Bug 1353652 - Initial Draft of MPRIS API Provider (Media API on Linux) r=alwu

Differential Revision: https://phabricator.services.mozilla.com/D47999

--HG--
extra : moz-landing-system : lando

.clang-format-ignore

@@ -59,6 +59,9 @@ tools/clang-tidy/test/.*
 # We are testing the incorrect formatting.
 tools/lint/test/files/file-whitespace/
 
+# Contains an XML definition and formatting would break the layout
+widget/gtk/MPRISInterfaceDescription.h
+
 # The XPTCall stubs files have some inline assembly macros
 # that get reformatted badly. See bug 1510781.
 xpcom/reflect/xptcall/md/win32/.*

widget/gtk/MPRISInterfaceDescription.h

+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef WIDGET_GTK_MPRIS_INTERFACE_DESCRIPTION_H_
+#define WIDGET_GTK_MPRIS_INTERFACE_DESCRIPTION_H_
+
+#include <gio/gio.h>
+
+extern const gchar introspection_xml[] =
+    // adopted from https://github.com/freedesktop/mpris-spec/blob/master/spec/org.mpris.MediaPlayer2.xml
+    // everything starting with tp can be removed, as it is used for HTML Spec Documentation Generation
+    "<node>"
+        "<interface name=\"org.mpris.MediaPlayer2\">"
+            "<annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"true\"/>"
+            "<method name=\"Raise\"/>"
+            "<method name=\"Quit\"/>"
+            "<property name=\"CanQuit\" type=\"b\" access=\"read\"/>"
+        #ifdef MPRIS_FULLSCREEN
+            "<property name=\"Fullscreen\" type=\"b\" access=\"readwrite\">"
+                "<annotation name=\"org.mpris.MediaPlayer2.property.optional\" value=\"true\"/>"
+            "</property>"
+            "<property name=\"CanSetFullscreen\" type=\"b\" access=\"read\">"
+                "<annotation name=\"org.mpris.MediaPlayer2.property.optional\" value=\"true\"/>"
+            "</property>"
+        #endif
+            "<property name=\"CanRaise\" type=\"b\" access=\"read\"/>"
+            "<property name=\"HasTrackList\" type=\"b\" access=\"read\"/>"
+            "<property name=\"Identity\" type=\"s\" access=\"read\"/>"
+        #ifdef MPRIS_DESKTOP_ENTRY
+            "<property name=\"DesktopEntry\" type=\"s\" access=\"read\">"
+                "<annotation name=\"org.mpris.MediaPlayer2.property.optional\" value=\"true\"/>"
+            "</property>"
+        #endif
+            "<property name=\"SupportedUriSchemes\" type=\"as\" access=\"read\"/>"
+            "<property name=\"SupportedMimeTypes\" type=\"as\" access=\"read\"/>"
+        "</interface>"
+            // Note that every property emits a changed signal (which is default) apart from Position.
+        "<interface name=\"org.mpris.MediaPlayer2.Player\">"
+            "<method name=\"Next\"/>"
+            "<method name=\"Previous\"/>"
+            "<method name=\"Pause\"/>"
+            "<method name=\"PlayPause\"/>"
+            "<method name=\"Stop\"/>"
+            "<method name=\"Play\"/>"
+            "<method name=\"Seek\">"
+                "<arg direction=\"in\" type=\"x\" name=\"Offset\"/>"
+            "</method>"
+            "<method name=\"SetPosition\">"
+                "<arg direction=\"in\" type=\"o\" name=\"TrackId\"/>"
+                "<arg direction=\"in\" type=\"x\" name=\"Position\"/>"
+            "</method>"
+            "<method name=\"OpenUri\">"
+                "<arg direction=\"in\" type=\"s\" name=\"Uri\"/>"
+            "</method>"
+            "<property name=\"PlaybackStatus\" type=\"s\" access=\"read\">"
+                "<annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"true\"/>"
+            "</property>"
+        #ifdef MPRIS_LOOP_STATUS
+            "<property name=\"LoopStatus\" type=\"s\" access=\"readwrite\">"
+                "<annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"true\"/>"
+                "<annotation name=\"org.mpris.MediaPlayer2.property.optional\" value=\"true\"/>"
+            "</property>"
+        #endif
+            "<property name=\"Rate\" type=\"d\" access=\"readwrite\">"
+                "<annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"true\"/>"
+            "</property>"
+        #ifdef MRPIS_SHUFFLE
+            "<property name=\"Shuffle\" type=\"b\" access=\"readwrite\">"
+                "<annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"true\"/>"
+                "<annotation name=\"org.mpris.MediaPlayer2.property.optional\" value=\"true\"/>"
+            "</property>"
+        #endif
+            "<property name=\"Metadata\" type=\"a{sv}\" access=\"read\">"
+                "<annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"true\"/>"
+            "</property>"
+            "<property name=\"Volume\" type=\"d\" access=\"readwrite\">"
+                "<annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"true\"/>"
+            "</property>"
+            "<property name=\"Position\" type=\"x\" access=\"read\">"
+                "<annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"false\"/>"
+            "</property>"
+            "<property name=\"MinimumRate\" type=\"d\" access=\"read\">"
+                "<annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"true\"/>"
+            "</property>"
+            "<property name=\"MaximumRate\" type=\"d\" access=\"read\">"
+                "<annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"true\"/>"
+            "</property>"
+            "<property name=\"CanGoNext\" type=\"b\" access=\"read\">"
+                "<annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"true\"/>"
+            "</property>"
+            "<property name=\"CanGoPrevious\" type=\"b\" access=\"read\">"
+                "<annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"true\"/>"
+            "</property>"
+            "<property name=\"CanPlay\" type=\"b\" access=\"read\">"
+                "<annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"true\"/>"
+            "</property>"
+            "<property name=\"CanPause\" type=\"b\" access=\"read\">"
+                "<annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"true\"/>"
+            "</property>"
+            "<property name=\"CanSeek\" type=\"b\" access=\"read\">"
+                "<annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"true\"/>"
+            "</property>"
+            "<property name=\"CanControl\" type=\"b\" access=\"read\">"
+                "<annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"false\"/>"
+            "</property>"
+            "<signal name=\"Seeked\">"
+                "<arg name=\"Position\" type=\"x\"/>"
+            "</signal>"
+        "</interface>"
+    "</node>";
+
+#endif  // WIDGET_GTK_MPRIS_INTERFACE_DESCRIPTION_H_

