ES6Timer

es6timer.js

const STATE_READY = 1;
const STATE_PLAYING = 2;
const STATE_PAUSE = 3;
const STATE_END = 0;

class Timer {
    constructor(updateFunc, sec) {
        this.sec = sec;
        this.updateFunc = updateFunc;
        this.state = STATE_READY;
    }

    start() {
        this.date = Date.now();
        this._run();
        this.state = STATE_PLAYING;
    }
    
    _run() {
        const ms = Date.now() - this.date;
        const nokori = this.sec*1000 - ms;
        if(nokori <= 0) {
            this.updateFunc(0);
            this.destroy();
        } else 
        if(!this.isPause && this.updateFunc){
            this.updateFunc(nokori);
            setTimeout(this._run.bind(this), 33);
        }
    }
    
    add(sec) {
        this.date = this.date + (sec * 1000);
    }
    
    pause() {
        this.state = STATE_PAUSE;
        this.isPause = true;
        this.pauseData = Date.now();
    }

    resume() {
        this.isPause = false;
        this.date =  this.date + (Date.now() - this.pauseData);
        this.state = STATE_PLAYING;
        this._run();
        
    }

    destroy() {
        delete this.isPause;
        delete this.updateFunc;
        delete this.sec;
        delete this.date;
        this.state = STATE_END;
    }
    static get STATE_READY() {
        return STATE_READY;
    }
    static get STATE_PLAYING() {
        return STATE_PLAYING;
    }
    static get STATE_PAUSE() {
        return STATE_PAUSE;
    }
    static get STATE_END() {
        return STATE_END;
    }
}

export default Timer;