Resize base layer in Stack before drawing

core/src/renderer.rs

@@ -60,8 +60,8 @@ pub trait Renderer {
     /// Fills a [`Quad`] with the provided [`Background`].
     fn fill_quad(&mut self, quad: Quad, background: impl Into<Background>);
 
-    /// Clears all of the recorded primitives in the [`Renderer`].
+    /// Resets the [`Renderer`] to start drawing in the `new_bounds` from scratch.
-    fn clear(&mut self);
+    fn reset(&mut self, new_bounds: Rectangle);
 }
 
 /// A polygon with four sides.

core/src/renderer/null.rs

@@ -16,7 +16,7 @@ impl Renderer for () {
 
     fn end_transformation(&mut self) {}
 
-    fn clear(&mut self) {}
+    fn reset(&mut self, _new_bounds: Rectangle) {}
 
     fn fill_quad(
         &mut self,

graphics/src/layer.rs

@@ -158,12 +158,15 @@ impl<T: Layer> Stack<T> {
 
     /// Clears the layers of the [`Stack`], allowing reuse.
     ///
+    /// It resizes the base layer bounds to the `new_bounds`.
+    ///
     /// This will normally keep layer allocations for future drawing operations.
-    pub fn clear(&mut self) {
+    pub fn reset(&mut self, new_bounds: Rectangle) {
         for layer in self.layers[..self.active_count].iter_mut() {
             layer.reset();
         }
 
+        self.layers[0].resize(new_bounds);
         self.current = 0;
         self.active_count = 1;
         self.previous.clear();

renderer/src/fallback.rs

@@ -46,8 +46,8 @@ where
         delegate!(self, renderer, renderer.fill_quad(quad, background.into()));
     }
 
-    fn clear(&mut self) {
+    fn reset(&mut self, new_bounds: Rectangle) {
-        delegate!(self, renderer, renderer.clear());
+        delegate!(self, renderer, renderer.reset(new_bounds));
     }
 
     fn start_layer(&mut self, bounds: Rectangle) {

runtime/src/user_interface.rs

@@ -482,10 +482,8 @@ where
         style: &renderer::Style,
         cursor: mouse::Cursor,
     ) {
-        // TODO: Move to shell level (?)
-        renderer.clear();
-
         let viewport = Rectangle::with_size(self.bounds);
+        renderer.reset(viewport);
 
         let base_cursor = match &self.overlay {
             None

tiny_skia/src/lib.rs

@@ -225,8 +225,8 @@ impl core::Renderer for Renderer {
         layer.draw_quad(quad, background.into(), transformation);
     }
 
-    fn clear(&mut self) {
+    fn reset(&mut self, new_bounds: Rectangle) {
-        self.layers.clear();
+        self.layers.reset(new_bounds);
     }
 }
 

wgpu/src/lib.rs

@@ -648,8 +648,8 @@ impl core::Renderer for Renderer {
         layer.draw_quad(quad, background.into(), transformation);
     }
 
-    fn clear(&mut self) {
+    fn reset(&mut self, new_bounds: Rectangle) {
-        self.layers.clear();
+        self.layers.reset(new_bounds);
     }
 }