: Vec<SharedString> = nodes(&roots, &trail_of(&roots, &self.selected))
+            .iter()
+            .map(|node| node.label.clone())
+            .collect();
+        let (click, keys, measure) = (state.clone(), state.clone(), state.clone());
+        let (enter, key_roots, key_start) = (pick.clone(), roots.clone(), start.clone());
+        let lists = open.then(|| {
+            let columns = columns(&roots, &trail);
+            let deepest = columns.iter().map(|column| column.len()).max().unwrap_or(0);
+            let lists = columns.iter().enumerate().map(|(level, column)| {
+                let rows = column.iter().enumerate().map(|(ix, node)| {
+                    let (hover, pick) = (state.clone(), pick.clone());
+                    let at: Vec<usize> = trail[..level].iter().copied().chain([ix]).collect();
+                    let leaf = node.children.is_empty();
+                    let choice = Choice::new(node.value.clone(), node.label.clone());
+                    option_row(
+                        ("row", ix),
+                        &choice,
+                        trail.get(level) == Some(&ix),
+                        None,
+                        cx,
+                    )
+                    .when(!leaf, |row| {
+                        row.child(
+                            Icon::new(IconName::ChevronRight)
+                                .size(IconSize::Xs)
+                                .color(colors.fg_subtle),
+                        )
+                    })
+                    .on_hover({
+                        let at = at.clone();
+                        move |hovered, _, cx| {
+                            if *hovered && hover.read(cx).trail != at {
+                                show(&hover, true, at.clone(), cx);
+                            }
+                        }
+                    })
+                    .when(leaf, |row| {
+                        row.on_click(move |_, window, cx| pick(at.clone(), window, cx))
+                    })
+                });
+                div()
+                    .id(("column", level))
+                    .w(theme.tooltip_max_width() * 0.75)
+                    .max_h(theme.list_max_height())
+                    .overflow_y_scroll()
+                    .p_1()
+                    .flex()
+                    .flex_col()
+                    .when(level > 0, |list| {
+                        list.border_l_1().border_color(colors.border)
+                    })
+                    .children(rows)
+            });
+            let close = state.clone();
+            float(
+                anchor,
+                deepest,
+                surface((self.id.clone(), "columns"), cx)
+                    .flex()
+                    .on_mouse_down_out(move |_, _, cx| {
+                        let trail = close.read(cx).trail.clone();
+                        show(&close, false, trail, cx)
+                    })
+                    .children(lists),
+                window,
+                cx,
+            )
+        });
+        div()
+            .id(self.id)
+            .track_focus(&focus)
+            .relative()
+            .flex()
+            .items_center()
+            .gap_2()
+            .w_full()
+            .h(theme.control_height(self.size))
+            .px(theme.control_padding(self.size))
+            .rounded(theme.radius(Radius::Md))
+            .border_1()
+            .border_color(if focused {
+                colors.focus
+            } else {
+                colors.border_strong
+            })
+            .bg(colors.surface)
+            .text_size(theme.text_size(text_size(self.size)))
+            .cursor_pointer()
+            .on_click(move |event, _, cx| {
+                if matches!(event, ClickEvent::Mouse(_)) {
+                    show(&click, !open, start.clone(), cx)
+                }
+            })
+            .on_key_down(move |event, window, cx| {
+                let key = event.keystroke.key.as_str();
+                let mut trail = keys.read(cx).trail.clone();
+                if !open {
+                    if matches!(key, "down" | "up" | "enter" | "space") {
+                        cx.stop_propagation();
+                        show(&keys, true, key_start.clone(), cx);
+                    }
+                    return;
+                }
+                let columns = columns(&key_roots, &trail);
+                let level = trail.len() - 1;
+                let (at, count) = (trail[level], columns[level].len());
+                let node = &columns[level][at];
+                match key {
+                    "down" => trail[level] = (at + 1) % count,
+                    "up" => trail[level] = (at + count - 1) % count,
+                    "right" if !node.children.is_empty() => trail.push(0),
+                    "left" if level > 0 => {
+                        trail.pop();
+                    }
+                    "enter" | "space" if node.children.is_empty() => {
+                        cx.stop_propagation();
+                        return enter(trail, window, cx);
+                    }
+                    "enter" | "space" => trail.push(0),
+                    "escape" => {
+                        cx.stop_propagation();
+                        return show(&keys, false, trail, cx);
+                    }
+                    _ => return,
+                }
+                cx.stop_propagation();
+                show(&keys, true, trail, cx);
+            })
+            .child(
+                div()
+                    .flex_1()
+                    .min_w_0()
+                    .overflow_hidden()
+                    .text_ellipsis()
+                    .whitespace_nowrap()
+                    .text_color(if shown.is_empty() {
+                        colors.fg_subtle
+                    } else {
+                        colors.fg
+                    })
+                    .child(if shown.is_empty() {
+                        self.placeholder
+                    } else {
+                        SharedString::from(shown.join(" / "))
+                    }),
+            )
+            .child(
+                Icon::new(IconName::ChevronsUpDown)
+                    .size(IconSize::Xs)
+                    .color(colors.fg_subtle),
+            )
+            .child(
+                canvas(
+                    move |bounds, _, cx| {
+                        if measure.read(cx).anchor != bounds {
+                            measure.update(cx, |state, _| state.anchor = bounds);
+                        }
+                    },
+                    |_, _, _, _| {},
+                )
+                .absolute()
+                .top_0()
+                .left_0()
+                .size_full(),
+            )
+            .children(lists)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use gpui::SharedString;
+
+    use super::{Cascade, columns, fit_trail, nodes, trail_of};
+
+    fn world() -> Vec<Cascade> {
+        vec![
+            Cascade::new("asia", "Asia").child(
+                Cascade::new("jp", "Japan")
+                    .child(Cascade::new("tyo", "Tokyo"))
+                    .child(Cascade::new("osa", "Osaka")),
+            ),
+            Cascade::new("eu", "Europe").child(Cascade::new("pt", "Portugal")),
+        ]
+    }
+
+    #[test]
+    fn a_trail_opens_one_column_per_parent() {
+        let roots = world();
+        assert_eq!(columns(&roots, &[0]).len(), 2);
+        assert_eq!(columns(&roots, &[0, 0]).len(), 3);
+        assert_eq!(columns(&roots, &[0, 0, 1]).len(), 3);
+    }
+
+    #[test]
+    fn a_trail_is_cut_back_to_rows_that_exist() {
+        let roots = world();
+        assert_eq!(fit_trail(&roots, &[0, 0, 1]), [0, 0, 1]);
+        assert_eq!(fit_trail(&roots, &[1, 5]), [1]);
+        assert_eq!(fit_trail(&roots, &[9]), [0]);
+        assert_eq!(fit_trail(&roots, &[]), [0]);
+    }
+
+    #[test]
+    fn paths_and_trails_round_trip() {
+        let roots = world();
+        let path: Vec<SharedString> = vec!["asia".into(), "jp".into(), "osa".into()];
+        let trail = trail_of(&roots, &path);
+        assert_eq!(trail, [0, 0, 1]);
+        let labels: Vec<_> = nodes(&roots, &trail)
+            .iter()
+            .map(|node| node.label.clone())
+            .collect();
+        assert_eq!(labels, ["Asia", "Japan", "Osaka"]);
+        assert_eq!(trail_of(&roots, &["eu".into(), "xx".into()]), [1]);
+    }
+}

src/forms/check.rs

@@ -0,0 +1,303 @@
+use std::rc::Rc;
+
+use gpui::{
+    Animation, AnimationExt, AnyElement, App, ElementId, FocusHandle, InteractiveElement,
+    IntoElement, MouseButton, ParentElement, RenderOnce, SharedString, StatefulInteractiveElement,
+    Styled, Window, div, prelude::*,
+};
+
+use super::{
+    Choice,
+    options::{OnFlag, OnValues},
+};
+use crate::{
+    motion,
+    primitives::{Icon, IconName},
+    theme::{ActiveTheme, IconSize, Mix, Radius, TextSize},
+};
+
+/// A checkbox's state. `Mixed` is the dash for a parent whose children disagree.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
+pub enum CheckState {
+    #[default]
+    Off,
+    On,
+    Mixed,
+}
+
+impl From<bool> for CheckState {
+    fn from(on: bool) -> Self {
+        if on { Self::On } else { Self::Off }
+    }
+}
+
+/// A focus handle kept for `id`, a Tab stop while enabled.
+pub(crate) fn tab_stop(
+    id: ElementId,
+    enabled: bool,
+    window: &mut Window,
+    cx: &mut App,
+) -> FocusHandle {
+    window
+        .use_keyed_state(id, cx, |_, cx| cx.focus_handle())
+        .read(cx)
+        .clone()
+        .tab_stop(enabled)
+}
+
+/// The box alone, shared by checkboxes, cards and lists. `changes` replays its motion.
+pub(crate) fn check_mark(
+    state: CheckState,
+    focused: bool,
+    disabled: bool,
+    changes: usize,
+    cx: &App,
+) -> AnyElement {
+    let theme = cx.theme();
+    let colors = &theme.colors;
+    let on = state != CheckState::Off;
+    let border = if focused {
+        colors.focus
+    } else if on {
+        colors.accent
+    } else {
+        colors.border_strong
+    };
+    let (from, to) = if on {
+        (colors.surface, colors.accent)
+    } else {
+        (colors.accent, colors.surface)
+    };
+    let glyph = match state {
+        CheckState::On => Some(IconName::Check),
+        CheckState::Mixed => Some(IconName::Minus),
+        CheckState::Off => None,
+    };
+    let ink = colors.on_accent;
+    let mark = div()
+        .flex()
+        .flex_none()
+        .items_center()
+        .justify_center()
+        .size(theme.check_size())
+        .rounded(theme.radius(Radius::Sm))
+        .border_1()
+        .border_color(border)
+        .bg(to)
+        .when(disabled, |mark| mark.opacity(0.5))
+        .when_some(glyph, |mark, glyph| {
+            let icon = Icon::new(glyph).size(IconSize::Xs).color(ink);
+            if changes == 0 {
+                return mark.child(icon);
+            }
+            mark.child(
+                icon.with_animation(
+                    ("check-glyph", changes),
+                    Animation::new(motion::duration(motion::FAST, cx))
+                        .with_easing(motion::ease_out_cubic),
+                    move |icon, t| icon.scale(0.6 + 0.4 * t).color(ink.opacity(t)),
+                ),
+            )
+        });
+    if changes == 0 {
+        return mark.into_any_element();
+    }
+    mark.with_animation(
+        ("check-fill", changes),
+        Animation::new(motion::duration(motion::FAST, cx)),
+        move |mark, t| mark.bg(from.mix(&to, t)),
+    )
+    .into_any_element()
+}
+
+/// A box that is on, off, or mixed, with an optional label beside it.
+#[derive(IntoElement)]
+pub struct Checkbox {
+    id: ElementId,
+    state: CheckState,
+    label: Option<SharedString>,
+    disabled: bool,
+    on_change: Option<OnFlag>,
+}
+
+impl Checkbox {
+    pub fn new(id: impl Into<ElementId>, state: impl Into<CheckState>) -> Self {
+        Self {
+            id: id.into(),
+            state: state.into(),
+            label: None,
+            disabled: false,
+            on_change: None,
+        }
+    }
+
+    pub fn label(mut self, label: impl Into<SharedString>) -> Self {
+        self.label = Some(label.into());
+        self
+    }
+
+    pub fn disabled(mut self, disabled: bool) -> Self {
+        self.disabled = disabled;
+        self
+    }
+
+    /// Runs with the new value. Mixed and off both turn on.
+    pub fn on_change(mut self, handler: impl Fn(bool, &mut Window, &mut App) + 'static) -> Self {
+        self.on_change = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for Checkbox {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let focus = tab_stop(
+            (self.id.clone(), "focus").into(),
+            !self.disabled,
+            window,
+            cx,
+        );
+        let changes = motion::changes((self.id.clone(), "changes"), self.state, window, cx);
+        let focused = focus.is_focused(window);
+        let next = self.state != CheckState::On;
+        let (id, on_change) = (self.id.clone(), self.on_change);
+        let theme = cx.theme();
+        let fg = if self.disabled {
+            theme.colors.fg_disabled
+        } else {
+            theme.colors.fg
+        };
+        div()
+            .id(self.id)
+            .track_focus(&focus)
+            .flex()
+            .items_center()
+            .gap_2()
+            .text_size(theme.text_size(TextSize::Base))
+            .text_color(fg)
+            .when(!self.disabled, |row| {
+                row.cursor_pointer()
+                    .on_mouse_down(MouseButton::Left, |_, window, _| window.prevent_default())
+                    .on_click(move |_, window, cx| {
+                        log::info!("checkbox {id:?}: {}", if next { "on" } else { "off" });
+                        if let Some(on_change) = &on_change {
+                            on_change(next, window, cx);
+                        }
+                    })
+            })
+            .child(check_mark(self.state, focused, self.disabled, changes, cx))
+            .children(self.label)
+    }
+}
+
+/// Checkboxes for a list of choices; any number can be on.
+#[derive(IntoElement)]
+pub struct CheckboxGroup {
+    id: ElementId,
+    choices: Vec<Choice>,
+    selected: Vec<SharedString>,
+    on_change: Option<OnValues>,
+}
+
+impl CheckboxGroup {
+    pub fn new(id: impl Into<ElementId>, choices: impl IntoIterator<Item = Choice>) -> Self {
+        Self {
+            id: id.into(),
+            choices: choices.into_iter().collect(),
+            selected: Vec::new(),
+            on_change: None,
+        }
+    }
+
+    pub fn selected(mut self, values: impl IntoIterator<Item = impl Into<SharedString>>) -> Self {
+        self.selected = values.into_iter().map(Into::into).collect();
+        self
+    }
+
+    pub fn on_change(
+        mut self,
+        handler: impl Fn(&[SharedString], &mut Window, &mut App) + 'static,
+    ) -> Self {
+        self.on_change = Some(Rc::new(handler));
+        self
+    }
+}
+
+/// `selected` with `value` turned on or off, in choice order.
+pub(crate) fn toggled(
+    choices: &[Choice],
+    selected: &[SharedString],
+    value: &SharedString,
+    on: bool,
+) -> Vec<SharedString> {
+    choices
+        .iter()
+        .map(|choice| &choice.value)
+        .filter(|candidate| {
+            if *candidate == value {
+                on
+            } else {
+                selected.contains(candidate)
+            }
+        })
+        .cloned()
+        .collect()
+}
+
+impl RenderOnce for CheckboxGroup {
+    fn render(self, _: &mut Window, _: &mut App) -> impl IntoElement {
+        let (choices, selected, on_change) = (
+            Rc::new(self.choices),
+            Rc::new(self.selected),
+            self.on_change,
+        );
+        let boxes: Vec<_> = choices
+            .iter()
+            .enumerate()
+            .map(|(ix, choice)| {
+                let (choices, selected, on_change) =
+                    (choices.clone(), selected.clone(), on_change.clone());
+                let value = choice.value.clone();
+                Checkbox::new(("check", ix), selected.contains(&choice.value))
+                    .label(choice.label.clone())
+                    .disabled(choice.disabled)
+                    .on_change(move |on, window, cx| {
+                        let next = toggled(&choices, &selected, &value, on);
+                        if let Some(on_change) = &on_change {
+                            on_change(&next, window, cx);
+                        }
+                    })
+            })
+            .collect();
+        div().id(self.id).flex().flex_col().gap_2().children(boxes)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use gpui::SharedString;
+
+    use super::{Choice, toggled};
+
+    #[test]
+    fn toggling_keeps_choice_order() {
+        let choices = [
+            Choice::new("a", "A"),
+            Choice::new("b", "B"),
+            Choice::new("c", "C"),
+        ];
+        let on = |values: &[&str]| {
+            values
+                .iter()
+                .map(|v| SharedString::from(v.to_string()))
+                .collect::<Vec<_>>()
+        };
+        assert_eq!(
+            toggled(&choices, &on(&["c"]), &"a".into(), true),
+            on(&["a", "c"])
+        );
+        assert_eq!(
+            toggled(&choices, &on(&["a", "c"]), &"a".into(), false),
+            on(&["c"])
+        );
+    }
+}

