T25a Generative: prompt and settings

PromptEnhancer offers a fuller prompt with the words it adds washed,
split at punctuation; Use this takes it into the field, Keep mine
lets it go. StylePresetPicker and AspectRatioPicker are rows of Tab
stops, the chosen one in accent; a ratio chip draws its shape.
SeedInput keeps digits up to u32::MAX and rolls one with a die.
NegativePromptInput and ImageGenerationPanel point to forms::TagInput
and forms::Form. theme.generative() holds the chapter's sizes. The
gallery's preset pictures are the atrium photo in five styles.

TASKS.md

@@ -83,7 +83,12 @@ Per-component lines live in `tasks/`. Tags there:
 - [x] T24d Agent · Previews
 - [x] T24e Agent · Environment
 - [x] T24f Agent · Control and cost
-- [ ] T25 Generative
+- [ ] T25a Generative · Prompt and settings
+- [ ] T25b Generative · Queue and results
+- [ ] T25c Generative · Canvas
+- [ ] T25d Generative · Sound and motion
+- [ ] T25e Generative · Models
+- [ ] T25f Generative · Data and prompts
 - [ ] T26 Media
 - [ ] T27 Files
 - [ ] T28 Messaging

assets/icons/ban.svg

@@ -0,0 +1,16 @@
+<!-- @license lucide-static v1.48.0 - ISC -->
+<svg
+  class="lucide lucide-ban"
+  xmlns="http://www.w3.org/2000/svg"
+  width="24"
+  height="24"
+  viewBox="0 0 24 24"
+  fill="none"
+  stroke="currentColor"
+  stroke-width="2"
+  stroke-linecap="round"
+  stroke-linejoin="round"
+>
+  <circle cx="12" cy="12" r="10" />
+  <path d="M4.929 4.929 19.07 19.071" />
+</svg>

assets/icons/dices.svg

@@ -0,0 +1,20 @@
+<!-- @license lucide-static v1.48.0 - ISC -->
+<svg
+  class="lucide lucide-dices"
+  xmlns="http://www.w3.org/2000/svg"
+  width="24"
+  height="24"
+  viewBox="0 0 24 24"
+  fill="none"
+  stroke="currentColor"
+  stroke-width="2"
+  stroke-linecap="round"
+  stroke-linejoin="round"
+>
+  <rect width="12" height="12" x="2" y="10" rx="2" ry="2" />
+  <path d="m17.92 14 3.5-3.5a2.24 2.24 0 0 0 0-3l-5-4.92a2.24 2.24 0 0 0-3 0L10 6" />
+  <path d="M6 18h.01" />
+  <path d="M10 14h.01" />
+  <path d="M15 6h.01" />
+  <path d="M18 9h.01" />
+</svg>

examples/gallery/pages/generative/mod.rs

@@ -0,0 +1,26 @@
+mod panel;
+
+use gpui::{AnyElement, App, IntoElement, ParentElement, Window, div};
+
+use super::Page;
+use crate::script::Step;
+
+pub const PAGE: Page = Page {
+    number: 25,
+    slug: "generative",
+    title: "Generative",
+    summary: "Making pictures, sound and video with a model: the prompt and its settings, the queue and what comes back, the canvas, and the models behind them.",
+    render,
+    script: SCRIPT,
+};
+
+const SCRIPT: &[Step] = &[
+    Step::DownAt("gen-enhancer", 356.0, 124.0),
+    Step::UpAt("gen-enhancer", 356.0, 124.0),
+    Step::Wait(1400),
+    Step::Shot("suggested"),
+];
+
+fn render(window: &mut Window, cx: &mut App) -> AnyElement {
+    div().child(panel::panel(window, cx)).into_any_element()
+}

