Port 'Screencast' demo to Python

demos/Screencast/main.py

@@ -0,0 +1,93 @@
+import gi
+
+gi.require_version("Xdp", "1.0")
+gi.require_version("XdpGtk4", "1.0")
+from gi.repository import GObject, Gio, Gst, Xdp, XdpGtk4
+import workbench
+import sys
+
+Gst.init(None)
+
+portal = Xdp.Portal()
+parent = XdpGtk4.parent_new_gtk(workbench.window)
+output = workbench.builder.get_object("output")
+button = workbench.builder.get_object("button")
+
+
+def on_session_start(session, result):
+    success = session.start_finish(result)
+    if not success:
+        print("Could not start session")
+        return
+
+    pw_remote = session.open_pipewire_remote()
+
+    # Create the pipeline
+    pipeline = Gst.Pipeline()
+
+    # Create elements
+    source = Gst.ElementFactory.make("pipewiresrc", "source")
+    queue = Gst.ElementFactory.make("queue", "queue")  # add a queue element
+    paintable_sink = Gst.ElementFactory.make(
+        "gtk4paintablesink",
+        "paintable_sink",
+    )
+    glsinkbin = Gst.ElementFactory.make("glsinkbin", "glsinkbin")
+
+    # Set up and Link Pipeline
+    source.set_property(
+        "fd", pw_remote
+    )  # pw_remote is the file descriptor obtained from libportal
+
+    # Obtain the node id from the screencast session
+    streams = session.get_streams()
+
+    # Assuming there's only one stream for simplicity
+    node_id = streams[0][0]
+    if not node_id:
+        print("No available node id", file=sys.stderr)
+        return
+
+    # Set the path property of pipewiresrc
+    source.set_property("path", node_id)
+
+    glsinkbin.set_property("sink", paintable_sink)
+
+    pipeline.add(source)
+    pipeline.add(queue)
+    pipeline.add(glsinkbin)
+    source.link(queue)
+    queue.link(glsinkbin)
+
+    paintable = paintable_sink.get_property("paintable")
+    output.set_paintable(paintable)
+
+    # Start the pipeline
+    pipeline.set_state(Gst.State.PLAYING)
+
+    # Handle cleanup on application exit
+    output.connect("destroy", lambda _: pipeline.set_state(Gst.State.NONE))
+
+
+def on_screencast_session_create(portal, result):
+    session = portal.create_screencast_session_finish(result)
+    if not session:
+        print("Permission denied")
+        return
+
+    session.start(parent, None, on_session_start)
+
+
+def start_screencast_session():
+    portal.create_screencast_session(
+        Xdp.OutputType.MONITOR,
+        Xdp.ScreencastFlags.NONE,
+        Xdp.CursorMode.EMBEDDED,
+        Xdp.PersistMode.TRANSIENT,
+        None,
+        None,
+        on_screencast_session_create,
+    )
+
+
+button.connect("clicked", lambda _: start_screencast_session())