Fix cursor issue in KDE and implement local cursor size accessibility…

… settings (#72)

* Prevent cursor issues in KDE desktop environments

* Improve cursor exception handling

* Cursor size accessibility

* Change command line option help

docker-compose.yaml

@@ -66,7 +66,7 @@ services:
       WEBRTC_ENABLE_RESIZE: ${WEBRTC_ENABLE_RESIZE}
 
       # DEBUG remote cursors
-      DEBUG_CURSORS: ${DEBUG_CURSORS:-false}
+      WEBRTC_DEBUG_CURSORS: ${WEBRTC_DEBUG_CURSORS:-false}
 
       # Start full XFCE4 session, vs just X11 server.
       START_XFCE4: ${START_XFCE4:-true}

src/selkies_gstreamer/__main__.py

@@ -394,8 +394,14 @@ def main():
     parser.add_argument('--enable_cursors',
                         default=os.environ.get('WEBRTC_ENABLE_CURSORS', 'true'),
                         help='Enable passing remote cursors to client')
+    parser.add_argument('--debug_cursors',
+                        default=os.environ.get('WEBRTC_DEBUG_CURSORS', 'false'),
+                        help='Enable cursor debug logging')
+    parser.add_argument('--cursor_size',
+                        default=os.environ.get('WEBRTC_CURSOR_SIZE', '24'),
+                        help='Cursor size in points for the local cursor, configure the remote cursor size in the remote desktop environment')
     parser.add_argument('--metrics_port',
-                        default=os.environ.get('METRICS_PORT', '8000'),
+                        default=os.environ.get('WEBRTC_METRICS_PORT', '8000'),
                         help='Port to start metrics server on')
     parser.add_argument('--debug', action='store_true',
                         help='Enable debug logging')
@@ -510,6 +516,8 @@ async def on_signalling_error(e):
     curr_video_bitrate = int(args.video_bitrate)
     curr_audio_bitrate = int(args.audio_bitrate)
     enable_cursors = args.enable_cursors.lower() == "true"
+    cursor_debug = args.debug_cursors.lower() == "true"
+    cursor_size = int(args.cursor_size)
 
     # Create instance of app
     app = GSTWebRTCApp(stun_servers, turn_servers, enable_audio, curr_fps, args.encoder, curr_video_bitrate, curr_audio_bitrate)
@@ -532,7 +540,7 @@ async def on_signalling_error(e):
     signalling.on_session = app.start_pipeline
 
     # Initialize the Xinput instance
-    webrtc_input = WebRTCInput(args.uinput_mouse_socket, args.uinput_js_socket, args.enable_clipboard.lower(), enable_cursors)
+    webrtc_input = WebRTCInput(args.uinput_mouse_socket, args.uinput_js_socket, args.enable_clipboard.lower(), enable_cursors, cursor_size, cursor_debug)
 
     # Handle changed cursors
     webrtc_input.on_cursor_change = lambda data: app.send_cursor_data(data)

src/selkies_gstreamer/webrtc_input.py

@@ -96,7 +96,7 @@ class WebRTCInputError(Exception):
 
 
 class WebRTCInput:
-    def __init__(self, uinput_mouse_socket_path="", uinput_js_socket_path="", enable_clipboard="", enable_cursors=True):
+    def __init__(self, uinput_mouse_socket_path="", uinput_js_socket_path="", enable_clipboard="", enable_cursors=True, cursor_size=24, cursor_debug=False):
         """Initializes WebRTC input instance
         """
         self.clipboard_running = False
@@ -111,9 +111,9 @@ def __init__(self, uinput_mouse_socket_path="", uinput_js_socket_path="", enable
         self.enable_cursors = enable_cursors
         self.cursors_running = False
         self.cursor_cache = {}
-        self.cursor_resize_width = 24
-        self.cursor_resize_height = 24
-        self.cursor_debug = os.environ.get("DEBUG_CURSORS", "false").lower() == "true"
+        self.cursor_resize_width = cursor_size
+        self.cursor_resize_height = cursor_size
+        self.cursor_debug = cursor_debug
 
         self.keyboard = None
         self.mouse = None
@@ -425,26 +425,32 @@ def start_cursor_monitor(self):
         logger.info("watching for cursor changes")
 
         # Fetch initial cursor
-        image = self.xdisplay.xfixes_get_cursor_image(screen.root)
-        self.cursor_cache[image.cursor_serial] = self.cursor_to_msg(image, self.cursor_resize_width, self.cursor_resize_height)
-        self.on_cursor_change(self.cursor_cache[image.cursor_serial])
+        try:
+            image = self.xdisplay.xfixes_get_cursor_image(screen.root)
+            self.cursor_cache[image.cursor_serial] = self.cursor_to_msg(image, self.cursor_resize_width, self.cursor_resize_height)
+            self.on_cursor_change(self.cursor_cache[image.cursor_serial])
+        except Exception as e:
+            logger.warning("exception from fetching cursor image: %s" % e)
 
         while self.cursors_running:
-            e = self.xdisplay.next_event()
-            if (e.type, 0) == self.xdisplay.extension_event.DisplayCursorNotify:
-                cache_key = e.cursor_serial
+            event = self.xdisplay.next_event()
+            if (event.type, 0) == self.xdisplay.extension_event.DisplayCursorNotify:
+                cache_key = event.cursor_serial
                 if cache_key in self.cursor_cache:
                     if self.cursor_debug:
                         logger.warning("cursor changed to cached serial: {}".format(cache_key))
                 else:
-                    # Request the cursor image.
-                    cursor = self.xdisplay.xfixes_get_cursor_image(screen.root)
+                    try:
+                        # Request the cursor image.
+                        cursor = self.xdisplay.xfixes_get_cursor_image(screen.root)
 
-                    # Convert cursor image and cache.
-                    self.cursor_cache[cache_key] = self.cursor_to_msg(cursor, self.cursor_resize_width, self.cursor_resize_height)
+                        # Convert cursor image and cache.
+                        self.cursor_cache[cache_key] = self.cursor_to_msg(cursor, self.cursor_resize_width, self.cursor_resize_height)
 
-                    if self.cursor_debug:
-                        logger.warning("New cursor: position={},{}, size={}x{}, length={}, xyhot={},{}, cursor_serial={}".format(cursor.x, cursor.y, cursor.width,cursor.height, len(cursor.cursor_image), cursor.xhot, cursor.yhot, cursor.cursor_serial))
+                        if self.cursor_debug:
+                            logger.warning("New cursor: position={},{}, size={}x{}, length={}, xyhot={},{}, cursor_serial={}".format(cursor.x, cursor.y, cursor.width,cursor.height, len(cursor.cursor_image), cursor.xhot, cursor.yhot, cursor.cursor_serial))
+                    except Exception as e:
+                        logger.warning("exception from fetching cursor image: %s" % e)
 
                 self.on_cursor_change(self.cursor_cache.get(cache_key))