Detect change on video/viewport intersection when rendered remotely

media/remoting/remoting_renderer_controller.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/remoting/remoting_renderer_controller.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/threading/thread_checker.h"
 #include "media/remoting/remoting_cdm_context.h"
@@ skipping 25 matching lines @@
   } else {
     VLOG(1) << "Failed to start remoting.";
     remote_rendering_started_ = false;
   }
 }
 
 void RemotingRendererController::OnSessionStateChanged() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   VLOG(1) << "OnSessionStateChanged: " << remoting_source_->state();
+  if (!sink_available_changed_cb_.is_null())
+    sink_available_changed_cb_.Run(IsRemoteSinkAvailable());
+
   UpdateAndMaybeSwitch();
 }
 
+bool RemotingRendererController::IsRemoteSinkAvailable() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  switch (remoting_source_->state()) {
+    case SESSION_CAN_START:
+    case SESSION_STARTING:
+    case SESSION_STARTED:
+      return true;
+    case SESSION_UNAVAILABLE:
+    case SESSION_STOPPING:
+    case SESSION_PERMANENTLY_STOPPED:
+      return false;
+  }
+}
+
 void RemotingRendererController::OnEnteredFullscreen() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   is_fullscreen_ = true;
   UpdateAndMaybeSwitch();
 }
 
 void RemotingRendererController::OnExitedFullscreen() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
@@ skipping 30 matching lines @@
 
 void RemotingRendererController::SetSwitchRendererCallback(
     const base::Closure& cb) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(!cb.is_null());
 
   switch_renderer_cb_ = cb;
   UpdateAndMaybeSwitch();
 }
 
+void RemotingRendererController::SetRemoteSinkAvailableChangedCallback(
+    const base::Callback<void(bool)>& cb) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(!cb.is_null());

[miu, 2016/12/10 02:18:37]

nit: It's probably okay for this to be a null callback, if client code ever
wants to "unset" the callback.

[xjz, 2016/12/12 18:58:45]

Done.

+
+  sink_available_changed_cb_ = cb;
+  sink_available_changed_cb_.Run(IsRemoteSinkAvailable());
+}
+
 base::WeakPtr<remoting::RpcBroker> RemotingRendererController::GetRpcBroker()
     const {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   return remoting_source_->GetRpcBroker()->GetWeakPtr();
 }
 
 void RemotingRendererController::StartDataPipe(
     std::unique_ptr<mojo::DataPipe> audio_data_pipe,
     std::unique_ptr<mojo::DataPipe> video_data_pipe,
@@ skipping 145 matching lines @@
     // and never back to the local renderer. The RemotingCdmController will
     // force-stop the session when remoting has ended; so no need to call
     // StopRemoting() from here.
     DCHECK(!is_encrypted_);
     switch_renderer_cb_.Run();
     remoting_source_->StopRemoting(this);
   }
 }
 
 }  // namespace media