snapshot of https://github.com/ActivityWatch/aw-watcher-window.git (master, 2026-09-16; blobs > 131072B omitted)

aw_watcher_window/xlib.py

@@ -0,0 +1,174 @@
+import logging
+from typing import Optional
+
+import Xlib
+import Xlib.display
+from Xlib import X
+from Xlib.xobject.drawable import Window
+
+from .exceptions import FatalError
+
+logger = logging.getLogger(__name__)
+
+display = Xlib.display.Display()
+screen = display.screen()
+
+NET_WM_NAME = display.intern_atom("_NET_WM_NAME")
+UTF8_STRING = display.intern_atom("UTF8_STRING")
+
+
+def _get_current_window_id() -> Optional[int]:
+    atom = display.get_atom("_NET_ACTIVE_WINDOW")
+    window_prop = screen.root.get_full_property(atom, X.AnyPropertyType)
+
+    if window_prop is None:
+        logger.warning("window_prop was None")
+        return None
+
+    # window_prop may contain more than one value, but it seems that it's always the first we want.
+    # The second has in my attempts always been 0 or rubbish.
+    window_id = window_prop.value[0]
+    return window_id if window_id != 0 else None
+
+
+def _get_window(window_id: int) -> Window:
+    return display.create_resource_object("window", window_id)
+
+
+def get_current_window() -> Optional[Window]:
+    """
+    Returns the current window, or None if no window is active.
+    """
+    try:
+        window_id = _get_current_window_id()
+        if window_id is None:
+            return None
+        else:
+            return _get_window(window_id)
+    except Xlib.error.ConnectionClosedError:
+        # when the X server closes the connection, we should exit
+        # note that stdio is probably closed at this point, so we can't print anything (causes OSError)
+        try:
+            logger.warning("X server closed connection, exiting")
+        except OSError:
+            pass
+        raise FatalError()
+
+
+# Things that can lead to unknown cls/name:
+#  - (cls+name) Empty desktop in xfce (no window focused)
+#  - (name) Chrome (fixed, didn't support when WM_NAME was UTF8_STRING)
+
+
+def get_window_name(window: Window) -> str:
+    """After some annoying debugging I resorted to pretty much copying selfspy.
+    Source: https://github.com/gurgeh/selfspy/blob/8a34597f81000b3a1be12f8cde092a40604e49cf/selfspy/sniff_x.py#L165"""
+    try:
+        d = window.get_full_property(NET_WM_NAME, UTF8_STRING)
+    except Xlib.error.XError as e:
+        logger.warning(
+            f"Unable to get window property NET_WM_NAME, got a {type(e).__name__} exception from Xlib"
+        )
+        # I strongly suspect window.get_wm_name() will also fail and we should return "unknown" right away.
+        # But I don't know, so I pass the thing on, for now.
+        d = None
+    if d is None or d.format != 8:
+        try:
+            # Fallback.
+            r = window.get_wm_name()
+            if r is None:
+                return "unknown"
+            elif isinstance(r, str):
+                return r
+            else:
+                logger.warning(
+                    "I don't think this case will ever happen, but not sure so leaving this message here just in case."
+                )
+                return r.decode("latin1")  # WM_NAME with type=STRING.
+        except Xlib.error.BadWindow as e:
+            # I comment on the log, the number of messages that pop up is very annoying
+            # Also, it does not give much information about the error
+            # But I leave it in case someone sees it useful
+            # logger.warning(
+            #     f"Unable to get window property WM_NAME, got a {type(e).__name__} exception from Xlib"
+            # )
+            return "unknown"
+    else:
+        # Fixing utf8 issue on Ubuntu (https://github.com/gurgeh/selfspy/issues/133)
+        # Thanks to https://github.com/gurgeh/selfspy/issues/133#issuecomment-142943681
+        try:
+            return d.value.decode("utf8")
+        except UnicodeError:
+            logger.warning(
+                f"Failed to decode one or more characters which will be skipped, bytes are: {d.value}"
+            )
+            if isinstance(d.value, bytes):
+                return d.value.decode("utf8", "ignore")
+            else:
+                return d.value.encode("utf8").decode("utf8", "ignore")
+
+
+def get_window_class(window: Window) -> str:
+    cls = None
+
+    try:
+        cls = window.get_wm_class()
+    except Xlib.error.BadWindow:
+        logger.warning("Unable to get window class, got a BadWindow exception.")
+
+    # TODO: Is this needed?
+    # nikanar: Indeed, it seems that it is. But it would be interesting to see how often this succeeds, and if it is low, maybe fail earlier.
+    if not cls:
+        print("")
+        logger.warning("Code made an unclear branch")
+        try:
+            window = window.query_tree().parent
+        except Xlib.error.BadWindow:
+            # I comment on the log, the number of messages that pop up is very annoying
+            # Also, it does not give much information about the error
+            # But I leave it in case someone sees it useful
+            # logger.warning(
+            #     "Unable to get window query_tree().parent, got a BadWindow exception."
+            # )
+            return "unknown"
+        except Xlib.error.XError as e:
+            logger.warning(
+                f"Unable to get window query_tree().parent, got a {type(e).__name__} exception from Xlib"
+            )
+            return "unknown"
+        if window:
+            return get_window_class(window)
+        else:
+            return "unknown"
+
+    cls = cls[1]
+    return cls
+
+
+def get_window_pid(window: Window) -> str:
+    atom = display.get_atom("_NET_WM_PID")
+    pid_property = window.get_full_property(atom, X.AnyPropertyType)
+    if pid_property:
+        pid = pid_property.value[-1]
+        return pid
+    else:
+        # TODO: Needed?
+        raise Exception("pid_property was None")
+
+
+if __name__ == "__main__":
+    from time import sleep
+
+    while True:
+        print("-" * 20)
+        window = get_current_window()
+        if window is None:
+            print("unable to get active window")
+            name, cls = "unknown", "unknown"
+        else:
+            cls = get_window_class(window)
+            name = get_window_name(window)
+        print("name:", name)
+        print("class:", cls)
+
+        sleep(1)