examples/gallery/pages/generative/panel.rs

@@ -0,0 +1,183 @@
+use std::{rc::Rc, time::Duration};
+
+use ely_gpui_component::{
+    buttons::{Button, ButtonVariant},
+    forms::{Form, FormField, TagInput, TextInput},
+    generative::{AspectRatioPicker, PromptEnhancer, SeedInput, StylePreset, StylePresetPicker},
+    typography::Caption,
+};
+use gpui::{App, Entity, IntoElement, ParentElement, SharedString, Styled, Window, div, px};
+
+use crate::{
+    probe::probe,
+    ui::{keep, section, set},
+};
+
+type Run = Rc<dyn Fn(&mut Window, &mut App)>;
+
+/// What an enhancer might give back; the demo adds light, material and lens.
+fn fuller(prompt: &str) -> String {
+    format!(
+        "{prompt}, pale limestone, soft morning light through tall windows, long shadows, 35mm, quiet and airy"
+    )
+}
+
+fn presets() -> Vec<StylePreset> {
+    let preset = |key: &str, name: &str, picture: Option<&str>| StylePreset {
+        key: key.to_string().into(),
+        name: name.to_string().into(),
+        picture: picture.map(|path| path.to_string().into()),
+    };
+    vec![
+        preset("none", "None", None),
+        preset(
+            "photo",
+            "Photographic",
+            Some(asset!("styles/photographic.jpg")),
+        ),
+        preset("mono", "Monochrome", Some(asset!("styles/monochrome.jpg"))),
+        preset("line", "Line art", Some(asset!("styles/line-art.jpg"))),
+        preset("wash", "Watercolor", Some(asset!("styles/watercolor.jpg"))),
+        preset("film", "Cinematic", Some(asset!("styles/cinematic.jpg"))),
+    ]
+}
+
+/// The demo's settings: a suggestion on its way or offered, the left-out words, style, shape, and the last run.
+#[derive(Clone)]
+struct Settings {
+    enhancing: bool,
+    suggestion: Option<SharedString>,
+    left_out: Vec<SharedString>,
+    style: SharedString,
+    ratio: (u32, u32),
+    ran: Option<SharedString>,
+}
+
+fn edit(settings: &Entity<Settings>, cx: &mut App, change: impl FnOnce(&mut Settings)) {
+    let mut next = settings.read(cx).clone();
+    change(&mut next);
+    set(settings, next, cx)
+}
+
+pub fn panel(window: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let prompt = window.use_keyed_state("gen-prompt-field", cx, |window, cx| {
+        let mut input = TextInput::new(window, cx)
+            .multi_line(3, 6)
+            .placeholder("Describe a picture");
+        input.set_text("a spiral staircase in a white atrium", cx);
+        input
+    });
+    let seed = window.use_keyed_state("gen-seed-field", cx, |window, cx| {
+        let mut input = TextInput::new(window, cx);
+        input.set_text("2710", cx);
+        input
+    });
+    let settings = keep(
+        "gen-settings",
+        || Settings {
+            enhancing: false,
+            suggestion: None,
+            left_out: vec!["blurry".into(), "watermark".into(), "people".into()],
+            style: "photo".into(),
+            ratio: (3, 2),
+            ran: None,
+        },
+        window,
+        cx,
+    );
+    let now = settings.read(cx).clone();
+    let run: Run = {
+        let (settings, seed, prompt) = (settings.clone(), seed.clone(), prompt.clone());
+        Rc::new(move |_, cx| {
+            let seed = SeedInput::read(&seed, cx)
+                .map_or("a new seed".to_string(), |seed| format!("seed {seed}"));
+            let words = prompt.read(cx).text().split_whitespace().count();
+            let line = format!("Queued: {words} words, {seed}");
+            edit(&settings, cx, |settings| settings.ran = Some(line.into()));
+        })
+    };
+    let (asked, resolved, tagged, styled, shaped) = (
+        settings.clone(),
+        settings.clone(),
+        settings.clone(),
+        settings.clone(),
+        settings,
+    );
+    let enhancer = PromptEnhancer::new("gen-prompt", &prompt)
+        .enhancing(now.enhancing)
+        .on_enhance(move |text, _, cx| {
+            edit(&asked, cx, |settings| settings.enhancing = true);
+            let (asked, text) = (asked.clone(), fuller(text));
+            cx.spawn(async move |cx| {
+                cx.background_executor()
+                    .timer(Duration::from_millis(900))
+                    .await;
+                cx.update(|cx| {
+                    edit(&asked, cx, |settings| {
+                        settings.enhancing = false;
+                        settings.suggestion = Some(text.into());
+                    })
+                })
+                .ok();
+            })
+            .detach();
+        })
+        .on_resolve(move |_, _, cx| edit(&resolved, cx, |settings| settings.suggestion = None));
+    let enhancer = match now.suggestion {
+        Some(text) => enhancer.suggestion(text),
+        None => enhancer,
+    };
+    let submit = run.clone();
+    section(
+        "ImageGenerationPanel / PromptEnhancer / NegativePromptInput / StylePresetPicker / AspectRatioPicker / SeedInput",
+        "A picture's settings in one form: the prompt, which Enhance offers to fill out, the words it adds washed; what to leave out; a style; a shape; and a seed, empty for a new one each run. Cmd-Enter generates.",
+        cx,
+    )
+    .child(
+        div().w(px(400.)).child(
+            Form::new("gen-form")
+                .on_submit(move |window, cx| submit(window, cx))
+                .child(probe(
+                    "gen-enhancer",
+                    div().w(px(400.)).child(FormField::new("gen-prompt-label", "Prompt").child(enhancer)),
+                ))
+                .child(
+                    FormField::new("gen-left-out", "Leave out").child(
+                        TagInput::new("gen-left-out-tags", now.left_out)
+                            .placeholder("A word, then Enter")
+                            .on_change(move |tags, _, cx| edit(&tagged, cx, |settings| settings.left_out = tags)),
+                    ),
+                )
+                .child(
+                    FormField::new("gen-style", "Style").child(
+                        StylePresetPicker::new("gen-styles", presets(), now.style)
+                            .on_select(move |key, _, cx| {
+                                let key = key.clone();
+                                edit(&styled, cx, |settings| settings.style = key)
+                            }),
+                    ),
+                )
+                .child(
+                    FormField::new("gen-shape", "Shape").child(
+                        AspectRatioPicker::new("gen-ratios", [(1, 1), (4, 5), (3, 2), (16, 9), (9, 16)], now.ratio)
+                            .on_select(move |ratio, _, cx| edit(&shaped, cx, |settings| settings.ratio = ratio)),
+                    ),
+                )
+                .child(FormField::new("gen-seed", "Seed").child(SeedInput::new("gen-seed-input", &seed)))
+                .child(
+                    div()
+                        .flex()
+                        .flex_col()
+                        .gap_2()
+                        .child(
+                            Button::new("gen-generate", "Generate")
+                                .variant(ButtonVariant::Primary)
+                                .full_width()
+                                .shortcut("secondary-enter")
+                                .on_click(move |_, window, cx| run(window, cx)),
+                        )
+                        .children(now.ran.map(Caption::new)),
+                ),
+        ),
+    )
+}

examples/gallery/pages/mod.rs

@@ -10,6 +10,7 @@ mod editor;
 mod feedback;
 mod finance;
 mod forms;
+mod generative;
 mod git;
 mod layout;
 mod lists;
@@ -63,6 +64,7 @@ pub const ALL: &[Page] = &[
     collab::PAGE,
     chat::PAGE,
     agent::PAGE,
+    generative::PAGE,
     theme::PAGE,
 ];
 