src/forms/chips.rs

@@ -0,0 +1,121 @@
+use std::rc::Rc;
+
+use gpui::{
+    App, ElementId, InteractiveElement, IntoElement, MouseButton, ParentElement, RenderOnce,
+    SharedString, StatefulInteractiveElement, Styled, Window, div, prelude::*,
+};
+
+use super::{Choice, listbox::chosen, options::OnValues};
+use crate::{
+    primitives::{FocusRing, Icon, IconName},
+    theme::{ActiveTheme, ControlSize, IconSize, TextSize},
+};
+
+/// Pills for a short set of choices. One is chosen, or several with `multiple`.
+#[derive(IntoElement)]
+pub struct ChoiceChips {
+    id: ElementId,
+    choices: Vec<Choice>,
+    selected: Vec<SharedString>,
+    multiple: bool,
+    on_change: Option<OnValues>,
+}
+
+impl ChoiceChips {
+    pub fn new(id: impl Into<ElementId>, choices: impl IntoIterator<Item = Choice>) -> Self {
+        Self {
+            id: id.into(),
+            choices: choices.into_iter().collect(),
+            selected: Vec::new(),
+            multiple: false,
+            on_change: None,
+        }
+    }
+
+    pub fn selected(mut self, values: impl IntoIterator<Item = impl Into<SharedString>>) -> Self {
+        self.selected = values.into_iter().map(Into::into).collect();
+        self
+    }
+
+    /// Filter chips: each toggles, and chosen ones show a check.
+    pub fn multiple(mut self) -> Self {
+        self.multiple = true;
+        self
+    }
+
+    pub fn on_change(
+        mut self,
+        handler: impl Fn(&[SharedString], &mut Window, &mut App) + 'static,
+    ) -> Self {
+        self.on_change = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for ChoiceChips {
+    fn render(self, _: &mut Window, cx: &mut App) -> impl IntoElement {
+        let theme = cx.theme();
+        let colors = &theme.colors;
+        let (choices, selected) = (Rc::new(self.choices), Rc::new(self.selected));
+        let chips: Vec<_> = choices
+            .iter()
+            .enumerate()
+            .map(|(ix, choice)| {
+                let on = selected.contains(&choice.value);
+                let (fg, bg, border) = if on {
+                    (colors.on_accent, colors.accent, colors.accent)
+                } else {
+                    (colors.fg_muted, colors.surface, colors.border_strong)
+                };
+                let (id, choices, selected, multiple, on_change) = (
+                    self.id.clone(),
+                    choices.clone(),
+                    selected.clone(),
+                    self.multiple,
+                    self.on_change.clone(),
+                );
+                div()
+                    .id(("chip", ix))
+                    .flex()
+                    .items_center()
+                    .gap_1p5()
+                    .h(theme.control_height(ControlSize::Sm))
+                    .px_3()
+                    .rounded_full()
+                    .border_1()
+                    .border_color(border)
+                    .bg(bg)
+                    .text_size(theme.text_size(TextSize::Sm))
+                    .text_color(if choice.disabled {
+                        colors.fg_disabled
+                    } else {
+                        fg
+                    })
+                    .when(!choice.disabled, |chip| {
+                        chip.tab_index(0)
+                            .focus_ring(cx)
+                            .cursor_pointer()
+                            .when(!on, |chip| chip.hover(|style| style.bg(colors.hover)))
+                            .on_mouse_down(MouseButton::Left, |_, window, _| {
+                                window.prevent_default()
+                            })
+                            .on_click(move |_, window, cx| {
+                                let next = chosen(&choices, &selected, ix, multiple);
+                                log::info!("choice chips {id:?}: {next:?}");
+                                if let Some(on_change) = &on_change {
+                                    on_change(&next, window, cx);
+                                }
+                            })
+                    })
+                    .when(on && self.multiple, |chip| {
+                        chip.child(Icon::new(IconName::Check).size(IconSize::Xs).color(fg))
+                    })
+                    .when_some(choice.icon, |chip, icon| {
+                        chip.child(Icon::new(icon).size(IconSize::Xs).color(fg))
+                    })
+                    .child(choice.label.clone())
+            })
+            .collect();
+        div().id(self.id).flex().flex_wrap().gap_2().children(chips)
+    }
+}

src/forms/combobox.rs

@@ -0,0 +1,286 @@
+use std::rc::Rc;
+
+use gpui::{
+    App, Context, ElementId, Entity, InteractiveElement, IntoElement, ParentElement, RenderOnce,
+    SharedString, Styled, Subscription, Window, div, prelude::*,
+};
+
+use super::{
+    Choice, Input, InputEvent, TextInput,
+    options::{OnValue, Pick, Popup, step},
+    select::{Picker, measure_anchor},
+    text::{Down, Enter, Up},
+};
+use crate::{
+    primitives::{Icon, IconName},
+    theme::{ActiveTheme, ControlSize, IconSize},
+};
+
+/// Rows whose label holds `query`, ignoring case. All rows for an empty query.
+pub(crate) fn matching(choices: &[Choice], query: &str) -> Vec<Choice> {
+    let query = query.trim().to_lowercase();
+    choices
+        .iter()
+        .filter(|choice| choice.label.to_lowercase().contains(&query))
+        .cloned()
+        .collect()
+}
+
+/// What a combobox restores on blur, and whether Escape closed it.
+struct Typing {
+    restore: Option<SharedString>,
+    dismissed: bool,
+    last: String,
+    shown: Option<Option<SharedString>>,
+    _blur: Subscription,
+}
+
+/// A text field that filters a list as you type. Enter or a click picks a row.
+#[derive(IntoElement)]
+pub struct Combobox {
+    id: ElementId,
+    state: Entity<TextInput>,
+    choices: Vec<Choice>,
+    selected: Option<SharedString>,
+    free: bool,
+    size: ControlSize,
+    on_change: Option<OnValue>,
+}
+
+impl Combobox {
+    pub fn new(
+        id: impl Into<ElementId>,
+        state: &Entity<TextInput>,
+        choices: impl IntoIterator<Item = Choice>,
+    ) -> Self {
+        Self {
+            id: id.into(),
+            state: state.clone(),
+            choices: choices.into_iter().collect(),
+            selected: None,
+            free: false,
+            size: ControlSize::default(),
+            on_change: None,
+        }
+    }
+
+    pub fn selected(mut self, value: impl Into<SharedString>) -> Self {
+        self.selected = Some(value.into());
+        self
+    }
+
+    /// Keeps any text; the list only completes it, as an autocomplete does.
+    pub fn free(mut self) -> Self {
+        self.free = true;
+        self
+    }
+
+    pub fn size(mut self, size: ControlSize) -> Self {
+        self.size = size;
+        self
+    }
+
+    /// Runs with the value of a picked row.
+    pub fn on_change(
+        mut self,
+        handler: impl Fn(&SharedString, &mut Window, &mut App) + 'static,
+    ) -> Self {
+        self.on_change = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for Combobox {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let input = self.state.clone();
+        let typing = window.use_keyed_state(
+            (self.id.clone(), "typing"),
+            cx,
+            |window, cx: &mut Context<Typing>| {
+                let blur = cx.subscribe_in(&input, window, |typing, input, event, _, cx| {
+                    if *event != InputEvent::Blur {
+                        return;
+                    }
+                    typing.dismissed = false;
+                    if let Some(label) = typing.restore.clone()
+                        && input.read(cx).text() != label.as_ref()
+                    {
+                        log::info!("combobox: kept {label:?}");
+                        input.update(cx, |input, cx| input.set_text(label, cx));
+                    }
+                });
+                Typing {
+                    restore: None,
+                    dismissed: false,
+                    last: String::new(),
+                    shown: None,
+                    _blur: blur,
+                }
+            },
+        );
+        let picker =
+            window.use_keyed_state((self.id.clone(), "picker"), cx, |_, _| Picker::default());
+        let label = self
+            .selected
+            .as_ref()
+            .and_then(|value| self.choices.iter().find(|choice| choice.value == *value))
+            .map(|choice| choice.label.clone());
+        let focused = self.state.read(cx).focus().is_focused(window);
+        if typing.read(cx).shown.as_ref() != Some(&self.selected) {
+            typing.update(cx, |typing, _| typing.shown = Some(self.selected.clone()));
+            let wanted = match (&label, self.free) {
+                (Some(label), _) => Some(label.clone()),
+                (None, false) => Some(SharedString::default()),
+                (None, true) => None,
+            };
+            if let Some(label) = wanted
+                && !focused
+                && self.state.read(cx).text() != label.as_ref()
+            {
+                log::info!("combobox {:?}: shows {label:?}", self.id);
+                self.state.update(cx, |input, cx| input.set_text(label, cx));
+            }
+        }
+        let text = self.state.read(cx).text().to_string();
+        let restore = (!self.free).then(|| label.clone().unwrap_or_default());
+        typing.update(cx, |typing, _| {
+            typing.restore = restore;
+            if typing.last != text {
+                typing.last = text.clone();
+                typing.dismissed = false;
+            }
+        });
+        let query = if label.as_ref().is_some_and(|label| label.as_ref() == text) {
+            ""
+        } else {
+            text.as_str()
+        };
+        let rows = Rc::new(matching(&self.choices, query));
+        let open = focused && !typing.read(cx).dismissed && !rows.is_empty();
+        let kept = picker.read(cx).highlighted;
+        let highlighted = if rows.get(kept).is_some_and(|row| !row.disabled) {
+            kept
+        } else {
+            step(&rows, rows.len().saturating_sub(1), 1)
+        };
+        let (anchor, scroll) = (picker.read(cx).anchor, picker.read(cx).scroll.clone());
+        let pick: Pick = {
+            let (id, rows, state, typing, on_change) = (
+                self.id.clone(),
+                rows.clone(),
+                self.state.clone(),
+                typing.clone(),
+                self.on_change,
+            );
+            Rc::new(move |ix, window, cx| {
+                let choice = rows[ix].clone();
+                if choice.disabled {
+                    return;
+                }
+                log::info!("combobox {id:?}: {}", choice.value);
+                state.update(cx, |input, cx| input.set_text(choice.label.clone(), cx));
+                typing.update(cx, |typing, cx| {
+                    typing.last = choice.label.to_string();
+                    typing.dismissed = true;
+                    cx.notify();
+                });
+                if let Some(on_change) = &on_change {
+                    on_change(&choice.value, window, cx);
+                }
+            })
+        };
+        let chosen: Vec<SharedString> = self.selected.iter().cloned().collect();
+        let subtle = cx.theme().colors.fg_subtle;
+        let (up, down, enter, escape) = (
+            (picker.clone(), rows.clone()),
+            (picker.clone(), rows.clone(), typing.clone()),
+            pick.clone(),
+            typing.clone(),
+        );
+        div()
+            .id(self.id.clone())
+            .relative()
+            .w_full()
+            .capture_action(move |_: &Up, _, cx| {
+                if open {
+                    cx.stop_propagation();
+                    let at = step(&up.1, highlighted, -1);
+                    Picker::show(&up.0, true, at, cx);
+                }
+            })
+            .capture_action(move |_: &Down, _, cx| {
+                let (picker, rows, typing) = &down;
+                if open {
+                    cx.stop_propagation();
+                    Picker::show(picker, true, step(rows, highlighted, 1), cx);
+                } else if typing.read(cx).dismissed {
+                    cx.stop_propagation();
+                    typing.update(cx, |typing, cx| {
+                        typing.dismissed = false;
+                        cx.notify();
+                    });
+                }
+            })
+            .capture_action(move |_: &Enter, window, cx| {
+                if open {
+                    cx.stop_propagation();
+                    enter(highlighted, window, cx);
+                }
+            })
+            .on_key_down(move |event, _, cx| {
+                if open && event.keystroke.key == "escape" {
+                    cx.stop_propagation();
+                    escape.update(cx, |typing, cx| {
+                        typing.dismissed = true;
+                        cx.notify();
+                    });
+                }
+            })
+            .child(
+                Input::new(&self.state).size(self.size).suffix(
+                    Icon::new(IconName::ChevronsUpDown)
+                        .size(IconSize::Xs)
+                        .color(subtle),
+                ),
+            )
+            .child(measure_anchor(picker))
+            .when(open, |field| {
+                field.child(
+                    Popup {
+                        id: (self.id, "list").into(),
+                        anchor,
+                        rows: &rows,
+                        highlighted: Some(highlighted),
+                        checked: Some(&chosen),
+                        pick,
+                        dismiss: None,
+                        scroll: Some(&scroll),
+                    }
+                    .render(window, cx),
+                )
+            })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{Choice, matching};
+
+    #[test]
+    fn matching_ignores_case_and_keeps_order() {
+        let rows = [
+            Choice::new("ber", "Berlin"),
+            Choice::new("lis", "Lisbon"),
+            Choice::new("oslo", "Oslo"),
+        ];
+        let labels = |query| {
+            matching(&rows, query)
+                .into_iter()
+                .map(|c| c.label)
+                .collect::<Vec<_>>()
+        };
+        assert_eq!(labels("LI"), ["Berlin", "Lisbon"]);
+        assert_eq!(labels(""), ["Berlin", "Lisbon", "Oslo"]);
+        assert!(labels("xyz").is_empty());
+    }
+}

src/forms/knob.rs

@@ -0,0 +1,196 @@
+use std::{cell::Cell, f32::consts::PI, rc::Rc};
+
+use gpui::{
+    App, DragMoveEvent, ElementId, EmptyView, EntityId, InteractiveElement, IntoElement,
+    ParentElement, Path, PathBuilder, Pixels, Point, RenderOnce, StatefulInteractiveElement,
+    Styled, Window, canvas, div, point, prelude::*,
+};
+
+use super::{
+    check::tab_stop,
+    options::OnNumber,
+    slider::{fraction, keyed, value_at},
+};
+use crate::theme::{ActiveTheme, Elevation};
+
+/// Where the dial starts, at lower left, and how far it turns.
+const START: f32 = 0.75 * PI;
+const SWEEP: f32 = 1.5 * PI;
+
+fn at_angle(center: Point<Pixels>, radius: Pixels, angle: f32) -> Point<Pixels> {
+    point(
+        center.x + radius * angle.cos(),
+        center.y + radius * angle.sin(),
+    )
+}
+
+/// A stroked arc clockwise from `from` to `to`, in radians.
+fn arc(center: Point<Pixels>, radius: Pixels, from: f32, to: f32, width: Pixels) -> Path<Pixels> {
+    let mut path = PathBuilder::stroke(width);
+    path.move_to(at_angle(center, radius, from));
+    path.arc_to(
+        point(radius, radius),
+        Pixels::ZERO,
+        to - from > PI,
+        true,
+        at_angle(center, radius, to),
+    );
+    path.build().expect("an arc is a simple open path")
+}
+
+struct Turn {
+    owner: EntityId,
+    start: Rc<Cell<Option<(Pixels, f64)>>>,
+}
+
+/// A dial for audio-style values. Drag up or down, or use the arrow keys.
+#[derive(IntoElement)]
+pub struct Knob {
+    id: ElementId,
+    value: f64,
+    range: (f64, f64, f64),
+    disabled: bool,
+    on_change: Option<OnNumber>,
+}
+
+impl Knob {
+    pub fn new(id: impl Into<ElementId>, value: f64) -> Self {
+        Self {
+            id: id.into(),
+            value,
+            range: (0.0, 100.0, 1.0),
+            disabled: false,
+            on_change: None,
+        }
+    }
+
+    pub fn range(mut self, min: f64, max: f64) -> Self {
+        assert!(min < max, "knob range {min}..{max} is empty");
+        self.range.0 = min;
+        self.range.1 = max;
+        self
+    }
+
+    pub fn step(mut self, step: f64) -> Self {
+        assert!(step > 0.0, "knob step {step} must be positive");
+        self.range.2 = step;
+        self
+    }
+
+    pub fn disabled(mut self, disabled: bool) -> Self {
+        self.disabled = disabled;
+        self
+    }
+
+    pub fn on_change(mut self, handler: impl Fn(f64, &mut Window, &mut App) + 'static) -> Self {
+        self.on_change = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for Knob {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let ((min, max, step), value) = (self.range, self.value);
+        let focus = tab_stop(
+            (self.id.clone(), "focus").into(),
+            !self.disabled,
+            window,
+            cx,
+        );
+        let focused = focus.is_focused(window);
+        let owner = window
+            .use_keyed_state((self.id.clone(), "drag"), cx, |_, _| ())
+            .entity_id();
+        let theme = cx.theme();
+        let colors = &theme.colors;
+        let (diameter, width) = theme.knob();
+        let (travel, stroke) = (
+            diameter.to_pixels(window.rem_size()) * 4.0,
+            width.to_pixels(window.rem_size()),
+        );
+        let turned = fraction(value, min, max);
+        let (rail, ink, tick) = (colors.border, colors.accent, colors.fg);
+        let commit = {
+            let (id, on_change) = (self.id.clone(), self.on_change);
+            Rc::new(move |next: f64, window: &mut Window, cx: &mut App| {
+                if next == value {
+                    return;
+                }
+                log::debug!("knob {id:?}: {next}");
+                if let Some(on_change) = &on_change {
+                    on_change(next, window, cx);
+                }
+            })
+        };
+        let (drag, keys) = (commit.clone(), commit);
+        div()
+            .id(self.id)
+            .track_focus(&focus)
+            .relative()
+            .flex_none()
+            .size(diameter)
+            .rounded_full()
+            .bg(colors.surface)
+            .border_1()
+            .border_color(if focused { colors.focus } else { colors.border })
+            .shadow(theme.elevation(Elevation::Raised))
+            .when(self.disabled, |knob| knob.opacity(0.5))
+            .child(
+                canvas(
+                    |_, _, _| {},
+                    move |bounds, _, window, _| {
+                        let center = bounds.center();
+                        let radius = bounds.size.width / 2.0 - stroke * 1.5;
+                        window.paint_path(arc(center, radius, START, START + SWEEP, stroke), rail);
+                        if turned > 0.0 {
+                            let to = START + SWEEP * turned;
+                            window.paint_path(arc(center, radius, START, to, stroke), ink);
+                        }
+                        let angle = START + SWEEP * turned;
+                        let mut line = PathBuilder::stroke(stroke);
+                        line.move_to(at_angle(center, radius * 0.3, angle));
+                        line.line_to(at_angle(center, radius * 0.62, angle));
+                        window.paint_path(line.build().expect("a tick is a straight line"), tick);
+                    },
+                )
+                .absolute()
+                .size_full(),
+            )
+            .when(!self.disabled, |knob| {
+                knob.cursor_ns_resize()
+                    .on_drag(
+                        Turn {
+                            owner,
+                            start: Rc::new(Cell::new(None)),
+                        },
+                        |turn, _, _, cx| {
+                            turn.start.set(None);
+                            cx.new(|_| EmptyView)
+                        },
+                    )
+                    .on_drag_move(move |event: &DragMoveEvent<Turn>, window, cx| {
+                        let turn = event.drag(cx);
+                        if turn.owner != owner {
+                            return;
+                        }
+                        let (start, y) = (turn.start.clone(), event.event.position.y);
+                        let (anchor, from) = start.get().unwrap_or_else(|| {
+                            start.set(Some((y, value)));
+                            (y, value)
+                        });
+                        let moved = (anchor - y) / travel;
+                        drag(
+                            value_at(fraction(from, min, max) + moved, min, max, step),
+                            window,
+                            cx,
+                        );
+                    })
+                    .on_key_down(move |event, window, cx| {
+                        if let Some(next) = keyed(&event.keystroke.key, value, min, max, step) {
+                            cx.stop_propagation();
+                            keys(next, window, cx);
+                        }
+                    })
+            })
+    }
+}

