[Android] A prototype of the interactive media notification.

content/browser/media/android/media_session.cc

 // 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.
 
 #include "content/browser/media/android/media_session.h"
 
 #include "base/android/jni_android.h"
 #include "content/browser/media/android/media_session_observer.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_contents_delegate.h"
 #include "jni/MediaSession_jni.h"
 
+

[mlamouri (slow - plz ping), 2015/06/18 16:43:22]

nit: remove empty line

[mlamouri (slow - plz ping), 2015/06/22 14:34:17]

double nit: you didn't do it.

[whywhat, 2015/06/23 19:39:10]

Do you check the diff that you commented on? :)

 namespace content {
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(MediaSession);
 
 MediaSession::PlayerIdentifier::PlayerIdentifier(MediaSessionObserver* observer,
                                                  int player_id)
     : observer(observer),
       player_id(player_id) {
 }
 
@@ skipping 40 matching lines @@
   // to request audio focus again.
   if (audio_focus_state_ == State::Active &&
       (audio_focus_type_ == Type::Content || audio_focus_type_ == type)) {
     players_.insert(PlayerIdentifier(observer, player_id));
     return true;
   }
 
   State old_audio_focus_state = audio_focus_state_;
   audio_focus_state_ = RequestSystemAudioFocus(type) ? State::Active
                                                      : State::Suspended;
+  Type old_audio_focus_type = audio_focus_type_;
   audio_focus_type_ = type;
 
   if (audio_focus_state_ != State::Active)
     return false;
 
   // The session should be reset if a player is starting while all players are
   // suspended.
-  if (old_audio_focus_state != State::Active)
+  if (old_audio_focus_state != State::Active) {
+    // Hide the controls if the type switched from Content to Transient.
+    if (audio_focus_type_ == Type::Transient)
+      HideMediaControlsIfNeeded(old_audio_focus_type);
     players_.clear();
+  }
 
   players_.insert(PlayerIdentifier(observer, player_id));
+  ShowMediaControlsIfNeeded(audio_focus_type_);
 
   return true;
 }
 
 void MediaSession::RemovePlayer(MediaSessionObserver* observer,
                                 int player_id) {
   auto it = players_.find(PlayerIdentifier(observer, player_id));
   if (it != players_.end())
     players_.erase(it);
 
   AbandonSystemAudioFocusIfNeeded();
 }
 
 void MediaSession::RemovePlayers(MediaSessionObserver* observer) {
   for (auto it = players_.begin(); it != players_.end();) {
     if (it->observer == observer)
       players_.erase(it++);
     else
       ++it;
   }
 
   AbandonSystemAudioFocusIfNeeded();
 }
 
 void MediaSession::OnSuspend(JNIEnv* env, jobject obj, jboolean temporary) {
   OnSuspend(temporary);
+
+  if (temporary) {
+    // Reflect the paused state on the media controls.
+    ShowMediaControlsIfNeeded(audio_focus_type_);
+  } else {
+    HideMediaControlsIfNeeded(audio_focus_type_);
+  }

[mlamouri (slow - plz ping), 2015/06/18 16:43:22]

Shouldn't that be in the ::OnSuspend(bool) method?

[whywhat, 2015/06/19 16:00:34]

OnSuspend(bool) is called from the controls so it seems strange - the controls
would update the session and the session would update the controls in response.

[mlamouri (slow - plz ping), 2015/06/22 14:34:17]

Hmm, I see. Could you rename OnSuspend() to OnSuspendInternal() then? The intent
was that one method would bridge to the other, this is no longer the case so we
should avoid confusion with the name.

[whywhat, 2015/06/23 19:39:10]

Ok.

On 2015/06/22 at 14:34:17, Mounir Lamouri wrote:

 }
 
 void MediaSession::OnResume(JNIEnv* env, jobject obj) {
   OnResume();
+  ShowMediaControlsIfNeeded(audio_focus_type_);

[mlamouri (slow - plz ping), 2015/06/18 16:43:22]

ditto

[whywhat, 2015/06/19 16:00:34]

ditto

+}
+
+void MediaSession::OnControlsPause() {
+  DCHECK(!IsPaused());
+
+  // Since the playback can be resumed, it's a transient suspension.
+  OnSuspend(true);
+}
+
+void MediaSession::OnControlsResume() {
+  DCHECK(IsPaused());
+
+  OnResume();
+}
+
+bool MediaSession::IsPaused() {
+  return audio_focus_state_ != State::Active;
 }
 
 void MediaSession::ResetJavaRefForTest() {
   j_media_session_.Reset();
 }
 
 bool MediaSession::IsActiveForTest() const {
   return audio_focus_state_ == State::Active;
 }
 
 MediaSession::Type MediaSession::audio_focus_type_for_test() const {
   return audio_focus_type_;
 }
 
+void MediaSession::RemoveAllPlayersForTest() {
+  players_.clear();
+  AbandonSystemAudioFocusIfNeeded();
+}
+
 void MediaSession::OnSuspend(bool temporary) {
   if (temporary)
     audio_focus_state_ = State::TemporarilySuspended;
   else
     audio_focus_state_ = State::Suspended;
 
   for (const auto& it : players_)
     it.observer->OnSuspend(it.player_id);
 }
 
@@ skipping 35 matching lines @@
     return;
 
   // During tests, j_media_session_ might be null.
   if (!j_media_session_.is_null()) {
     JNIEnv* env = base::android::AttachCurrentThread();
     DCHECK(env);
     Java_MediaSession_abandonAudioFocus(env, j_media_session_.obj());
   }
 
   audio_focus_state_ = State::Suspended;
+  HideMediaControlsIfNeeded(audio_focus_type_);
+}
+
+void MediaSession::ShowMediaControlsIfNeeded(Type audio_focus_type) {
+  if (audio_focus_type == Type::Content && web_contents()->GetDelegate())
+    web_contents()->GetDelegate()->ShowMediaControls(web_contents());
+}
+
+void MediaSession::HideMediaControlsIfNeeded(Type audio_focus_type) {
+  if (audio_focus_type == Type::Content && web_contents()->GetDelegate())

[mlamouri (slow - plz ping), 2015/06/18 16:43:22]

Why do we need to check the |audio_focus_type|?

[whywhat, 2015/06/19 16:00:34]

Because we don't want to have controls for transient type and having a check
here avoids redundancy.

+    web_contents()->GetDelegate()->HideMediaControls(web_contents());
 }
 
 }  // namespace content