src/generative/mod.rs

@@ -0,0 +1,11 @@
+mod prompt;
+mod ratio;
+mod seed;
+mod style;
+#[cfg(all(test, feature = "test-support"))]
+mod tests;
+
+pub use prompt::PromptEnhancer;
+pub use ratio::AspectRatioPicker;
+pub use seed::SeedInput;
+pub use style::{StylePreset, StylePresetPicker};

src/generative/prompt.rs

@@ -0,0 +1,238 @@
+use std::{ops::Range, rc::Rc};
+
+use gpui::{
+    App, ElementId, Entity, Focusable, FontWeight, HighlightStyle, IntoElement, ParentElement,
+    RenderOnce, SharedString, Styled, StyledText, Window, div,
+};
+use similar::{ChangeTag, TextDiff};
+
+use crate::{
+    buttons::{Button, ButtonVariant},
+    forms::{Input, OnFlag, TextInput},
+    motion::{Entrance, Transition},
+    primitives::{Icon, IconName},
+    theme::{ActiveTheme, ControlSize, IconSize, Radius, TextSize},
+};
+
+type OnText = Rc<dyn Fn(&str, &mut Window, &mut App)>;
+
+/// Byte ranges of `new` that `old` lacks, word by word: neighbors joined, spaces and punctuation trimmed from each end.
+pub(crate) fn added_words(old: &str, new: &str) -> Vec<Range<usize>> {
+    let diff = TextDiff::from_unicode_words(old, new);
+    let mut ranges: Vec<Range<usize>> = Vec::new();
+    let mut at = 0;
+    for change in diff.iter_all_changes() {
+        let len = change.value().len();
+        match change.tag() {
+            ChangeTag::Delete => continue,
+            ChangeTag::Equal => {}
+            ChangeTag::Insert => match ranges.last_mut() {
+                Some(last) if last.end == at => last.end = at + len,
+                _ => ranges.push(at..at + len),
+            },
+        }
+        at += len;
+    }
+    ranges
+        .into_iter()
+        .filter_map(|range| {
+            let word = &new[range.clone()];
+            let glue = |ch: char| ch.is_whitespace() || ch.is_ascii_punctuation();
+            let start = range.start + word.len() - word.trim_start_matches(glue).len();
+            let end = range.end - (word.len() - word.trim_end_matches(glue).len());
+            (start < end).then_some(start..end)
+        })
+        .collect()
+}
+
+/// A prompt and a way to rewrite it: Enhance asks the owner for a fuller prompt, offered with the words it adds washed; Use this takes it, Keep mine lets it go.
+#[derive(IntoElement)]
+pub struct PromptEnhancer {
+    id: ElementId,
+    field: Entity<TextInput>,
+    enhancing: bool,
+    suggestion: Option<SharedString>,
+    on_enhance: Option<OnText>,
+    on_resolve: Option<OnFlag>,
+}
+
+impl PromptEnhancer {
+    /// `field` is the owner's prompt.
+    pub fn new(id: impl Into<ElementId>, field: &Entity<TextInput>) -> Self {
+        Self {
+            id: id.into(),
+            field: field.clone(),
+            enhancing: false,
+            suggestion: None,
+            on_enhance: None,
+            on_resolve: None,
+        }
+    }
+
+    /// While the owner writes a suggestion.
+    pub fn enhancing(mut self, enhancing: bool) -> Self {
+        self.enhancing = enhancing;
+        self
+    }
+
+    /// A fuller prompt to offer.
+    pub fn suggestion(mut self, text: impl Into<SharedString>) -> Self {
+        self.suggestion = Some(text.into());
+        self
+    }
+
+    /// Gets the prompt to rewrite, trimmed.
+    pub fn on_enhance(mut self, handler: impl Fn(&str, &mut Window, &mut App) + 'static) -> Self {
+        self.on_enhance = Some(Rc::new(handler));
+        self
+    }
+
+    /// Gets whether the suggestion was taken; a taken one is already in the field.
+    pub fn on_resolve(mut self, handler: impl Fn(bool, &mut Window, &mut App) + 'static) -> Self {
+        self.on_resolve = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for PromptEnhancer {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let last = window.use_keyed_state((self.id.clone(), "offer"), cx, |_, _| {
+            SharedString::default()
+        });
+        if let Some(text) = self
+            .suggestion
+            .as_ref()
+            .filter(|text| *last.read(cx) != **text)
+        {
+            last.update(cx, |last, _| *last = text.clone());
+        }
+        let (offered, shown) = (last.read(cx).clone(), self.suggestion.is_some());
+        let prompt = self.field.read(cx).text().trim().to_string();
+        let words = added_words(&prompt, &offered);
+        let theme = cx.theme();
+        let colors = theme.colors.clone();
+        let enhance = self.on_enhance.map(|enhance| {
+            Button::new((self.id.clone(), "enhance"), "Enhance")
+                .variant(ButtonVariant::Ghost)
+                .size(ControlSize::Sm)
+                .icon(IconName::Sparkles)
