Implement CanvasRenderingContext2D.canvas.

src/components/script/dom/canvasrenderingcontext2d.rs

@@ -5,9 +5,10 @@
 use dom::bindings::codegen::Bindings::CanvasRenderingContext2DBinding;
 use dom::bindings::codegen::Bindings::CanvasRenderingContext2DBinding::CanvasRenderingContext2DMethods;
 use dom::bindings::global::{GlobalRef, GlobalField};
-use dom::bindings::js::{JSRef, Temporary};
+use dom::bindings::js::{JS, JSRef, Temporary};
 use dom::bindings::trace::Untraceable;
 use dom::bindings::utils::{Reflector, Reflectable, reflect_dom_object};
+use dom::htmlcanvaselement::HTMLCanvasElement;
 
 use geom::point::Point2D;
 use geom::rect::Rect;
@@ -20,19 +21,21 @@ pub struct CanvasRenderingContext2D {
     reflector_: Reflector,
     global: GlobalField,
     renderer: Untraceable<Sender<CanvasMsg>>,
+    canvas: JS<HTMLCanvasElement>,
 }
 
 impl CanvasRenderingContext2D {
-    pub fn new_inherited(global: &GlobalRef, size: Size2D<i32>) -> CanvasRenderingContext2D {
+    pub fn new_inherited(global: &GlobalRef, canvas: &JSRef<HTMLCanvasElement>, size: Size2D<i32>) -> CanvasRenderingContext2D {
         CanvasRenderingContext2D {
             reflector_: Reflector::new(),
             global: GlobalField::from_rooted(global),
             renderer: Untraceable::new(CanvasRenderTask::start(size)),
+            canvas: JS::from_rooted(canvas),
         }
     }
 
-    pub fn new(global: &GlobalRef, size: Size2D<i32>) -> Temporary<CanvasRenderingContext2D> {
+    pub fn new(global: &GlobalRef, canvas: &JSRef<HTMLCanvasElement>, size: Size2D<i32>) -> Temporary<CanvasRenderingContext2D> {
-        reflect_dom_object(box CanvasRenderingContext2D::new_inherited(global, size),
+        reflect_dom_object(box CanvasRenderingContext2D::new_inherited(global, canvas, size),
                            global, CanvasRenderingContext2DBinding::Wrap)
     }
 
@@ -42,6 +45,10 @@ impl CanvasRenderingContext2D {
 }
 
 impl<'a> CanvasRenderingContext2DMethods for JSRef<'a, CanvasRenderingContext2D> {
+    fn Canvas(&self) -> Temporary<HTMLCanvasElement> {
+        Temporary::new(self.canvas)
+    }
+
     fn FillRect(&self, x: f64, y: f64, width: f64, height: f64) {
         let rect = Rect(Point2D(x as f32, y as f32), Size2D(width as f32, height as f32));
         self.renderer.send(FillRect(rect));

src/components/script/dom/htmlcanvaselement.rs

@@ -85,7 +85,7 @@ impl<'a> HTMLCanvasElementMethods for JSRef<'a, HTMLCanvasElement> {
         if self.context.get().is_none() {
             let window = window_from_node(self).root();
             let (w, h) = (self.width.get() as i32, self.height.get() as i32);
-            let context = CanvasRenderingContext2D::new(&Window(*window), Size2D(w, h));
+            let context = CanvasRenderingContext2D::new(&Window(*window), self, Size2D(w, h));
             self.context.assign(Some(context));
         }
         self.context.get().map(|context| Temporary::new(context))

src/components/script/dom/webidls/CanvasRenderingContext2D.webidl

@@ -8,7 +8,7 @@
 interface CanvasRenderingContext2D {
 
   // back-reference to the canvas
-  //readonly attribute HTMLCanvasElement canvas;
+  readonly attribute HTMLCanvasElement canvas;
 
   // canvas dimensions
   //         attribute unsigned long width;