Upgrade KWin script to detect screen about to turn off and wake

supagu · March 27, 2026, 8:18am

Some years ago I developed a KWin script to use CEC device to turn the screen on and off automatically using a KWin script.
My old post is here: Determine when monitor is turned on or off via python dbus - #14 by supagu

I have some some code that used to work (I think it was using Qt5), now it appears not to work (My computer is using Qt6):

github.com/bit-shift-io/scripts

cec_kwin/package/contents/code/main.js

master

function callDbusMethod(methodName, args) {
    print("[cec_kwin] callDbusMethod: ", methodName, " args:", args)
    callDBus("io.bitshift.dbus_service", "/io/bitshift/dbus_service", "io.bitshift.dbus_service", methodName, args, function (r) {
        print("[cec_kwin]", methodName, "successfully called. Returned:", r)
    })
}

function aboutToTurnOff() {
    callDbusMethod("aboutToTurnOff")
}

function wakeUp() {
    callDbusMethod("wakeUp")
}

function screensChanged() {
    let screens = workspace.screens
    print("[cec_kwin] screensChanged.", screens.length, "screens found.")

    if (screens.length) {

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The problem is with this line of code:
firstScreen.aboutToTurnOff.connect(aboutToTurnOff)

Gives me the error:
/home/server/.local/share/kwin/scripts/cec_kwin/contents/code/main.js:22: error: Cannot call method ‘connect’ of undefined

It seems that “aboutToTurnOff” is no longer available.
Was this renamed or is there some other method to detect this now?

I can’t seem to find any good KWin script documentation.

pg-tips · March 27, 2026, 12:17pm

Not an answer, but the question has also been asked here: