Timer

Note

Timer is not an actual element visible in the tree, therefore it doesn’t have the common properties such as x, y, width, height, etc. It also doesn’t take room in a layout and cannot have any children or be inherited from.

This example shows a timer that counts down from 10 to 0 every second:

import { Button } from "std-widgets.slint";
export component Example inherits Window {
    property <int> value: 10;
    timer := Timer {
        interval: 1s;
        running: true;
        triggered() => {
            value -= 1;
            if (value == 0) {
                self.running = false;
            }
        }
    }
    HorizontalLayout {
        Text { text: value; }
        Button {
            text: "Reset";
            clicked() => { value = 10; timer.running = true; }
        }
    }
}

Use the Timer pseudo-element to schedule a callback at a given interval. The timer is only running when the running property is set to true. To stop or start the timer, set that property to true or false. It can be also set to a binding expression. When already running, the timer will be restarted if the interval property is changed.

Caution

By default the Timer is always running running: true. This can result in constant CPU usage and power usage so ensure that you set running to false when you don’t want the timer to run.

property <int> count: 0;
Timer {
    interval: 8s; // every 8 seconds the timer will activate (tick)
    triggered() => { // The triggered callback activates every time the timer ticks
        if count >= 5 {
            self.running = false; // stop the timer after 5 ticks
        }
        count += 1;
    }
}

interval

duration default: 0ms

The interval between timer ticks. This property is mandatory.

running

bool default: true

true if the timer is running. (default value: true)

Callbacks

triggered()

Invoked every time the timer ticks (every interval).