--- title: "Qt Timers" date: 2020-03-19T17:30:04-04:00 draft: false tags: ["C++"] medium_enabled: true --- Qt has two great timers, one that repeats an action after a certain interval, and one that is meant for one-off operations. They call these `QTimer` and `QTimer::singleShot` respectively. This post is going to assume that we're working with a class named `Test` that inherits `QObject`. Let us first look at the one that repeats. This code needs to be inside a class that inherits `QObject`. ```c++ void Test::callbackRepeat(void) { // Code that executes when the timer times out } // ...... int interval = 1000; // Units: milliseconds QTimer* timer = new QTimer(this); timer->start(interval); connect(timer, &QTimer::timeout, this, &Test::callbackRepeat); ``` Now for the one-off... ```c++ void Test::callback(void) { // Code that executes when the timer times out } // ...... int timeout = 1000; // Units: milliseconds QTimer::singleShot(timeout, this, &Test::callback) ```