Modify child_window example

examples/child_window.rs

@@ -56,15 +56,21 @@ fn main() -> Result<(), impl std::error::Error> {
                     event: KeyEvent { state: ElementState::Pressed, .. },
                     ..
                 } => {
+                    let child_index = self.windows.len() - 1;
                     let parent_window = self.windows.get(&self.parent_window_id.unwrap()).unwrap();
-                    let child_window = spawn_child_window(parent_window.as_ref(), event_loop);
+                    let child_window =
+                        spawn_child_window(parent_window.as_ref(), event_loop, child_index as i32);
                     let child_id = child_window.id();
                     println!("Child window created with id: {child_id:?}");
                     self.windows.insert(child_id, child_window);
                 },
                 WindowEvent::RedrawRequested => {
                     if let Some(window) = self.windows.get(&window_id) {
-                        fill::fill_window(window.as_ref());
+                        if window_id == self.parent_window_id.unwrap() {
+                            fill::fill_window(window.as_ref(), 0xff181818);
+                        } else {
+                            fill::fill_window(window.as_ref(), 0xffbbbbbb);
+                        }
                     }
                 },
                 _ => (),
@@ -75,12 +81,20 @@ fn main() -> Result<(), impl std::error::Error> {
     fn spawn_child_window(
         parent: &dyn Window,
         event_loop: &dyn ActiveEventLoop,
+        child_count: i32,
     ) -> Box<dyn Window> {
         let parent = parent.raw_window_handle().unwrap();
+
+        // As child count increases, x goes from 0*128 to 5*128 and then repeats
+        let x: f64 = child_count.rem_euclid(5) as f64 * 128.0;
+
+        // After 5 windows have been put side by side horizontally, a new row starts
+        let y: f64 = (child_count / 5) as f64 * 96.0;
+
         let mut window_attributes = WindowAttributes::default()
             .with_title("child window")
-            .with_surface_size(LogicalSize::new(200.0f32, 200.0f32))
-            .with_position(Position::Logical(LogicalPosition::new(0.0, 0.0)))
+            .with_surface_size(LogicalSize::new(128.0f32, 96.0))
+            .with_position(Position::Logical(LogicalPosition::new(x, y)))
             .with_visible(true);
         // `with_parent_window` is unsafe. Parent window must be a valid window.
         window_attributes = unsafe { window_attributes.with_parent_window(Some(parent)) };

examples/control_flow.rs

@@ -114,7 +114,7 @@ impl ApplicationHandler for ControlFlowDemo {
             WindowEvent::RedrawRequested => {
                 let window = self.window.as_ref().unwrap();
                 window.pre_present_notify();
-                fill::fill_window(window.as_ref());
+                fill::fill_window(window.as_ref(), 0xff181818);
             },
             _ => (),
         }

examples/pump_events.rs

@@ -43,7 +43,7 @@ fn main() -> std::process::ExitCode {
             match event {
                 WindowEvent::CloseRequested => event_loop.exit(),
                 WindowEvent::RedrawRequested => {
-                    fill::fill_window(window.as_ref());
+                    fill::fill_window(window.as_ref(), 0xff181818);
                     window.request_redraw();
                 },
                 _ => (),

examples/run_on_demand.rs

@@ -69,7 +69,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
                     self.window = None;
                 },
                 WindowEvent::RedrawRequested => {
-                    fill::fill_window(window.as_ref());
+                    fill::fill_window(window.as_ref(), 0xff181818);
                 },
                 _ => (),
             }

examples/util/fill.rs

@@ -70,7 +70,7 @@ mod platform {
         }
     }
 
-    pub fn fill_window(window: &dyn Window) {
+    pub fn fill_window(window: &dyn Window, color: u32) {
         GC.with(|gc| {
             let size = window.surface_size();
             let (Some(width), Some(height)) =
@@ -84,13 +84,12 @@ mod platform {
             let surface =
                 gc.get_or_insert_with(|| GraphicsContext::new(window)).create_surface(window);
 
-            // Fill a buffer with a solid color.
-            const DARK_GRAY: u32 = 0xff181818;
+            // Fill a buffer with a solid color
 
             surface.resize(width, height).expect("Failed to resize the softbuffer surface");
 
             let mut buffer = surface.buffer_mut().expect("Failed to get the softbuffer buffer");
-            buffer.fill(DARK_GRAY);
+            buffer.fill(color);
             buffer.present().expect("Failed to present the softbuffer buffer");
         })
     }
@@ -108,7 +107,7 @@ mod platform {
 
 #[cfg(any(target_os = "android", target_os = "ios"))]
 mod platform {
-    pub fn fill_window(_window: &dyn winit::window::Window) {
+    pub fn fill_window(_window: &dyn winit::window::Window, _color: u32) {
         // No-op on mobile platforms.
     }
 

examples/x11_embed.rs

@@ -38,7 +38,7 @@ fn main() -> Result<(), Box<dyn Error>> {
                 WindowEvent::CloseRequested => event_loop.exit(),
                 WindowEvent::RedrawRequested => {
                     window.pre_present_notify();
-                    fill::fill_window(window.as_ref());
+                    fill::fill_window(window.as_ref(), 0xff181818);
                 },
                 _ => (),
             }