mpris2: Add an Mpris2 DBus Connection

And implement the MediaPlayer2 interface on top of it.

Implements: #7 ("Add MPRIS2 Support")
Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>

.gitignore

@@ -6,3 +6,4 @@
 *.patch
 PKGBUILD
 emmental.gresource*
+emmental/mpris2/*.xml

.gitmodules

@@ -1,3 +1,6 @@
 [submodule "aur"]
 	path = aur
 	url = ssh://aur@aur.archlinux.org/emmental.git
+[submodule "mpris-spec"]
+	path = mpris-spec
+	url = https://github.com/freedesktop/mpris-spec.git

Makefile

@@ -6,11 +6,12 @@ export EMMENTAL_LIB   = ${PREFIX}/lib/emmental
 export EMMENTAL_BIN   = ${PREFIX}/bin
 export EMMENTAL_SHARE = ${PREFIX}/share
 
-all: emmental.gresource flake8
+all: emmental.gresource mpris2 flake8
 
 clean:
 	find . -type f -name "*gresource*" -exec rm {} \+
 	find . -type d -name __pycache__ -exec rm -r {} \+
+	find emmental/mpris2/ -type f -name "*.xml" -exec rm {} \+
 	find data/ -type d -name "Test Album" -exec rm -r {} \+
 	find data/ -type d -name "Test Library" -exec rm -r {} \+
 
@@ -18,6 +19,16 @@ clean:
 flake8:
 	flake8 emmental/ tests/
 
+mpris-spec/Makefile:
+	git submodule init mpris-spec
+	git submodule update
+
+emmental/mpris2/MediaPlayer2.xml: mpris-spec/Makefile
+	cp mpris-spec/spec/org.mpris.MediaPlayer2.xml emmental/mpris2/MediaPlayer2.xml
+
+.PHONY: mpris2
+mpris2: emmental/mpris2/MediaPlayer2.xml
+
 .PHONY: emmental.gresource.xml
 emmental.gresource.xml:
 	exec tools/find-resources.py
@@ -49,7 +60,7 @@ pkgbuild:
 	cd aur && makepkg --printsrcinfo > .SRCINFO
 
 .PHONY: pytest
-pytest: emmental.gresource
+pytest: emmental.gresource mpris2
 	pytest
 
 .PHONY: tests

emmental/__init__.py

@@ -2,6 +2,7 @@
 """Set up our Application."""
 from . import gsetup
 from . import db
+from . import mpris2
 from . import options
 from gi.repository import GObject
 from gi.repository import GLib
@@ -16,6 +17,7 @@ class Application(Adw.Application):
     """Our custom Adw.Application."""
 
     db = GObject.Property(type=db.Connection)
+    mpris = GObject.Property(type=mpris2.Connection)
 
     def __init__(self):
         """Initialize an Application."""
@@ -35,6 +37,7 @@ class Application(Adw.Application):
         """Handle the Adw.Application::startup signal."""
         Adw.Application.do_startup(self)
         self.db = db.Connection()
+        self.mpris = mpris2.Connection()
 
         gsetup.add_style()
         self.db.load()
@@ -46,6 +49,9 @@ class Application(Adw.Application):
     def do_shutdown(self) -> None:
         """Handle the Adw.Application::shutdown signal."""
         Adw.Application.do_shutdown(self)
+        if self.mpris is not None:
+            self.mpris.disconnect()
+            self.mpris = None
         if self.db is not None:
             self.db.close()
             self.db = None

