input.js

export class InputHandler {
    constructor(game){
        this.game = game;
        this.keys = [];
        this.touchY = '';
        this.touchTreshold = 30;
        window.addEventListener('keydown', e => {
            // If key is arrowdown and the key that was pressed is not
            // included in the this.keys array, push arrowdown into this.keys array
            if ((e.key === "ArrowDown" || 
                e.key === "ArrowUp" ||
                e.key === "ArrowLeft" ||
                e.key === "ArrowRight" ||
                e.key === " "
             ) && this.keys.indexOf(e.key) === -1){
                this.keys.push(e.key);
            } else if (e.key === 'd') {
                this.game.debug = !this.game.debug;
            } else if (e.key === "Enter" && this.game.gameOver) {
                this.game.restart();
            }

        });
        window.addEventListener('keyup', e => {
            // If key that was released is arrowdown, Use splice method to 
            // remove it from this.keys array 
            if (e.key === 'ArrowDown' || 
                e.key ==='ArrowUp' ||
                e.key === "ArrowLeft" ||
                e.key === "ArrowRight" ||
                e.key === " "){
                this.keys.splice(this.keys.indexOf(e.key), 1)
            }
        // Whenever someone touches browser window
        });
        window.addEventListener('touchstart', e => {
            this.touchY = e.changedTouches[0].pageY;

        });
        window.addEventListener('touchmove', e => {
            const swipeDistance = e.changedTouches[0].pageY - this.touchY
            
            if (swipeDistance < -this.touchThreshold && this.keys.indexOf('swipe up') === -1) this.keys.push('swipe up');
            else if (swipeDistance > this.touchTreshold && this.keys.indexOf('swipe down') === -1) {
                this.keys.push('swipe down');
                if (this.game.gameOver) this.game.restart()
            }
        });
        window.addEventListener('touchend', e => {
            this.keys.splice(this.keys.indexOf('swipe up'), 1);
            this.keys.splice(this.keys.indexOf('swipe down'), 1);
        });
    }
}