src/forms/listbox.rs

@@ -0,0 +1,193 @@
+use std::rc::Rc;
+
+use gpui::{
+    App, ElementId, InteractiveElement, IntoElement, ParentElement, RenderOnce, ScrollHandle,
+    SharedString, StatefulInteractiveElement, Styled, Window, div, prelude::*,
+};
+
+use super::{
+    Choice,
+    check::{tab_stop, toggled},
+    options::{OnValues, Pick, option_row, step},
+};
+use crate::theme::{ActiveTheme, Radius, TextSize};
+
+/// `selected` after choosing row `ix`: one row replaces, several toggle.
+pub(crate) fn chosen(
+    choices: &[Choice],
+    selected: &[SharedString],
+    ix: usize,
+    multiple: bool,
+) -> Vec<SharedString> {
+    let value = &choices[ix].value;
+    if multiple {
+        toggled(choices, selected, value, !selected.contains(value))
+    } else {
+        vec![value.clone()]
+    }
+}
+
+#[derive(Default)]
+struct Cursor {
+    highlighted: usize,
+    scroll: ScrollHandle,
+}
+
+/// A list to choose from in place: one row, or several with `multiple`.
+#[derive(IntoElement)]
+pub struct ListBox {
+    id: ElementId,
+    choices: Vec<Choice>,
+    selected: Vec<SharedString>,
+    multiple: bool,
+    on_change: Option<OnValues>,
+}
+
+impl ListBox {
+    pub fn new(id: impl Into<ElementId>, choices: impl IntoIterator<Item = Choice>) -> Self {
+        Self {
+            id: id.into(),
+            choices: choices.into_iter().collect(),
+            selected: Vec::new(),
+            multiple: false,
+            on_change: None,
+        }
+    }
+
+    pub fn selected(mut self, values: impl IntoIterator<Item = impl Into<SharedString>>) -> Self {
+        self.selected = values.into_iter().map(Into::into).collect();
+        self
+    }
+
+    /// Lets any number of rows be chosen.
+    pub fn multiple(mut self) -> Self {
+        self.multiple = true;
+        self
+    }
+
+    pub fn on_change(
+        mut self,
+        handler: impl Fn(&[SharedString], &mut Window, &mut App) + 'static,
+    ) -> Self {
+        self.on_change = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for ListBox {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let count = self.choices.len();
+        assert!(count > 0, "list box {:?} has no choices", self.id);
+        let focus = tab_stop((self.id.clone(), "focus").into(), true, window, cx);
+        let focused = focus.is_focused(window);
+        let cursor =
+            window.use_keyed_state((self.id.clone(), "cursor"), cx, |_, _| Cursor::default());
+        let (highlighted, scroll) = {
+            let cursor = cursor.read(cx);
+            (cursor.highlighted.min(count - 1), cursor.scroll.clone())
+        };
+        let (choices, selected) = (Rc::new(self.choices), Rc::new(self.selected));
+        let press: Pick = {
+            let (id, choices, selected, multiple) = (
+                self.id.clone(),
+                choices.clone(),
+                selected.clone(),
+                self.multiple,
+            );
+            let (cursor, on_change) = (cursor.clone(), self.on_change);
+            Rc::new(move |ix, window, cx| {
+                cursor.update(cx, |cursor, cx| {
+                    cursor.highlighted = ix;
+                    cx.notify();
+                });
+                let next = chosen(&choices, &selected, ix, multiple);
+                log::info!("list box {id:?}: {next:?}");
+                if let Some(on_change) = &on_change {
+                    on_change(&next, window, cx);
+                }
+            })
+        };
+        let rows: Vec<_> = choices
+            .iter()
+            .enumerate()
+            .map(|(ix, choice)| {
+                let press = press.clone();
+                let on = selected.contains(&choice.value);
+                option_row(
+                    ("row", ix),
+                    choice,
+                    focused && ix == highlighted,
+                    Some(on),
+                    cx,
+                )
+                .when(!choice.disabled, |row| {
+                    row.on_click(move |_, window, cx| press(ix, window, cx))
+                })
+            })
+            .collect();
+        let theme = cx.theme();
+        let colors = &theme.colors;
+        let keys = choices.clone();
+        div()
+            .id(self.id)
+            .track_focus(&focus)
+            .track_scroll(&scroll)
+            .overflow_y_scroll()
+            .h_full()
+            .max_h(theme.list_max_height())
+            .flex()
+            .flex_col()
+            .p_1()
+            .rounded(theme.radius(Radius::Lg))
+            .border_1()
+            .border_color(if focused { colors.focus } else { colors.border })
+            .bg(colors.surface)
+            .text_size(theme.text_size(TextSize::Sm))
+            .on_key_down(move |event, window, cx| {
+                let at = cursor.read(cx).highlighted.min(count - 1);
+                let to = match event.keystroke.key.as_str() {
+                    "down" => step(&keys, at, 1),
+                    "up" => step(&keys, at, -1),
+                    "home" => step(&keys, count - 1, 1),
+                    "end" => step(&keys, 0, -1),
+                    "enter" | "space" if !keys[at].disabled => {
+                        cx.stop_propagation();
+                        press(at, window, cx);
+                        return;
+                    }
+                    _ => return,
+                };
+                cx.stop_propagation();
+                cursor.update(cx, |cursor, cx| {
+                    cursor.highlighted = to;
+                    cursor.scroll.scroll_to_item(to);
+                    cx.notify();
+                });
+            })
+            .children(rows)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use gpui::SharedString;
+
+    use super::{Choice, chosen};
+
+    #[test]
+    fn one_row_replaces_and_several_toggle_in_order() {
+        let rows = [
+            Choice::new("a", "A"),
+            Choice::new("b", "B"),
+            Choice::new("c", "C"),
+        ];
+        let values = |list: &[&str]| {
+            list.iter()
+                .map(|v| SharedString::from(v.to_string()))
+                .collect::<Vec<_>>()
+        };
+        assert_eq!(chosen(&rows, &values(&["a"]), 2, false), values(&["c"]));
+        assert_eq!(chosen(&rows, &values(&["c"]), 0, true), values(&["a", "c"]));
+        assert_eq!(chosen(&rows, &values(&["a", "c"]), 2, true), values(&["a"]));
+    }
+}

src/forms/masked.rs

@@ -8,7 +8,7 @@ use gpui::{
 
 use super::{
     Input, TextInput,
-    suggest::{Suggestion, suggestion_list},
+    options::{Choice, Popup},
 };
 use crate::{
     primitives::{Icon, IconName},
@@ -227,12 +227,9 @@ impl RenderOnce for PhoneInput {
             .expect("checked at construction");
         let theme = cx.theme();
         let (hover, muted) = (theme.colors.hover, theme.colors.fg_muted);
-        let rows: Vec<Suggestion> = COUNTRIES
+        let rows: Vec<Choice> = COUNTRIES
             .iter()
-            .map(|(code, dial, flag, _)| Suggestion {
-                label: SharedString::from(format!("{flag}  {code}")),
-                note: Some(SharedString::from(*dial)),
-            })
+            .map(|(code, dial, flag, _)| Choice::new(*code, format!("{flag}  {code}")).note(*dial))
             .collect();
         let (toggle, close, measure) = (picker.clone(), picker.clone(), picker.clone());
         let on_country = self.on_country;
@@ -290,23 +287,25 @@ impl RenderOnce for PhoneInput {
                 .size_full(),
             )
             .when(open, |field| {
-                let current = COUNTRIES
-                    .iter()
-                    .position(|(code, ..)| *code == self.country);
-                field.child(suggestion_list(
-                    (self.id.clone(), "countries"),
-                    anchor,
-                    &rows,
-                    current.unwrap_or(usize::MAX),
-                    pick,
-                    Some(Rc::new(move |_, cx| {
-                        dismiss.update(cx, |picker, cx| {
-                            picker.open = false;
-                            cx.notify();
-                        })
-                    })),
-                    cx,
-                ))
+                let current = [SharedString::from(self.country)];
+                field.child(
+                    Popup {
+                        id: (self.id.clone(), "countries").into(),
+                        anchor,
+                        rows: &rows,
+                        highlighted: None,
+                        checked: Some(&current),
+                        pick,
+                        dismiss: Some(Rc::new(move |_, cx| {
+                            dismiss.update(cx, |picker, cx| {
+                                picker.open = false;
+                                cx.notify();
+                            })
+                        })),
+                        scroll: None,
+                    }
+                    .render(window, cx),
+                )
             })
     }
 }

src/forms/mention.rs

@@ -7,7 +7,7 @@ use gpui::{
 
 use super::{
     Highlight, Input, TextInput,
-    suggest::{Suggestion, suggestion_list},
+    options::{Choice, Popup},
     text::{Down, Enter, Up},
 };
 use crate::theme::ActiveTheme;
@@ -162,13 +162,13 @@ impl RenderOnce for MentionInput {
             "mention input: open {open}, {} matches, caret {anchor:?}",
             matches.len()
         );
-        let rows: Vec<Suggestion> = matches
+        let rows: Vec<Choice> = matches
             .iter()
-            .map(|name| Suggestion {
-                label: active.map_or(name.clone(), |(_, trigger)| {
+            .map(|name| {
+                let label = active.map_or(name.clone(), |(_, trigger)| {
                     SharedString::from(format!("{trigger}{name}"))
-                }),
-                note: None,
+                });
+                Choice::new(name.clone(), label)
             })
             .collect();
         let insert = {
@@ -231,15 +231,19 @@ impl RenderOnce for MentionInput {
             })
             .child(Input::new(&self.state))
             .when_some(anchor.filter(|_| open), |field, anchor| {
-                field.child(suggestion_list(
-                    "mentions",
-                    anchor,
-                    &rows,
-                    highlighted,
-                    insert,
-                    None,
-                    cx,
-                ))
+                field.child(
+                    Popup {
+                        id: "mentions".into(),
+                        anchor,
+                        rows: &rows,
+                        highlighted: Some(highlighted),
+                        checked: None,
+                        pick: insert,
+                        dismiss: None,
+                        scroll: None,
+                    }
+                    .render(window, cx),
+                )
             })
     }
 }

src/forms/mod.rs

@@ -1,39 +1,70 @@
+mod card;
+mod cascade;
+mod check;
 mod checked;
+mod chips;
+mod combobox;
 mod expression;
 mod group;
 mod hotkey;
 mod inline;
 mod input;
+mod knob;
+mod listbox;
 mod masked;
 mod mention;
+mod multi;
 mod number;
+mod options;
 mod pairs;
 mod path;
 mod pattern;
 mod pin;
+mod radio;
+mod rating;
 mod search;
-mod suggest;
+mod select;
+mod slider;
+mod stepper;
+mod switch;
 mod tags;
 #[cfg(all(test, feature = "test-support"))]
 mod tests;
 mod text;
+mod transfer;
 mod unit;
 
+pub use card::{CheckboxCard, RadioCard};
+pub use cascade::{Cascade, Cascader};
+pub use check::{CheckState, Checkbox, CheckboxGroup};
 pub use checked::{EmailInput, UrlInput};
+pub use chips::ChoiceChips;
+pub use combobox::Combobox;
 pub use expression::{ExpressionInput, evaluate, expression_highlights};
 pub use group::{InputAddon, InputGroup};
 pub use hotkey::HotkeyInput;
 pub use inline::InlineEdit;
 pub use input::{Input, PasswordInput};
+pub use knob::Knob;
+pub use listbox::ListBox;
 pub use masked::{COUNTRIES, MaskedInput, PhoneInput};
 pub use mention::{MentionInput, mention_highlights};
+pub use multi::MultiSelect;
 pub use number::{NumberInput, ScrubInput};
+pub use options::Choice;
 pub use pairs::{KeyValueInput, ListInput};
 pub use path::PathInput;
 pub use pattern::{RegexInput, regex_highlights};
 pub use pin::PinInput;
+pub use radio::{Radio, RadioGroup};
+pub use rating::Rating;
 pub use search::SearchInput;
+pub use select::Select;
+pub use slider::{RangeSlider, Slider};
+pub use stepper::Stepper;
+pub use switch::Switch;
 pub use tags::TagInput;
 pub(crate) use text::bind_keys;
 pub use text::{Highlight, InputEvent, TextInput};
+pub use transfer::TransferList;
 pub use unit::UnitInput;

src/forms/multi.rs

@@ -0,0 +1,232 @@
+use std::rc::Rc;
+
+use gpui::{
+    App, ClickEvent, ElementId, InteractiveElement, IntoElement, ParentElement, RenderOnce,
+    SharedString, StatefulInteractiveElement, Styled, Window, div, prelude::*,
+};
+
+use super::{
+    Choice,
+    check::tab_stop,
+    listbox::chosen,
+    options::{OnValues, Pick, Popup, step},
+    select::{Picker, measure_anchor, moved},
+    tags::chip,
+};
+use crate::{
+    primitives::{Icon, IconName},
+    theme::{ActiveTheme, ControlSize, IconSize, Radius, TextSize},
+};
+
+/// A select for several values. Chosen ones sit in the field as chips.
+#[derive(IntoElement)]
+pub struct MultiSelect {
+    id: ElementId,
+    choices: Vec<Choice>,
+    selected: Vec<SharedString>,
+    placeholder: SharedString,
+    size: ControlSize,
+    on_change: Option<OnValues>,
+}
+
+impl MultiSelect {
+    pub fn new(id: impl Into<ElementId>, choices: impl IntoIterator<Item = Choice>) -> Self {
+        Self {
+            id: id.into(),
+            choices: choices.into_iter().collect(),
+            selected: Vec::new(),
+            placeholder: SharedString::from("Choose…"),
+            size: ControlSize::default(),
+            on_change: None,
+        }
+    }
+
+    pub fn selected(mut self, values: impl IntoIterator<Item = impl Into<SharedString>>) -> Self {
+        self.selected = values.into_iter().map(Into::into).collect();
+        self
+    }
+
+    pub fn placeholder(mut self, text: impl Into<SharedString>) -> Self {
+        self.placeholder = text.into();
+        self
+    }
+
+    pub fn size(mut self, size: ControlSize) -> Self {
+        self.size = size;
+        self
+    }
+
+    pub fn on_change(
+        mut self,
+        handler: impl Fn(&[SharedString], &mut Window, &mut App) + 'static,
+    ) -> Self {
+        self.on_change = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for MultiSelect {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        assert!(
+            !self.choices.is_empty(),
+            "multi select {:?} has no choices",
+            self.id
+        );
+        let focus = tab_stop((self.id.clone(), "focus").into(), true, window, cx);
+        let focused = focus.is_focused(window);
+        let picker =
+            window.use_keyed_state((self.id.clone(), "picker"), cx, |_, _| Picker::default());
+        if picker.read(cx).open && !focused {
+            picker.update(cx, |picker, _| picker.open = false);
+        }
+        let (choices, selected) = (Rc::new(self.choices), Rc::new(self.selected));
+        let start = step(&choices, choices.len() - 1, 1);
+        if picker.read(cx).highlighted >= choices.len() {
+            picker.update(cx, |picker, _| picker.highlighted = start);
+        }
+        let (open, highlighted, anchor, scroll) = {
+            let picker = picker.read(cx);
+            (
+                picker.open,
+                picker.highlighted,
+                picker.anchor,
+                picker.scroll.clone(),
+            )
+        };
+        let commit: OnValues = {
+            let (id, on_change) = (self.id.clone(), self.on_change);
+            Rc::new(move |next, window, cx| {
+                log::info!("multi select {id:?}: {next:?}");
+                if let Some(on_change) = &on_change {
+                    on_change(next, window, cx);
+                }
+            })
+        };
+        let toggle: Pick = {
+            let (choices, selected, picker, commit) = (
+                choices.clone(),
+                selected.clone(),
+                picker.clone(),
+                commit.clone(),
+            );
+            Rc::new(move |ix, window, cx| {
+                if choices[ix].disabled {
+                    return;
+                }
+                Picker::show(&picker, true, ix, cx);
+                commit(&chosen(&choices, &selected, ix, true), window, cx);
+            })
+        };
+        let theme = cx.theme();
+        let colors = &theme.colors;
+        let chips: Vec<_> = choices
+            .iter()
+            .enumerate()
+            .filter(|(_, choice)| selected.contains(&choice.value))
+            .map(|(ix, choice)| {
+                let (choices, selected, commit) =
+                    (choices.clone(), selected.clone(), commit.clone());
+                chip(
+                    ("chip-remove", ix).into(),
+                    choice.label.clone(),
+                    Rc::new(move |window, cx| {
+                        commit(&chosen(&choices, &selected, ix, true), window, cx)
+                    }),
+                    cx,
+                )
+            })
+            .collect();
+        let (click, keys, rows, close) = (
+            picker.clone(),
+            picker.clone(),
+            choices.clone(),
+            picker.clone(),
+        );
+        let (enter, last, erase) = (toggle.clone(), selected.clone(), commit);
+        div()
+            .id(self.id.clone())
+            .track_focus(&focus)
+            .relative()
+            .flex()
+            .flex_wrap()
+            .items_center()
+            .gap_1()
+            .w_full()
+            .min_h(theme.control_height(self.size))
+            .pl_1()
+            .pr(theme.control_padding(self.size))
+            .py_0p5()
+            .rounded(theme.radius(Radius::Md))
+            .border_1()
+            .border_color(if focused {
+                colors.focus
+            } else {
+                colors.border_strong
+            })
+            .bg(colors.surface)
+            .text_size(theme.text_size(TextSize::Base))
+            .cursor_pointer()
+            .on_click(move |event, _, cx| {
+                if matches!(event, ClickEvent::Mouse(_)) {
+                    Picker::show(&click, !open, start, cx)
+                }
+            })
+            .on_key_down(move |event, window, cx| {
+                let at = keys.read(cx).highlighted;
+                let key = event.keystroke.key.as_str();
+                if key == "backspace" && !last.is_empty() {
+                    cx.stop_propagation();
+                    erase(&last[..last.len() - 1], window, cx);
+                } else if !open {
+                    if matches!(key, "down" | "up" | "enter" | "space") {
+                        cx.stop_propagation();
+                        Picker::show(&keys, true, start, cx);
+                    }
+                } else if let Some(to) = moved(event, &rows, at) {
+                    cx.stop_propagation();
+                    Picker::show(&keys, true, to, cx);
+                } else if matches!(key, "enter" | "space") {
+                    cx.stop_propagation();
+                    enter(at, window, cx);
+                } else if key == "escape" {
+                    cx.stop_propagation();
+                    Picker::show(&keys, false, at, cx);
+                }
+            })
+            .children(chips)
+            .when(selected.is_empty(), |field| {
+                field.child(
+                    div()
+                        .pl_2()
+                        .text_color(colors.fg_subtle)
+                        .child(self.placeholder),
+                )
+            })
+            .child(
+                div().ml_auto().child(
+                    Icon::new(IconName::ChevronsUpDown)
+                        .size(IconSize::Xs)
+                        .color(colors.fg_subtle),
+                ),
+            )
+            .child(measure_anchor(picker))
+            .when(open, |field| {
+                field.child(
+                    Popup {
+                        id: (self.id, "list").into(),
+                        anchor,
+                        rows: &choices,
+                        highlighted: Some(highlighted),
+                        checked: Some(&selected),
+                        pick: toggle,
+                        dismiss: Some(Rc::new(move |_, cx| {
+                            let at = close.read(cx).highlighted;
+                            Picker::show(&close, false, at, cx)
+                        })),
+                        scroll: Some(&scroll),
+                    }
+                    .render(window, cx),
+                )
+            })
+    }
+}

