T24c: Agent, changes

- FileChangeCard: a proposed change to one file, its path and counts,
  Reject and Accept in a slot that keeps presses off the header; opened,
  the diff through a headless git::DiffViewer with its folds opening
- MultiFileDiffReview: every file at once, the total counts, how many are
  reviewed, Reject all and Accept all; verdicts as collab::Decision
- git::DiffViewer gains headless, leaving the file's header to its owner
- CommandExecutionCard is terminal::CommandBlock
- gallery: three proposed files and a command's block

examples/gallery/pages/agent/changes.rs

@@ -0,0 +1,93 @@
+use std::time::Duration;
+
+use ely_gpui_component::{
+    agent::{ChangeState, FileChange, MultiFileDiffReview},
+    collab::Decision,
+    terminal::{CommandBlock, CommandState},
+};
+use gpui::{App, IntoElement, ParentElement, Styled, Window, div, px};
+
+use crate::{
+    probe::probe,
+    ui::{keep, section, set},
+};
+
+const LIFT_OLD: &str =
+    "pub fn lift(color: Hsla, by: f32) -> Hsla {\n    color.mix(white(), by)\n}\n";
+const LIFT_NEW: &str = "pub fn lift(color: Hsla, by: f32, dark: bool) -> Hsla {\n    let by = if dark { by * 1.5 } else { by };\n    color.mix(white(), by.min(1.0))\n}\n";
+const TOKENS_OLD: &str =
+    "pub const ACCENT_LIFT: f32 = 0.12;\npub const SURFACE_LIFT: f32 = 0.04;\n";
+const TOKENS_NEW: &str =
+    "pub const ACCENT_LIFT: f32 = 0.18;\npub const SURFACE_LIFT: f32 = 0.04;\n";
+const NOTE_NEW: &str = "## 0.9\n\nDark themes lift their accents further.\n";
+
+fn changes() -> Vec<FileChange> {
+    [
+        ("src/theme/lift.rs", LIFT_OLD, LIFT_NEW),
+        ("src/theme/tokens.rs", TOKENS_OLD, TOKENS_NEW),
+        ("CHANGELOG.md", "", NOTE_NEW),
+    ]
+    .into_iter()
+    .map(|(path, old, new)| FileChange {
+        path: path.into(),
+        old: old.into(),
+        new: new.into(),
+        state: ChangeState::Proposed,
+    })
+    .collect()
+}
+
+/// `changes` after `decision`.
+fn decided(mut changes: Vec<FileChange>, decision: Decision) -> Vec<FileChange> {
+    let verdict = |accepted| {
+        if accepted {
+            ChangeState::Accepted
+        } else {
+            ChangeState::Rejected
+        }
+    };
+    match decision {
+        Decision::Accept(ix) => changes[ix].state = verdict(true),
+        Decision::Reject(ix) => changes[ix].state = verdict(false),
+        Decision::AcceptAll | Decision::RejectAll => {
+            let state = verdict(decision == Decision::AcceptAll);
+            for change in changes
+                .iter_mut()
+                .filter(|change| change.state == ChangeState::Proposed)
+            {
+                change.state = state;
+            }
+        }
+    }
+    changes
+}
+
+pub fn changes_section(window: &mut Window, cx: &mut App) -> impl IntoElement + use<> {
+    let files = keep("agent-changes", changes, window, cx);
+    let now = files.read(cx).clone();
+    section(
+        "FileChangeCard / MultiFileDiff Review / CommandExecutionCard",
+        "What an agent would change, file by file: how much moves, the diff a press away, and a verdict each or for all. A command it ran is terminal::CommandBlock.",
+        cx,
+    )
+    .child(
+        probe(
+            "agent-changes",
+            div().w(px(640.)).child(
+                MultiFileDiffReview::new("agent-review", now).on_decide(move |decision, _, cx| {
+                    let next = decided(files.read(cx).clone(), decision);
+                    set(&files, next, cx)
+                }),
+            ),
+        ),
+    )
+    .child(
+        div().w(px(640.)).child(CommandBlock::new(
+            "agent-command",
+            "~/ely",
+            "cargo test --lib theme",
+            "\u{1b}[32m   Compiling\u{1b}[0m ely-gpui-component v0.9.0\n\u{1b}[32m    Finished\u{1b}[0m test profile in 8.4s\nrunning 12 tests\ntest theme::lift_keeps_hue ... \u{1b}[32mok\u{1b}[0m\ntest theme::dark_lifts_further ... \u{1b}[32mok\u{1b}[0m\n\ntest result: \u{1b}[32mok\u{1b}[0m. 12 passed; 0 failed",
+            CommandState::Done { code: 0, took: Duration::from_millis(9_200) },
+        )),
+    )
+}

examples/gallery/pages/agent/mod.rs

@@ -1,3 +1,4 @@
+mod changes;
 mod progress;
 mod tools;
 
@@ -10,7 +11,7 @@ pub const PAGE: Page = Page {
     number: 24,
     slug: "agent",
     title: "Agent",
-    summary: "An assistant at work: the tools it calls, what it asks before it acts, and how far it has come.",
+    summary: "An assistant at work: the tools it calls, what it asks before it acts, how far it has come and what it would change.",
     render,
     script: SCRIPT,
 };
@@ -31,6 +32,13 @@ const SCRIPT: &[Step] = &[
     Step::Click("agent-advance"),
     Step::Wait(300),
     Step::Shot("plan"),
+    Step::DownAt("agent-changes", 30.0, 51.0),
+    Step::UpAt("agent-changes", 30.0, 51.0),
+    Step::Wait(300),
+    Step::Shot("changes"),
+    Step::DownAt("agent-changes", 30.0, 51.0),
+    Step::UpAt("agent-changes", 30.0, 51.0),
+    Step::Wait(200),
 ];
 
 fn render(window: &mut Window, cx: &mut App) -> AnyElement {
@@ -39,5 +47,6 @@ fn render(window: &mut Window, cx: &mut App) -> AnyElement {
         .child(tools::approval(window, cx))
         .child(progress::steps(window, cx))
         .child(progress::agents(window, cx))
+        .child(changes::changes_section(window, cx))
         .into_any_element()
 }