synchronous_compositor.h revision 5d1f7b1de12d16ceb2c938c56701a3e8bfa558f7 
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 "base/memory/ref_counted.h"
9#include "content/common/content_export.h"
10#include "gpu/command_buffer/service/in_process_command_buffer.h"
11#include "ui/gfx/rect.h"
12#include "ui/gfx/size.h"
13
14class SkCanvas;
15
16namespace gfx {
17class GLSurface;
18class Transform;
19};
20
21namespace content {
22
23class WebContents;
24
25class SynchronousCompositorClient;
26
27struct CONTENT_EXPORT SynchronousCompositorMemoryPolicy {
28  // Memory limit for rendering and pre-rendering.
29  size_t bytes_limit;
30
31  // Limit of number of GL resources used for rendering and pre-rendering.
32  size_t num_resources_limit;
33
34  SynchronousCompositorMemoryPolicy();
35
36  bool operator==(const SynchronousCompositorMemoryPolicy& other) const;
37  bool operator!=(const SynchronousCompositorMemoryPolicy& other) const;
38};
39
40// Interface for embedders that wish to direct compositing operations
41// synchronously under their own control. Only meaningful when the
42// kEnableSyncrhonousRendererCompositor flag is specified.
43class CONTENT_EXPORT SynchronousCompositor {
44 public:
45  // Must be called once per WebContents instance. Will create the compositor
46  // instance as needed, but only if |client| is non-NULL.
47  static void SetClientForWebContents(WebContents* contents,
48                                      SynchronousCompositorClient* client);
49
50  // Allows changing or resetting the client to NULL (this must be used if
51  // the client is being deleted prior to the DidDestroyCompositor() call
52  // being received by the client). Ownership of |client| remains with
53  // the caller.
54  virtual void SetClient(SynchronousCompositorClient* client) = 0;
55
56  static void SetGpuService(
57      scoped_refptr<gpu::InProcessCommandBuffer::Service> service);
58
59  // Synchronously initialize compositor for hardware draw. Can only be called
60  // while compositor is in software only mode, either after compositor is
61  // first created or after ReleaseHwDraw is called. It is invalid to
62  // DemandDrawHw before this returns true. |surface| is the GLSurface that
63  // should be used to create the underlying hardware context.
64  virtual bool InitializeHwDraw(scoped_refptr<gfx::GLSurface> surface) = 0;
65
66  // Reverse of InitializeHwDraw above. Can only be called while hardware draw
67  // is already initialized. Brings compositor back to software only mode and
68  // releases all hardware resources.
69  virtual void ReleaseHwDraw() = 0;
70
71  // "On demand" hardware draw. The content is first clipped to |damage_area|,
72  // then transformed through |transform|, and finally clipped to |view_size|
73  // and by the existing stencil buffer if any.
74  virtual bool DemandDrawHw(
75      gfx::Size surface_size,
76      const gfx::Transform& transform,
77      gfx::Rect viewport,
78      gfx::Rect clip,
79      bool stencil_enabled) = 0;
80
81  // "On demand" SW draw, into the supplied canvas (observing the transform
82  // and clip set there-in).
83  virtual bool DemandDrawSw(SkCanvas* canvas) = 0;
84
85  // Set the memory limit policy of this compositor.
86  virtual void SetMemoryPolicy(
87      const SynchronousCompositorMemoryPolicy& policy) = 0;
88
89  // Should be called by the embedder after the embedder had modified the
90  // scroll offset of the root layer (as returned by
91  // SynchronousCompositorClient::GetTotalRootLayerScrollOffset).
92  virtual void DidChangeRootLayerScrollOffset() = 0;
93
94 protected:
95  virtual ~SynchronousCompositor() {}
96};
97
98}  // namespace content
99
100#endif  // CONTENT_PUBLIC_BROWSER_ANDROID_SYNCHRONOUS_COMPOSITOR_H_
101