Keyboard input

Using keyDown and keyUp events from input to listen to keyboard input.

Key codes are used to know which key is pressed on the keyboard and depend on the user keyboard layout (QWERTY, AZERTY...).

Scan codes represent physical keys on the keyboard. They are useful because they always follow a standard QWERTY layout and are independent from the user's keyboard layout. For example, if you want your W,A,S,D controls to work with any keyboard, you should use scan codes!

import ceramic.Key;
import ceramic.KeyCode;
import ceramic.ScanCode;
import ceramic.Scene;
import ceramic.Text;

class MainScene extends Scene {

    /**
     * A text object to display info about keyboard input
     */
    var text:Text;

    /**
     * The list of currently pressed key codes
     */
    var pressedKeyCodes:Array<KeyCode> = [];

    /**
     * The list of currently pressed scan codes
     */
    var pressedScanCodes:Array<ScanCode> = [];

    override function create() {

        // Use a text object to display info about keyboard input
        text = new Text();
        text.anchor(0.5, 0.5);
        text.pos(width * 0.5, height * 0.5);
        text.align = CENTER;
        add(text);

        // Bind keyboard input events
        input.onKeyDown(this, keyDown);
        input.onKeyUp(this, keyUp);

        updateText();

    }

    function keyDown(key:Key) {

        if (!pressedKeyCodes.contains(key.keyCode)) {
            pressedKeyCodes.push(key.keyCode);
            pressedScanCodes.push(key.scanCode);
        }

        updateText();

    }

    function keyUp(key:Key) {

        pressedKeyCodes.remove(key.keyCode);
        pressedScanCodes.remove(key.scanCode);

        updateText();

    }

    function updateText() {

        // Update text depending on the currently pressed keys

        if (pressedKeyCodes.length > 0) {
            var content = [];
            for (i in 0...pressedKeyCodes.length) {
                var keyCode = pressedKeyCodes[i];
                var scanCode = pressedScanCodes[i];
                content.push(
                    KeyCode.name(keyCode) +
                    ' (key code)          ' +
                    ScanCode.name(scanCode) +
                    ' (scan code)'
                );
            }
            text.content = content.join('\n');
        }
        else {
            text.content = 'press any key (keyboard)';
        }

    }

}

Next example ➔ Gamepad input