content/browser/renderer_host/begin_frame_observer_proxy.cc

   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 #include "content/browser/renderer_host/begin_frame_observer_proxy.h"
   6
   7 namespace content {
   8
   9 BeginFrameObserverProxy::BeginFrameObserverProxy(
  10     BeginFrameObserverProxyClient* client)
  11     : needs_begin_frames_(false),
  12       client_(client),
  13       compositor_(nullptr) {
  14 }
  15
  16 BeginFrameObserverProxy::~BeginFrameObserverProxy() {
  17   DCHECK(!compositor_);
  18 }
  19
  20 void BeginFrameObserverProxy::SetNeedsBeginFrames(bool needs_begin_frames) {
  21   if (needs_begin_frames_ == needs_begin_frames)
  22     return;
  23
  24   needs_begin_frames_ = needs_begin_frames;
  25
  26   // In some cases, BeginFrame message is requested before |client_|'s window is
  27   // added in the root window hierarchy.
  28   if (!compositor_)
  29     return;
  30
  31   if (needs_begin_frames)
  32     StartObservingBeginFrames();
  33   else
  34     StopObservingBeginFrames();
  35 }
  36
  37 void BeginFrameObserverProxy::SetCompositor(ui::Compositor* compositor) {
  38   DCHECK(!compositor_);
  39   DCHECK(compositor);
  40
  41   compositor_ = compositor;
  42   compositor_->AddObserver(this);
  43   if (needs_begin_frames_)
  44     StartObservingBeginFrames();
  45 }
  46
  47 void BeginFrameObserverProxy::ResetCompositor() {
  48   if (!compositor_)
  49     return;
  50   compositor_->RemoveObserver(this);
  51
  52   if (needs_begin_frames_)
  53     StopObservingBeginFrames();
  54   compositor_ = nullptr;
  55 }
  56
  57 void BeginFrameObserverProxy::OnSendBeginFrame(const cc::BeginFrameArgs& args) {
  58   if (last_sent_begin_frame_args_.frame_time != args.frame_time)
  59     client_->SendBeginFrame(args);
  60   last_sent_begin_frame_args_ = args;
  61 }
  62
  63 void BeginFrameObserverProxy::OnCompositingShuttingDown(
  64     ui::Compositor* compositor) {
  65   ResetCompositor();
  66 }
  67
  68 void BeginFrameObserverProxy::StartObservingBeginFrames() {
  69   DCHECK(compositor_);
  70   compositor_->AddBeginFrameObserver(this);
  71 }
  72
  73 void BeginFrameObserverProxy::StopObservingBeginFrames() {
  74   DCHECK(compositor_);
  75   compositor_->RemoveBeginFrameObserver(this);
  76 }
  77
  78 }  // namespace content