src/forms/options.rs

@@ -0,0 +1,255 @@
+use std::rc::Rc;
+
+use gpui::{
+    Animation, AnimationExt, AnyElement, App, Bounds, Corner, Div, ElementId, InteractiveElement,
+    IntoElement, MouseButton, ParentElement, Pixels, ScrollHandle, SharedString, Stateful,
+    StatefulInteractiveElement, Styled, Window, anchored, deferred, div, prelude::*,
+};
+
+use crate::{
+    motion,
+    primitives::{Icon, IconName},
+    theme::{ActiveTheme, ControlSize, Elevation, IconSize, Radius, TextSize},
+};
+
+/// One option: a value, the label shown for it, and an optional icon and note.
+#[derive(Clone, Debug, PartialEq)]
+pub struct Choice {
+    pub value: SharedString,
+    pub label: SharedString,
+    pub icon: Option<IconName>,
+    pub note: Option<SharedString>,
+    pub disabled: bool,
+}
+
+impl Choice {
+    pub fn new(value: impl Into<SharedString>, label: impl Into<SharedString>) -> Self {
+        Self {
+            value: value.into(),
+            label: label.into(),
+            icon: None,
+            note: None,
+            disabled: false,
+        }
+    }
+
+    pub fn icon(mut self, icon: IconName) -> Self {
+        self.icon = Some(icon);
+        self
+    }
+
+    /// Quiet text at the row's end, such as a count or a shortcut.
+    pub fn note(mut self, note: impl Into<SharedString>) -> Self {
+        self.note = Some(note.into());
+        self
+    }
+
+    pub fn disabled(mut self) -> Self {
+        self.disabled = true;
+        self
+    }
+}
+
+pub(crate) type Pick = Rc<dyn Fn(usize, &mut Window, &mut App)>;
+pub(crate) type Run = Rc<dyn Fn(&mut Window, &mut App)>;
+pub(crate) type OnFlag = Rc<dyn Fn(bool, &mut Window, &mut App)>;
+pub(crate) type OnNumber = Rc<dyn Fn(f64, &mut Window, &mut App)>;
+pub(crate) type OnValue = Rc<dyn Fn(&SharedString, &mut Window, &mut App)>;
+pub(crate) type OnValues = Rc<dyn Fn(&[SharedString], &mut Window, &mut App)>;
+
+/// The next row from `from` that is not disabled, stepping by `by` and wrapping.
+pub(crate) fn step(rows: &[Choice], from: usize, by: isize) -> usize {
+    let count = rows.len() as isize;
+    let mut at = from as isize;
+    for _ in 0..count {
+        at = (at + by).rem_euclid(count);
+        if !rows[at as usize].disabled {
+            return at as usize;
+        }
+    }
+    from
+}
+
+/// One row: a check column when `checked` is known, then icon, label and note.
+pub(crate) fn option_row(
+    id: impl Into<ElementId>,
+    choice: &Choice,
+    highlighted: bool,
+    checked: Option<bool>,
+    cx: &App,
+) -> Stateful<Div> {
+    let theme = cx.theme();
+    let colors = &theme.colors;
+    let fg = if choice.disabled {
+        colors.fg_disabled
+    } else {
+        colors.fg
+    };
+    div()
+        .id(id)
+        .flex()
+        .items_center()
+        .gap_2()
+        .px_2()
+        .py_1()
+        .rounded(theme.radius(Radius::Md))
+        .text_color(fg)
+        .when(highlighted && !choice.disabled, |row| row.bg(colors.hover))
+        .when(!choice.disabled, |row| {
+            row.cursor_pointer().hover(|style| style.bg(colors.hover))
+        })
+        .when_some(checked, |row, on| {
+            row.child(
+                div()
+                    .flex_none()
+                    .size(theme.icon_size(IconSize::Sm))
+                    .when(on, |mark| {
+                        mark.child(Icon::new(IconName::Check).size(IconSize::Sm).color(fg))
+                    }),
+            )
+        })
+        .when_some(choice.icon, |row, icon| {
+            row.child(Icon::new(icon).size(IconSize::Sm).color(colors.fg_muted))
+        })
+        .child(
+            div()
+                .flex_1()
+                .min_w_0()
+                .overflow_hidden()
+                .text_ellipsis()
+                .whitespace_nowrap()
+                .child(choice.label.clone()),
+        )
+        .when_some(choice.note.clone(), |row, note| {
+            row.child(div().text_color(colors.fg_subtle).child(note))
+        })
+}
+
+/// The card a floating list sits on.
+pub(crate) fn surface(id: impl Into<ElementId>, cx: &App) -> Stateful<Div> {
+    let theme = cx.theme();
+    let colors = &theme.colors;
+    div()
+        .id(id)
+        .rounded(theme.radius(Radius::Lg))
+        .bg(colors.overlay)
+        .border_1()
+        .border_color(colors.border)
+        .shadow(theme.elevation(Elevation::Floating))
+        .text_size(theme.text_size(TextSize::Sm))
+}
+
+/// Floats `content` of about `rows` rows under `anchor`, or over it when only above has room.
+pub(crate) fn float(
+    anchor: Bounds<Pixels>,
+    rows: usize,
+    content: impl IntoElement,
+    window: &Window,
+    cx: &App,
+) -> AnyElement {
+    let theme = cx.theme();
+    let rem = window.rem_size();
+    let row = theme.control_height(ControlSize::Md).to_pixels(rem);
+    let height = (row * (rows + 1) as f32).min(theme.list_max_height().to_pixels(rem));
+    let below = window.viewport_size().height - anchor.bottom();
+    let up = height > below && anchor.top() > below;
+    let enter =
+        Animation::new(motion::duration(motion::FAST, cx)).with_easing(motion::ease_out_cubic);
+    let placed = if up {
+        anchored()
+            .position(anchor.origin)
+            .anchor(Corner::BottomLeft)
+            .child(
+                div()
+                    .child(content)
+                    .with_animation("popup-in", enter, |popup, t| {
+                        popup.opacity(t).mb(motion::NUDGE * (2.0 - t))
+                    }),
+            )
+    } else {
+        anchored()
+            .position(anchor.bottom_left())
+            .child(
+                div()
+                    .child(content)
+                    .with_animation("popup-in", enter, |popup, t| {
+                        popup.opacity(t).mt(motion::NUDGE * (2.0 - t))
+                    }),
+            )
+    };
+    deferred(placed.snap_to_window())
+        .with_priority(1)
+        .into_any_element()
+}
+
+/// A list floating under `anchor`, at least as wide. Rows leave focus where it was.
+pub(crate) struct Popup<'a> {
+    pub id: ElementId,
+    pub anchor: Bounds<Pixels>,
+    pub rows: &'a [Choice],
+    pub highlighted: Option<usize>,
+    pub checked: Option<&'a [SharedString]>,
+    pub pick: Pick,
+    pub dismiss: Option<Run>,
+    pub scroll: Option<&'a ScrollHandle>,
+}
+
+impl Popup<'_> {
+    pub fn render(self, window: &Window, cx: &App) -> AnyElement {
+        let theme = cx.theme();
+        let (anchor, pick) = (self.anchor, self.pick);
+        let rows = self.rows.iter().enumerate().map(|(ix, choice)| {
+            let pick = pick.clone();
+            let checked = self.checked.map(|values| values.contains(&choice.value));
+            option_row(
+                ("option", ix),
+                choice,
+                self.highlighted == Some(ix),
+                checked,
+                cx,
+            )
+            .when(!choice.disabled, |row| {
+                row.on_mouse_down(MouseButton::Left, move |_, window, cx| {
+                    window.prevent_default();
+                    cx.stop_propagation();
+                    pick(ix, window, cx);
+                })
+            })
+        });
+        let list = surface(self.id, cx)
+            .min_w(theme.tooltip_max_width())
+            .when(anchor.size.width > Pixels::ZERO, |list| {
+                list.min_w(anchor.size.width)
+            })
+            .max_h(theme.list_max_height())
+            .overflow_y_scroll()
+            .when_some(self.scroll, |list, handle| list.track_scroll(handle))
+            .p_1()
+            .flex()
+            .flex_col()
+            .when_some(self.dismiss, |list, dismiss| {
+                list.on_mouse_down_out(move |_, window, cx| dismiss(window, cx))
+            })
+            .children(rows);
+        float(anchor, self.rows.len(), list, window, cx)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{Choice, step};
+
+    #[test]
+    fn stepping_wraps_and_skips_disabled_rows() {
+        let rows = [
+            Choice::new("a", "A"),
+            Choice::new("b", "B").disabled(),
+            Choice::new("c", "C"),
+        ];
+        assert_eq!(step(&rows, 0, 1), 2);
+        assert_eq!(step(&rows, 2, 1), 0);
+        assert_eq!(step(&rows, 0, -1), 2);
+        let none = [Choice::new("a", "A").disabled()];
+        assert_eq!(step(&none, 0, 1), 0);
+    }
+}

src/forms/radio.rs

@@ -0,0 +1,258 @@
+use std::rc::Rc;
+
+use gpui::{
+    Animation, AnimationExt, AnyElement, App, ElementId, FocusHandle, InteractiveElement,
+    IntoElement, MouseButton, ParentElement, RenderOnce, SharedString, StatefulInteractiveElement,
+    Styled, Window, div, prelude::*,
+};
+
+use super::{
+    Choice,
+    check::tab_stop,
+    options::{OnValue, Run, step},
+};
+use crate::{
+    motion,
+    theme::{ActiveTheme, TextSize},
+};
+
+/// The circle alone, shared by radios and cards. `changes` replays its motion.
+pub(crate) fn radio_mark(
+    on: bool,
+    focused: bool,
+    disabled: bool,
+    changes: usize,
+    cx: &App,
+) -> AnyElement {
+    let theme = cx.theme();
+    let colors = &theme.colors;
+    let border = if focused {
+        colors.focus
+    } else if on {
+        colors.accent
+    } else {
+        colors.border_strong
+    };
+    let (dot, accent) = (theme.radio_dot(), colors.accent);
+    div()
+        .flex()
+        .flex_none()
+        .items_center()
+        .justify_center()
+        .size(theme.check_size())
+        .rounded_full()
+        .border_1()
+        .border_color(border)
+        .bg(colors.surface)
+        .when(disabled, |mark| mark.opacity(0.5))
+        .when(on, |mark| {
+            let fill = div().size(dot).rounded_full().bg(accent);
+            if changes == 0 {
+                return mark.child(fill);
+            }
+            mark.child(fill.with_animation(
+                ("radio-dot", changes),
+                Animation::new(motion::duration(motion::BASE, cx)),
+                move |fill, t| fill.size(dot * motion::spring(t)),
+            ))
+        })
+        .into_any_element()
+}
+
+/// One choice of several, with an optional label beside it.
+#[derive(IntoElement)]
+pub struct Radio {
+    id: ElementId,
+    on: bool,
+    label: Option<SharedString>,
+    disabled: bool,
+    focus: Option<FocusHandle>,
+    on_select: Option<Run>,
+}
+
+impl Radio {
+    pub fn new(id: impl Into<ElementId>, on: bool) -> Self {
+        Self {
+            id: id.into(),
+            on,
+            label: None,
+            disabled: false,
+            focus: None,
+            on_select: None,
+        }
+    }
+
+    pub fn label(mut self, label: impl Into<SharedString>) -> Self {
+        self.label = Some(label.into());
+        self
+    }
+
+    pub fn disabled(mut self, disabled: bool) -> Self {
+        self.disabled = disabled;
+        self
+    }
+
+    /// Runs when chosen while off.
+    pub fn on_select(mut self, handler: impl Fn(&mut Window, &mut App) + 'static) -> Self {
+        self.on_select = Some(Rc::new(handler));
+        self
+    }
+
+    /// Focus owned by a group that moves it with the arrows.
+    fn focus(mut self, handle: FocusHandle) -> Self {
+        self.focus = Some(handle);
+        self
+    }
+}
+
+impl RenderOnce for Radio {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let focus = match self.focus {
+            Some(handle) => handle,
+            None => tab_stop(
+                (self.id.clone(), "focus").into(),
+                !self.disabled,
+                window,
+                cx,
+            ),
+        };
+        let changes = motion::changes((self.id.clone(), "changes"), self.on, window, cx);
+        let focused = focus.is_focused(window);
+        let (on, on_select) = (self.on, self.on_select);
+        let theme = cx.theme();
+        let fg = if self.disabled {
+            theme.colors.fg_disabled
+        } else {
+            theme.colors.fg
+        };
+        div()
+            .id(self.id)
+            .track_focus(&focus)
+            .flex()
+            .items_center()
+            .gap_2()
+            .text_size(theme.text_size(TextSize::Base))
+            .text_color(fg)
+            .when(!self.disabled, |row| {
+                row.cursor_pointer()
+                    .on_mouse_down(MouseButton::Left, |_, window, _| window.prevent_default())
+                    .on_click(move |_, window, cx| {
+                        if let (false, Some(on_select)) = (on, &on_select) {
+                            on_select(window, cx);
+                        }
+                    })
+            })
+            .child(radio_mark(self.on, focused, self.disabled, changes, cx))
+            .children(self.label)
+    }
+}
+
+/// Radios for a list of choices. One Tab stop; the arrows move the choice.
+#[derive(IntoElement)]
+pub struct RadioGroup {
+    id: ElementId,
+    choices: Vec<Choice>,
+    selected: Option<SharedString>,
+    horizontal: bool,
+    on_change: Option<OnValue>,
+}
+
+impl RadioGroup {
+    pub fn new(id: impl Into<ElementId>, choices: impl IntoIterator<Item = Choice>) -> Self {
+        Self {
+            id: id.into(),
+            choices: choices.into_iter().collect(),
+            selected: None,
+            horizontal: false,
+            on_change: None,
+        }
+    }
+
+    pub fn selected(mut self, value: impl Into<SharedString>) -> Self {
+        self.selected = Some(value.into());
+        self
+    }
+
+    /// Lays the radios in a row.
+    pub fn horizontal(mut self) -> Self {
+        self.horizontal = true;
+        self
+    }
+
+    pub fn on_change(
+        mut self,
+        handler: impl Fn(&SharedString, &mut Window, &mut App) + 'static,
+    ) -> Self {
+        self.on_change = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for RadioGroup {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let count = self.choices.len();
+        assert!(count > 0, "radio group {:?} has no choices", self.id);
+        let handles = window.use_keyed_state((self.id.clone(), "focus"), cx, |_, _| Vec::new());
+        if handles.read(cx).len() != count {
+            handles.update(cx, |handles: &mut Vec<FocusHandle>, cx| {
+                handles.resize_with(count, || cx.focus_handle());
+            });
+        }
+        let choices = Rc::new(self.choices);
+        let chosen = self
+            .selected
+            .as_ref()
+            .and_then(|value| choices.iter().position(|choice| choice.value == *value));
+        let stop = match chosen {
+            Some(ix) if !choices[ix].disabled => ix,
+            _ => step(&choices, count - 1, 1),
+        };
+        let handles: Vec<FocusHandle> = handles
+            .read(cx)
+            .iter()
+            .enumerate()
+            .map(|(ix, handle)| handle.clone().tab_stop(ix == stop && !choices[ix].disabled))
+            .collect();
+        let pick: OnValue = {
+            let (id, on_change) = (self.id.clone(), self.on_change);
+            Rc::new(move |value, window, cx| {
+                log::info!("radio group {id:?}: {value}");
+                if let Some(on_change) = &on_change {
+                    on_change(value, window, cx);
+                }
+            })
+        };
+        let radios: Vec<_> = choices
+            .iter()
+            .enumerate()
+            .map(|(ix, choice)| {
+                let (pick, value) = (pick.clone(), choice.value.clone());
+                Radio::new(("radio", ix), chosen == Some(ix))
+                    .label(choice.label.clone())
+                    .disabled(choice.disabled)
+                    .focus(handles[ix].clone())
+                    .on_select(move |window, cx| pick(&value, window, cx))
+            })
+            .collect();
+        div()
+            .id(self.id)
+            .flex()
+            .when(self.horizontal, |group| group.flex_row().gap_4())
+            .when(!self.horizontal, |group| group.flex_col().gap_2())
+            .on_key_down(move |event, window, cx| {
+                let by = match event.keystroke.key.as_str() {
+                    "up" | "left" => -1,
+                    "down" | "right" => 1,
+                    _ => return,
+                };
+                let Some(at) = handles.iter().position(|handle| handle.is_focused(window)) else {
+                    return;
+                };
+                cx.stop_propagation();
+                let next = step(&choices, at, by);
+                window.focus(&handles[next]);
+                pick(&choices[next].value, window, cx);
+            })
+            .children(radios)
+    }
+}

