synchronous_compositor.h revision fb250657ef40d7500f20882d5c9909c1013367d3 
1// Copyright 2013 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_PUBLIC_BROWSER_ANDROID_SYNCHRONOUS_COMPOSITOR_H_
6#define CONTENT_PUBLIC_BROWSER_ANDROID_SYNCHRONOUS_COMPOSITOR_H_
7
8#include "content/common/content_export.h"
9#include "ui/gfx/rect.h"
10#include "ui/gfx/size.h"
11
12class SkCanvas;
13
14namespace gfx {
15class Transform;
16};
17
18namespace content {
19
20class WebContents;
21
22class SynchronousCompositorClient;
23
24// Interface for embedders that wish to direct compositing operations
25// synchronously under their own control. Only meaningful when the
26// kEnableSyncrhonousRendererCompositor flag is specified.
27class CONTENT_EXPORT SynchronousCompositor {
28 public:
29  // Must be called once per WebContents instance. Will create the compositor
30  // instance as needed, but only if |client| is non-NULL.
31  static void SetClientForWebContents(WebContents* contents,
32                                      SynchronousCompositorClient* client);
33
34  // Allows changing or resetting the client to NULL (this must be used if
35  // the client is being deleted prior to the DidDestroyCompositor() call
36  // being received by the client). Ownership of |client| remains with
37  // the caller.
38  virtual void SetClient(SynchronousCompositorClient* client) = 0;
39
40  // Synchronously initialize compositor for hardware draw. Can only be called
41  // while compositor is in software only mode, either after compositor is
42  // first created or after ReleaseHwDraw is called. It is invalid to
43  // DemandDrawHw before this returns true.
44  virtual bool InitializeHwDraw() = 0;
45
46  // Reverse of InitializeHwDraw above. Can only be called while hardware draw
47  // is already initialized. Brings compositor back to software only mode and
48  // releases all hardware resources.
49  virtual void ReleaseHwDraw() = 0;
50
51  // "On demand" hardware draw. The content is first clipped to |damage_area|,
52  // then transformed through |transform|, and finally clipped to |view_size|
53  // and by the existing stencil buffer if any.
54  virtual bool DemandDrawHw(
55      gfx::Size view_size,
56      const gfx::Transform& transform,
57      gfx::Rect damage_area,
58      bool stencil_enabled) = 0;
59
60  // "On demand" SW draw, into the supplied canvas (observing the transform
61  // and clip set there-in).
62  virtual bool DemandDrawSw(SkCanvas* canvas) = 0;
63
64  // Should be called by the embedder after the embedder had modified the
65  // scroll offset of the root layer (as returned by
66  // SynchronousCompositorClient::GetTotalRootLayerScrollOffset).
67  virtual void DidChangeRootLayerScrollOffset() = 0;
68
69 protected:
70  virtual ~SynchronousCompositor() {}
71};
72
73}  // namespace content
74
75#endif  // CONTENT_PUBLIC_BROWSER_ANDROID_SYNCHRONOUS_COMPOSITOR_H_
76