One proxy, and a macro instead of a shared test module

`Proxy` is the task queue as well as the way an application sends its own
events, so `ProxyQueue` is gone. `schedule_redraw` becomes
`request_redraw_if_needed`, which says what the comment beside it was
saying.

`assert_corners!` replaces the region helper, so `tests/common` goes with
it, and the scroll test now states both corners rather than one number.

src/default/mod.rs

@@ -49,9 +49,7 @@ pub enum DefaultEvent<State: DefaultAppState> {
     Update(Box<dyn TaskUpdate<DefaultRsc<State>>>),
 }
 
-struct ProxyQueue<State: DefaultAppState>(EventLoopProxy<DefaultEvent<State>>);
+impl<State: DefaultAppState> TaskQueue<DefaultRsc<State>> for Proxy<State> {
-
-impl<State: DefaultAppState> TaskQueue<DefaultRsc<State>> for ProxyQueue<State> {
     fn send(&self, update: Box<dyn TaskUpdate<DefaultRsc<State>>>) {
         let _ = self.0.send_event(DefaultEvent::Update(update));
     }
@@ -212,7 +210,7 @@ impl<State: DefaultAppState> AppState for DefaultApp<State> {
             .create_window(State::window_attributes())
             .unwrap();
         let default_state = DefaultUiState::new(window);
-        let mut rsc = DefaultRsc::init(Arc::new(ProxyQueue(proxy.clone())));
+        let mut rsc = DefaultRsc::init(Arc::new(Proxy(proxy.clone())));
         let state = State::new(default_state, &mut rsc, Proxy(proxy));
         let render = UiRenderState::new();
         Self { rsc, state, render }
@@ -223,9 +221,7 @@ impl<State: DefaultAppState> AppState for DefaultApp<State> {
             DefaultEvent::User(event) => self.state.event(event, &mut self.rsc, &mut self.render),
             DefaultEvent::Update(update) => update(&mut self.state, &mut self.rsc),
         }
-        // An update is not a reason to draw; whether it made anything dirty
+        self.request_redraw_if_needed();
-        // is. That is why a task posts here rather than asking for a redraw.
-        self.schedule_redraw();
     }
 
     fn window_event(&mut self, event: WindowEvent, event_loop: &ActiveEventLoop) {
@@ -309,7 +305,7 @@ impl<State: DefaultAppState> AppState for DefaultApp<State> {
             _ => (),
         }
         state.window_event(event, rsc, render);
-        self.schedule_redraw();
+        self.request_redraw_if_needed();
         self.state.default_state_mut().input.end_frame();
     }
 
@@ -319,7 +315,7 @@ impl<State: DefaultAppState> AppState for DefaultApp<State> {
 }
 
 impl<State: DefaultAppState> DefaultApp<State> {
-    fn schedule_redraw(&mut self) {
+    fn request_redraw_if_needed(&mut self) {
         let ui_state = self.state.default_state_mut();
         if self.render.needs_redraw(&ui_state.root, self.rsc.widgets()) {
             ui_state.renderer.window().request_redraw();

src/harness.rs

@@ -22,6 +22,25 @@ impl TaskQueue<DefaultRsc<HarnessState>> for Queue {
     }
 }
 
+/// `assert_eq!` for where a frame put a widget, which `PixelRegion` cannot do
+/// for itself: it neither compares nor prints.
+#[macro_export]
+macro_rules! assert_corners {
+    ($harness:expr, $id:expr, ($x0:expr, $y0:expr), ($x1:expr, $y1:expr)) => {{
+        let region = $harness.region(&$id).expect("widget drew nothing");
+        assert_eq!(
+            (
+                region.top_left.x,
+                region.top_left.y,
+                region.bot_right.x,
+                region.bot_right.y
+            ),
+            ($x0 as f32, $y0 as f32, $x1 as f32, $y1 as f32)
+        );
+    }};
+}
+pub use crate::assert_corners;
+
 #[derive(Default)]
 pub struct HarnessState {
     pub root: Option<StrongWidget>,

tests/common/mod.rs

@@ -1,13 +0,0 @@
-use iris::harness::Harness;
-use iris::prelude::*;
-
-/// `PixelRegion` neither compares nor prints.
-pub fn corners(h: &Harness, id: &impl IdLike) -> (f32, f32, f32, f32) {
-    let region = h.region(id).expect("widget drew nothing");
-    (
-        region.top_left.x,
-        region.top_left.y,
-        region.bot_right.x,
-        region.bot_right.y,
-    )
-}

tests/layout.rs

@@ -1,9 +1,6 @@
 //! Where a frame puts things, with no window to put them in.
 
-mod common;
+use iris::harness::{Harness, assert_corners};
-
-use common::corners;
-use iris::harness::Harness;
 use iris::prelude::*;
 
 /// A fixed 100 wide, and the rest of the 400 to its neighbour.
@@ -19,8 +16,8 @@ fn a_span_gives_each_child_the_width_it_asked_for() {
     let mut h = Harness::new((400, 200));
     let (left, right) = two_rects(&mut h);
 
-    assert_eq!(corners(&h, &left), (0.0, 0.0, 100.0, 200.0));
+    assert_corners!(h, left, (0, 0), (100, 200));
-    assert_eq!(corners(&h, &right), (100.0, 0.0, 400.0, 200.0));
+    assert_corners!(h, right, (100, 0), (400, 200));
 }
 
 #[test]
@@ -32,6 +29,6 @@ fn resizing_relays_out_against_the_new_output() {
     assert!(h.needs_redraw());
     h.frame();
 
-    assert_eq!(corners(&h, &left), (0.0, 0.0, 100.0, 100.0));
+    assert_corners!(h, left, (0, 0), (100, 100));
-    assert_eq!(corners(&h, &right), (100.0, 0.0, 800.0, 100.0));
+    assert_corners!(h, right, (100, 0), (800, 100));
 }

tests/scroll.rs

@@ -1,9 +1,6 @@
 //! Scrolling moves content and stops at its ends.
 
-mod common;
+use iris::harness::{Harness, assert_corners};
-
-use common::corners;
-use iris::harness::Harness;
 use iris::prelude::*;
 
 #[test]
@@ -16,14 +13,14 @@ fn a_wheel_scrolls_the_content_and_stops_at_its_end() {
     h.move_to((200, 100));
 
     // `Scroll` starts snapped to the end.
-    assert_eq!(corners(&h, &top).1, -200.0);
+    assert_corners!(h, top, (0, -200), (400, 0));
 
     // The handler scales a wheel line by 50.
     h.scroll((0, 1));
     h.frame();
-    assert_eq!(corners(&h, &top).1, -150.0);
+    assert_corners!(h, top, (0, -150), (400, 50));
 
     h.scroll((0, 10));
     h.frame();
-    assert_eq!(corners(&h, &top).1, 0.0);
+    assert_corners!(h, top, (0, 0), (400, 200));
 }