ui/gfx/vsync_provider.h

   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 UI_GFX_VSYNC_PROVIDER_H_
   6 #define UI_GFX_VSYNC_PROVIDER_H_
   7
   8 #include "base/callback.h"
   9 #include "base/time/time.h"
  10 #include "ui/gfx/gfx_export.h"
  11
  12 namespace gfx {
  13
  14 class GFX_EXPORT VSyncProvider {
  15  public:
  16   virtual ~VSyncProvider() {}
  17
  18   typedef base::Callback<
  19       void(const base::TimeTicks timebase, const base::TimeDelta interval)>
  20       UpdateVSyncCallback;
  21
  22   // Get the time of the most recent screen refresh, along with the time
  23   // between consecutive refreshes. The callback is called as soon as
  24   // the data is available: it could be immediately from this method,
  25   // later via a PostTask to the current MessageLoop, or never (if we have
  26   // no data source). We provide the strong guarantee that the callback will
  27   // not be called once the instance of this class is destroyed.
  28   virtual void GetVSyncParameters(const UpdateVSyncCallback& callback) = 0;
  29 };
  30
  31 }  // namespace gfx
  32
  33 #endif  // UI_GFX_VSYNC_PROVIDER_H_