ares-ide/enyo/source/kernel/job.js

A browser-based code editor and UI designer for Enyo 2 projects

/**
	Invokes function _inJob_ after _inWait_ milliseconds have elapsed since the
	last time _inJobName_ was referenced.

	Jobs can be used to throttle behaviors.  If some event may occur once or
	multiple times, but we want a response to occur only once every _n_	seconds,
	we can use a job.

		onscroll: function() {
			// updateThumb will be called, but only when 1s has elapsed since the
			// last onscroll
			enyo.job("updateThumb", this.bindSafely("updateThumb"), 1000);
		}
*/
enyo.job = function(inJobName, inJob, inWait) {
	enyo.job.stop(inJobName);
	enyo.job._jobs[inJobName] = setTimeout(function() {
		enyo.job.stop(inJobName);
		inJob();
	}, inWait);
};

/**
	Cancels the named job, if it has not already fired.
*/
enyo.job.stop = function(inJobName) {
	if (enyo.job._jobs[inJobName]) {
		clearTimeout(enyo.job._jobs[inJobName]);
		delete enyo.job._jobs[inJobName];
	}
};

/**
	Invoke _inJob_ immediately, then prevent any other calls to
	enyo.job.throttle with the same _inJobName_ from running for
	the next _inWait_ milliseconds.

	This is used for throttling user events when you want an
	immediate response, but later invocations might just be noise
	if they arrive too often.
*/
enyo.job.throttle = function(inJobName, inJob, inWait) {
	// if we still have a job with this name pending, return immediately
	if (enyo.job._jobs[inJobName]) {
		return;
	}
	inJob();
	enyo.job._jobs[inJobName] = setTimeout(function() {
		enyo.job.stop(inJobName);
	}, inWait);
};

enyo.job._jobs = {};