Bug 1631196 - Implement MPRIS Raise event by focusing the window playing media. r=alwu

Implement MPRIS Raise event by focusing the window playing media.

Differential Revision: https://phabricator.services.mozilla.com/D71450

dom/chrome-webidl/ChromeUtils.webidl

@@ -714,6 +714,7 @@ enum PopupBlockerState {
 
 // Keep this in sync with MediaControlKeysEvent in MediaControlKeysEvent.h!
 enum MediaControlKeysTestEvent {
+  "focus",
   "play",
   "pause",
   "playPause",

dom/media/mediacontrol/MediaControlKeysEvent.cpp

@@ -38,6 +38,9 @@ void MediaControlKeysHandler::OnKeyPressed(MediaControlKeysEvent aKeyEvent) {
   }
 
   switch (aKeyEvent) {
+    case MediaControlKeysEvent::eFocus:
+      controller->Focus();
+      return;
     case MediaControlKeysEvent::ePlay:
       controller->Play();
       return;

dom/media/mediacontrol/MediaControlKeysEvent.h

@@ -27,6 +27,7 @@ enum class MediaControlKeysEvent : uint32_t {
   eNextTrack,
   eSeekBackward,
   eSeekForward,
+  eFocus,
   // Keep this the last element, or you have to modify the serialized structure
   // in `MediaControlIPC.h` when you use other element as the last one.
   eStop,

dom/media/mediacontrol/MediaController.cpp

@@ -36,6 +36,12 @@ MediaController::~MediaController() {
   }
 };
 
+void MediaController::Focus() {
+  LOG("Focus");
+  UpdateMediaControlKeysEventToContentMediaIfNeeded(
+      MediaControlKeysEvent::eFocus);
+}
+
 void MediaController::Play() {
   LOG("Play");
   SetGuessedPlayState(MediaSessionPlaybackState::Playing);

dom/media/mediacontrol/MediaController.h

@@ -52,6 +52,8 @@ class MediaController final
 
   explicit MediaController(uint64_t aContextId);
 
+  // Focus the window currently playing media.
+  void Focus();
   void Play();
   void Pause();
   void Stop();

dom/media/mediacontrol/PlaybackController.cpp

@@ -7,6 +7,7 @@
 #include "MediaControlUtils.h"
 #include "mozilla/dom/MediaSession.h"
 #include "mozilla/dom/Navigator.h"
+#include "nsFocusManager.h"
 
 // avoid redefined macro in unified build
 #undef LOG
@@ -33,6 +34,14 @@ MediaSession* PlaybackController::GetMediaSession() {
                                              : nullptr;
 }
 
+void PlaybackController::Focus() {
+  // Focus is not part of the MediaSession standard, so always use the
+  // default behavior and focus the window currently playing media.
+  if (RefPtr<nsPIDOMWindowOuter> win = mBC->GetDOMWindow()) {
+    nsFocusManager::FocusWindow(win, CallerType::System);
+  }
+}
+
 void PlaybackController::Play() {
   const MediaSessionAction action = MediaSessionAction::Play;
   RefPtr<MediaSession> session = GetMediaSession();
@@ -126,6 +135,9 @@ void MediaActionHandler::HandleMediaControlKeysEvent(
     BrowsingContext* aContext, MediaControlKeysEvent aEvent) {
   PlaybackController controller(aContext);
   switch (aEvent) {
+    case MediaControlKeysEvent::eFocus:
+      controller.Focus();
+      return;
     case MediaControlKeysEvent::ePlay:
       controller.Play();
       return;

dom/media/mediacontrol/PlaybackController.h

@@ -38,6 +38,7 @@ class MOZ_STACK_CLASS PlaybackController {
   explicit PlaybackController(BrowsingContext* aContext);
   ~PlaybackController() = default;
 
+  void Focus();
   void Play();
   void Pause();
   void SeekBackward();

widget/gtk/MPRISServiceHandler.cpp

@@ -500,11 +500,7 @@ GVariant* MPRISServiceHandler::SupportedMimeTypes() {
   return g_variant_builder_end(&builder);
 }
 
-constexpr bool MPRISServiceHandler::CanRaise() { return false; }
-
-void MPRISServiceHandler::Raise() {
-  MOZ_ASSERT_UNREACHABLE("CanRaise is false, this method is not implemented");
-}
+constexpr bool MPRISServiceHandler::CanRaise() { return true; }
 
 constexpr bool MPRISServiceHandler::CanQuit() { return false; }
 
@@ -631,6 +627,11 @@ void MPRISServiceHandler::EmitEvent(mozilla::dom::MediaControlKeysEvent event) {
   }
 }
 
+void MPRISServiceHandler::Raise() {
+  LOG("Raise");
+  EmitEvent(mozilla::dom::MediaControlKeysEvent::eFocus);
+}
+
 void MPRISServiceHandler::Next() {
   LOG("Next");
   EmitEvent(mozilla::dom::MediaControlKeysEvent::eNextTrack);