widget/gtk/MPRISServiceHandler.h

+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef WIDGET_GTK_MPRIS_SERVICE_HANDLER_H_
+#define WIDGET_GTK_MPRIS_SERVICE_HANDLER_H_
+
+#include <gio/gio.h>
+#include "mozilla/dom/MediaControlKeysEvent.h"
+#include "mozilla/Attributes.h"
+
+#define DBUS_MRPIS_SERVICE_NAME "org.mpris.MediaPlayer2.firefox"
+#define DBUS_MPRIS_OBJECT_PATH "/org/mpris/MediaPlayer2"
+
+namespace mozilla {
+namespace widget {
+
+struct MPRISMetadata {
+  const char* mKey;
+  GVariant* mValue;
+};
+
+/**
+ * This class implements the "MPRIS" D-Bus Service
+ * (https://specifications.freedesktop.org/mpris-spec/2.2),
+ * which is used to communicate with the Desktop Environment about the
+ * Multimedia playing in Gecko.
+ * Note that this interface requires many methods which may not be supported by
+ * Gecko, the interface
+ * however provides CanXYZ properties for these methods, so the method is
+ * defined but won't be executed.
+ *
+ * Also note that the following defines are for parts that the MPRIS Spec
+ * defines optional. The code won't
+ * compile with any of the defines set, yet, as those aren't implemented yet and
+ * probably never will be of
+ * use for gecko. For sake of completeness, they have been added until the
+ * decision about their implementation
+ * is finally made.
+ *
+ * The constexpr'ed methods are capabilities of the user agent known at compile
+ * time, e.g. we decided at
+ * compile time whether we ever want to support closing the user agent via MPRIS
+ * (Quit() and CanQuit()).
+ *
+ * Other properties like CanPlay() might depend on the runtime state (is there
+ * media available for playback?)
+ * and thus aren't a constexpr but merely a const method.
+ */
+class MPRISServiceHandler final : public dom::MediaControlKeysEventSource {
+  NS_INLINE_DECL_REFCOUNTING(MPRISServiceHandler, override)
+ public:
+  // Note that this constructor does NOT initialize the MPRIS Service but only
+  // this class. The method Open() is responsible for registering and MAY FAIL.
+  MPRISServiceHandler() = default;
+  bool Open() override;
+  void Close() override;
+  bool IsOpened() const override;
+
+  // From the EventSource.
+  void SetPlaybackState(dom::PlaybackState aState) override;
+
+  // GetPlaybackState returns dom::PlaybackState. GetPlaybackStatus returns this
+  // state converted into d-bus variants.
+  GVariant* GetPlaybackStatus() const;
+
+// Implementations of the MPRIS API Methods/Properties. constexpr'ed properties
+// will be what the user agent doesn't support and thus they are known at
+// compile time.
+#ifdef MPRIS_FULLSCREEN
+  bool GetFullscreen();
+  void SetFullscreen(bool aFullscreen);
+  bool CanSetFullscreen();
+#endif
+  bool HasTrackList();
+  const char* Identity();
+#ifdef MPRIS_DESKTOP_ENTRY
+  const char* DesktopEntry();
+#endif
+  GVariant* SupportedUriSchemes();
+  GVariant* SupportedMimeTypes();
+  constexpr bool CanRaise();
+  void Raise();
+  constexpr bool CanQuit();
+  void Quit();
+
+  // :Player::Methods
+  void Next();
+  void Previous();