+                .loading(self.enhancing)
+                .disabled(prompt.is_empty() || self.enhancing)
+                .on_click(move |_, window, cx| {
+                    log::info!("prompt enhancer: asked with {} characters", prompt.len());
+                    enhance(&prompt, window, cx)
+                })
+        });
+        let answer = |taken: bool| {
+            let (field, text, resolve) =
+                (self.field.clone(), offered.clone(), self.on_resolve.clone());
+            move |_: &gpui::ClickEvent, window: &mut Window, cx: &mut App| {
+                if taken {
+                    field.update(cx, |input, cx| input.set_text(text.to_string(), cx));
+                }
+                log::info!(
+                    "prompt enhancer: suggestion {}",
+                    if taken { "taken" } else { "kept out" }
+                );
+                window.focus(&field.focus_handle(cx));
+                if let Some(resolve) = &resolve {
+                    resolve(taken, window, cx);
+                }
+            }
+        };
+        let wash = HighlightStyle {
+            background_color: Some(colors.success_subtle),
+            ..HighlightStyle::default()
+        };
+        let card = div()
+            .mt_1()
+            .flex()
+            .flex_col()
+            .gap_3()
+            .p_3()
+            .rounded(theme.radius(Radius::Md))
+            .border_1()
+            .border_color(colors.border)
+            .bg(colors.surface)
+            .child(
+                div()
+                    .flex()
+                    .items_center()
+                    .gap_1p5()
+                    .text_size(theme.text_size(TextSize::Xs))
+                    .font_weight(FontWeight::MEDIUM)
+                    .text_color(colors.fg_muted)
+                    .child(
+                        Icon::new(IconName::Sparkles)
+                            .size(IconSize::Xs)
+                            .color(colors.fg_muted),
+                    )
+                    .child("Suggested"),
+            )
+            .child(
+                div()
+                    .text_size(theme.text_size(TextSize::Sm))
+                    .text_color(colors.fg)
+                    .child(
+                        StyledText::new(offered.clone())
+                            .with_highlights(words.into_iter().map(|range| (range, wash))),
+                    ),
+            )
+            .child(
+                div()
+                    .flex()
+                    .flex_wrap()
+                    .gap_2()
+                    .child(
+                        Button::new((self.id.clone(), "take"), "Use this")
+                            .variant(ButtonVariant::Primary)
+                            .size(ControlSize::Sm)
+                            .disabled(!shown)
+                            .on_click(answer(true)),
+                    )
+                    .child(
+                        Button::new((self.id.clone(), "keep"), "Keep mine")
+                            .variant(ButtonVariant::Ghost)
+                            .size(ControlSize::Sm)
+                            .disabled(!shown)
+                            .on_click(answer(false)),
+                    ),
+            );
+        div()
+            .w_full()
+            .flex()
+            .flex_col()
+            .gap_2()
+            .child(Input::new(&self.field))
+            .children(enhance.map(|button| div().flex().justify_end().child(button)))
+            .child(
+                Transition::new((self.id.clone(), "offered"), shown)
+                    .entrance(Entrance::Rise)
+                    .child(card),
+            )
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::added_words;
+
+    #[test]
+    fn added_words_are_the_new_runs_without_their_spaces() {
+        let new = "a fluffy cat asleep on a sunlit mat";
+        let ranges = added_words("a cat on a mat", new);
+        let words: Vec<&str> = ranges.iter().map(|range| &new[range.clone()]).collect();
+        assert_eq!(words, ["fluffy", "asleep", "sunlit"]);
+        let new = "a white atrium, pale limestone";
+        let ranges = added_words("a white atrium", new);
+        let words: Vec<&str> = ranges.iter().map(|range| &new[range.clone()]).collect();
+        assert_eq!(
+            words,
+            ["pale limestone"],
+            "a comma added after a kept word stays plain"
+        );
+        assert!(added_words("same words", "same words").is_empty());
+        let whole = 2..7;
+        assert_eq!(added_words("", "  a cat "), [whole]);
+    }
+}

