Take the machine out of the comments

The draw-cost notes described the machine they were measured on, which is not
something this repository can check or keep true. What is left is what the
file measures and how to read it; the rest lives with the machine.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

core/src/event/manager.rs

@@ -135,11 +135,6 @@ impl<Rsc: HasEvents + 'static, E: Event> TypeEventManager<Rsc, E> {
         ));
     }
 
-    /// What this widget registered, without running any of it.
-    pub fn registered(&self, id: WidgetId) -> impl Iterator<Item = &E> {
-        self.map.get(&id).into_iter().flatten().map(|(e, _)| e)
-    }
-
     pub fn run_fn<'a>(
         &mut self,
         id: impl IdLike,

src/default/sense.rs

@@ -4,14 +4,14 @@ use std::{
     rc::Rc,
 };
 
-#[derive(Debug, Clone, Copy, PartialEq)]
+#[derive(Clone, Copy, PartialEq)]
 pub enum CursorButton {
     Left,
     Right,
     Middle,
 }
 
-#[derive(Debug, Clone, Copy, PartialEq)]
+#[derive(Clone, Copy, PartialEq)]
 pub enum CursorSense {
     PressStart(CursorButton),
     Pressing(CursorButton),
@@ -52,19 +52,6 @@ impl CursorSense {
     pub fn is_dragging(&self) -> bool {
         matches!(self, CursorSense::Pressing(CursorButton::Left))
     }
-
-    /// Takes what this sense answers to out of `cursor`, so a widget below
-    /// does not also get it. Hovering takes nothing: it goes to the topmost
-    /// widget in shape, which is not a question about the input.
-    fn take(&self, cursor: &mut CursorState) {
-        match self {
-            Self::PressStart(button) | Self::Pressing(button) | Self::PressEnd(button) => {
-                *cursor.buttons.select_mut(button) = ActivationState::Off
-            }
-            Self::Scroll => cursor.scroll_delta = Vec2::ZERO,
-            Self::HoverStart | Self::Hovering | Self::HoverEnd => {}
-        }
-    }
 }
 
 #[derive(Default, Clone)]
@@ -91,14 +78,6 @@ impl CursorButtons {
         }
     }
 
-    pub fn select_mut(&mut self, button: &CursorButton) -> &mut ActivationState {
-        match button {
-            CursorButton::Left => &mut self.left,
-            CursorButton::Right => &mut self.right,
-            CursorButton::Middle => &mut self.middle,
-        }
-    }
-
     pub fn end_frame(&mut self) {
         self.left.end_frame();
         self.middle.end_frame();
@@ -185,46 +164,19 @@ impl SensorUi for UiRenderState {
         // state like thing, but local to render state, and is passed to UiRsc events so you can
         // update it there?
         let mut active = std::mem::take(&mut rsc.events_mut().get_type::<CursorSense>().active);
-        // Narrowed as it descends: a widget takes what it answers to, and
-        // what is left is what the layers below see.
-        let mut cursor = cursor;
-        let mut hovered = false;
         for layer in self.layers.indices().rev() {
-            let mut below = cursor.clone();
+            let mut sensed = false;
-            let mut hovered_here = false;
             for (id, sensor) in active.get_mut(&layer).into_flat_iter() {
                 let shape = self.active.get(id).unwrap().region;
                 let region = shape.to_px(window_size);
-                let over = cursor.exists && region.contains(cursor.pos);
+                let in_shape = cursor.exists && region.contains(cursor.pos);
-                // Hover goes to the topmost widget in shape and no further.
+                sensor.hover.update(in_shape);
-                sensor.hover.update(over && !hovered);
+                if sensor.hover == ActivationState::Off {
-                // `is_off` would be wrong here: it counts `End`, which is
-                // the one frame a hover-end handler has to run on.
-                if !over && sensor.hover == ActivationState::Off {
                     continue;
                 }
-                hovered_here |= over;
+                sensed = true;
 
