使用Python xlib在活动X窗口更改时获取通知

Question

我想监控在运行X的Linux系统上哪个窗口是活动的，以及该活动窗口何时被调整大小或移动。我可以监视活动窗口（它保存在根窗口上的_NET_ACTIVE_WINDOW属性中，我可以注册根窗口上的PropertyNotify事件以发现该属性何时更改）。但是，我不知道如何监视活动窗口，以了解它是否被调整大小或移动

import Xlib
import Xlib.display

disp = Xlib.display.Display()
Xroot = disp.screen().root
NET_ACTIVE_WINDOW = disp.intern_atom('_NET_ACTIVE_WINDOW')
Xroot.change_attributes(event_mask=Xlib.X.PropertyChangeMask)

while True:
    # loop until an event happens that we care about
    # we care about a change to which window is active
    # (NET_ACTIVE_WINDOW property changes on the root)
    # or about the currently active window changing
    # in size or position (don't know how to do this)
    event = disp.next_event()
    if (event.type == Xlib.X.PropertyNotify and
            event.atom == NET_ACTIVE_WINDOW):
        active = disp.get_input_focus().focus
        try:
            name = active.get_wm_class()[1]
        except TypeError:
            name = "unknown"
        print("The active window has changed! It is now", name)

有办法做到这一点吗？它可能涉及侦听当前活动窗口上的ConfigureNotify事件（并在该窗口变为活动状态时调用该窗口上的change_attributes以设置适当的掩码），但我无法使其正常工作

（注意：我没有使用Gtk，所以请不要使用Gtk解决方案。）

更新：通过观察活动窗口中_NET_WM_OPAQUE_REGION属性值的变化（因为我正确地接收到PropertyChange事件，尽管我没有接收到ConfigureNotify事件），有一种相当可疑的方法来检测窗口大小的变化。然而，不清楚是否所有的窗口管理器都设置了这个属性，这只会改变窗口的大小；它不会在窗口移动时更改（也不会更改任何其他属性）

Answer 1

执行此操作的方法是在根窗口上为SubstructureNotifyMask选择，然后读取所有ConfigureNotify事件并忽略我们关心的窗口以外的事件，因此：

import Xlib
import Xlib.display

disp = Xlib.display.Display()
Xroot = disp.screen().root
NET_ACTIVE_WINDOW = disp.intern_atom('_NET_ACTIVE_WINDOW')
Xroot.change_attributes(event_mask=Xlib.X.PropertyChangeMask |
                        Xlib.X.SubstructureNotifyMask)

windows = []

while True:
    # loop until an event happens that we care about
    # we care about a change to which window is active
    # (NET_ACTIVE_WINDOW property changes on the root)
    # or about the currently active window changing
    # in size or position (ConfigureNotify event for
    # our window or one of its ancestors)
    event = disp.next_event()
    if (event.type == Xlib.X.PropertyNotify and
            event.atom == NET_ACTIVE_WINDOW):
        active = disp.get_input_focus().focus
        try:
            name = active.get_wm_class()[1]
        except TypeError:
            name = "unknown"
        print("The active window has changed! It is now", name)

        # Because an X window is not necessarily just what one thinks of
        # as a window (the window manager may add an invisible frame, and
        # so on), we record not just the active window but its ancestors
        # up to the root, and treat a ConfigureNotify on any of those
        # ancestors as meaning that the active window has been moved or resized
        pointer = active
        windows = []
        while pointer.id != Xroot.id:
            windows.append(pointer)
            pointer = pointer.query_tree().parent
    elif event.type == Xlib.X.ConfigureNotify and event.window in windows:
        print("Active window size/position is now", event.x, event.y,
              event.width, event.height)