src/generative/ratio.rs

@@ -0,0 +1,164 @@
+use std::rc::Rc;
+
+use gpui::{
+    App, ElementId, FontWeight, InteractiveElement, IntoElement, MouseButton, ParentElement,
+    RenderOnce, StatefulInteractiveElement, Styled, Window, div, prelude::*,
+};
+
+use crate::{
+    primitives::tab_stop,
+    theme::{ActiveTheme, IconSize, Radius, TextSize},
+    typography::tabular,
+};
+
+type OnRatio = Rc<dyn Fn((u32, u32), &mut Window, &mut App)>;
+
+/// The share of a square a `width:height` shape spans across and down; its long side spans it all.
+pub(crate) fn span(width: u32, height: u32) -> (f32, f32) {
+    assert!(width > 0 && height > 0, "a ratio of {width}:{height}");
+    let (width, height) = (width as f32, height as f32);
+    let long = width.max(height);
+    (width / long, height / long)
+}
+
+/// A picture's shape: a chip per ratio, each with an outline drawn to its proportions. The chosen chip takes accent; each is a Tab stop.
+#[derive(IntoElement)]
+pub struct AspectRatioPicker {
+    id: ElementId,
+    ratios: Vec<(u32, u32)>,
+    selected: (u32, u32),
+    on_select: Option<OnRatio>,
+}
+
+impl AspectRatioPicker {
+    /// `selected` is one of `ratios`, each `(width, height)`.
+    pub fn new(
+        id: impl Into<ElementId>,
+        ratios: impl IntoIterator<Item = (u32, u32)>,
+        selected: (u32, u32),
+    ) -> Self {
+        let ratios: Vec<(u32, u32)> = ratios.into_iter().collect();
+        assert!(
+            ratios.contains(&selected),
+            "ratio {}:{} is not among the ratios",
+            selected.0,
+            selected.1
+        );
+        Self {
+            id: id.into(),
+            ratios,
+            selected,
+            on_select: None,
+        }
+    }
+
+    pub fn on_select(
+        mut self,
+        handler: impl Fn((u32, u32), &mut Window, &mut App) + 'static,
+    ) -> Self {
+        self.on_select = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for AspectRatioPicker {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let chips: Vec<_> = self
+            .ratios
+            .iter()
+            .map(|&(width, height)| {
+                let id: ElementId = (self.id.clone(), format!("ratio-{width}-{height}")).into();
+                let focus = tab_stop((id.clone(), "focus").into(), true, window, cx);
+                (id, focus.is_focused(window), focus, (width, height))
+            })
+            .collect();
+        let theme = cx.theme();
+        let colors = theme.colors.clone();
+        let glyph = theme.icon_size(IconSize::Md);
+        div()
+            .w_full()
+            .flex()
+            .flex_wrap()
+            .gap_2()
+            .children(chips.into_iter().map(|(id, focused, focus, ratio)| {
+                let chosen = ratio == self.selected;
+                let ink = if chosen {
+                    colors.accent
+                } else {
+                    colors.fg_muted
+                };
+                let border = if focused {
+                    colors.focus
+                } else if chosen {
+                    colors.accent
+                } else {
+                    colors.border
+                };
+                let (across, down) = span(ratio.0, ratio.1);
+                let pick = self.on_select.clone();
+                div()
+                    .id(id)
+                    .track_focus(&focus)
+                    .flex()
+                    .items_center()
+                    .gap_1p5()
+                    .px_2p5()
+                    .py_1()
+                    .rounded(theme.radius(Radius::Md))
+                    .border_1()
+                    .border_color(border)
+                    .text_size(theme.text_size(TextSize::Sm))
+                    .font_weight(FontWeight::MEDIUM)
+                    .text_color(ink)
+                    .cursor_pointer()
+                    .when(!chosen && !focused, |chip| {
+                        chip.hover(|style| style.border_color(colors.border_strong))
+                    })
+                    .on_mouse_down(MouseButton::Left, |_, window, _| window.prevent_default())
+                    .on_click(move |_, window, cx| {
+                        if chosen {
+                            return;
+                        }
+                        log::info!("aspect ratio: {}:{}", ratio.0, ratio.1);
+                        if let Some(pick) = &pick {
+                            pick(ratio, window, cx);
+                        }
+                    })
+                    .child(
+                        div()
+                            .flex_none()
+                            .size(glyph)
+                            .flex()
+                            .items_center()
+                            .justify_center()
+                            .child(
+                                div()
+                                    .w(glyph * across)
+                                    .h(glyph * down)
+                                    .rounded(theme.radius(Radius::Sm))
+                                    .border_1()
+                                    .border_color(ink),
+                            ),
+                    )
+                    .child(tabular(div()).child(format!("{}:{}", ratio.0, ratio.1)))
+            }))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::span;
+
+    #[test]
+    fn a_ratio_spans_its_long_side_whole() {
+        assert_eq!(span(16, 9), (1.0, 0.5625));
+        assert_eq!(span(9, 16), (0.5625, 1.0));
+        assert_eq!(span(1, 1), (1.0, 1.0));
+    }
+
+    #[test]
+    #[should_panic(expected = "a ratio of 0:1")]
+    fn an_empty_side_fails_loud() {
+        span(0, 1);
+    }
+}

src/generative/seed.rs

@@ -0,0 +1,92 @@
+use std::{
+    hash::{BuildHasher, Hasher, RandomState},
+    ops::Range,
+    rc::Rc,
+};
+
+use gpui::{App, ElementId, Entity, IntoElement, RenderOnce, Window};
+
+use crate::{
+    buttons::IconButton,
+    forms::{InputAddon, InputGroup, TextInput},
+    primitives::IconName,
+};
+
+/// Fits an edit into a seed: digits only, and nothing past `u32::MAX`; a refused edit keeps the text.
+pub(crate) fn digits(text: &str, range: Range<usize>, typed: &str) -> (String, usize) {
+    let kept: String = typed.chars().filter(char::is_ascii_digit).collect();
+    let next = format!("{}{kept}{}", &text[..range.start], &text[range.end..]);
+    if next.is_empty() || next.parse::<u32>().is_ok() {
+        (next, range.start + kept.len())
+    } else {
+        (text.to_string(), range.start)
+    }
+}
+
+/// A seed from the system's source of randomness.
+fn roll() -> u32 {
+    RandomState::new().build_hasher().finish() as u32
+}
+
+/// A generation's seed in the owner's field: digits up to `u32::MAX`, empty for a new one each run, and a die that rolls one.
+#[derive(IntoElement)]
+pub struct SeedInput {
+    id: ElementId,
+    field: Entity<TextInput>,
+}
+
+impl SeedInput {
+    pub fn new(id: impl Into<ElementId>, field: &Entity<TextInput>) -> Self {
+        Self {
+            id: id.into(),
+            field: field.clone(),
+        }
+    }
+
+    /// The seed in `field`; none while it is empty.
+    pub fn read(field: &Entity<TextInput>, cx: &App) -> Option<u32> {
+        let text = field.read(cx).text();
+        (!text.is_empty()).then(|| text.parse().expect("a seed field holds digits"))
+    }
+}
+
+impl RenderOnce for SeedInput {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let fitted = window.use_keyed_state((self.id.clone(), "fitted"), cx, |_, _| false);
+        if !*fitted.read(cx) {
+            fitted.update(cx, |fitted, _| *fitted = true);
+            self.field.update(cx, |input, cx| {
+                input.set_fit(Rc::new(digits));
+                let text = input.text().to_string();
+                input.set_text(text, cx);
+                input.set_placeholder("Random", cx);
+            });
+        }
+        let field = self.field.clone();
+        InputGroup::new(&self.field).after(InputAddon::new(
+            IconButton::new((self.id.clone(), "roll"), IconName::Dices)
+                .tooltip("Roll a seed")
+                .on_click(move |_, _, cx| {
+                    let seed = roll();
+                    log::info!("seed input: rolled {seed}");
+                    field.update(cx, |input, cx| input.set_text(seed.to_string(), cx));
+                }),
+        ))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::digits;
+
+    #[test]
+    fn a_seed_keeps_digits_up_to_the_largest() {
+        assert_eq!(digits("12", 2..2, "3a4"), ("1234".to_string(), 4));
+        assert_eq!(digits("", 0..0, "12,345"), ("12345".to_string(), 5));
+        assert_eq!(
+            digits("4294967295", 10..10, "1"),
+            ("4294967295".to_string(), 10)
+        );
+        assert_eq!(digits("1234", 1..3, ""), ("14".to_string(), 1));
+    }
+}

