JQuery: How to call RESIZE event only once it's FINISHED resizing?

Question

How do I call a function once the browser windows has FINISHED resizing?

I\'m trying to do it like so, but am having problems. I\'m using the JQuery Resize

Answer 1

This is my approach:

document.addEventListener('DOMContentLoaded', function(){
    var tos = {};
    var idi = 0;
    var fn  = function(id)
    {
        var len = Object.keys(tos).length;

        if(len == 0)
            return;

        to = tos[id];
        delete tos[id];

        if(len-1 == 0)
            console.log('Resize finished trigger');
    };

    window.addEventListener('resize', function(){
        idi++;
        var id = 'id-'+idi;
        tos[id] = window.setTimeout(function(){fn(id)}, 500);
    });
});

The resize-event-listener catches all incoming resize calls, creates a timeout-function for each and saves the timeout-identifier along with an iterating number prepended by 'id-' (to be usable as array key) in the tos-array.

each time, the timout triggers, it calls the fn-function, that checks, if that was the last timeout in the tos array (the fn-function deletes every executed timout). if true (= if(len-1 == 0)), the resizing is finished.

Answer 2

Underscore.js has a couple of great methods for this task: throttle and debounce. Even if you're not using Underscore, take a look at the source of these functions. Here's an example:

var redraw = function() {'redraw logic here'};
var debouncedRedraw = _.debounce(redraw, 750);
$(window).on('resize', debouncedRedraw);

Answer 3

jQuery provides an off method to remove event handler

$(window).resize(function(){
    if(magic == true) {
        $(window).off('resize', arguments.callee);
    }
});

Answer 4

Just to add to the above, it is common to get unwanted resize events because of scroll bars popping in and out, here is some code to avoid that:

function registerResize(f) {
    $(window).resize(function() {
        clearTimeout(this.resizeTimeout);
        this.resizeTimeout = setTimeout(function() {
            var oldOverflow = document.body.style.overflow;
            document.body.style.overflow = "hidden";
            var currHeight = $(window).height(),
                currWidth = $(window).width();
            document.body.style.overflow = oldOverflow;

            var prevUndefined = (typeof this.prevHeight === 'undefined' || typeof this.prevWidth === 'undefined');
            if (prevUndefined || this.prevHeight !== currHeight || this.prevWidth !== currWidth) {
                //console.log('Window size ' + (prevUndefined ? '' : this.prevHeight + "," + this.prevWidth) + " -> " + currHeight + "," + currWidth);
                this.prevHeight = currHeight;
                this.prevWidth = currWidth;

                f(currHeight, currWidth);
            }
        }, 200);
    });
    $(window).resize(); // initialize
}

registerResize(function(height, width) {
    // this will be called only once per resize regardless of scrollbars changes
});

see jsfiddle

Answer 5

You can use setTimeout() and clearTimeout() in conjunction with jQuery.data:

$(window).resize(function() {
    clearTimeout($.data(this, 'resizeTimer'));
    $.data(this, 'resizeTimer', setTimeout(function() {
        //do something
        alert("Haven't resized in 200ms!");
    }, 200));
});

Update

I wrote an extension to enhance jQuery's default on (& bind)-event-handler. It attaches an event handler function for one or more events to the selected elements if the event was not triggered for a given interval. This is useful if you want to fire a callback only after a delay, like the resize event, or else. https://github.com/yckart/jquery.unevent.js

;(function ($) {
    var methods = { on: $.fn.on, bind: $.fn.bind };
    $.each(methods, function(k){
        $.fn[k] = function () {
            var args = [].slice.call(arguments),
                delay = args.pop(),
                fn = args.pop(),
                timer;

            args.push(function () {
                var self = this,
                    arg = arguments;
                clearTimeout(timer);
                timer = setTimeout(function(){
                    fn.apply(self, [].slice.call(arg));
                }, delay);
            });

            return methods[k].apply(this, isNaN(delay) ? arguments : args);
        };
    });
}(jQuery));

Use it like any other on or bind-event handler, except that you can pass an extra parameter as a last:

$(window).on('resize', function(e) {
    console.log(e.type + '-event was 200ms not triggered');
}, 200);

http://jsfiddle.net/ARTsinn/EqqHx/

Answer 6

var lightbox_resize = false;
$(window).resize(function() {
    console.log(true);
    if (lightbox_resize)
        clearTimeout(lightbox_resize);
    lightbox_resize = setTimeout(function() {
        console.log('resize');
    }, 500);
});