+  void Pause();
+  void PlayPause();
+  void Stop();
+  void Play();
+  void Seek(int64_t aOffset);
+  void SetPosition(char* aTrackId, int64_t aPosition);
+  // bool is our custom addition: return false whether opening fails/is not
+  // supported for that URI it will raise a DBUS Error
+  bool OpenUri(char* aUri);
+
+#ifdef MPRIS_LOOP_STATUS
+  MPRISLoopStatus GetLoopStatus();
+#endif
+
+  double GetRate() const;
+  bool SetRate(double aRate);
+  constexpr double GetMinimumRate();
+  constexpr double GetMaximumRate();
+
+#ifdef MPRIS_SHUFFLE
+  bool GetShuffle() const;
+  void SetShuffle(bool aShuffle);
+#endif
+
+  std::vector<struct MPRISMetadata> GetDefaultMetadata();
+  double GetVolume() const;
+  bool SetVolume(double aVolume);
+  int64_t GetPosition() const;
+
+  bool CanGoNext() const;
+  bool CanGoPrevious() const;
+  bool CanPlay() const;
+  bool CanPause() const;
+  bool CanSeek() const;
+  bool CanControl() const;
+
+ private:
+  ~MPRISServiceHandler();
+
+  // Note: Registration Ids for the D-Bus start with 1, so a value of 0
+  // indicates an error (or an object which wasn't initialized yet)
+
+  // a handle to our bus registration/ownership
+  guint mOwnerId = 0;
+  // This is for the interface org.mpris.MediaPlayer2
+  guint mRootRegistrationId = 0;
+  // This is for the interface org.mpris.MediaPlayer2.Player
+  guint mPlayerRegistrationId = 0;
+  GDBusNodeInfo* mIntrospectionData = nullptr;
+  GDBusConnection* mConnection = nullptr;
+  bool mInitialized = false;
+
+  // non-public API, called from events
+  void OnNameAcquired(GDBusConnection* aConnection, const gchar* aName);
+  void OnNameLost(GDBusConnection* aConnection, const gchar* aName);
+  void OnBusAcquired(GDBusConnection* aConnection, const gchar* aName);
+
+  static void OnNameAcquiredStatic(GDBusConnection* aConnection,
+                                   const gchar* aName, gpointer aUserData);
+  static void OnNameLostStatic(GDBusConnection* aConnection, const gchar* aName,
+                               gpointer aUserData);
+  static void OnBusAcquiredStatic(GDBusConnection* aConnection,
+                                  const gchar* aName, gpointer aUserData);
+
+  void EmitEvent(mozilla::dom::MediaControlKeysEvent event);
+};
+
+}  // namespace widget
+}  // namespace mozilla
+
+#endif  // WIDGET_GTK_MPRIS_SERVICE_HANDLER_H_

widget/gtk/MediaKeysEventSourceFactory.cpp

@@ -3,12 +3,12 @@
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "MediaKeysEventSourceFactory.h"
+#include "MPRISServiceHandler.h"
 
 namespace mozilla::widget {
 
 mozilla::dom::MediaControlKeysEventSource* CreateMediaControlKeysEventSource() {
-  // TODO : will implement this in bug 1353652.
-  return nullptr;
+  return new MPRISServiceHandler();
 }
 
 }  // namespace mozilla::widget

widget/gtk/moz.build

@@ -32,6 +32,7 @@ EXPORTS.mozilla += [
 UNIFIED_SOURCES += [
     'IMContextWrapper.cpp',
     'mozcontainer.cpp',
+    'MPRISServiceHandler.cpp',
     'NativeKeyBindings.cpp',
     'nsAppShell.cpp',
     'nsBidiKeyboard.cpp',