src/view/InputHandler.ts


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'use strict';


import Direction from '../model/Direction';


class InputHandler {
        keys: {[key: number]: boolean} = {};

        private listeners: (() => void)[] = [];

        private callListeners(): void {
                this.listeners.forEach(l => l());
        }

        constructor(private relevantKeys: {[key: number]: boolean}) {
                window.addEventListener('keydown', (ev) => {
                        if (!relevantKeys[ev.keyCode])
                                return;

                        ev.preventDefault();

                        if (!this.keys[ev.keyCode]) {
                                this.keys[ev.keyCode] = true;
                                this.callListeners();
                        }
                });

                window.addEventListener('keyup', (ev) => {
                        if (!relevantKeys[ev.keyCode])
                                return;

                        ev.preventDefault();

                        if (this.keys[ev.keyCode]) {
                                delete this.keys[ev.keyCode];
                                this.callListeners();
                        }
                });
        }

        addListener(l: () => void) {
                this.listeners.push(l);
        }
}

module InputHandler {
        export const Left = 37;
        export const Up = 38;
        export const Right = 39;
        export const Down = 40;
};

export default InputHandler;