Implementation of MediaCodecPlayer stage 1

media/base/android/media_codec_player_state.h

+// Copyright 2015 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_BASE_ANDROID_MEDIA_CODEC_PLAYER_STATE_H_
+#define MEDIA_BASE_ANDROID_MEDIA_CODEC_PLAYER_STATE_H_
+
+#include "base/macros.h"
+#include "media/base/android/demuxer_android.h"
+#include "ui/gl/android/scoped_java_surface.h"
+
+#define DEFINE_INSTANCE(TypeName)                 \
+ public:                                          \
+  static TypeName * Instance() {                  \
+    static TypeName singleton; return &singleton; \
+  }                                               \
+  const char* name() override {                   \
+    return #TypeName ;                            \
+  }                                               \
+ private:                                         \
+   TypeName() {}                                  \
+   DISALLOW_COPY_AND_ASSIGN(TypeName);
+
+
+namespace media {
+
+/*
+
+       --------------------------> Paused
+       |  StopDone:
+       |                            ^  |
+       |                            |  |
+       |                    Pause:  |  |  Start: dec.Prefetch
+       |                            |  |
+       |                            |  |
+       |                            |  |
+       |                            |  v          PrefetchDone,
+       |                                           no surface:
+       |   ------------------>   Prefetching   -------------->     Waiting
+       |   |                                                     for surface
+       |   |                          |                             /
+       |   |                          |                            /
+       |   | StopDone w/              |                           /
+       |   | pending start:           | PrefetchDone:            /
+       |   |    dec.Prefetch          |   dec.Start             /
+       |   |                          |                        / SetSurface:
+       |   |                          |                       /     dec.Start
+       |   |                          |                      /
+       |   |                          v                     /
+       |   |                                               /
+       |   |                        Playing    <----------/
+       |   |
+       |   |                          |
+       |   |                          |
+       |   |                          | Pause: dec.RequestToStop
+       |   |                          |
+       |   |                          |
+       |   |                          v
+       |   |
+       --------------------------  Stopping
+
+ */
+
+// Implementaton of the State pattern:
+//
+// PlayerState is an abstract state that has virtual methods for
+// every possible event. Normally these methods do nothing.
+//
+// Concrete states (StatePaused, StatePlaying etc.) inherit from this
+// PlayerState and implement the event handlers for the events expected
+// to these states. If an event handler is omitted in a concrete state,
+// the PlayerState method is called which usually means empty implementation
+// and the event is ignored.
+
+class MediaCodecPlayer;
+
+class MediaCodecPlayerState {
+ public:
+  virtual const char* name() = 0;
+  virtual void EventRemoveVideoSurface(MediaCodecPlayer* player) {}
+  virtual void EventSetVideoSurface(MediaCodecPlayer* player) {}
+  virtual void EventStart(MediaCodecPlayer* player) {}
+  virtual void EventPause(MediaCodecPlayer* player) {}
+  virtual void EventSeekTo(MediaCodecPlayer* player,
+                           base::TimeDelta timestamp) {}
+  virtual void EventDemuxerConfigsAvailable(MediaCodecPlayer* player,
+                                            const DemuxerConfigs& params);
+  virtual void EventDemuxerSeekDone(MediaCodecPlayer* player) {}
+  virtual void EventPrefetchDone(MediaCodecPlayer* player) {}
+  virtual void EventStopDone(MediaCodecPlayer* player) {}
+  virtual void EventStarvation(MediaCodecPlayer* player) {}
+  virtual void EventRelease(MediaCodecPlayer* player);
+  virtual void EventError(MediaCodecPlayer* player);
+};
+
+class StatePaused : public MediaCodecPlayerState {
+  DEFINE_INSTANCE(StatePaused);
+ public:
+  void EventStart(MediaCodecPlayer* player) override;
+};
+
+class StatePrefetching : public MediaCodecPlayerState {
+  DEFINE_INSTANCE(StatePrefetching);
+ public:
+  void EventPause(MediaCodecPlayer* player) override;
+  void EventPrefetchDone(MediaCodecPlayer* player) override;
+};
+
+class StateWaitingForConfig : public MediaCodecPlayerState {
+  DEFINE_INSTANCE(StateWaitingForConfig);
+ public:
+  void EventDemuxerConfigsAvailable(MediaCodecPlayer* player,
+                                    const DemuxerConfigs& params) override;
+  void EventPause(MediaCodecPlayer* player) override;
+};
+
+class StateWaitingForSurface : public MediaCodecPlayerState {
+  DEFINE_INSTANCE(StateWaitingForSurface);
+ public:
+  void EventSetVideoSurface(MediaCodecPlayer* player) override;
+  void EventPause(MediaCodecPlayer* player) override;
+};
+
+class StatePlaying : public MediaCodecPlayerState {
+  DEFINE_INSTANCE(StatePlaying);
+ public:
+  void EventPause(MediaCodecPlayer* player) override;
+  void EventStarvation(MediaCodecPlayer* player) override;
+  void EventStopDone(MediaCodecPlayer* player) override;
+  void EventError(MediaCodecPlayer* player) override;
+};
+
+class StateStopping : public MediaCodecPlayerState {
+  DEFINE_INSTANCE(StateStopping);
+ public:
+  void EventStart(MediaCodecPlayer* player) override;
+  void EventStopDone(MediaCodecPlayer* player) override;
+};
+
+class StateWaitingForSeek : public MediaCodecPlayerState {
+  DEFINE_INSTANCE(StateWaitingForSeek);
+ public:
+};
+
+class StateError : public MediaCodecPlayerState {
+  DEFINE_INSTANCE(StateError);
+ public:
+};
+
+}  // namespace media
+
+#endif // MEDIA_BASE_ANDROID_MEDIA_CODEC_PLAYER_STATE_H_