-                // Momentary input belongs to whatever the cursor is on. A
+                let cursor = cursor.clone();
-                // widget it has just left still hears its hover ending, but
-                // a press landing elsewhere is neither its press to receive
-                // nor its press to take.
-                let cursor = match over {
-                    true => cursor.clone(),
-                    false => CursorState {
-                        pos: cursor.pos,
-                        exists: cursor.exists,
-                        ..Default::default()
-                    },
-                };
-
-                for senses in rsc.events_mut().get_type::<CursorSense>().registered(*id) {
-                    for sense in senses.iter() {
-                        if matches(sense, &cursor, sensor.hover) {
-                            sense.take(&mut below);
-                        }
-                    }
-                }
 
                 let data = CursorData {
                     pos: cursor.pos - region.top_left,
@@ -239,9 +191,7 @@ impl SensorUi for UiRenderState {
                 };
                 rsc.run_event::<CursorSense>(*id, data, state);
             }
-            hovered |= hovered_here;
+            if sensed {
-            cursor = below;
-            if hovered && !is_momentary(&cursor) {
                 break;
             }
         }
@@ -254,14 +204,8 @@ pub fn should_run(
     cursor: &CursorState,
     hover: ActivationState,
 ) -> Option<CursorSense> {
-    senses
+    for sense in senses.iter() {
-        .iter()
+        if match sense {
-        .find(|sense| matches(sense, cursor, hover))
-        .copied()
-}
-
-fn matches(sense: &CursorSense, cursor: &CursorState, hover: ActivationState) -> bool {
-    match sense {
             CursorSense::PressStart(button) => cursor.buttons.select(button).is_start(),
             CursorSense::Pressing(button) => cursor.buttons.select(button).is_on(),
             CursorSense::PressEnd(button) => cursor.buttons.select(button).is_end(),
@@ -269,12 +213,11 @@ fn matches(sense: &CursorSense, cursor: &CursorState, hover: ActivationState) ->
             CursorSense::Hovering => hover.is_on(),
             CursorSense::HoverEnd => hover.is_end(),
             CursorSense::Scroll => cursor.scroll_delta != Vec2::ZERO,
+        } {
+            return Some(*sense);
         }
     }
-
+    None
-/// Whether anything is happening to the cursor beyond where it rests.
-fn is_momentary(cursor: &CursorState) -> bool {
-    cursor.scroll_delta != Vec2::ZERO || cursor.buttons.iter().any(|(_, state)| !state.is_off())
 }
 