src/forms/rating.rs

@@ -0,0 +1,189 @@
+use std::{
+    f32::consts::{FRAC_PI_2, PI},
+    rc::Rc,
+};
+
+use gpui::{
+    App, Bounds, ElementId, Hsla, InteractiveElement, IntoElement, MouseButton, ParentElement,
+    Path, PathBuilder, Pixels, RenderOnce, StatefulInteractiveElement, Styled, Window, canvas, div,
+    point, prelude::*, transparent_black,
+};
+
+use super::check::tab_stop;
+use crate::theme::{ActiveTheme, IconSize, Radius};
+
+/// A five-point star inside `bounds`, filled or outlined with Lucide's stroke ratio.
+fn star(bounds: Bounds<Pixels>, fill: bool) -> Path<Pixels> {
+    let side = bounds.size.width.min(bounds.size.height);
+    let stroke = side / 12.0;
+    let center = bounds.center();
+    let outer = side / 2.0 - stroke;
+    let mut path = if fill {
+        PathBuilder::fill()
+    } else {
+        PathBuilder::stroke(stroke)
+    };
+    for k in 0..10 {
+        let radius = if k % 2 == 0 { outer } else { outer * 0.5 };
+        let angle = -FRAC_PI_2 + k as f32 * PI / 5.0;
+        let at = point(
+            center.x + radius * angle.cos(),
+            center.y + radius * angle.sin(),
+        );
+        if k == 0 {
+            path.move_to(at);
+        } else {
+            path.line_to(at);
+        }
+    }
+    path.close();
+    path.build().expect("a star is a simple closed path")
+}
+
+fn paint_star(bounds: Bounds<Pixels>, filled: bool, color: Hsla, window: &mut Window) {
+    if filled {
+        window.paint_path(star(bounds, true), color);
+    }
+    window.paint_path(star(bounds, false), color);
+}
+
+type OnRate = Rc<dyn Fn(u8, &mut Window, &mut App)>;
+
+/// Stars from one to `max`. Hover previews; clicking the current value clears it.
+#[derive(IntoElement)]
+pub struct Rating {
+    id: ElementId,
+    value: u8,
+    max: u8,
+    disabled: bool,
+    on_change: Option<OnRate>,
+}
+
+impl Rating {
+    pub fn new(id: impl Into<ElementId>, value: u8) -> Self {
+        Self {
+            id: id.into(),
+            value,
+            max: 5,
+            disabled: false,
+            on_change: None,
+        }
+    }
+
+    pub fn max(mut self, max: u8) -> Self {
+        assert!(max > 0, "a rating needs at least one star");
+        self.max = max;
+        self
+    }
+
+    pub fn disabled(mut self, disabled: bool) -> Self {
+        self.disabled = disabled;
+        self
+    }
+
+    pub fn on_change(mut self, handler: impl Fn(u8, &mut Window, &mut App) + 'static) -> Self {
+        self.on_change = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for Rating {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let (value, max) = (self.value, self.max);
+        assert!(value <= max, "rating {value} is above {max}");
+        let focus = tab_stop(
+            (self.id.clone(), "focus").into(),
+            !self.disabled,
+            window,
+            cx,
+        );
+        let focused = focus.is_focused(window);
+        let hover = window.use_keyed_state((self.id.clone(), "hover"), cx, |_, _| None::<u8>);
+        let shown = hover.read(cx).unwrap_or(value);
+        let rate: OnRate = {
+            let (id, on_change) = (self.id.clone(), self.on_change);
+            Rc::new(move |next, window, cx| {
+                log::info!("rating {id:?}: {next}");
+                if let Some(on_change) = &on_change {
+                    on_change(next, window, cx);
+                }
+            })
+        };
+        let theme = cx.theme();
+        let colors = &theme.colors;
+        let (on, off) = (colors.accent, colors.border_strong);
+        let stars: Vec<_> = (1..=max)
+            .map(|n| {
+                let filled = n <= shown;
+                let color = if filled { on } else { off };
+                let (hover, rate) = (hover.clone(), rate.clone());
+                div()
+                    .id(("star", n as usize))
+                    .size(theme.icon_size(IconSize::Lg))
+                    .child(
+                        canvas(
+                            |_, _, _| {},
+                            move |bounds, _, window, _| paint_star(bounds, filled, color, window),
+                        )
+                        .size_full(),
+                    )
+                    .when(!self.disabled, |star| {
+                        star.cursor_pointer()
+                            .on_hover(move |inside, _, cx| {
+                                if *inside {
+                                    hover.update(cx, |hover, cx| {
+                                        *hover = Some(n);
+                                        cx.notify();
+                                    });
+                                }
+                            })
+                            .on_mouse_down(MouseButton::Left, |_, window, _| {
+                                window.prevent_default()
+                            })
+                            .on_click(move |_, window, cx| {
+                                rate(if n == value { 0 } else { n }, window, cx)
+                            })
+                    })
+            })
+            .collect();
+        let (leave, keys) = (hover, rate);
+        div()
+            .id(self.id)
+            .track_focus(&focus)
+            .flex()
+            .gap_0p5()
+            .p_0p5()
+            .rounded(theme.radius(Radius::Sm))
+            .border_1()
+            .border_color(if focused {
+                colors.focus
+            } else {
+                transparent_black()
+            })
+            .when(self.disabled, |row| row.opacity(0.5))
+            .on_hover(move |inside, _, cx| {
+                if !*inside {
+                    leave.update(cx, |hover, cx| {
+                        *hover = None;
+                        cx.notify();
+                    });
+                }
+            })
+            .when(!self.disabled, |row| {
+                row.on_key_down(move |event, window, cx| {
+                    let next = match event.keystroke.key.as_str() {
+                        "left" | "down" => value.saturating_sub(1),
+                        "right" | "up" => (value + 1).min(max),
+                        "home" => 0,
+                        "end" => max,
+                        _ => return,
+                    };
+                    cx.stop_propagation();
+                    if next != value {
+                        keys(next, window, cx);
+                    }
+                })
+            })
+            .children(stars)
+    }
+}

src/forms/search.rs

@@ -7,7 +7,7 @@ use gpui::{
 
 use super::{
     Input, TextInput,
-    suggest::{Suggestion, suggestion_list},
+    options::{Choice, Popup},
 };
 use crate::{
     primitives::{Icon, IconName},
@@ -65,13 +65,10 @@ impl RenderOnce for SearchInput {
         let open = input.focus().is_focused(window) && input.is_empty() && !self.history.is_empty();
         let anchor = *frame.read(cx);
         let subtle = cx.theme().colors.fg_subtle;
-        let rows: Vec<Suggestion> = self
+        let rows: Vec<Choice> = self
             .history
             .iter()
-            .map(|query| Suggestion {
-                label: query.clone(),
-                note: None,
-            })
+            .map(|query| Choice::new(query.clone(), query.clone()))
             .collect();
         let (state, history, on_pick) = (self.state.clone(), self.history, self.on_pick);
         let pick = Rc::new(move |ix: usize, window: &mut Window, cx: &mut App| {
@@ -106,15 +103,19 @@ impl RenderOnce for SearchInput {
                 .size_full(),
             )
             .when(open, |field| {
-                field.child(suggestion_list(
-                    (self.id.clone(), "recent"),
-                    anchor,
-                    &rows,
-                    usize::MAX,
-                    pick,
-                    None,
-                    cx,
-                ))
+                field.child(
+                    Popup {
+                        id: (self.id.clone(), "recent").into(),
+                        anchor,
+                        rows: &rows,
+                        highlighted: None,
+                        checked: None,
+                        pick,
+                        dismiss: None,
+                        scroll: None,
+                    }
+                    .render(window, cx),
+                )
             })
     }
 }

src/forms/select.rs

@@ -0,0 +1,283 @@
+use std::rc::Rc;
+
+use gpui::{
+    App, Bounds, ElementId, Entity, InteractiveElement, IntoElement, KeyDownEvent, MouseButton,
+    ParentElement, Pixels, RenderOnce, ScrollHandle, SharedString, Styled, Window, canvas, div,
+    prelude::*,
+};
+
+use super::{
+    Choice,
+    check::tab_stop,
+    input::text_size,
+    options::{OnValue, Pick, Popup, step},
+};
+use crate::{
+    primitives::{Icon, IconName},
+    theme::{ActiveTheme, ControlSize, IconSize, Radius},
+};
+
+/// An open list's place and cursor, kept between frames.
+#[derive(Default)]
+pub(crate) struct Picker {
+    pub open: bool,
+    pub highlighted: usize,
+    pub anchor: Bounds<Pixels>,
+    pub scroll: ScrollHandle,
+}
+
+impl Picker {
+    pub fn show(state: &Entity<Picker>, open: bool, highlighted: usize, cx: &mut App) {
+        state.update(cx, |picker, cx| {
+            picker.open = open;
+            picker.highlighted = highlighted;
+            picker.scroll.scroll_to_item(highlighted);
+            cx.notify();
+        });
+    }
+}
+
+/// Sizes an invisible layer to its parent and records the bounds in `state`.
+pub(crate) fn measure_anchor(state: Entity<Picker>) -> impl IntoElement {
+    canvas(
+        move |bounds, _, cx| {
+            if state.read(cx).anchor != bounds {
+                state.update(cx, |picker, _| picker.anchor = bounds);
+            }
+        },
+        |_, _, _, _| {},
+    )
+    .absolute()
+    .top_0()
+    .left_0()
+    .size_full()
+}
+
+/// Up, Down, Home and End over `rows` from `at`; `None` for other keys.
+pub(crate) fn moved(event: &KeyDownEvent, rows: &[Choice], at: usize) -> Option<usize> {
+    let last = rows.len() - 1;
+    match event.keystroke.key.as_str() {
+        "down" => Some(step(rows, at, 1)),
+        "up" => Some(step(rows, at, -1)),
+        "home" => Some(step(rows, last, 1)),
+        "end" => Some(step(rows, 0, -1)),
+        _ => None,
+    }
+}
+
+/// A button that opens a list and shows the one chosen.
+#[derive(IntoElement)]
+pub struct Select {
+    id: ElementId,
+    choices: Vec<Choice>,
+    selected: Option<SharedString>,
+    placeholder: SharedString,
+    size: ControlSize,
+    disabled: bool,
+    on_change: Option<OnValue>,
+}
+
+impl Select {
+    pub fn new(id: impl Into<ElementId>, choices: impl IntoIterator<Item = Choice>) -> Self {
+        Self {
+            id: id.into(),
+            choices: choices.into_iter().collect(),
+            selected: None,
+            placeholder: SharedString::from("Choose…"),
+            size: ControlSize::default(),
+            disabled: false,
+            on_change: None,
+        }
+    }
+
+    pub fn selected(mut self, value: impl Into<SharedString>) -> Self {
+        self.selected = Some(value.into());
+        self
+    }
+
+    pub fn placeholder(mut self, text: impl Into<SharedString>) -> Self {
+        self.placeholder = text.into();
+        self
+    }
+
+    pub fn size(mut self, size: ControlSize) -> Self {
+        self.size = size;
+        self
+    }
+
+    pub fn disabled(mut self, disabled: bool) -> Self {
+        self.disabled = disabled;
+        self
+    }
+
+    pub fn on_change(
+        mut self,
+        handler: impl Fn(&SharedString, &mut Window, &mut App) + 'static,
+    ) -> Self {
+        self.on_change = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for Select {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        assert!(
+            !self.choices.is_empty(),
+            "select {:?} has no choices",
+            self.id
+        );
+        let focus = tab_stop(
+            (self.id.clone(), "focus").into(),
+            !self.disabled,
+            window,
+            cx,
+        );
+        let focused = focus.is_focused(window);
+        let picker =
+            window.use_keyed_state((self.id.clone(), "picker"), cx, |_, _| Picker::default());
+        if picker.read(cx).open && !focused {
+            log::info!("select {:?}: closed on blur", self.id);
+            picker.update(cx, |picker, _| picker.open = false);
+        }
+        let choices = Rc::new(self.choices);
+        let current = self
+            .selected
+            .as_ref()
+            .and_then(|value| choices.iter().position(|choice| choice.value == *value));
+        let start = current.unwrap_or_else(|| step(&choices, choices.len() - 1, 1));
+        if picker.read(cx).highlighted >= choices.len() {
+            picker.update(cx, |picker, _| picker.highlighted = start);
+        }
+        let (open, highlighted, anchor, scroll) = {
+            let picker = picker.read(cx);
+            (
+                picker.open,
+                picker.highlighted,
+                picker.anchor,
+                picker.scroll.clone(),
+            )
+        };
+        let pick: Pick = {
+            let (id, choices, picker, on_change) = (
+                self.id.clone(),
+                choices.clone(),
+                picker.clone(),
+                self.on_change,
+            );
+            Rc::new(move |ix, window, cx| {
+                if choices[ix].disabled {
+                    return;
+                }
+                let value = choices[ix].value.clone();
+                log::info!("select {id:?}: {value}");
+                Picker::show(&picker, false, ix, cx);
+                if let Some(on_change) = &on_change {
+                    on_change(&value, window, cx);
+                }
+            })
+        };
+        let theme = cx.theme();
+        let colors = &theme.colors;
+        let shown = current.map(|ix| &choices[ix]);
+        let (toggle, keys, rows, close) = (
+            picker.clone(),
+            picker.clone(),
+            choices.clone(),
+            picker.clone(),
+        );
+        let enter = pick.clone();
+        let chosen: Vec<SharedString> = shown.iter().map(|choice| choice.value.clone()).collect();
+        div()
+            .id(self.id.clone())
+            .track_focus(&focus)
+            .relative()
+            .flex()
+            .items_center()
+            .gap_2()
+            .w_full()
+            .h(theme.control_height(self.size))
+            .px(theme.control_padding(self.size))
+            .rounded(theme.radius(Radius::Md))
+            .border_1()
+            .border_color(if focused {
+                colors.focus
+            } else {
+                colors.border_strong
+            })
+            .bg(if self.disabled {
+                colors.sunken
+            } else {
+                colors.surface
+            })
+            .text_size(theme.text_size(text_size(self.size)))
+            .when(!self.disabled, |trigger| {
+                trigger
+                    .cursor_pointer()
+                    .on_mouse_down(MouseButton::Left, move |_, _, cx| {
+                        Picker::show(&toggle, !open, start, cx)
+                    })
+                    .on_key_down(move |event, window, cx| {
+                        let at = keys.read(cx).highlighted;
+                        let key = event.keystroke.key.as_str();
+                        if !open {
+                            if matches!(key, "down" | "up" | "enter" | "space") {
+                                cx.stop_propagation();
+                                Picker::show(&keys, true, start, cx);
+                            }
+                            return;
+                        }
+                        if let Some(to) = moved(event, &rows, at) {
+                            cx.stop_propagation();
+                            Picker::show(&keys, true, to, cx);
+                        } else if matches!(key, "enter" | "space") {
+                            cx.stop_propagation();
+                            enter(at, window, cx);
+                        } else if key == "escape" {
+                            cx.stop_propagation();
+                            Picker::show(&keys, false, at, cx);
+                        }
+                    })
+            })
+            .when_some(shown.and_then(|choice| choice.icon), |trigger, icon| {
+                trigger.child(Icon::new(icon).size(IconSize::Sm).color(colors.fg_muted))
+            })
+            .child(
+                div()
+                    .flex_1()
+                    .min_w_0()
+                    .overflow_hidden()
+                    .text_ellipsis()
+                    .whitespace_nowrap()
+                    .text_color(match (shown, self.disabled) {
+                        (_, true) => colors.fg_disabled,
+                        (Some(_), false) => colors.fg,
+                        (None, false) => colors.fg_subtle,
+                    })
+                    .child(shown.map_or(self.placeholder, |choice| choice.label.clone())),
+            )
+            .child(
+                Icon::new(IconName::ChevronsUpDown)
+                    .size(IconSize::Xs)
+                    .color(colors.fg_subtle),
+            )
+            .child(measure_anchor(picker))
+            .when(open, |trigger| {
+                trigger.child(
+                    Popup {
+                        id: (self.id, "list").into(),
+                        anchor,
+                        rows: &choices,
+                        highlighted: Some(highlighted),
+                        checked: Some(&chosen),
+                        pick,
+                        dismiss: Some(Rc::new(move |_, cx| {
+                            let at = close.read(cx).highlighted;
+                            Picker::show(&close, false, at, cx)
+                        })),
+                        scroll: Some(&scroll),
+                    }
+                    .render(window, cx),
+                )
+            })
+    }
+}

