Introduce fill_rectangle to Renderer trait

graphics/src/renderer.rs

@@ -70,6 +70,16 @@ where
         });
     }
 
+    fn fill_rectangle(&mut self, quad: renderer::Quad) {
+        self.primitives.push(Primitive::Quad {
+            bounds: quad.bounds,
+            background: quad.background,
+            border_radius: quad.border_radius,
+            border_width: quad.border_width,
+            border_color: quad.border_color,
+        });
+    }
+
     fn clear(&mut self) {
         self.primitives.clear();
     }

native/src/renderer.rs

@@ -29,7 +29,7 @@ mod null;
 pub use null::Null;
 
 use crate::layout;
-use crate::{Element, Rectangle, Vector};
+use crate::{Background, Color, Element, Rectangle, Vector};
 
 /// A component that can take the state of a user interface and produce an
 /// output for its users.
@@ -59,4 +59,15 @@ pub trait Renderer: Sized {
     );
 
     fn clear(&mut self);
+
+    fn fill_rectangle(&mut self, quad: Quad);
+}
+
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub struct Quad {
+    pub bounds: Rectangle,
+    pub background: Background,
+    pub border_radius: f32,
+    pub border_width: f32,
+    pub border_color: Color,
 }

native/src/renderer/null.rs

@@ -37,6 +37,8 @@ impl Renderer for Null {
     }
 
     fn clear(&mut self) {}
+
+    fn fill_rectangle(&mut self, _quad: renderer::Quad) {}
 }
 
 impl renderer::Text for Null {