content/browser/renderer_host/begin_frame_observer_proxy.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CONTENT_BROWSER_RENDERER_HOST_BEGIN_FRAME_OBSERVER_PROXY_H_
   6 #define CONTENT_BROWSER_RENDERER_HOST_BEGIN_FRAME_OBSERVER_PROXY_H_
   7
   8 #include "content/common/content_export.h"
   9 #include "ui/compositor/compositor.h"
  10 #include "ui/compositor/compositor_observer.h"
  11
  12 namespace cc {
  13 struct BeginFrameArgs;
  14 }
  15
  16 namespace content {
  17
  18 // This is the interface from the BeginFrameObserverProxy which manages sending
  19 // BeginFrame messages.
  20 class BeginFrameObserverProxyClient {
  21  public:
  22   virtual void SendBeginFrame(const cc::BeginFrameArgs& args) = 0;
  23 };
  24
  25 // This class is used to manage all of the RenderWidgetHostView state and
  26 // functionality that is associated with BeginFrame message handling.
  27 class CONTENT_EXPORT BeginFrameObserverProxy
  28     : public ui::CompositorBeginFrameObserver {
  29  public:
  30   explicit BeginFrameObserverProxy(BeginFrameObserverProxyClient* client);
  31   ~BeginFrameObserverProxy() override;
  32
  33   void SetNeedsBeginFrames(bool needs_begin_frames);
  34
  35   void SetCompositor(ui::Compositor* compositor);
  36   void ResetCompositor();
  37
  38   // Overridden from ui::CompositorBeginFrameObserver:
  39   void OnSendBeginFrame(const cc::BeginFrameArgs& args) override;
  40
  41  private:
  42   void StartObservingBeginFrames();
  43   void StopObservingBeginFrames();
  44
  45   // True when RenderWidget needs a BeginFrame message.
  46   bool needs_begin_frames_;
  47
  48   // Used whether to send begin frame to client or not. When |args| from
  49   // Compositor is different from this, send to client.
  50   cc::BeginFrameArgs last_sent_begin_frame_args_;
  51
  52   BeginFrameObserverProxyClient* client_;
  53   ui::Compositor* compositor_;
  54
  55   DISALLOW_COPY_AND_ASSIGN(BeginFrameObserverProxy);
  56 };
  57
  58 }  // namespace content
  59
  60 #endif  // CONTENT_BROWSER_RENDERER_HOST_BEGIN_FRAME_OBSERVER_PROXY_H_