Monitor the intersection of video and viewport.

media/remoting/remoting_controller.h

 // 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.
 
 #ifndef MEDIA_REMOTING_REMOTING_CONTROLLER_H_
 #define MEDIA_REMOTING_REMOTING_CONTROLLER_H_
 
 #include "base/callback.h"
 #include "base/memory/weak_ptr.h"
+#include "base/timer/timer.h"
 #include "media/base/media_observer.h"
 #include "media/mojo/interfaces/remoting.mojom.h"
 #include "mojo/public/cpp/bindings/binding.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 }
 
 // This class does the following:
 // 1) Sends/Receives messages from/to Remoter;
@@ skipping 25 matching lines @@
 
   // RemotingSource implementations.
   void OnSinkAvailable() override;
   void OnSinkGone() override;
   void OnStarted() override;
   void OnStartFailed(mojom::RemotingStartFailReason reason) override;
   void OnMessageFromSink(const std::vector<uint8_t>& message) override;
   void OnStopped(mojom::RemotingStopReason reason) override;
 
   // MediaObserver implementations.
-  // This is called when the video element or its ancestor enters full screen.
-  // We currently use this as an indicator for immersive playback. May add other
-  // criteria (e.g. the actual display width/height of the video element) in
-  // future.
   void OnEnteredFullscreen() override;
   void OnExitedFullscreen() override;
+  void OnVideoViewportIntersectionChanged(
+      const ViewportIntersectionInfo& info) override;
   void OnSetCdm(CdmContext* cdm_context) override;
   void OnMetadataChanged(const PipelineMetadata& metadata) override;
 
   using SwitchRendererCallback = base::Callback<void()>;
   void SetSwitchRendererCallback(const SwitchRendererCallback& cb);
 
   // Tells which renderer should be used.
   bool is_remoting() const {
     DCHECK(task_runner_->BelongsToCurrentThread());
     return is_remoting_;
@@ skipping 12 matching lines @@
   // Helper to decide whether to enter or leave Remoting mode.
   bool ShouldBeRemoting();
 
   // Determines whether to enter or leave Remoting mode and switches if
   // necessary.
   void UpdateAndMaybeSwitch();
 
   // Callback from RpcBroker when sending message to remote sink.
   void OnSendMessageToSink(std::unique_ptr<std::vector<uint8_t>> message);
 
+  // Callback from |viewport_fill_debouncer_timer_| when video keeps covering
+  // most of the viewport for a certain time.
+  void OnViewportMostlyFilledAndUnchanging();
+
   // Handle incomging and outgoing RPC message.
   std::unique_ptr<remoting::RpcBroker> rpc_broker_;
 
   // Indicates if this media element or its ancestor enters full screen.
   bool is_fullscreen_ = false;
 
   // Indicates the remoting sink availablity.
   bool is_sink_available_ = false;
 
   // Indicates if remoting is started.
   bool is_remoting_ = false;
 
   // Indicates whether audio or video is encrypted.
   bool is_encrypted_ = false;
 
   // Current audio/video config.
   VideoDecoderConfig video_decoder_config_;
   AudioDecoderConfig audio_decoder_config_;
   bool has_audio_ = false;
   bool has_video_ = false;
 
+  // Indicates whether video covers most of the viewport.
+  bool is_mostly_filling_viewport_ = false;
+  // Video/Viewport ratio meeting/exceeding the threshold should hold steady for
+  // a certain time before attempting to start remoting.
+  base::OneShotTimer viewport_fill_debouncer_timer_;
+
   // The callback to switch the media renderer.
   SwitchRendererCallback switch_renderer_cb_;
 
   mojo::Binding<mojom::RemotingSource> binding_;
   mojom::RemoterPtr remoter_;
 
   // TODO(xjz): Add a media thread task runner for the received RPC messages for
   // remoting media renderer in the up-coming change.
   const scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   base::WeakPtrFactory<RemotingController> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RemotingController);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_REMOTING_REMOTING_CONTROLLER_H_