javascript debounce

debounce.js

/**
* Debounce creates a FUNCTION that when invoked, delays invoking func for wait milliseconds since
* the last time it is called.
*
* Examples of where this may be useful:
*
*   // Avoiding repeated costly operations while a window size is in flux
*   jQuery(window).on('resize', debounce(calculateLayout, 150));
*
*   // Avoiding triggering an event on a double button press
*   jQuery('#postbox').on('click', debounce(sendMail, 2000));
*
* @param {number} func
* @param {number} milliseconds
* @retun {function} a function that will wait {@param wait} milliseconds since it's last called
*   to invoke {@param func}.
*/
function debounce(func, wait, maxWait) {
    var timeoutId,
        timeoutIdMax;
    
    return function() {
        if (timeoutId) {
            window.clearTimeout(timeoutId);
        }
        if (!timeoutIdMax) {
            
            timeoutIdMax = window.setTimeout(function () {
                window.clearTimeout(timeoutId);
                func();
            }, maxWait); // you want to make sure foo executes and timeoutId is cancelled
        }
        
        timeoutId = window.setTimeout(function() {
            func();
            if (timeoutIdMax) window.clearTimeout(timeoutIdMax);
        }, wait); // you want to make sure foo executes maxTimeoutId is cancelled
    };
};