src/generative/style.rs

@@ -0,0 +1,148 @@
+use std::rc::Rc;
+
+use gpui::{
+    App, ElementId, InteractiveElement, IntoElement, MouseButton, ParentElement, RenderOnce,
+    SharedString, StatefulInteractiveElement, Styled, Window, div, transparent_black,
+};
+
+use crate::{
+    documents::source,
+    forms::OnValue,
+    primitives::{Icon, IconName, Image, tab_stop},
+    theme::{ActiveTheme, IconSize, Radius, TextSize},
+    typography::Ellipsis,
+};
+
+/// A style to generate in: its key, its name, and a picture of it; one with no picture draws a plain tile.
+#[derive(Clone, Debug, PartialEq)]
+pub struct StylePreset {
+    pub key: SharedString,
+    pub name: SharedString,
+    pub picture: Option<SharedString>,
+}
+
+/// Styles to generate in, a tile each with its picture and name. The chosen tile takes accent; each is a Tab stop.
+#[derive(IntoElement)]
+pub struct StylePresetPicker {
+    id: ElementId,
+    presets: Vec<StylePreset>,
+    selected: SharedString,
+    on_select: Option<OnValue>,
+}
+
+impl StylePresetPicker {
+    /// `selected` names one of `presets` by key.
+    pub fn new(
+        id: impl Into<ElementId>,
+        presets: impl IntoIterator<Item = StylePreset>,
+        selected: impl Into<SharedString>,
+    ) -> Self {
+        let (presets, selected): (Vec<StylePreset>, SharedString) =
+            (presets.into_iter().collect(), selected.into());
+        assert!(
+            presets.iter().any(|preset| preset.key == selected),
+            "style {selected} is not among the presets"
+        );
+        Self {
+            id: id.into(),
+            presets,
+            selected,
+            on_select: None,
+        }
+    }
+
+    pub fn on_select(
+        mut self,
+        handler: impl Fn(&SharedString, &mut Window, &mut App) + 'static,
+    ) -> Self {
+        self.on_select = Some(Rc::new(handler));
+        self
+    }
+}
+
+impl RenderOnce for StylePresetPicker {
+    fn render(self, window: &mut Window, cx: &mut App) -> impl IntoElement {
+        let tiles: Vec<_> = self
+            .presets
+            .into_iter()
+            .map(|preset| {
+                let id: ElementId = (self.id.clone(), format!("preset-{}", preset.key)).into();
+                let focus = tab_stop((id.clone(), "focus").into(), true, window, cx);
+                (id, focus.is_focused(window), focus, preset)
+            })
+            .collect();
+        let theme = cx.theme();
+        let colors = theme.colors.clone();
+        let side = theme.generative().preset;
+        div()
+            .w_full()
+            .flex()
+            .flex_wrap()
+            .gap_3()
+            .children(tiles.into_iter().map(|(id, focused, focus, preset)| {
+                let chosen = preset.key == self.selected;
+                let ring = if focused {
+                    colors.focus
+                } else if chosen {
+                    colors.accent
+                } else {
+                    transparent_black()
+                };
+                let (key, pick) = (preset.key.clone(), self.on_select.clone());
+                let inner = theme.radius(Radius::Md);
+                let picture = match &preset.picture {
+                    Some(path) => Image::new((id.clone(), "picture"), source(path))
+                        .size_full()
+                        .rounded(inner)
+                        .into_any_element(),
+                    None => div()
+                        .size_full()
+                        .rounded(inner)
+                        .flex()
+                        .items_center()
+                        .justify_center()
+                        .bg(colors.sunken)
+                        .child(
+                            Icon::new(IconName::Ban)
+                                .size(IconSize::Md)
+                                .color(colors.fg_subtle),
+                        )
+                        .into_any_element(),
+                };
+                div()
+                    .id(id)
+                    .track_focus(&focus)
+                    .w(side)
+                    .flex()
+                    .flex_col()
+                    .gap_1p5()
+                    .cursor_pointer()
+                    .on_mouse_down(MouseButton::Left, |_, window, _| window.prevent_default())
+                    .on_click(move |_, window, cx| {
+                        if chosen {
+                            return;
+                        }
+                        log::info!("style preset: {key}");
+                        if let Some(pick) = &pick {
+                            pick(&key, window, cx);
+                        }
+                    })
+                    .child(
+                        div()
+                            .size(side)
+                            .p_0p5()
+                            .rounded(theme.radius(Radius::Lg))
+                            .border_1()
+                            .border_color(ring)
+                            .child(picture),
+                    )
+                    .child(
+                        div()
+                            .px_0p5()
+                            .text_size(theme.text_size(TextSize::Xs))
+                            .text_color(if chosen { colors.fg } else { colors.fg_muted })
+                            .child(Ellipsis::new(preset.name)),
+                    )
+            }))
+    }
+}

