How to listen to key press repetitively in Dart for games?

First of all, don't listen to keyPress events, because the "initial delay" depends on the operating system configuration! In fact, keyPress events may not even fire repetitively.

What you need to do is to listen to keyDown and keyUp events. You can make a helper for this.

class Keyboard {  HashMap<int, int> _keys = new HashMap<int, int>();  Keyboard() {    window.onKeyDown.listen((KeyboardEvent e) {      // If the key is not set yet, set it with a timestamp.      if (!_keys.containsKey(e.keyCode))        _keys[e.keyCode] = e.timeStamp;    });    window.onKeyUp.listen((KeyboardEvent e) {      _keys.remove(e.keyCode);    });  }  /**   * Check if the given key code is pressed. You should use the [KeyCode] class.   */  isPressed(int keyCode) => _keys.containsKey(keyCode);}

Then depending on what you do in your game, you probably have "a game loop" of some sort, in your update() method that gets called in every once in a while:

class Game {  Keyboard keyboard;  Game() {    keyboard = new Keyboard();    window.requestAnimationFrame(update);  }  update(e) {    if (keyboard.isPressed(KeyCode.A))      print('A is pressed!');    window.requestAnimationFrame(update);  }}

Now your game loop checks repetitively for A key pressing.