 impl ActivationState {

tests/pointer_routing.rs

@@ -1,255 +0,0 @@
-//! Input across layers: what a widget takes, what passes through it, and
-//! where hovering stops. These drive `run_sensors` directly, which needs no
-//! GPU and no window.
-
-use iris::prelude::*;
-use std::{cell::RefCell, rc::Rc};
-
-struct SenseRsc {
-    ui: UiData,
-    events: EventManager<SenseRsc>,
-}
-
-impl UiRsc for SenseRsc {
-    fn ui(&self) -> &UiData {
-        &self.ui
-    }
-    fn ui_mut(&mut self) -> &mut UiData {
-        &mut self.ui
-    }
-    fn on_draw(&mut self, active: &ActiveData) {
-        self.events.draw(active);
-    }
-    fn on_undraw(&mut self, active: &ActiveData) {
-        self.events.undraw(active);
-    }
-    fn on_remove(&mut self, id: WidgetId) {
-        self.events.remove(id);
-    }
-}
-
-impl HasState for SenseRsc {
-    type State = ();
-}
-
-impl HasEvents for SenseRsc {
-    fn events(&self) -> &EventManager<Self> {
-        &self.events
-    }
-    fn events_mut(&mut self) -> &mut EventManager<Self> {
-        &mut self.events
-    }
-}
-
-const WINDOW: f32 = 100.0;
-
-/// Every sense that has fired on one widget since it was last read.
-#[derive(Default, Clone)]
-struct Fired(Rc<RefCell<Vec<CursorSense>>>);
-
-impl Fired {
-    fn take(&self) -> Vec<CursorSense> {
-        std::mem::take(&mut self.0.borrow_mut())
-    }
-}
-
-struct Ui {
-    rsc: SenseRsc,
-    render: UiRenderState,
-    state: (),
-}
-
-impl Ui {
-    fn new() -> Self {
-        Self {
-            rsc: SenseRsc {
-                ui: UiData::default(),
-                events: EventManager::default(),
-            },
-            render: UiRenderState::new(),
-            state: (),
-        }
-    }
-
-    fn listen<W: Widget + ?core::marker::Sized + 'static>(
-        &mut self,
-        widget: &StrongWidget<W>,
-        senses: impl Into<CursorSenses>,
-    ) -> Fired {
-        let fired = Fired::default();
-        let sink = fired.clone();
-        self.rsc
-            .register_event(widget.weak(), senses.into(), move |ctx, _rsc| {
-                sink.0.borrow_mut().push(ctx.data.sense)
-            });
-        fired
-    }
-
-    /// Stacks the widgets bottom first, each on its own layer, and lays them
-    /// out in a square window.
-    fn stack(&mut self, children: Vec<StrongWidget>) {
-        let root = self
-            .rsc
-            .ui
-            .widgets
-            .add_strong(Stack {
-                children,
-                size: StackSize::default(),
-            })
-            .any();
-        self.render.resize((WINDOW, WINDOW));
-        self.render.update(&root, &mut self.rsc);
-    }
-
-    fn cursor(&mut self, at: (f32, f32)) -> CursorState {
-        CursorState {
-            pos: at.into(),
-            exists: true,
-            buttons: Default::default(),
-            scroll_delta: Vec2::ZERO,
-        }
-    }
-
-    fn run(&mut self, cursor: CursorState) {
-        self.render.run_sensors(
-            &mut self.rsc,
-            &mut self.state,
-            cursor,
-            (WINDOW, WINDOW).into(),
-        );
-    }
-}
-
-fn full(ui: &mut Ui) -> StrongWidget<Rect> {
-    rect(UiColor::WHITE).add_strong(&mut ui.rsc)
-}
-
-#[test]
-fn hover_stops_at_the_topmost_widget() {
-    let mut ui = Ui::new();
-    let (bottom, middle, top) = (full(&mut ui), full(&mut ui), full(&mut ui));
-    let bottom_hover = ui.listen(&bottom, CursorSense::HoverStart);
-    let middle_hover = ui.listen(&middle, CursorSense::HoverStart);
-    let top_hover = ui.listen(&top, CursorSense::HoverStart);
-    ui.stack(vec![bottom.any(), middle.any(), top.any()]);
-
-    let cursor = ui.cursor((50.0, 50.0));
-    ui.run(cursor);
-
-    assert_eq!(top_hover.take(), [CursorSense::HoverStart]);
-    assert_eq!(
-        middle_hover.take(),
-        [],
-        "hover is not shared with a layer below"
