cables_dev/cables/src/core/timer.js

import { EventTarget } from "./eventtarget.js";

/** @namespace CABLES */

export const internalNow = function ()
{
    return window.performance.now();
};



/**
 * current time in milliseconds
 * @memberof CABLES
 * @function now
 * @static
 */
export const now = function ()
{
    return internalNow();
};

// ----------------------------

/**
 * Measuring time
 * @namespace external:CABLES#Timer
 * @hideconstructor
 * @class
 */
const Timer = function ()
{
    EventTarget.apply(this);

    this._timeStart = internalNow();
    this._timeOffset = 0;

    this._currentTime = 0;
    this._lastTime = 0;
    this._paused = true;
    this._delay = 0;
    this.overwriteTime = -1;
};


Timer.prototype._internalNow = function ()
{
    if (this._ts) return this._ts;
    return internalNow();
};

Timer.prototype._getTime = function ()
{
    this._lastTime = (this._internalNow() - this._timeStart) / 1000;
    return this._lastTime + this._timeOffset;
};

Timer.prototype.setDelay = function (d)
{
    this._delay = d;
    this.emitEvent("timeChange");
};

/**
 * @function
 * @memberof Timer
 * @instance
 * @description returns true if timer is playing
 * @return {Boolean} value
 */
Timer.prototype.isPlaying = function ()
{
    return !this._paused;
};

/**
 * @function
 * @memberof Timer
 * @instance
 * @param ts
 * @description update timer
 * @return {Number} time
 */
Timer.prototype.update = function (ts)
{
    if (ts) this._ts = ts;
    if (this._paused) return;
    this._currentTime = this._getTime();

    return this._currentTime;
};

/**
 * @function
 * @memberof Timer
 * @instance
 * @return {Number} time in milliseconds
 */
Timer.prototype.getMillis = function ()
{
    return this.get() * 1000;
};

/**
 * @function
 * @memberof Timer
 * @instance
 * @return {Number} value time in seconds
 */
Timer.prototype.get = Timer.prototype.getTime = function ()
{
    if (this.overwriteTime >= 0) return this.overwriteTime - this._delay;
    return this._currentTime - this._delay;
};

/**
 * toggle between play/pause state
 * @function
 * @memberof Timer
 * @instance
 */
Timer.prototype.togglePlay = function ()
{
    if (this._paused) this.play();
    else this.pause();
};

/**
 * set current time
 * @function
 * @memberof Timer
 * @instance
 * @param {Number} t
 */
Timer.prototype.setTime = function (t)
{
    if (isNaN(t) || t < 0) t = 0;
    this._timeStart = this._internalNow();
    this._timeOffset = t;
    this._currentTime = t;
    this.emitEvent("timeChange");
};

Timer.prototype.setOffset = function (val)
{
    if (this._currentTime + val < 0)
    {
        this._timeStart = this._internalNow();
        this._timeOffset = 0;
        this._currentTime = 0;
    }
    else
    {
        this._timeOffset += val;
        this._currentTime = this._lastTime + this._timeOffset;
    }
    this.emitEvent("timeChange");
};

/**
 * (re)starts the timer
 * @function
 * @memberof Timer
 * @instance
 */
Timer.prototype.play = function ()
{
    this._timeStart = this._internalNow();
    this._paused = false;
    this.emitEvent("playPause");
};

/**
 * pauses the timer
 * @function
 * @memberof Timer
 * @instance
 */
Timer.prototype.pause = function ()
{
    this._timeOffset = this._currentTime;
    this._paused = true;
    this.emitEvent("playPause");
};

export { Timer };