src/generative/tests/mod.rs

@@ -0,0 +1,216 @@
+use std::{cell::RefCell, rc::Rc};
+
+use gpui::{
+    AppContext as _, Context, Entity, IntoElement, KeyBinding, KeyUpEvent, Keystroke,
+    ParentElement, Render, SharedString, Styled, TestAppContext, VisualTestContext, Window, div,
+    px,
+};
+
+use crate::{
+    forms::{self, TextInput},
+    generative::{AspectRatioPicker, PromptEnhancer, SeedInput, StylePreset, StylePresetPicker},
+    primitives::FocusNext,
+    theme::Theme,
+};
+
+fn settle(cx: &mut VisualTestContext) {
+    cx.run_until_parked();
+    cx.update(|window, _| window.refresh());
+    cx.run_until_parked();
+}
+
+/// Presses and releases `key`, a frame apart.
+fn press(key: &str, cx: &mut VisualTestContext) {
+    cx.simulate_keystrokes(key);
+    settle(cx);
+    cx.simulate_event(KeyUpEvent {
+        keystroke: Keystroke::parse(key).expect("a key"),
+    });
+    settle(cx);
+}
+
+fn tab(times: usize, cx: &mut VisualTestContext) {
+    for _ in 0..times {
+        cx.update(|window, _| window.focus_next());
+    }
+}
+
+fn setup(cx: &mut TestAppContext) {
+    cx.update(|cx| {
+        Theme::init(cx);
+        forms::bind_keys(cx);
+        cx.bind_keys([KeyBinding::new("tab", FocusNext, None)]);
+    });
+}
+
+/// A prompt with its enhancer, a suggestion the test sets, and what it heard.
+struct Enhancing {
+    field: Entity<TextInput>,
+    suggestion: Option<SharedString>,
+    heard: Vec<String>,
+}
+
+impl Render for Enhancing {
+    fn render(&mut self, _: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
+        let (asked, resolved) = (cx.entity(), cx.entity());
+        let enhancer = PromptEnhancer::new("enhancer", &self.field)
+            .on_enhance(move |prompt, _, cx| {
+                asked.update(cx, |view, _| view.heard.push(format!("asked {prompt}")))
+            })
+            .on_resolve(move |taken, _, cx| {
+                resolved.update(cx, |view, _| {
+                    view.heard.push(format!("taken {taken}"));
+                    view.suggestion = None;
+                })
+            });
+        let enhancer = match &self.suggestion {
+            Some(text) => enhancer.suggestion(text.clone()),
+            None => enhancer,
+        };
+        div().w(px(420.0)).child(enhancer)
+    }
+}
+
+fn enhancing(cx: &mut TestAppContext) -> (Entity<Enhancing>, &mut VisualTestContext) {
+    setup(cx);
+    let (view, cx) = cx.add_window_view(|window, cx| Enhancing {
+        field: cx.new(|cx| TextInput::new(window, cx)),
+        suggestion: None,
+        heard: Vec::new(),
+    });
+    cx.update(|window, _| window.activate_window());
+    settle(cx);
+    (view, cx)
+}
+
+#[gpui::test]
+fn enhance_asks_with_the_trimmed_prompt_and_use_this_takes_the_offer(cx: &mut TestAppContext) {
+    let (view, cx) = enhancing(cx);
+    tab(1, cx);
+    cx.simulate_input("  a cat  ");
+    tab(1, cx);
+    press("enter", cx);
+    view.update(cx, |view, cx| {
+        view.suggestion = Some("a fluffy cat asleep".into());
+        cx.notify();
+    });
+    settle(cx);
+    tab(1, cx);
+    press("enter", cx);
+    view.read_with(cx, |view, cx| {
+        assert_eq!(view.heard, ["asked a cat", "taken true"]);
+        assert_eq!(view.field.read(cx).text(), "a fluffy cat asleep");
+    });
+}
+
+#[gpui::test]
+fn keep_mine_leaves_the_prompt_as_written(cx: &mut TestAppContext) {
+    let (view, cx) = enhancing(cx);
+    tab(1, cx);
+    cx.simulate_input("a cat");
+    view.update(cx, |view, cx| {
+        view.suggestion = Some("a fluffy cat".into());
+        cx.notify();
+    });
+    settle(cx);
+    tab(3, cx);
+    press("enter", cx);
+    view.read_with(cx, |view, cx| {
+        assert_eq!(view.heard, ["taken false"]);
+        assert_eq!(view.field.read(cx).text(), "a cat");
+    });
+}
+
+/// Three presets, two ratios, a seed, and every pick heard.
+struct Picks {
+    seed: Entity<TextInput>,
+    style: SharedString,
+    heard: Rc<RefCell<Vec<String>>>,
+}
+
+impl Render for Picks {
+    fn render(&mut self, _: &mut Window, _: &mut Context<Self>) -> impl IntoElement {
+        let (styled, shaped) = (self.heard.clone(), self.heard.clone());
+        let preset = |key: &str| StylePreset {
+            key: key.to_string().into(),
+            name: key.to_string().into(),
+            picture: None,
+        };
+        div()
+            .w(px(420.0))
+            .child(
+                StylePresetPicker::new(
+                    "styles",
+                    [preset("a"), preset("b"), preset("c")],
+                    self.style.clone(),
+                )
+                .on_select(move |key, _, _| styled.borrow_mut().push(format!("style {key}"))),
+            )
+            .child(
+                AspectRatioPicker::new("ratios", [(1, 1), (4, 3)], (1, 1)).on_select(
+                    move |ratio, _, _| {
+                        shaped
+                            .borrow_mut()
+                            .push(format!("ratio {}:{}", ratio.0, ratio.1))
+                    },
+                ),
+            )
+            .child(SeedInput::new("seed", &self.seed))
+    }
+}
+
+fn picks(
+    cx: &mut TestAppContext,
+) -> (
+    Entity<Picks>,
+    Rc<RefCell<Vec<String>>>,
+    &mut VisualTestContext,
+) {
+    setup(cx);
+    let heard = Rc::new(RefCell::new(Vec::new()));
+    let store = heard.clone();
+    let (view, cx) = cx.add_window_view(|window, cx| Picks {
+        seed: cx.new(|cx| TextInput::new(window, cx)),
+        style: "a".into(),
+        heard: store,
+    });
+    cx.update(|window, _| window.activate_window());
+    settle(cx);
+    (view, heard, cx)
+}
+
+#[gpui::test]
+fn tabs_reach_each_tile_and_chip_and_enter_picks_it(cx: &mut TestAppContext) {
+    let (_, heard, cx) = picks(cx);
+    tab(1, cx);
+    press("enter", cx);
+    tab(1, cx);
+    press("enter", cx);
+    tab(3, cx);
+    press("enter", cx);
+    assert_eq!(
+        *heard.borrow(),
+        ["style b", "ratio 4:3"],
+        "the chosen tile stays quiet"
+    );
+}
+
+#[gpui::test]
+fn a_seed_keeps_digits_and_the_die_rolls_one(cx: &mut TestAppContext) {
+    let (view, _, cx) = picks(cx);
+    tab(6, cx);
+    cx.simulate_input("12a3");
+    view.read_with(cx, |view, cx| {
+        assert_eq!(SeedInput::read(&view.seed, cx), Some(123))
+    });
+    tab(1, cx);
+    press("enter", cx);
+    view.read_with(cx, |view, cx| {
+        let text = view.seed.read(cx).text().to_string();
+        assert_ne!(text, "123", "the die rolls a new seed");
+        assert_eq!(
+            SeedInput::read(&view.seed, cx).map(|seed| seed.to_string()),
+            Some(text)
+        );
+    });
+}

