content/browser/frame_host/cross_process_frame_connector.h

   1 // Copyright 2014 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_FRAME_HOST_CROSS_PROCESS_FRAME_CONNECTOR_H_
   6 #define CONTENT_BROWSER_FRAME_HOST_CROSS_PROCESS_FRAME_CONNECTOR_H_
   7
   8 #include "cc/output/compositor_frame.h"
   9 #include "ui/gfx/rect.h"
  10
  11 namespace IPC {
  12 class Message;
  13 }
  14
  15 struct FrameHostMsg_BuffersSwappedACK_Params;
  16 struct GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params;
  17
  18 namespace content {
  19 class RenderFrameHostImpl;
  20 class RenderWidgetHostImpl;
  21 class RenderWidgetHostViewChildFrame;
  22
  23 // CrossProcessFrameConnector provides the platform view abstraction for
  24 // RenderWidgetHostViewChildFrame allowing RWHVChildFrame to remain ignorant
  25 // of RenderFrameHost.
  26 //
  27 // The RenderWidgetHostView of an out-of-process child frame needs to
  28 // communicate with the swapped out RenderFrameHost representing this frame
  29 // in the process of the parent frame. For example, assume you have this page:
  30 //
  31 //   -----------------
  32 //   | frame 1       |
  33 //   |  -----------  |
  34 //   |  | frame 2 |  |
  35 //   |  -----------  |
  36 //   -----------------
  37 //
  38 // If frames 1 and 2 are in process A and B, there are 4 RenderFrameHosts:
  39 //   A1 - RFH for frame 1 in process A
  40 //   B1 - Swapped out RFH for frame 1 in process B
  41 //   A2 - Swapped out RFH for frame 2 in process A
  42 //   B2 - RFH for frame 2 in process B
  43 //
  44 // B2, having a parent frame in a diferent process, will have a
  45 // RenderWidgetHostViewChildFrame. This RenderWidgetHostViewChildFrame needs
  46 // to communicate with A2 so that the painting logic in process A can
  47 // composite B2's data with A1's. CrossProcessFrameConnector bridges between
  48 // B2's RenderWidgetHostViewChildFrame and A2 to allow for this communication.
  49 // (Note: B1 is only mentioned for completeness. It is not needed in this
  50 // example.)
  51 //
  52 // CrossProcessFrameConnector objects are owned by the child frame's
  53 // RenderFrameHostManager. When a child frame swaps, SetChildFrameView() is
  54 // called to update to the new view.
  55 //
  56 // TODO(kenrb): Double-check this comment's accuracy.
  57 class CrossProcessFrameConnector {
  58  public:
  59   // |frame_proxy_in_parent_renderer| corresponds to A2 in the example above.
  60   explicit CrossProcessFrameConnector(
  61       RenderFrameHostImpl* frame_proxy_in_parent_renderer);
  62   virtual ~CrossProcessFrameConnector();
  63
  64   bool OnMessageReceived(const IPC::Message &msg);
  65
  66   // |view| corresponds to B2's RenderWidgetHostViewChildFrame in the example
  67   // above.
  68   void SetView(RenderWidgetHostViewChildFrame* view);
  69
  70   // 'Platform' functionality exposed to RenderWidgetHostViewChildFrame.
  71   // These methods can forward messages to the child frame proxy in the parent
  72   // frame renderer or attempt to handle them within the browser process.
  73   void ChildFrameBuffersSwapped(
  74       const GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params& params,
  75       int gpu_host_id);
  76
  77   void ChildFrameCompositorFrameSwapped(
  78       uint32 output_surface_id,
  79       scoped_ptr<cc::CompositorFrame> frame);
  80
  81   gfx::Rect ChildFrameRect();
  82
  83  private:
  84   // Handlers for messages received from the parent frame.
  85   void OnBuffersSwappedACK(
  86       const FrameHostMsg_BuffersSwappedACK_Params& params);
  87
  88   // The RenderFrameHost that routes messages to the parent frame's renderer
  89   // process.
  90   // TODO(kenrb): The type becomes RenderFrameProxyHost when that class comes
  91   // to exist.
  92   RenderFrameHostImpl* frame_proxy_in_parent_renderer_;
  93
  94   // The RenderWidgetHostView for the frame. Initially NULL.
  95   RenderWidgetHostViewChildFrame* view_;
  96
  97   gfx::Rect child_frame_rect_;
  98 };
  99
 100 }  // namespace content
 101
 102 #endif  // CONTENT_BROWSER_FRAME_HOST_CROSS_PROCESS_FRAME_CONNECTOR_H_
 103