Mac: Shift more code into C++ classes from ObjC classes

content/browser/compositor/browser_compositor_view_private_mac.h

 // Copyright 2014 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 CONTENT_BROWSER_COMPOSITOR_BROWSER_COMPOSITOR_VIEW_PRIVATE_MAC_H_
 #define CONTENT_BROWSER_COMPOSITOR_BROWSER_COMPOSITOR_VIEW_PRIVATE_MAC_H_
 
 #include "content/browser/compositor/browser_compositor_view_mac.h"
 
+@class BrowserCompositorViewCocoa;
+
 namespace content {
-class BrowserCompositorViewCocoaHelper;
-}
 
-// An NSView drawn by a ui::Compositor. This structure is expensive to create,
-// because it has a ui::Compositor. As a result, this structure may be recycled
-// across multiple BrowserCompositorViewMac objects.
-@interface BrowserCompositorViewCocoa : NSView {
+// BrowserCompositorViewCocoaClient is the interface through which
+// gfx::NativeWidget (aka NSView aka BrowserCompositorViewCocoa) calls back to
+// BrowserCompositorViewMacInternal.
+class BrowserCompositorViewCocoaClient {
+ public:
+  virtual void GotAcceleratedIOSurfaceFrame(
+      IOSurfaceID io_surface_id,
+      int output_surface_id,
+      const std::vector<ui::LatencyInfo>& latency_info,
+      gfx::Size pixel_size,
+      float scale_factor) = 0;
+
+  virtual void GotSoftwareFrame(
+      cc::SoftwareFrameData* frame_data,
+      float scale_factor,
+      SkCanvas* canvas) = 0;
+};
+
+// BrowserCompositorViewMacInternal owns a NSView and a ui::Compositor that
+// draws that view.
+class BrowserCompositorViewMacInternal
+    : public BrowserCompositorViewCocoaClient,
+      public CompositingIOSurfaceLayerClient {
+ public:
+  BrowserCompositorViewMacInternal();
+  virtual ~BrowserCompositorViewMacInternal();
+
+  void SetClient(BrowserCompositorViewMacClient* client);
+  void ResetClient();
+
+  ui::Compositor* compositor() const { return compositor_.get(); }
+
+ private:
+  // BrowserCompositorViewCocoaClient implementation:
+  virtual void GotAcceleratedIOSurfaceFrame(
+      IOSurfaceID io_surface_id,
+      int output_surface_id,
+      const std::vector<ui::LatencyInfo>& latency_info,
+      gfx::Size pixel_size,
+      float scale_factor) OVERRIDE;
+  virtual void GotSoftwareFrame(
+      cc::SoftwareFrameData* frame_data,
+      float scale_factor,
+      SkCanvas* canvas) OVERRIDE;
+
+  // CompositingIOSurfaceLayerClient implementation:
+  virtual void AcceleratedLayerDidDrawFrame(bool succeeded) OVERRIDE;
+
+  // The client of the BrowserCompositorViewMac that is using this as its
+  // internals.
+  BrowserCompositorViewMacClient* client_;
+
+  // The NSView drawn by the |compositor_|
+  base::scoped_nsobject<BrowserCompositorViewCocoa> cocoa_view_;
+
+  // The compositor drawing the contents of |cooca_view_|. Note that this must
+  // be declared after |cocoa_view_|, so that it be destroyed first (because it
+  // will reach into |cocoa_view_|).
   scoped_ptr<ui::Compositor> compositor_;
 
+
   // A flipped layer, which acts as the parent of the compositing and software
   // layers. This layer is flipped so that the we don't need to recompute the
   // origin for sub-layers when their position changes (this is impossible when
   // using remote layers, as their size change cannot be synchronized with the
   // window). This indirection is needed because flipping hosted layers (like
   // |background_layer_| of RenderWidgetHostViewCocoa) leads to unpredictable
   // behavior.
   base::scoped_nsobject<CALayer> flipped_layer_;
 
   base::scoped_nsobject<CompositingIOSurfaceLayer> accelerated_layer_;
   int accelerated_layer_output_surface_id_;
   std::vector<ui::LatencyInfo> accelerated_latency_info_;
 
   base::scoped_nsobject<SoftwareLayer> software_layer_;
-
-  content::BrowserCompositorViewMacClient* client_;
-  scoped_ptr<content::BrowserCompositorViewCocoaHelper> helper_;
-}
-
-// Change the client and superview of the view. If this is set to NULL then
-// the compositor will be prepared to be recycled.
-- (void)setClient:(content::BrowserCompositorViewMacClient*)client;
-
-// This is called to destroy the underlying ui::Compositor, if it is known
-// that this will not be recycled again.
-- (void)destroyCompositor;
-
-// Access the underlying ui::Compositor for this view.
-- (ui::Compositor*)compositor;
-
-// Called when the accelerated or software layer draws its frame to the screen.
-- (void)layerDidDrawFrame;
-
-// Called when an error is encountered while drawing to the screen.
-- (void)gotAcceleratedLayerError;
-
-@end  // BrowserCompositorViewCocoa
-
-namespace content {
-
-// This class implements the parts of BrowserCompositorViewCocoa that need to
-// be a C++ class and not an Objective C class.
-class BrowserCompositorViewCocoaHelper
-    : public content::CompositingIOSurfaceLayerClient {
- public:
-  BrowserCompositorViewCocoaHelper(BrowserCompositorViewCocoa* view)
-      : view_(view) {}
-  virtual ~BrowserCompositorViewCocoaHelper() {}
-
- private:
-  // CompositingIOSurfaceLayerClient implementation:
-  virtual void AcceleratedLayerDidDrawFrame(bool succeeded) OVERRIDE;
-
-  BrowserCompositorViewCocoa* view_;
 };
 
 }  // namespace content
 
+// BrowserCompositorViewCocoa is the actual NSView to which the layers drawn
+// by the ui::Compositor are attached.
+@interface BrowserCompositorViewCocoa : NSView {
+  content::BrowserCompositorViewCocoaClient* client_;
+}
+
+- (id)initWithClient:(content::BrowserCompositorViewCocoaClient*)client;
+
+// Mark that the client provided at initialization is no longer valid and may
+// not be called back into.
+- (void)resetClient;
+@end
+
 #endif  // CONTENT_BROWSER_COMPOSITOR_BROWSER_COMPOSITOR_VIEW_PRIVATE_MAC_H_