index.js

const PIXI = require('pixi.js');
const Events = require('nom-events');

class Keyboard {
	constructor() {
		this.keyStates = new Map();
    this.events = new Events();
	}
  
  clear() {
    this.keyStates.clear();
  }
  
  update() {
    this.keyStates.forEach((value, keyCode) => {
      const event = this.keyStates.get(keyCode);

      event.alreadyPressed = true;
      
      if (event.wasReleased) {
        this.keyStates.delete(keyCode);
      }

      keyboard.events.call('down', keyCode, event);
      keyboard.events.call('down_' + keyCode, keyCode, event);
    });
  }
  
  isKeyDown(...args) {
    let result = false;
    for(let keyCode of args) {
      const event = this.keyStates.get(keyCode);
      if (event && !event.wasReleased)
        result = true;
    }
    
    return result;
  }
  
  isKeyUp(...args) {
    return !this.isKeyDown(args);
  }
  
  isKeyPressed(...args) {
    let result = false;
    
    if (args.length == 0)
      return false;
    
    for(let keyCode of args) {
      const event = this.keyStates.get(keyCode);
      if (event && !event.wasReleased && !event.alreadyPressed)
        result = true;
    }

    return result;
  }
  
  isKeyReleased(...args) {
    let result = false;
    
    if (args.length == 0)
      return false;
    
    for(let keyCode of args) {
      const event = this.keyStates.get(keyCode);
      if (event && event.wasReleased)
        result = true;
    }

    return result;
  }
}

const keyboard = new Keyboard();

window.addEventListener(
  "keydown", (event) => {
    if (!keyboard.keyStates.get(event.code)) {
      keyboard.keyStates.set(event.code, event);
      keyboard.events.call('pressed', event.code, event);
      keyboard.events.call('pressed_' + event.code, event.code, event);
    }
  }, false
);

window.addEventListener(
  "keyup", (event) => {
    event = keyboard.keyStates.get(event.code);
    if (event) {
      //keyboard.keyStates.set(event.code, event);
      event.wasReleased = true;
      keyboard.events.call('released', event.code, event);
      keyboard.events.call('released_' + event.code, event.code, event);
    }
  }, false
);

/*keyboard.events.on('pressed', null, (keyCode, event) => {
  console.log('dd', keyCode);
});*/
/*
setInterval(() => {
  console.log(keyboard.isKeyReleased('KeyA'));
  keyboard.update();
}, 0);*/

module.exports = keyboard;