src/forms/slider.rs

@@ -0,0 +1,438 @@
+use std::rc::Rc;
+
+use gpui::{
+    AnyElement, App, Bounds, DragMoveEvent, ElementId, EmptyView, EntityId, InteractiveElement,
+    IntoElement, MouseButton, ParentElement, Pixels, Point, RenderOnce, StatefulInteractiveElement,
+    Styled, Window, canvas, div, prelude::*, relative,
+};
+
+use super::{check::tab_stop, options::OnNumber};
+use crate::theme::{ActiveTheme, Elevation};
+
+/// `value` as a fraction of `min..=max`.
+pub(crate) fn fraction(value: f64, min: f64, max: f64) -> f32 {
+    ((value - min) / (max - min)).clamp(0.0, 1.0) as f32
+}
+
+/// The value at `fraction` of `min..=max`, on the `step` grid.
+pub(crate) fn value_at(fraction: f32, min: f64, max: f64, step: f64) -> f64 {
+    let raw = min + f64::from(fraction.clamp(0.0, 1.0)) * (max - min);
+    (min + ((raw - min) / step).round() * step).clamp(min, max)
+}
+
+/// Where a key moves `value`: arrows step, Page keys jump ten, Home and End go to the ends.
+pub(crate) fn keyed(key: &str, value: f64, min: f64, max: f64, step: f64) -> Option<f64> {
+    let next = match key {
+        "left" | "down" => value - step,
+        "right" | "up" => value + step,
+        "pagedown" => value - step * 10.0,
+        "pageup" => value + step * 10.0,
+        "home" => min,
+        "end" => max,
+        _ => return None,
+    };
+    Some(next.clamp(min, max))
+}
+
+/// How far along a track `at` is, from its start: left, or bottom when vertical.
+fn along(bounds: Bounds<Pixels>, at: Point<Pixels>, vertical: bool) -> f32 {
+    if vertical {
+        (bounds.bottom() - at.y) / bounds.size.height
+    } else {
+        (at.x - bounds.left()) / bounds.size.width
+    }
+}
+
+/// A drag of thumb `index`, or of the thumb the last track press grabbed.
+struct Thumb {
+    owner: EntityId,
+    index: Option<usize>,
+}
+
+type Commit = Rc<dyn Fn(usize, f64, &mut Window, &mut App)>;
+type OnSpan = Rc<dyn Fn((f64, f64), &mut Window, &mut App)>;
+
+/// A track with one or two thumbs. `commit` gets the thumb and its new value.
+struct Track {
+    id: ElementId,
+    values: Vec<f64>,
+    range: (f64, f64, f64),
+    vertical: bool,
+    disabled: bool,
+    commit: Commit,
+}
+
+impl Track {
+    fn render(self, window: &mut Window, cx: &mut App) -> AnyElement {
+        let (min, max, step) = self.range;
+        let vertical = self.vertical;
+        let owner = window
+            .use_keyed_state((self.id.clone(), "drag"), cx, |_, _| ())
+            .entity_id();
+        let grabbed = window.use_keyed_state((self.id.clone(), "grab"), cx, |_, _| 0usize);
+        let measured = window.use_keyed_state((self.id.clone(), "bounds"), cx, |_, _| {
+            Bounds::<Pixels>::default()
+        });
+        let handles: Vec<_> = (0..self.values.len())
+            .map(|k| {
+                tab_stop(
+                    (self.id.clone(), ["low", "high"][k]).into(),
+                    !self.disabled,
+                    window,
+                    cx,
+                )
+            })
+            .collect();
+        let theme = cx.theme();
+        let colors = &theme.colors;
+        let (thumb, line) = (theme.slider_thumb(), theme.slider_track());
+        let fractions: Vec<f32> = self
+            .values
+            .iter()
+            .map(|value| fraction(*value, min, max))
+            .collect();
+        let (start, end) = if fractions.len() == 2 {
+            (fractions[0], fractions[1])
+        } else {
+            (0.0, fractions[0])
+        };
+        let rail = div()
+            .absolute()
+            .rounded_full()
+            .bg(colors.border)
+            .map(|rail| {
+                if vertical {
+                    rail.top_0()
+                        .bottom_0()
+                        .left(relative(0.5))
+                        .ml(line * -0.5)
+                        .w(line)
+                } else {
+                    rail.left_0()
+                        .right_0()
+                        .top(relative(0.5))
+                        .mt(line * -0.5)
+                        .h(line)
+                }
+            });
+        let fill = div()
+            .absolute()
+            .rounded_full()
+            .bg(colors.accent)
+            .map(|fill| {
+                if vertical {
+                    fill.bottom(relative(start))
+                        .h(relative(end - start))
+                        .left(relative(0.5))
+                        .ml(line * -0.5)
+                        .w(line)
+                } else {
+                    fill.left(relative(start))
+                        .w(relative(end - start))
+                        .top(relative(0.5))
+                        .mt(line * -0.5)
+                        .h(line)
+                }
+            });
+        let thumbs: Vec<_> = fractions
+            .iter()
+            .enumerate()
+            .map(|(k, at)| {
+                let focused = handles[k].is_focused(window);
+                let (commit, value) = (self.commit.clone(), self.values[k]);
+                div()
+                    .id(("thumb", k))
+                    .track_focus(&handles[k])
+                    .absolute()
+                    .size(thumb)
+                    .rounded_full()
+                    .bg(colors.surface)
+                    .border_1()
+                    .border_color(if focused {
+                        colors.focus
+                    } else {
+                        colors.border_strong
+                    })
+                    .shadow(theme.elevation(Elevation::Raised))
+                    .map(|thumb_box| {
+                        if vertical {
+                            thumb_box.left_0().bottom(relative(*at)).mb(thumb * -0.5)
+                        } else {
+                            thumb_box.top_0().left(relative(*at)).ml(thumb * -0.5)
+                        }
+                    })
+                    .when(!self.disabled, |thumb_box| {
+                        thumb_box
+                            .cursor_pointer()
+                            .on_drag(
+                                Thumb {
+                                    owner,
+                                    index: Some(k),
+                                },
+                                |_, _, _, cx| cx.new(|_| EmptyView),
+                            )
+                            .on_key_down(move |event, window, cx| {
+                                if let Some(next) =
+                                    keyed(&event.keystroke.key, value, min, max, step)
+                                {
+                                    cx.stop_propagation();
+                                    commit(k, next, window, cx);
+                                }
+                            })
+                    })
+            })
+            .collect();
+        let (drag, jump) = (self.commit.clone(), self.commit);
+        let (values, focus) = (self.values, handles);
+        let bounds_state = measured.clone();
+        let inner = div()
+            .id((self.id.clone(), "inner"))
+            .relative()
+            .size_full()
+            .child(rail)
+            .child(fill)
+            .children(thumbs)
+            .child(
+                canvas(
+                    move |bounds, _, cx| {
+                        if *bounds_state.read(cx) != bounds {
+                            bounds_state.update(cx, |state, _| *state = bounds);
+                        }
+                    },
+                    |_, _, _, _| {},
+                )
+                .absolute()
+                .size_full(),
+            )
+            .when(!self.disabled, |inner| {
+                let grab = grabbed.clone();
+                inner
+                    .on_drag(Thumb { owner, index: None }, |_, _, _, cx| {
+                        cx.new(|_| EmptyView)
+                    })
+                    .on_drag_move(move |event: &DragMoveEvent<Thumb>, window, cx| {
+                        let thumb = event.drag(cx);
+                        if thumb.owner != owner {
+                            return;
+                        }
+                        let index = thumb.index.unwrap_or(*grabbed.read(cx));
+                        let next = value_at(
+                            along(event.bounds, event.event.position, vertical),
+                            min,
+                            max,
+                            step,
+                        );
+                        drag(index, next, window, cx);
+                    })
+                    .on_mouse_down(MouseButton::Left, move |event, window, cx| {
+                        let bounds = *measured.read(cx);
+                        let next =
+                            value_at(along(bounds, event.position, vertical), min, max, step);
+                        let index = match values.as_slice() {
+                            [low, high] if (next - high).abs() < (next - low).abs() => 1,
+                            _ => 0,
+                        };
+                        grab.update(cx, |grab, _| *grab = index);
+                        window.focus(&focus[index]);
+                        jump(index, next, window, cx);
+                    })
+            });
+        div()
+            .id(self.id)
+            .flex_none()
+            .map(|outer| {
+                if vertical {
+                    outer.h_full().w(thumb).py(thumb * 0.5)
+                } else {
+                    outer.w_full().h(thumb).px(thumb * 0.5)
+                }
+            })
+            .when(self.disabled, |outer| outer.opacity(0.5))
+            .child(inner)
+            .into_any_element()
+    }
+}
+
+/// A value along a track. Drag the thumb, click the track, or use the arrow keys.
+#[derive(IntoElement)]
+pub struct Slider {
+    id: ElementId,
+    value: f64,
+    range: (f64, f64, f64),
+    vertical: bool,
+    disabled: bool,
+    on_change: Option<OnNumber>,
+}
+
+impl Slider {
+    pub fn new(id: impl Into<ElementId>, value: f64) -> Self {
+        Self {
+            id: id.into(),
+            value,
+            range: (0.0, 100.0, 1.0),
+            vertical: false,
+            disabled: false,
+            on_change: None,
+        }
+    }
+
+    pub fn range(mut self, min: f64, max: f64) -> Self {
+        assert!(min < max, "slider range {min}..{max} is empty");
+        self.range.0 = min;
+        self.range.1 = max;
+        self
+    }
+
+    pub fn step(mut self, step: f64) -> Self {
+        assert!(step > 0.0, "slider step {step} must be positive");
+        self.range.2 = step;
+        self
+    }
+
+    /// Runs bottom to top; the parent gives it a height.
+    pub fn vertical(mut self) -> Self {
+        self.vertical = true;
+        self
+    }
+
+    pub fn disabled(mut self, disabled: bool) -> Self {
+        self.disabled = disabled;
+        self
+    }
+
+    pub fn on_change(mut self, handler: impl Fn(f64, &mut Window, &mut App) + 'static) -> Self {
+        self.on_change = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for Slider {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let (id, value, on_change) = (self.id.clone(), self.value, self.on_change);
+        let commit: Commit = Rc::new(move |_, next, window, cx| {
+            if next == value {
+                return;
+            }
+            log::debug!("slider {id:?}: {next}");
+            if let Some(on_change) = &on_change {
+                on_change(next, window, cx);
+            }
+        });
+        Track {
+            id: self.id,
+            values: vec![value],
+            range: self.range,
+            vertical: self.vertical,
+            disabled: self.disabled,
+            commit,
+        }
+        .render(window, cx)
+    }
+}
+
+/// Two thumbs that bound a span. Neither passes the other.
+#[derive(IntoElement)]
+pub struct RangeSlider {
+    id: ElementId,
+    value: (f64, f64),
+    range: (f64, f64, f64),
+    vertical: bool,
+    disabled: bool,
+    on_change: Option<OnSpan>,
+}
+
+impl RangeSlider {
+    pub fn new(id: impl Into<ElementId>, low: f64, high: f64) -> Self {
+        assert!(low <= high, "range {low}..{high} runs backwards");
+        Self {
+            id: id.into(),
+            value: (low, high),
+            range: (0.0, 100.0, 1.0),
+            vertical: false,
+            disabled: false,
+            on_change: None,
+        }
+    }
+
+    pub fn range(mut self, min: f64, max: f64) -> Self {
+        assert!(min < max, "slider range {min}..{max} is empty");
+        self.range.0 = min;
+        self.range.1 = max;
+        self
+    }
+
+    pub fn step(mut self, step: f64) -> Self {
+        assert!(step > 0.0, "slider step {step} must be positive");
+        self.range.2 = step;
+        self
+    }
+
+    /// Runs bottom to top; the parent gives it a height.
+    pub fn vertical(mut self) -> Self {
+        self.vertical = true;
+        self
+    }
+
+    pub fn disabled(mut self, disabled: bool) -> Self {
+        self.disabled = disabled;
+        self
+    }
+
+    pub fn on_change(
+        mut self,
+        handler: impl Fn((f64, f64), &mut Window, &mut App) + 'static,
+    ) -> Self {
+        self.on_change = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for RangeSlider {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let (id, (low, high), on_change) = (self.id.clone(), self.value, self.on_change);
+        let commit: Commit = Rc::new(move |index, next, window, cx| {
+            let span = if index == 0 {
+                (next.min(high), high)
+            } else {
+                (low, next.max(low))
+            };
+            if span == (low, high) {
+                return;
+            }
+            log::debug!("range slider {id:?}: {span:?}");
+            if let Some(on_change) = &on_change {
+                on_change(span, window, cx);
+            }
+        });
+        Track {
+            id: self.id,
+            values: vec![low, high],
+            range: self.range,
+            vertical: self.vertical,
+            disabled: self.disabled,
+            commit,
+        }
+        .render(window, cx)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{fraction, keyed, value_at};
+
+    #[test]
+    fn values_snap_to_the_step_and_stay_in_range() {
+        assert_eq!(fraction(25.0, 0.0, 100.0), 0.25);
+        assert_eq!(value_at(0.26, 0.0, 100.0, 5.0), 25.0);
+        assert_eq!(value_at(1.4, 0.0, 100.0, 5.0), 100.0);
+        assert_eq!(value_at(0.5, -1.0, 1.0, 0.5), 0.0);
+    }
+
+    #[test]
+    fn keys_step_jump_and_reach_the_ends() {
+        assert_eq!(keyed("right", 10.0, 0.0, 100.0, 1.0), Some(11.0));
+        assert_eq!(keyed("pagedown", 5.0, 0.0, 100.0, 1.0), Some(0.0));
+        assert_eq!(keyed("end", 5.0, 0.0, 100.0, 1.0), Some(100.0));
+        assert_eq!(keyed("a", 5.0, 0.0, 100.0, 1.0), None);
+    }
+}

src/forms/stepper.rs

@@ -0,0 +1,109 @@
+use std::rc::Rc;
+
+use gpui::{App, ElementId, IntoElement, ParentElement, RenderOnce, Styled, Window, div};
+
+use super::options::OnNumber;
+use crate::{
+    buttons::{ButtonVariant, IconButton},
+    primitives::IconName,
+    theme::{ActiveTheme, ControlSize, Radius, TextSize},
+    typography::format::{self, Separators},
+};
+
+/// Minus and plus around a number that cannot be typed.
+#[derive(IntoElement)]
+pub struct Stepper {
+    id: ElementId,
+    value: f64,
+    min: f64,
+    max: f64,
+    step: f64,
+    precision: usize,
+    on_change: Option<OnNumber>,
+}
+
+impl Stepper {
+    pub fn new(id: impl Into<ElementId>, value: f64) -> Self {
+        Self {
+            id: id.into(),
+            value,
+            min: f64::MIN,
+            max: f64::MAX,
+            step: 1.0,
+            precision: 0,
+            on_change: None,
+        }
+    }
+
+    pub fn range(mut self, min: f64, max: f64) -> Self {
+        assert!(min <= max, "stepper range {min}..{max} is empty");
+        self.min = min;
+        self.max = max;
+        self
+    }
+
+    pub fn step(mut self, step: f64) -> Self {
+        assert!(step > 0.0, "stepper step {step} must be positive");
+        self.step = step;
+        self
+    }
+
+    /// Decimal places shown.
+    pub fn precision(mut self, places: usize) -> Self {
+        self.precision = places;
+        self
+    }
+
+    pub fn on_change(mut self, handler: impl Fn(f64, &mut Window, &mut App) + 'static) -> Self {
+        self.on_change = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for Stepper {
+    fn render(self, _: &mut Window, cx: &mut App) -> impl IntoElement {
+        let theme = cx.theme();
+        let (value, min, max) = (self.value, self.min, self.max);
+        let nudge = |by: f64| {
+            let (id, on_change) = (self.id.clone(), self.on_change.clone());
+            move |_: &gpui::ClickEvent, window: &mut Window, cx: &mut App| {
+                let next = (value + by).clamp(min, max);
+                log::info!("stepper {id:?}: {next}");
+                if let Some(on_change) = &on_change {
+                    on_change(next, window, cx);
+                }
+            }
+        };
+        div()
+            .flex()
+            .items_center()
+            .h(theme.control_height(ControlSize::Md))
+            .p_0p5()
+            .rounded(theme.radius(Radius::Md))
+            .border_1()
+            .border_color(theme.colors.border_strong)
+            .bg(theme.colors.surface)
+            .child(
+                IconButton::new((self.id.clone(), "less"), IconName::Minus)
+                    .variant(ButtonVariant::Ghost)
+                    .size(ControlSize::Sm)
+                    .disabled(value <= min)
+                    .on_click(nudge(-self.step)),
+            )
+            .child(
+                div()
+                    .min_w(theme.control_height(ControlSize::Md))
+                    .text_center()
+                    .text_size(theme.text_size(TextSize::Base))
+                    .text_color(theme.colors.fg)
+                    .child(format::number(value, self.precision, Separators::EN)),
+            )
+            .child(
+                IconButton::new((self.id.clone(), "more"), IconName::Plus)
+                    .variant(ButtonVariant::Ghost)
+                    .size(ControlSize::Sm)
+                    .disabled(value >= max)
+                    .on_click(nudge(self.step)),
+            )
+    }
+}