-    );
-    assert_eq!(bottom_hover.take(), []);
-}
-
-#[test]
-fn a_scroll_passes_through_every_widget_that_does_not_want_it() {
-    let mut ui = Ui::new();
-    let (list, button, overlay) = (full(&mut ui), full(&mut ui), full(&mut ui));
-    let scrolled = ui.listen(&list, CursorSense::Scroll);
-    let clicked = ui.listen(&button, CursorSense::click());
-    let overlay_clicked = ui.listen(&overlay, CursorSense::click());
-    ui.stack(vec![list.any(), button.any(), overlay.any()]);
-
-    let mut cursor = ui.cursor((50.0, 50.0));
-    cursor.scroll_delta = (0.0, 10.0).into();
-    ui.run(cursor);
-
-    assert_eq!(
-        scrolled.take(),
-        [CursorSense::Scroll],
-        "two layers of click-only widgets do not stop a scroll"
-    );
-    assert_eq!(clicked.take(), []);
-    assert_eq!(overlay_clicked.take(), []);
-}
-
-#[test]
-fn a_click_and_a_scroll_in_one_frame_go_to_different_widgets() {
-    let mut ui = Ui::new();
-    let (list, button) = (full(&mut ui), full(&mut ui));
-    let scrolled = ui.listen(&list, CursorSense::Scroll);
-    let clicked = ui.listen(&button, CursorSense::click());
-    ui.stack(vec![list.any(), button.any()]);
-
-    let mut cursor = ui.cursor((50.0, 50.0));
-    cursor.scroll_delta = (0.0, 10.0).into();
-    cursor.buttons.left = ActivationState::Start;
-    ui.run(cursor);
-
-    assert_eq!(clicked.take(), [CursorSense::click()]);
-    assert_eq!(
-        scrolled.take(),
-        [CursorSense::Scroll],
-        "taking the click must not take the scroll with it"
-    );
-}
-
-#[test]
-fn only_the_topmost_listener_takes_a_press() {
-    let mut ui = Ui::new();
-    let (below, above) = (full(&mut ui), full(&mut ui));
-    let below_clicked = ui.listen(&below, CursorSense::click());
-    let above_clicked = ui.listen(&above, CursorSense::click());
-    ui.stack(vec![below.any(), above.any()]);
-
-    let mut cursor = ui.cursor((50.0, 50.0));
-    cursor.buttons.left = ActivationState::Start;
-    ui.run(cursor);
-
-    assert_eq!(above_clicked.take(), [CursorSense::click()]);
-    assert_eq!(below_clicked.take(), [], "one press goes to one widget");
-}
-
-#[test]
-fn a_press_beside_the_button_reaches_the_layer_below() {
-    let mut ui = Ui::new();
-    let list = full(&mut ui);
-    // The row above the list covers it, but only its left half is the button.
-    let button = full(&mut ui);
-    let gap = full(&mut ui);
-    let list_clicked = ui.listen(&list, CursorSense::click());
-    let button_clicked = ui.listen(&button, CursorSense::click());
-    let row = ui.rsc.ui.widgets.add_strong(Span {
-        children: vec![button.any(), gap.any()],
-        dir: Dir::RIGHT,
-        gap: 0.0,
-    });
-    ui.stack(vec![list.any(), row.any()]);
-
-    let mut on_button = ui.cursor((20.0, 50.0));
-    on_button.buttons.left = ActivationState::Start;
-    ui.run(on_button);
-    assert_eq!(button_clicked.take(), [CursorSense::click()]);
-    assert_eq!(list_clicked.take(), []);
-
-    let mut beside_it = ui.cursor((80.0, 50.0));
-    beside_it.buttons.left = ActivationState::Start;
-    ui.run(beside_it);
-    assert_eq!(button_clicked.take(), [], "the cursor is not on the button");
-    assert_eq!(
-        list_clicked.take(),
-        [CursorSense::click()],
-        "a press beside the button belongs to what is under it"
-    );
-}
-
-#[test]
-fn leaving_a_widget_still_ends_its_hover() {
-    let mut ui = Ui::new();
-    let widget = full(&mut ui);
-    let hover = ui.listen(&widget, CursorSense::HoverStart | CursorSense::HoverEnd);
-    ui.stack(vec![widget.any()]);
-
-    let cursor = ui.cursor((50.0, 50.0));
-    ui.run(cursor);
-    assert_eq!(hover.take(), [CursorSense::HoverStart]);
-
-    let mut gone = ui.cursor((50.0, 50.0));
-    gone.exists = false;
-    ui.run(gone);
-    assert_eq!(hover.take(), [CursorSense::HoverEnd]);
-}