emmental/mpris2/__init__.py

@@ -0,0 +1,46 @@
+# Copyright 2022 (c) Anna Schumaker.
+"""Implement the MPRIS2 Specification."""
+from gi.repository import GObject
+from gi.repository import Gio
+from . import application
+
+MPRIS2_ID = f"org.mpris.MediaPlayer2.emmental{'-debug' if __debug__ else ''}"
+
+
+class Connection(GObject.GObject):
+    """Our Mpris2 Object."""
+
+    dbus = GObject.Property(type=Gio.DBusConnection)
+
+    def __init__(self):
+        """Initialize Mpris2."""
+        super().__init__()
+        self.app = application.Application()
+
+        self.bind_property("dbus", self.app, "dbus")
+
+        self._busid = Gio.bus_own_name(Gio.BusType.SESSION, MPRIS2_ID,
+                                       Gio.BusNameOwnerFlags.NONE,
+                                       self.__on_bus_acquired, None,
+                                       self.__on_name_lost)
+
+    def __del__(self):
+        """Clean up."""
+        self.disconnect()
+
+    def __on_bus_acquired(self, dbus: Gio.DBusConnection, name: str) -> None:
+        self.dbus = dbus
+        self.app.register(dbus)
+
+    def __on_name_lost(self, dbus: Gio.DBusConnection, name: str) -> None:
+        self.app.unregister(dbus)
+
+    def disconnect(self):
+        """Disconnect from dbus."""
+        if self.dbus:
+            self.app.unregister(self.dbus)
+            self.dbus = None
+
+        if self._busid:
+            Gio.bus_unown_name(self._busid)
+            self._busid = None

emmental/mpris2/application.py

@@ -0,0 +1,49 @@
+# Copyright 2022 (c) Anna Schumaker.
+"""Our Mpris2 Application dbus Object."""
+import pathlib
+from gi.repository import GObject
+from gi.repository import GLib
+from . import dbus
+
+MPRIS2_XML = pathlib.Path(__file__).parent / "MediaPlayer2.xml"
+
+
+class Application(dbus.Object):
+    """The mpris2 Application dbus object."""
+
+    CanQuit = GObject.Property(type=bool, default=True)
+    Fullscreen = GObject.Property(type=bool, default=False)
+    CanSetFullscreen = GObject.Property(type=bool, default=True)
+    CanRaise = GObject.Property(type=bool, default=True)
+    HasTrackList = GObject.Property(type=bool, default=False)
+    Identity = GObject.Property(type=str, default="Emmental Music Player")
+    DesktopEntry = GObject.Property(type=str, default="emmental")
+
+    def __init__(self):
+        """Initialize the mpris2 application object."""
+        super().__init__(xml=MPRIS2_XML)
+
+    def do_notify(self, property: str) -> None:
+        """Notify DBus when the Fullscreen property changes."""
+        match property:
+            case "Fullscreen":
+                value = GLib.Variant("b", self.Fullscreen)
+                self.properties_changed({property: value})
+
+    @GObject.Property
+    def SupportedUriSchemes(self) -> list[str]:
+        """URI schemes supported by Emmental."""
+        return ["file"]
+
+    @GObject.Property
+    def SupportedMimeTypes(self) -> list[str]:
+        """Mime Types supported by Emmental."""
+        return ["audio"]
+
+    @GObject.Signal
+    def Raise(self) -> None:
+        """Raise the window."""
+
+    @GObject.Signal
+    def Quit(self) -> None:
+        """Quit Emmental."""