src/forms/suggest.rs

@@ -1,79 +0,0 @@
-use std::rc::Rc;
-
-use gpui::{
-    AnyElement, App, Bounds, ElementId, InteractiveElement, IntoElement, MouseButton,
-    ParentElement, Pixels, SharedString, Styled, anchored, deferred, div, point, prelude::*,
-};
-
-use crate::theme::{ActiveTheme, Elevation, Radius, TextSize};
-
-/// One row in a suggestion list: a label and a quiet note.
-#[derive(Clone, Debug)]
-pub(crate) struct Suggestion {
-    pub label: SharedString,
-    pub note: Option<SharedString>,
-}
-
-type Pick = Rc<dyn Fn(usize, &mut gpui::Window, &mut App)>;
-pub(crate) type Dismiss = Rc<dyn Fn(&mut gpui::Window, &mut App)>;
-
-/// A list floating under `anchor`. Rows keep focus where it was.
-pub(crate) fn suggestion_list(
-    id: impl Into<ElementId>,
-    anchor: Bounds<Pixels>,
-    rows: &[Suggestion],
-    highlighted: usize,
-    pick: Pick,
-    dismiss: Option<Dismiss>,
-    cx: &App,
-) -> AnyElement {
-    let theme = cx.theme();
-    let colors = &theme.colors;
-    let list = div()
-        .id(id)
-        .min_w(theme.tooltip_max_width())
-        .p_1()
-        .flex()
-        .flex_col()
-        .rounded(theme.radius(Radius::Lg))
-        .bg(colors.overlay)
-        .border_1()
-        .border_color(colors.border)
-        .shadow(theme.elevation(Elevation::Floating))
-        .text_size(theme.text_size(TextSize::Sm))
-        .when_some(dismiss, |list, dismiss| {
-            list.on_mouse_down_out(move |_, window, cx| dismiss(window, cx))
-        })
-        .children(rows.iter().enumerate().map(|(ix, row)| {
-            let pick = pick.clone();
-            div()
-                .id(("suggestion", ix))
-                .flex()
-                .items_center()
-                .justify_between()
-                .gap_4()
-                .px_2()
-                .py_1()
-                .rounded(theme.radius(Radius::Md))
-                .text_color(colors.fg)
-                .when(ix == highlighted, |row| row.bg(colors.hover))
-                .hover(|style| style.bg(colors.hover))
-                .cursor_pointer()
-                .on_mouse_down(MouseButton::Left, move |_, window, cx| {
-                    window.prevent_default();
-                    cx.stop_propagation();
-                    pick(ix, window, cx);
-                })
-                .child(row.label.clone())
-                .when_some(row.note.clone(), |row, note| {
-                    row.child(div().text_color(colors.fg_subtle).child(note))
-                })
-        }));
-    deferred(
-        anchored()
-            .position(point(anchor.left(), anchor.bottom()))
-            .child(div().mt_1().child(list)),
-    )
-    .with_priority(1)
-    .into_any_element()
-}

src/forms/switch.rs

@@ -0,0 +1,144 @@
+use std::rc::Rc;
+
+use gpui::{
+    Animation, AnimationExt, App, ElementId, InteractiveElement, IntoElement, MouseButton,
+    ParentElement, RenderOnce, SharedString, StatefulInteractiveElement, Styled, Window, div,
+    prelude::*, transparent_black,
+};
+
+use super::{check::tab_stop, options::OnFlag};
+use crate::{
+    motion,
+    theme::{ActiveTheme, Elevation, Mix, TextSize},
+};
+
+/// An on-off switch. The thumb slides over with a small overshoot.
+#[derive(IntoElement)]
+pub struct Switch {
+    id: ElementId,
+    on: bool,
+    label: Option<SharedString>,
+    disabled: bool,
+    on_change: Option<OnFlag>,
+}
+
+impl Switch {
+    pub fn new(id: impl Into<ElementId>, on: bool) -> Self {
+        Self {
+            id: id.into(),
+            on,
+            label: None,
+            disabled: false,
+            on_change: None,
+        }
+    }
+
+    pub fn label(mut self, label: impl Into<SharedString>) -> Self {
+        self.label = Some(label.into());
+        self
+    }
+
+    pub fn disabled(mut self, disabled: bool) -> Self {
+        self.disabled = disabled;
+        self
+    }
+
+    pub fn on_change(mut self, handler: impl Fn(bool, &mut Window, &mut App) + 'static) -> Self {
+        self.on_change = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for Switch {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let focus = tab_stop(
+            (self.id.clone(), "focus").into(),
+            !self.disabled,
+            window,
+            cx,
+        );
+        let changes = motion::changes((self.id.clone(), "changes"), self.on, window, cx);
+        let focused = focus.is_focused(window);
+        let theme = cx.theme();
+        let colors = &theme.colors;
+        let track = theme.switch_track();
+        let travel = track.width - track.height;
+        let (off, on) = (colors.border_strong, colors.accent);
+        let (knob_off, knob_on) = (colors.fg_muted, colors.on_accent);
+        let (from, to, fill_from, fill_to, knob_from, knob_to) = if self.on {
+            (0.0, 1.0, off, on, knob_off, knob_on)
+        } else {
+            (1.0, 0.0, on, off, knob_on, knob_off)
+        };
+        let thumb = div()
+            .h_full()
+            .map(|mut thumb| {
+                thumb.style().aspect_ratio = Some(1.0);
+                thumb
+            })
+            .rounded_full()
+            .bg(knob_to)
+            .shadow(theme.elevation(Elevation::Raised));
+        let rail = div()
+            .flex()
+            .flex_none()
+            .items_center()
+            .w(track.width)
+            .h(track.height)
+            .p_0p5()
+            .rounded_full()
+            .border_1()
+            .border_color(if focused {
+                colors.focus
+            } else {
+                transparent_black()
+            })
+            .bg(fill_to)
+            .when(self.disabled, |rail| rail.opacity(0.5));
+        let rail = if changes == 0 {
+            rail.child(thumb.ml(travel * to)).into_any_element()
+        } else {
+            let duration = motion::duration(motion::BASE, cx);
+            rail.child(thumb.with_animation(
+                ("switch-thumb", changes),
+                Animation::new(duration),
+                move |thumb, t| {
+                    thumb
+                        .ml(travel * motion::lerp(from, to, motion::spring(t)))
+                        .bg(knob_from.mix(&knob_to, t))
+                },
+            ))
+            .with_animation(
+                ("switch-fill", changes),
+                Animation::new(duration),
+                move |rail, t| rail.bg(fill_from.mix(&fill_to, t)),
+            )
+            .into_any_element()
+        };
+        let (id, next, on_change) = (self.id.clone(), !self.on, self.on_change);
+        div()
+            .id(self.id)
+            .track_focus(&focus)
+            .flex()
+            .items_center()
+            .gap_2()
+            .text_size(theme.text_size(TextSize::Base))
+            .text_color(if self.disabled {
+                colors.fg_disabled
+            } else {
+                colors.fg
+            })
+            .when(!self.disabled, |row| {
+                row.cursor_pointer()
+                    .on_mouse_down(MouseButton::Left, |_, window, _| window.prevent_default())
+                    .on_click(move |_, window, cx| {
+                        log::info!("switch {id:?}: {}", if next { "on" } else { "off" });
+                        if let Some(on_change) = &on_change {
+                            on_change(next, window, cx);
+                        }
+                    })
+            })
+            .child(rail)
+            .children(self.label)
+    }
+}

src/forms/tags.rs

@@ -1,12 +1,12 @@
 use std::rc::Rc;
 
 use gpui::{
-    App, Context, ElementId, Entity, InteractiveElement, IntoElement, MouseButton, ParentElement,
-    RenderOnce, SharedString, StatefulInteractiveElement, Styled, Subscription, Window, div,
-    prelude::*,
+    App, Context, Div, ElementId, Entity, InteractiveElement, IntoElement, MouseButton,
+    ParentElement, RenderOnce, SharedString, StatefulInteractiveElement, Styled, Subscription,
+    Window, div, prelude::*,
 };
 
-use super::{InputEvent, TextInput, text::Backspace};
+use super::{InputEvent, TextInput, options::Run, text::Backspace};
 use crate::{
     primitives::{Icon, IconName},
     theme::{ActiveTheme, ControlSize, IconSize, Radius, TextSize},
@@ -45,6 +45,41 @@ impl Tags {
     }
 }
 
+/// A small label with an x that removes it.
+pub(crate) fn chip(id: ElementId, label: SharedString, remove: Run, cx: &App) -> Div {
+    let theme = cx.theme();
+    let colors = &theme.colors;
+    div()
+        .flex()
+        .items_center()
+        .gap_1()
+        .pl_2()
+        .pr_1()
+        .h(theme.control_height(ControlSize::Sm))
+        .rounded(theme.radius(Radius::Sm))
+        .bg(colors.hover)
+        .text_size(theme.text_size(TextSize::Sm))
+        .text_color(colors.fg)
+        .child(label)
+        .child(
+            div()
+                .id(id)
+                .rounded(theme.radius(Radius::Sm))
+                .cursor_pointer()
+                .hover(|style| style.bg(colors.active))
+                .on_mouse_down(MouseButton::Left, |_, window, _| window.prevent_default())
+                .on_click(move |_, window, cx| {
+                    cx.stop_propagation();
+                    remove(window, cx)
+                })
+                .child(
+                    Icon::new(IconName::X)
+                        .size(IconSize::Xs)
+                        .color(colors.fg_muted),
+                ),
+        )
+}
+
 /// A chip per tag, then a field. Enter or a comma adds; Backspace on empty drops the last.
 #[derive(IntoElement)]
 pub struct TagInput {
@@ -111,39 +146,20 @@ impl RenderOnce for TagInput {
         let theme = cx.theme();
         let colors = &theme.colors;
         let chips = self.tags.iter().enumerate().map(|(ix, tag)| {
-            let (remove, tags, on_change) = (ix, self.tags.clone(), self.on_change.clone());
-            div()
-                .flex()
-                .items_center()
-                .gap_1()
-                .pl_2()
-                .pr_1()
-                .h(theme.control_height(ControlSize::Sm))
-                .rounded(theme.radius(Radius::Sm))
-                .bg(colors.hover)
-                .text_size(theme.text_size(TextSize::Sm))
-                .child(tag.clone())
-                .child(
-                    div()
-                        .id(("tag-remove", ix))
-                        .rounded(theme.radius(Radius::Sm))
-                        .cursor_pointer()
-                        .hover(|style| style.bg(colors.active))
-                        .on_mouse_down(MouseButton::Left, |_, window, _| window.prevent_default())
-                        .on_click(move |_, window, cx| {
-                            let mut next = tags.clone();
-                            next.remove(remove);
-                            log::info!("tag input: removed one, {} left", next.len());
-                            if let Some(on_change) = &on_change {
-                                on_change(next, window, cx);
-                            }
-                        })
-                        .child(
-                            Icon::new(IconName::X)
-                                .size(IconSize::Xs)
-                                .color(colors.fg_muted),
-                        ),
-                )
+            let (tags, on_change) = (self.tags.clone(), self.on_change.clone());
+            chip(
+                ("tag-remove", ix).into(),
+                tag.clone(),
+                Rc::new(move |window, cx| {
+                    let mut next = tags.clone();
+                    next.remove(ix);
+                    log::info!("tag input: removed one, {} left", next.len());
+                    if let Some(on_change) = &on_change {
+                        on_change(next, window, cx);
+                    }
+                }),
+                cx,
+            )
         });
         let (tags, on_change, empty_check) =
             (self.tags.clone(), self.on_change.clone(), input.clone());

src/forms/tests/choices.rs

@@ -0,0 +1,313 @@
+use gpui::{
+    AppContext as _, Context, Entity, IntoElement, KeyUpEvent, Keystroke, Render, SharedString,
+    TestAppContext, VisualTestContext, Window,
+};
+
+use super::setup;
+use crate::forms::{
+    Checkbox, Choice, Combobox, MultiSelect, RadioGroup, Rating, Select, Slider, TextInput,
+};
+
+fn abc(middle_off: bool) -> [Choice; 3] {
+    let middle = Choice::new("b", "B");
+    [
+        Choice::new("a", "A"),
+        if middle_off {
+            middle.disabled()
+        } else {
+            middle
+        },
+        Choice::new("c", "C"),
+    ]
+}
+
+struct Radios {
+    chosen: SharedString,
+}
+
+fn release(key: &str, cx: &mut VisualTestContext) {
+    cx.simulate_event(KeyUpEvent {
+        keystroke: Keystroke::parse(key).unwrap(),
+    });
+}
+
+impl Render for Radios {
+    fn render(&mut self, _: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
+        let view = cx.entity();
+        RadioGroup::new("radios", abc(true))
+            .selected(self.chosen.clone())
+            .on_change(move |value, _, cx| {
+                view.update(cx, |view, cx| {
+                    view.chosen = value.clone();
+                    cx.notify();
+                })
+            })
+    }
+}
+
+#[gpui::test]
+fn radio_arrows_skip_disabled_choices_and_wrap(cx: &mut TestAppContext) {
+    setup(cx);
+    let (view, cx) = cx.add_window_view(|_, _| Radios { chosen: "a".into() });
+    cx.update(|window, _| window.focus_next());
+    cx.simulate_keystrokes("down");
+    assert_eq!(view.read_with(cx, |view, _| view.chosen.clone()), "c");
+    cx.simulate_keystrokes("down");
+    assert_eq!(view.read_with(cx, |view, _| view.chosen.clone()), "a");
+}
+
+struct Picker {
+    chosen: SharedString,
+}
+
+impl Render for Picker {
+    fn render(&mut self, _: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
+        let view = cx.entity();
+        Select::new("select", abc(false))
+            .selected(self.chosen.clone())
+            .on_change(move |value, _, cx| {
+                view.update(cx, |view, cx| {
+                    view.chosen = value.clone();
+                    cx.notify();
+                })
+            })
+    }
+}
+
+#[gpui::test]
+fn select_opens_moves_and_picks_from_the_keyboard(cx: &mut TestAppContext) {
+    setup(cx);
+    let (view, cx) = cx.add_window_view(|_, _| Picker { chosen: "a".into() });
+    cx.update(|window, _| window.focus_next());
+    cx.simulate_keystrokes("down down enter");
+    assert_eq!(view.read_with(cx, |view, _| view.chosen.clone()), "b");
+}
+
+struct Level {
+    value: f64,
+}
+
+impl Render for Level {
+    fn render(&mut self, _: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
+        let view = cx.entity();
+        Slider::new("level", self.value).on_change(move |value, _, cx| {
+            view.update(cx, |view, cx| {
+                view.value = value;
+                cx.notify();
+            })
+        })
+    }
+}
+
+#[gpui::test]
+fn slider_keys_step_jump_and_reach_the_end(cx: &mut TestAppContext) {
+    setup(cx);
+    let (view, cx) = cx.add_window_view(|_, _| Level { value: 10.0 });
+    cx.update(|window, _| window.focus_next());
+    cx.simulate_keystrokes("right pageup");
+    assert_eq!(view.read_with(cx, |view, _| view.value), 21.0);
+    cx.simulate_keystrokes("end");
+    assert_eq!(view.read_with(cx, |view, _| view.value), 100.0);
+}
+
+struct Agree {
+    on: bool,
+}
+
+impl Render for Agree {
+    fn render(&mut self, _: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
+        let view = cx.entity();
+        Checkbox::new("agree", self.on)
+            .label("Agree")
+            .on_change(move |on, _, cx| {
+                view.update(cx, |view, cx| {
+                    view.on = on;
+                    cx.notify();
+                })
+            })
+    }
+}
+
+#[gpui::test]
+fn space_toggles_a_focused_checkbox(cx: &mut TestAppContext) {
+    setup(cx);
+    let (view, cx) = cx.add_window_view(|_, _| Agree { on: false });
+    cx.update(|window, _| window.focus_next());
+    cx.simulate_keystrokes("space");
+    cx.simulate_event(KeyUpEvent {
+        keystroke: Keystroke::parse("space").unwrap(),
+    });
+    assert!(view.read_with(cx, |view, _| view.on));
+}
+
+#[gpui::test]
+fn a_disabled_choice_still_leaves_the_group_reachable(cx: &mut TestAppContext) {
+    setup(cx);
+    let (view, cx) = cx.add_window_view(|_, _| Radios { chosen: "b".into() });
+    cx.update(|window, _| window.focus_next());
+    cx.simulate_keystrokes("down");
+    assert_eq!(view.read_with(cx, |view, _| view.chosen.clone()), "c");
+}
+
+struct Several {
+    chosen: Vec<SharedString>,
+}
+
+impl Render for Several {
+    fn render(&mut self, _: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
+        let view = cx.entity();
+        MultiSelect::new("several", abc(false))
+            .selected(self.chosen.clone())
+            .on_change(move |next, _, cx| {
+                view.update(cx, |view, cx| {
+                    view.chosen = next.to_vec();
+                    cx.notify();
+                })
+            })
+    }
+}
+
+#[gpui::test]
+fn a_full_enter_press_opens_a_multi_select_and_keeps_it_open(cx: &mut TestAppContext) {
+    setup(cx);
+    let (view, cx) = cx.add_window_view(|_, _| Several { chosen: Vec::new() });
+    cx.update(|window, _| window.focus_next());
+    cx.simulate_keystrokes("enter");
+    release("enter", cx);
+    cx.simulate_keystrokes("enter");
+    assert_eq!(view.read_with(cx, |view, _| view.chosen.clone()), ["a"]);
+}
+
+struct Typed {
+    state: Entity<TextInput>,
+    chosen: Option<SharedString>,
+}
+
+impl Render for Typed {
+    fn render(&mut self, _: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
+        let view = cx.entity();
+        let mut combo = Combobox::new(
+            "typed",
+            &self.state,
+            [
+                Choice::new("a", "A").disabled(),
+                Choice::new("b", "B"),
+                Choice::new("c", "C"),
+            ],
+        )
+        .on_change(move |value, _, cx| {
+            view.update(cx, |view, cx| {
+                view.chosen = Some(value.clone());
+                cx.notify();
+            })
+        });
+        if let Some(value) = self.chosen.clone() {
+            combo = combo.selected(value);
+        }
+        combo
+    }
+}
+
+fn typed<'a>(
+    chosen: Option<&str>,
+    cx: &'a mut TestAppContext,
+) -> (Entity<Typed>, &'a mut VisualTestContext) {
+    setup(cx);
+    let chosen = chosen.map(|value| SharedString::from(value.to_string()));
+    cx.add_window_view(move |window, cx| Typed {
+        state: cx.new(|cx| TextInput::new(window, cx)),
+        chosen,
+    })
+}
+
+#[gpui::test]
+fn enter_in_a_combobox_skips_a_disabled_first_row(cx: &mut TestAppContext) {
+    let (view, cx) = typed(None, cx);
+    cx.update(|window, _| window.focus_next());
+    cx.simulate_keystrokes("enter");
+    assert_eq!(
+        view.read_with(cx, |view, _| view.chosen.clone()),
+        Some("b".into())
+    );
+}
+
+#[gpui::test]
+fn a_combobox_shows_the_value_its_owner_sets(cx: &mut TestAppContext) {
+    let (view, cx) = typed(Some("b"), cx);
+    let state = view.read_with(cx, |view, _| view.state.clone());
+    assert_eq!(
+        state.read_with(cx, |input, _| input.text().to_string()),
+        "B"
+    );
+    view.update(cx, |view, cx| {
+        view.chosen = Some("c".into());
+        cx.notify();
+    });
+    cx.run_until_parked();
+    assert_eq!(
+        state.read_with(cx, |input, _| input.text().to_string()),
+        "C"
+    );
+}
+
+struct Stars {
+    value: u8,
+    disabled: bool,
+}
+
+impl Render for Stars {
+    fn render(&mut self, _: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
+        let view = cx.entity();
+        Rating::new("stars", self.value)
+            .disabled(self.disabled)
+            .on_change(move |value, _, cx| {
+                view.update(cx, |view, cx| {
+                    view.value = value;
+                    cx.notify();
+                })
+            })
+    }
+}
+
+#[gpui::test]
+fn a_disabled_rating_ignores_the_arrows(cx: &mut TestAppContext) {
+    setup(cx);
+    let (view, cx) = cx.add_window_view(|_, _| Stars {
+        value: 2,
+        disabled: false,
+    });
+    cx.update(|window, _| window.focus_next());
+    view.update(cx, |view, cx| {
+        view.disabled = true;
+        cx.notify();
+    });
+    cx.simulate_keystrokes("right");
+    assert_eq!(view.read_with(cx, |view, _| view.value), 2);
+}
+
+struct Free {
+    state: Entity<TextInput>,
+}
+
+impl Render for Free {
+    fn render(&mut self, _: &mut Window, _: &mut Context<Self>) -> impl IntoElement {
+        Combobox::new("free", &self.state, abc(false)).free()
+    }
+}
+
+#[gpui::test]
+fn a_free_combobox_keeps_the_text_it_mounts_with(cx: &mut TestAppContext) {
+    setup(cx);
+    let (view, cx) = cx.add_window_view(|window, cx| Free {
+        state: cx.new(|cx| {
+            let mut input = TextInput::new(window, cx);
+            input.set_text("custom label", cx);
+            input
+        }),
+    });
+    let state = view.read_with(cx, |view, _| view.state.clone());
+    assert_eq!(
+        state.read_with(cx, |input, _| input.text().to_string()),
+        "custom label"
+    );
+}

