Improve tour example

examples/ggez/renderer/debugger.rs

@@ -0,0 +1,30 @@
+use super::Renderer;
+use ggez::graphics::{Color, DrawMode, MeshBuilder, Rect};
+
+impl iced::renderer::Debugger for Renderer<'_> {
+    type Color = Color;
+
+    fn explain(&mut self, layout: &iced::Layout<'_>, color: Color) {
+        let bounds = layout.bounds();
+
+        let mut debug_mesh =
+            self.debug_mesh.take().unwrap_or(MeshBuilder::new());
+
+        debug_mesh.rectangle(
+            DrawMode::stroke(1.0),
+            Rect {
+                x: bounds.x,
+                y: bounds.y,
+                w: bounds.width,
+                h: bounds.height,
+            },
+            color,
+        );
+
+        self.debug_mesh = Some(debug_mesh);
+
+        for child in layout.children() {
+            self.explain(&child, color);
+        }
+    }
+}