emmental/mpris2/dbus.py

@@ -0,0 +1,89 @@
+# Copyright 2022 (c) Anna Schumaker.
+"""Our generic dbus object."""
+import pathlib
+from gi.repository import GObject
+from gi.repository import GLib
+from gi.repository import Gio
+
+OBJECT_PATH = "/org/mpris/MediaPlayer2"
+
+
+class Object(GObject.GObject):
+    """A generic dbus object."""
+
+    dbus = GObject.Property(type=Gio.DBusConnection)
+    nodeinfo = GObject.Property(type=Gio.DBusNodeInfo)
+    interface = GObject.Property(type=Gio.DBusInterfaceInfo)
+    registration = GObject.Property(type=int)
+
+    def __init__(self, xml: pathlib.Path = None):
+        """Initialize a dbus Object."""
+        super().__init__()
+        if xml and xml.is_file():
+            with open(xml, 'r') as f:
+                self.nodeinfo = Gio.DBusNodeInfo.new_for_xml(f.read())
+                self.interface = self.nodeinfo.interfaces[0]
+        self.connect("notify", self.__on_notify)
+
+    def __on_notify(self, object: GObject.GObject, param) -> None:
+        self.do_notify(param.name)
+
+    def do_notify(self, property: str) -> None:
+        """Handle a property value changing."""
+
+    def link_property(self, property: str, object: GObject.GObject,
+                      object_property: str) -> None:
+        """Link a dbus property to the object."""
+        self.bind_property(property, object, object_property,
+                           GObject.BindingFlags.BIDIRECTIONAL)
+
+    def properties_changed(self, changed: dict) -> None:
+        """Emit the org.freedesktop.DBus.PropertiesChanged signal."""
+        if self.dbus is None:
+            return
+
+        args = GLib.Variant.new_tuple(GLib.Variant("s", self.interface.name),
+                                      GLib.Variant("a{sv}", changed),
+                                      GLib.Variant("as", []))
+        self.dbus.emit_signal(None, OBJECT_PATH,
+                              "org.freedesktop.DBus.Properties",
+                              "PropertiesChanged", args)
+
+    def register(self, dbus: Gio.DBusConnection):
+        """Register this dbus Object."""
+        self.registration = dbus.register_object(OBJECT_PATH, self.interface,
+                                                 self.__method_call,
+                                                 self.__get_property,
+                                                 self.__set_property)
+
+    def unregister(self, dbus: Gio.DBusConnection):
+        """Unregister this Object from the bus."""
+        dbus.unregister_object(self.registration)
+        self.registration = 0
+
+    def __method_call(self, dbus: Gio.DBusConnection, sender: str, object: str,
+                      interface: str, method: str, parameters: GLib.Variant,
+                      invocation: Gio.DBusMethodInvocation) -> None:
+        if object != OBJECT_PATH or interface != self.interface.name:
+            return None
+
+        self.emit(method, *parameters.unpack())
+        invocation.return_value(GLib.Variant.new_tuple())
+
+    def __get_property(self, dbus: Gio.DBusConnection, sender: str,
+                       object: str, interface: str,
+                       property: str) -> GLib.Variant | None:
+        if object != OBJECT_PATH or interface != self.interface.name:
+            return None
+
+        if property_info := self.interface.lookup_property(property):
+            return GLib.Variant(property_info.signature,
+                                self.get_property(property))
+
+    def __set_property(self, dbus: Gio.DBusConnection, sender: str,
+                       object: str, interface: str, property: str,
+                       value: GLib.Variant) -> bool:
+        if object != OBJECT_PATH or interface != self.interface.name:
+            return None
+        self.set_property(property, value.unpack())
+        return True

mpris-spec

@@ -0,0 +1 @@
+Subproject commit 51e5848f9f763864568db233bffe98e3cb72bf13

tests/mpris2/test_application.py

@@ -0,0 +1,44 @@
+# Copyright 2022 (c) Anna Schumaker.
+"""Tests our Mpris Application object."""
+import pathlib
+import unittest
+import emmental.mpris2.application
+from gi.repository import Gio
+
+
+class TestRoot(unittest.TestCase):
+    """Test the mpris2 application object."""
+
+    def setUp(self):
+        """Set up common variables."""
+        self.app = emmental.mpris2.application.Application()
+
+    def test_xml_files(self):
+        """Test that the interface definition files exist."""
+        mpris2 = pathlib.Path(emmental.mpris2.__file__).parent
+        self.assertEqual(emmental.mpris2.application.MPRIS2_XML,
+                         mpris2 / "MediaPlayer2.xml")
+        self.assertTrue(emmental.mpris2.application.MPRIS2_XML.is_file())
+
+    def test_init(self):
+        """Test that the application object is configured correctly."""
+        self.assertIsInstance(self.app, emmental.mpris2.dbus.Object)
+        self.assertIsInstance(self.app.nodeinfo, Gio.DBusNodeInfo)
+        self.assertIsInstance(self.app.interface, Gio.DBusInterfaceInfo)
+
+    def test_properties(self):
+        """Test Application properties."""
+        self.assertTrue(self.app.CanQuit)
+        self.assertFalse(self.app.Fullscreen)
+        self.assertTrue(self.app.CanSetFullscreen)
+        self.assertTrue(self.app.CanRaise)
+        self.assertFalse(self.app.HasTrackList)
+        self.assertEqual(self.app.Identity, "Emmental Music Player")
+        self.assertEqual(self.app.DesktopEntry, "emmental")
+        self.assertEqual(self.app.SupportedUriSchemes, ["file"])
+        self.assertEqual(self.app.SupportedMimeTypes, ["audio"])
+
+    def test_signals(self):
+        """Test that Application signals exist."""
+        self.app.emit("Raise")
+        self.app.emit("Quit")