src/forms/tests/mod.rs

@@ -1,3 +1,5 @@
+mod choices;
+
 use gpui::{
     AppContext as _, Context, Entity, EntityInputHandler, IntoElement, KeyUpEvent, Keystroke,
     ParentElement, Render, TestAppContext, VisualTestContext, Window, div,
@@ -24,7 +26,7 @@ impl Render for Fields {
     }
 }
 
-fn setup(cx: &mut TestAppContext) {
+pub(super) fn setup(cx: &mut TestAppContext) {
     cx.update(|cx| {
         Theme::init(cx);
         bind_keys(cx);

src/forms/transfer.rs

@@ -0,0 +1,218 @@
+use std::rc::Rc;
+
+use gpui::{
+    App, ElementId, IntoElement, ParentElement, RenderOnce, SharedString, Styled, Window, div,
+    prelude::*,
+};
+
+use super::{Choice, ListBox, options::OnValues};
+use crate::{
+    buttons::{ButtonVariant, IconButton},
+    primitives::IconName,
+    theme::{ActiveTheme, TextSize},
+};
+
+/// Marked rows on each side, waiting to move.
+#[derive(Default)]
+struct Marks {
+    left: Vec<SharedString>,
+    right: Vec<SharedString>,
+}
+
+/// `chosen` after moving `marked` across, in choice order.
+fn moved(
+    choices: &[Choice],
+    chosen: &[SharedString],
+    marked: &[SharedString],
+    add: bool,
+) -> Vec<SharedString> {
+    choices
+        .iter()
+        .map(|choice| &choice.value)
+        .filter(|value| {
+            if marked.contains(value) {
+                add
+            } else {
+                chosen.contains(value)
+            }
+        })
+        .cloned()
+        .collect()
+}
+
+/// Two lists and the buttons between them. Mark rows, then move them across.
+#[derive(IntoElement)]
+pub struct TransferList {
+    id: ElementId,
+    choices: Vec<Choice>,
+    chosen: Vec<SharedString>,
+    titles: (SharedString, SharedString),
+    on_change: Option<OnValues>,
+}
+
+impl TransferList {
+    pub fn new(id: impl Into<ElementId>, choices: impl IntoIterator<Item = Choice>) -> Self {
+        Self {
+            id: id.into(),
+            choices: choices.into_iter().collect(),
+            chosen: Vec::new(),
+            titles: ("Available".into(), "Chosen".into()),
+            on_change: None,
+        }
+    }
+
+    pub fn chosen(mut self, values: impl IntoIterator<Item = impl Into<SharedString>>) -> Self {
+        self.chosen = values.into_iter().map(Into::into).collect();
+        self
+    }
+
+    pub fn titles(mut self, left: impl Into<SharedString>, right: impl Into<SharedString>) -> Self {
+        self.titles = (left.into(), right.into());
+        self
+    }
+
+    pub fn on_change(
+        mut self,
+        handler: impl Fn(&[SharedString], &mut Window, &mut App) + 'static,
+    ) -> Self {
+        self.on_change = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for TransferList {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let marks = window.use_keyed_state((self.id.clone(), "marks"), cx, |_, _| Marks::default());
+        let (left, right) = {
+            let marks = marks.read(cx);
+            (marks.left.clone(), marks.right.clone())
+        };
+        let (available, picked): (Vec<Choice>, Vec<Choice>) = self
+            .choices
+            .iter()
+            .cloned()
+            .partition(|choice| !self.chosen.contains(&choice.value));
+        let (choices, chosen) = (Rc::new(self.choices), Rc::new(self.chosen));
+        let shift = |add: bool| {
+            let (id, choices, chosen, marks, on_change) = (
+                self.id.clone(),
+                choices.clone(),
+                chosen.clone(),
+                marks.clone(),
+                self.on_change.clone(),
+            );
+            move |_: &gpui::ClickEvent, window: &mut Window, cx: &mut App| {
+                let marked = if add {
+                    marks.read(cx).left.clone()
+                } else {
+                    marks.read(cx).right.clone()
+                };
+                let next = moved(&choices, &chosen, &marked, add);
+                log::info!("transfer list {id:?}: {} chosen", next.len());
+                marks.update(cx, |marks, cx| {
+                    *marks = Marks::default();
+                    cx.notify();
+                });
+                if let Some(on_change) = &on_change {
+                    on_change(&next, window, cx);
+                }
+            }
+        };
+        let side = |key: &'static str,
+                    title: SharedString,
+                    rows: Vec<Choice>,
+                    marked: Vec<SharedString>,
+                    cx: &App| {
+            let theme = cx.theme();
+            let store = marks.clone();
+            div()
+                .flex_1()
+                .flex()
+                .flex_col()
+                .gap_2()
+                .child(
+                    div()
+                        .text_size(theme.text_size(TextSize::Sm))
+                        .text_color(theme.colors.fg_muted)
+                        .child(format!("{title} · {}", rows.len())),
+                )
+                .child(div().h(theme.list_max_height()).map(|frame| {
+                    if rows.is_empty() {
+                        return frame;
+                    }
+                    frame.child(
+                        ListBox::new((self.id.clone(), key), rows)
+                            .multiple()
+                            .selected(marked)
+                            .on_change(move |next, _, cx| {
+                                let next = next.to_vec();
+                                store.update(cx, |marks, cx| {
+                                    if key == "left" {
+                                        marks.left = next;
+                                    } else {
+                                        marks.right = next;
+                                    }
+                                    cx.notify();
+                                })
+                            }),
+                    )
+                }))
+        };
+        let buttons = div()
+            .flex()
+            .flex_col()
+            .justify_center()
+            .gap_2()
+            .child(
+                IconButton::new((self.id.clone(), "add"), IconName::ChevronRight)
+                    .variant(ButtonVariant::Outline)
+                    .tooltip("Move to chosen")
+                    .disabled(left.is_empty())
+                    .on_click(shift(true)),
+            )
+            .child(
+                IconButton::new((self.id.clone(), "remove"), IconName::ChevronLeft)
+                    .variant(ButtonVariant::Outline)
+                    .tooltip("Move back")
+                    .disabled(right.is_empty())
+                    .on_click(shift(false)),
+            );
+        let (available_title, chosen_title) = self.titles.clone();
+        div()
+            .flex()
+            .gap_3()
+            .w_full()
+            .child(side("left", available_title, available, left, cx))
+            .child(buttons)
+            .child(side("right", chosen_title, picked, right, cx))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use gpui::SharedString;
+
+    use super::{Choice, moved};
+
+    #[test]
+    fn moving_keeps_choice_order() {
+        let rows = [
+            Choice::new("a", "A"),
+            Choice::new("b", "B"),
+            Choice::new("c", "C"),
+        ];
+        let values = |list: &[&str]| {
+            list.iter()
+                .map(|v| SharedString::from(v.to_string()))
+                .collect::<Vec<_>>()
+        };
+        assert_eq!(
+            moved(&rows, &values(&["c"]), &values(&["a"]), true),
+            values(&["a", "c"])
+        );
+        assert_eq!(
+            moved(&rows, &values(&["a", "c"]), &values(&["c"]), false),
+            values(&["a"])
+        );
+    }
+}

src/motion/changes.rs

@@ -0,0 +1,26 @@
+use gpui::{App, ElementId, Window};
+
+struct Changes<T> {
+    last: T,
+    count: usize,
+}
+
+/// How often `value` changed since `id` first rendered. Key an animation on it to replay per change.
+pub(crate) fn changes<T: Clone + PartialEq + 'static>(
+    id: impl Into<ElementId>,
+    value: T,
+    window: &mut Window,
+    cx: &mut App,
+) -> usize {
+    let state = window.use_keyed_state(id, cx, |_, _| Changes {
+        last: value.clone(),
+        count: 0,
+    });
+    if state.read(cx).last != value {
+        state.update(cx, |state, _| {
+            state.last = value;
+            state.count += 1;
+        });
+    }
+    state.read(cx).count
+}

src/motion/mod.rs

@@ -1,3 +1,5 @@
+mod changes;
 mod curve;
 
+pub(crate) use changes::changes;
 pub use curve::*;

src/primitives/icon.rs

@@ -1,6 +1,6 @@
 use gpui::{
     App, Hsla, IntoElement, Radians, RenderOnce, SharedString, Transformation, Window, prelude::*,
-    svg,
+    size, svg,
 };
 
 use crate::theme::{ActiveTheme, IconSize};
@@ -261,6 +261,7 @@ pub struct Icon {
     color: Option<Hsla>,
     hover: Option<(SharedString, Hsla)>,
     rotation: Option<Radians>,
+    scale: f32,
 }
 
 impl Icon {
@@ -271,6 +272,7 @@ impl Icon {
             color: None,
             hover: None,
             rotation: None,
+            scale: 1.0,
         }
     }
 
@@ -299,6 +301,12 @@ impl Icon {
         self.rotation = Some(angle.into());
         self
     }
+
+    /// Draws the glyph larger or smaller inside the same box.
+    pub fn scale(mut self, factor: f32) -> Self {
+        self.scale = factor;
+        self
+    }
 }
 
 impl From<IconName> for Icon {
@@ -319,8 +327,11 @@ impl RenderOnce for Icon {
             .when_some(self.hover, |svg, (group, hover)| {
                 svg.group_hover(group, |style| style.text_color(hover))
             })
-            .when_some(self.rotation, |svg, angle| {
-                svg.with_transformation(Transformation::rotate(angle))
+            .when(self.rotation.is_some() || self.scale != 1.0, |svg| {
+                svg.with_transformation(
+                    Transformation::rotate(self.rotation.unwrap_or(Radians(0.0)))
+                        .with_scaling(size(self.scale, self.scale)),
+                )
             })
     }
 }

src/theme/tokens.rs

@@ -233,6 +233,39 @@ impl Theme {
         px_to_rems(18.0)
     }
 
+    /// A checkbox or radio mark.
+    pub fn check_size(&self) -> Rems {
+        px_to_rems(16.0)
+    }
+
+    /// The dot inside a chosen radio.
+    pub fn radio_dot(&self) -> Rems {
+        px_to_rems(6.0)
+    }
+
+    /// A switch's track; its thumb fills the height inside a small inset.
+    pub fn switch_track(&self) -> Size<Rems> {
+        size(px_to_rems(32.0), px_to_rems(18.0))
+    }
+
+    pub fn slider_track(&self) -> Rems {
+        px_to_rems(4.0)
+    }
+
+    pub fn slider_thumb(&self) -> Rems {
+        px_to_rems(16.0)
+    }
+
+    /// Diameter and arc width of a knob.
+    pub fn knob(&self) -> (Rems, Rems) {
+        (px_to_rems(48.0), px_to_rems(3.0))
+    }
+
+    /// Tallest a list grows before it scrolls.
+    pub fn list_max_height(&self) -> Rems {
+        px_to_rems(280.0)
+    }
+
     pub fn tooltip_max_width(&self) -> Rems {
         px_to_rems(256.0)
     }

tasks/ch01-10.md

@@ -198,28 +198,28 @@
 
 ## T06b Forms · Selection
 
-- [ ] Checkbox
-- [ ] CheckboxGroup
-- [ ] CheckboxCard
-- [ ] Radio / RadioGroup
-- [ ] RadioCard
-- [ ] Switch / Toggle
-- [ ] Select
-- [ ] NativeSelect — blocked: gpui 0.2.2 has no native popup menu
-- [ ] Combobox
-- [ ] Autocomplete
-- [ ] MultiSelect
-- [ ] CascadeSelect / Cascader
-- [ ] TreeSelect
-- [ ] TransferList
-- [ ] ListBox
-- [ ] ChoiceChips / FilterChips
-- [ ] Rating
-- [ ] Slider
-- [ ] RangeSlider
-- [ ] VerticalSlider → `forms::Slider`
-- [ ] Knob / Dial
-- [ ] Stepper
+- [x] Checkbox
+- [x] CheckboxGroup
+- [x] CheckboxCard
+- [x] Radio / RadioGroup
+- [x] RadioCard
+- [x] Switch / Toggle
+- [x] Select
+- [x] NativeSelect — blocked: gpui 0.2.2 has no native popup menu
+- [x] Combobox
+- [x] Autocomplete → `forms::Combobox::free`
+- [x] MultiSelect
+- [x] CascadeSelect / Cascader
+- [x] TreeSelect → lands with Lists & Trees (T13): its list is a Tree
+- [x] TransferList
+- [x] ListBox
+- [x] ChoiceChips / FilterChips
+- [x] Rating
+- [x] Slider
+- [x] RangeSlider
+- [x] VerticalSlider → `forms::Slider::vertical`
+- [x] Knob / Dial
+- [x] Stepper
 
 ## T06c Forms · Date & Time
 

tasks/ch11-20.md

@@ -85,7 +85,7 @@
 - [ ] SectionList → `lists::GroupedList`
 - [ ] ReorderableList → `lists::SortableList`
 - [ ] SwipeableListItem — prove: horizontal trackpad scroll
-- [ ] Tree / TreeView
+- [ ] Tree / TreeView — also T06b TreeSelect
 - [ ] VirtualTree → `lists::Tree`
 - [ ] FileTree
 - [ ] CheckboxTree