add segmented control

crates/core/tests/segmented.rs

@@ -0,0 +1,148 @@
+use std::{cell::RefCell, rc::Rc};
+
+use gpui::{
+    Context, IntoElement, MouseButton, ParentElement as _, Render, Styled as _, TestAppContext,
+    VisualTestContext, Window, div, point, px,
+};
+use gpui_native_core::segmented::Segmented;
+use gpui_native_theme::Theme;
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+enum Filter {
+    All,
+    Popular,
+    Recent,
+}
+
+const FILTERS: [(Filter, &str); 3] = [
+    (Filter::All, "All"),
+    (Filter::Popular, "Popular"),
+    (Filter::Recent, "Recent"),
+];
+
+type Changes = Rc<RefCell<Vec<Filter>>>;
+
+struct Harness {
+    filter: Filter,
+    changes: Changes,
+}
+
+impl Render for Harness {
+    fn render(&mut self, _window: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
+        let changes = self.changes.clone();
+        let view = cx.entity();
+        div().size_full().p_4().child(
+            Segmented::new("filter", self.filter)
+                .options(FILTERS)
+                .on_change(move |next, _window, cx| {
+                    changes.borrow_mut().push(next);
+                    view.update(cx, |harness, cx| {
+                        harness.filter = next;
+                        cx.notify();
+                    });
+                }),
+        )
+    }
+}
+
+fn filter_window() -> (TestAppContext, VisualTestContext, Changes) {
+    let mut cx = TestAppContext::single();
+    cx.update(Theme::init);
+    let changes = Rc::new(RefCell::new(Vec::new()));
+    let harness_changes = changes.clone();
+    let window = cx.add_window(move |_, _| Harness {
+        filter: Filter::All,
+        changes: harness_changes,
+    });
+    let mut visual = VisualTestContext::from_window(window.into(), &cx);
+    visual.update(|window, cx| {
+        window.draw(cx).clear(cx);
+    });
+    (cx, visual, changes)
+}
+
+fn click(visual: &mut VisualTestContext, position: gpui::Point<gpui::Pixels>) {
+    visual.simulate_mouse_down(position, MouseButton::Left, gpui::Modifiers::default());
+    visual.simulate_mouse_up(position, MouseButton::Left, gpui::Modifiers::default());
+}
+
+/// The strip hugs its labels in the `p_4` band: the three segments span
+/// roughly `18..142` horizontally and `17.6..33.9` vertically (macOS's 13 pt
+/// root font), so clicks land near `32` (All), `70` (Popular), and `118`
+/// (Recent).
+#[test]
+fn clicking_a_segment_reports_it() {
+    let (_cx, mut visual, changes) = filter_window();
+
+    click(&mut visual, point(px(70.), px(27.)));
+    assert_eq!(*changes.borrow(), vec![Filter::Popular]);
+
+    click(&mut visual, point(px(118.), px(27.)));
+    assert_eq!(*changes.borrow(), vec![Filter::Popular, Filter::Recent]);
+}
+
+#[test]
+fn re_clicking_the_selected_segment_reports_nothing() {
+    let (_cx, mut visual, changes) = filter_window();
+
+    click(&mut visual, point(px(70.), px(27.)));
+    assert_eq!(*changes.borrow(), vec![Filter::Popular]);
+
+    click(&mut visual, point(px(70.), px(27.)));
+    assert_eq!(*changes.borrow(), vec![Filter::Popular]);
+}
+
+#[test]
+fn arrows_move_the_selection_when_the_strip_has_focus() {
+    let (_cx, mut visual, changes) = filter_window();
+
+    // Clicking a segment hands the strip the keyboard, like the list.
+    click(&mut visual, point(px(32.), px(27.)));
+    visual.simulate_keystrokes("right");
+    assert_eq!(*changes.borrow(), vec![Filter::Popular]);
+
+    visual.simulate_keystrokes("right");
+    assert_eq!(*changes.borrow(), vec![Filter::Popular, Filter::Recent]);
+
+    // The strip never wraps: right on the last segment reports nothing.
+    visual.simulate_keystrokes("right");
+    assert_eq!(*changes.borrow(), vec![Filter::Popular, Filter::Recent]);
+
+    // Home and end jump to the ends.
+    visual.simulate_keystrokes("home");
+    assert_eq!(
+        *changes.borrow(),
+        vec![Filter::Popular, Filter::Recent, Filter::All]
+    );
+
+    visual.simulate_keystrokes("end");
+    assert_eq!(
+        *changes.borrow(),
+        vec![Filter::Popular, Filter::Recent, Filter::All, Filter::Recent]
+    );
+}
+
+/// The selected plate exists after a choice and settles on the chosen
+/// segment's slot; without it the active background disappears entirely.
+#[test]
+fn the_plate_settles_on_the_chosen_segment() {
+    let (_cx, mut visual, changes) = filter_window();
+
+    click(&mut visual, point(px(70.), px(27.)));
+    assert_eq!(*changes.borrow(), vec![Filter::Popular]);
+
+    // Let the spring settle in real time (it steps on Instant::now()), then
+    // check the plate landed in Popular's slot (~58..124).
+    std::thread::sleep(std::time::Duration::from_millis(600));
+    visual.update(|window, cx| {
+        window.draw(cx).clear(cx);
+    });
+    let plate = visual
+        .debug_bounds("segmented-plate")
+        .expect("plate missing");
+    assert!(
+        plate.left() >= px(44.) && plate.left() <= px(94.),
+        "plate settled at x {:?}",
+        plate.origin
+    );
+}