+namespace {
+
+class RasterBufferImpl : public RasterBuffer {
+ public:
+ RasterBufferImpl(ResourceProvider* resource_provider,
+ const Resource* resource,
+ SkMultiPictureDraw* multi_picture_draw)
+ : resource_provider_(resource_provider),
+ resource_(resource),
+ surface_(resource_provider->LockForWriteToSkSurface(resource->id())),
+ multi_picture_draw_(multi_picture_draw) {}
+ virtual ~RasterBufferImpl() {
+ resource_provider_->UnlockForWriteToSkSurface(resource_->id());
+ }
+
+ // Overridden from RasterBuffer:
+ virtual skia::RefPtr<SkCanvas> AcquireSkCanvas() OVERRIDE {
+ if (!surface_)
+ return skia::AdoptRef(SkCreateNullCanvas());
+
+ skia::RefPtr<SkCanvas> canvas = skia::SharePtr(recorder_.beginRecording(
+ resource_->size().width(), resource_->size().height()));
+
+ // Balanced with restore() call in ReleaseSkCanvas. save()/restore() calls
+ // are needed to ensure that canvas returns to its previous state after use.
+ canvas->save();
+ return canvas;
+ }
+ virtual void ReleaseSkCanvas(const skia::RefPtr<SkCanvas>& canvas) OVERRIDE {
+ if (!surface_)
+ return;
+
+ // Balanced with save() call in AcquireSkCanvas.
+ canvas->restore();
+
+ // Add the canvas and recorded picture to |multi_picture_draw_|.
+ skia::RefPtr<SkPicture> picture = skia::AdoptRef(recorder_.endRecording());
+ multi_picture_draw_->add(surface_->getCanvas(), picture.get());
+ }
+
+ private:
+ ResourceProvider* resource_provider_;
+ const Resource* resource_;
+ SkSurface* surface_;
+ SkMultiPictureDraw* multi_picture_draw_;
+ SkPictureRecorder recorder_;
+
+ DISALLOW_COPY_AND_ASSIGN(RasterBufferImpl);
+};
+
+} // namespace