Linux Title Context Update

[G-M0N3Y-2503]

In applications like Firefox the title updates on each webpage navigation.
Using RegEx it's possible to have different bindings per website,.
I haven't tried this but might be even more reliable using something like https://addons.mozilla.org/en-US/firefox/addon/tab-retitle/.

The only limitation is that the context only matches when the application is first focused.

As a workaround I can click off the browser than back on.
But I wonder if there is any way to detect this title change.

[houmain]

On X11 this is already working. Which desktop environment are you using? Gnome or KDE? Then the gnome-shell or KWin script would have to be modified. I don't know if they are sending some event when only the title changes.

[G-M0N3Y-2503]

Oh, thanks for the insight.
I'm using KDE/KWin/Wayland

[G-M0N3Y-2503]

I guess I'll add some logging to the Kwin script to see what's happening.
But I did find

/**
     * Receives events registered for using registerPropertyType.
     * Use readProperty() to get the property data.
     * Note that the property may be already set on the window, so doing the same
     * processing from windowAdded() (e.g. simply calling propertyNotify() from it)
     * is usually needed.
     * @param w The window whose property changed, is @c null if it is a root window property
     * @param atom The property
     * @since 4.7
     */
    void propertyNotify(KWin::EffectWindow* w, long atom);

And

/**
     * This signal gets emitted when the data on EffectWindow @p w for @p role changed.
     *
     * An Effect can connect to this signal to read the new value and react on it.
     * E.g. an Effect which does not operate on windows grabbed by another Effect wants
     * to cancel the already scheduled animation if another Effect adds a grab.
     *
     * @param w The EffectWindow for which the data changed
     * @param role The data role which changed
     * @see EffectWindow::setData
     * @see EffectWindow::data
     * @since 5.8.4
     **/
    void windowDataChanged(KWin::EffectWindow *w, int role);

Which seem interesting.

[G-M0N3Y-2503]

I got a local LLM to produce this that works for KDE6 at least.
client.captionChanged.connect on the active window seems to be what we want, but then we have to disconnect otherwise the calls just grow and left behind on nonactive windows.

const isKDE6 = typeof workspace.windowList === 'function';

const connectWindowActivated = isKDE6
    ? (handler) => workspace.windowActivated.connect(handler)
    : (handler) => workspace.clientActivated.connect(handler);

let activeClient = null;
const signalHandlers = new Map();

function sendWindowFocusDBus(client) {
    if (!client) return;
    callDBus(
        "com.github.houmain.Keymapper",
        "/com/github/houmain/Keymapper",
        "com.github.houmain.Keymapper",
        "WindowFocus",
        client.caption ?? "",
        client.resourceClass ?? ""
    );
}

function connectClientSignals(client) {
    if (!client) return;
    const handler = () => sendWindowFocusDBus(client);
    client.captionChanged.connect(handler);
    client.windowClassChanged.connect(handler);
    signalHandlers.set(client, handler);
}

function disconnectClientSignals(client) {
    if (!client) return;
    const handler = signalHandlers.get(client);
    if (!handler) return;
    client.captionChanged.disconnect(handler);
    client.windowClassChanged.disconnect(handler);
    signalHandlers.delete(client);
}

connectWindowActivated((client) => {
    if (activeClient && activeClient !== client) {
        disconnectClientSignals(activeClient);
    }
    activeClient = client;
    if (client) {
        sendWindowFocusDBus(client);
        connectClientSignals(client);
    }
});

[houmain]

@G-M0N3Y-2503 Thank you very much for researching!