Flesh out the Painting API a bit.

sky/engine/core/painting/Canvas.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef SKY_ENGINE_CORE_PAINTING_CANVAS_H_
 #define SKY_ENGINE_CORE_PAINTING_CANVAS_H_
 
 #include "sky/engine/core/painting/Paint.h"
 #include "sky/engine/platform/graphics/DisplayList.h"
 #include "sky/engine/tonic/dart_wrappable.h"
 #include "sky/engine/wtf/PassRefPtr.h"
 #include "sky/engine/wtf/RefCounted.h"
 
 namespace blink {
 class Element;
 
 class Canvas : public RefCounted<Canvas>, public DartWrappable {
     DEFINE_WRAPPERTYPEINFO();
 public:
     Canvas(const FloatSize& size);
     ~Canvas() override;
 
     // Width/Height define a culling rect which Skia may use for optimizing
     // out draw calls issued outside the rect.
-    double width() const { return m_size.width(); }
-    double height() const { return m_size.height(); }
+    float width() const { return m_size.width(); }
+    float height() const { return m_size.height(); }
 
-    void drawCircle(double x, double y, double radius, Paint* paint);
+    void save();
+    void saveLayer(const Vector<float>& bounds, const Paint* paint);

[reed1, 2015/05/13 21:20:10]

The bounds to saveLayer is optional (passing NULL should be fine), so we may
need this signature to be const * instead of &

[Matt Perry, 2015/05/13 21:22:00]

The IDL compiler dictates the interface. But passing null does work - it shows
up as an empty vector.

+    void restore();
+
+    void translate(float dx, float dy);
+    void scale(float sx, float sy);
+    void rotateDegrees(float degrees);
+    void skew(float sx, float sy);
+    void concat(const Vector<float>& matrix);
+
+    void clipRect(const Vector<float>& rect);
+
+    void drawPaint(Paint* paint);

[reed1, 2015/05/13 21:20:10]

const for drawPaint

[Matt Perry, 2015/05/13 21:22:00]

Oops, thanks. Will fix in a future CL.

+    void drawRect(const Vector<float>& rect, const Paint* paint);
+    void drawOval(const Vector<float>& rect, const Paint* paint);
+    void drawCircle(float x, float y, float radius, Paint* paint);

[reed1, 2015/05/13 21:20:11]

const for drawCircle

 
 protected:
     PassRefPtr<DisplayList> finishRecording();
 
     bool isRecording() const { return m_canvas; }
 
 private:
     FloatSize m_size;
     RefPtr<DisplayList> m_displayList;
     SkCanvas* m_canvas;
 };
 
 } // namespace blink
 
 #endif  // SKY_ENGINE_CORE_PAINTING_CANVAS_H_