tests/mpris2/test_dbus.py

@@ -0,0 +1,24 @@
+# Copyright 2022 (c) Anna Schumaker.
+"""Test our generic dbus object."""
+import unittest
+import emmental.mpris2.dbus
+from gi.repository import GObject
+
+
+class TestDbusObject(unittest.TestCase):
+    """Tests our generic mpris2 object."""
+
+    def setUp(self):
+        """Set up common variables."""
+        self.object = emmental.mpris2.dbus.Object()
+
+    def test_init(self):
+        """Test that the object is set up properly."""
+        self.assertIsInstance(self.object, GObject.GObject)
+        self.assertIsNone(self.object.dbus)
+        self.assertIsNone(self.object.nodeinfo)
+        self.assertIsNone(self.object.interface)
+        self.assertEqual(self.object.registration, 0)
+
+        self.assertEqual(emmental.mpris2.dbus.OBJECT_PATH,
+                         "/org/mpris/MediaPlayer2")

tests/mpris2/test_mpris2.py

@@ -0,0 +1,27 @@
+# Copyright 2022 (c) Anna Schumaker.
+"""Test our root mpris2 object."""
+import unittest
+import emmental.mpris2
+
+
+class TestMpris2(unittest.TestCase):
+    """Test our Mpris2 Connection."""
+
+    def setUp(self):
+        """Set up common variables."""
+        self.mpris2 = emmental.mpris2.Connection()
+
+    def tearDown(self):
+        """Clean up."""
+        self.mpris2.disconnect()
+
+    def test_init(self):
+        """Test that the Mpris Object is created properly."""
+        self.assertIsInstance(self.mpris2, emmental.mpris2.GObject.GObject)
+        self.assertIsInstance(self.mpris2.app,
+                              emmental.mpris2.application.Application)
+        self.assertIsNone(self.mpris2.dbus)
+        self.assertGreater(self.mpris2._busid, 0)
+
+        self.assertEqual(emmental.mpris2.MPRIS2_ID,
+                         "org.mpris.MediaPlayer2.emmental-debug")

tests/test_emmental.py

@@ -37,16 +37,24 @@ class TestEmmental(unittest.TestCase):
                      mock_load: unittest.mock.Mock):
         """Test that the startup signal works as expected."""
         self.assertIsNone(self.application.db)
+        self.assertIsNone(self.application.mpris)
 
         self.application.emit("startup")
         self.assertIsInstance(self.application.db, emmental.db.Connection)
+        self.assertIsInstance(self.application.mpris,
+                              emmental.mpris2.Connection)
+
         mock_startup.assert_called()
         mock_load.assert_called()
 
     def test_shutdown(self):
         """Test that the shutdown signal works as expected."""
         db = self.application.db = emmental.db.Connection()
+        mpris = self.application.mpris = emmental.mpris2.Connection()
 
         self.application.emit("shutdown")
         self.assertIsNone(self.application.db)
+        self.assertIsNone(self.application.mpris)
+
+        self.assertIsNone(mpris.dbus)
         self.assertFalse(db.connected)