src/lib.rs

@@ -12,6 +12,7 @@ pub mod editor;
 pub mod feedback;
 pub mod finance;
 pub mod forms;
+pub mod generative;
 pub mod git;
 pub mod layout;
 pub mod lists;

src/primitives/icon.rs

@@ -56,6 +56,7 @@ icons! {
     ArrowUpRight => "arrow-up-right",
     ArrowUp => "arrow-up",
     AtSign => "at-sign",
+    Ban => "ban",
     Battery => "battery",
     Bell => "bell",
     Bold => "bold",
@@ -115,6 +116,7 @@ icons! {
     Crop => "crop",
     Crosshair => "crosshair",
     Database => "database",
+    Dices => "dices",
     DollarSign => "dollar-sign",
     Dot => "dot",
     Download => "download",

src/theme/generative.rs

@@ -0,0 +1,18 @@
+use gpui::Rems;
+
+use super::{Theme, tokens::px_to_rems};
+
+/// Generative tools' measures.
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub struct GenerativeSizes {
+    /// A style preset's picture, square.
+    pub preset: Rems,
+}
+
+impl Theme {
+    pub fn generative(&self) -> GenerativeSizes {
+        GenerativeSizes {
+            preset: px_to_rems(88.0),
+        }
+    }
+}

src/theme/mod.rs

@@ -1,4 +1,5 @@
 mod chart;
+mod generative;
 mod palette;
 mod tokens;
 
@@ -8,6 +9,7 @@ use gpui::{App, Global, SharedString, WindowAppearance};
 
 use crate::motion;
 pub use chart::ChartSizes;
+pub use generative::GenerativeSizes;
 pub use palette::{Mix, Palette, Syntax};
 pub use tokens::{
     AvatarSize, ContainerSize, ControlSize, Density, Elevation, IconSize, Radius, TextSize,

tasks/ch21-30.md

@@ -208,33 +208,48 @@
 - [x] TraceViewer → `debug::TimelineProfiler` (a track per depth)
 - [x] EvalResultTable → `tables::DataTable` (Tag and Progress cells)
 
-## T25 Generative — `src/generative`
+## T25a Generative · Prompt and settings — `src/generative`
+
+- [x] ImageGenerationPanel → `forms::Form` of the fields below; Cmd-Enter generates
+- [x] PromptEnhancer
+- [x] NegativePromptInput → `forms::TagInput`
+- [x] StylePresetPicker
+- [x] SeedInput
+- [x] AspectRatioPicker
+
+## T25b Generative · Queue and results
 
-- [ ] ImageGenerationPanel
 - [ ] GenerationQueue
 - [ ] GenerationGrid
 - [ ] VariationPicker
-- [ ] PromptEnhancer
+- [ ] ImageCompare → `data_display::BeforeAfter`
-- [ ] NegativePromptInput
+- [ ] ABCompareView
-- [ ] StylePresetPicker
+
-- [ ] SeedInput
+## T25c Generative · Canvas
-- [ ] AspectRatioPicker
+
 - [ ] InpaintCanvas
 - [ ] MaskBrush
-- [ ] ImageCompare → `data_display::BeforeAfter`
+
+## T25d Generative · Sound and motion
+
 - [ ] AudioGenerationPlayer
 - [ ] VideoGenerationTimeline
 - [ ] TTSVoicePicker
+
+## T25e Generative · Models
+
 - [ ] ModelCard
 - [ ] ModelDownloadManager
 - [ ] ModelStatus
 - [ ] HardwareMonitor
 - [ ] FineTuneJobCard
+
+## T25f Generative · Data and prompts
+
 - [ ] DatasetViewer
 - [ ] EmbeddingVisualizer — 2D, 3D projection
 - [ ] PromptPlayground
 - [ ] PromptDiff / PromptVersionHistory
-- [ ] ABCompareView
 
 ## T26 Media — `src/media`