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2020-05-19 11:43:42 +03:00
javascript-detect-element-resize
================================
A Cross-Browser, Event-based, Element Resize Detection.
In short, this implementation does NOT use an internal timer to detect size changes (as most implementations I found do).
It uses `scroll` events on most browsers, and the [`onresize` event][5] on IE10 and below.
The method used not only detects javascript generated resize changes but also changes made from CSS pseudo classes e.g. :hover, CSS animations, etc.
About the libraries
===================
I was searching for a library that allowed me to detect when an DOM element changes size, and all solutions I found had two problems:
1. only available as jQuery libraries (so no standalone Javascript)
2. all had terrible performance (because all of them use timers to intermittently poll the size of the elements to detect a change).
Then I came across this [great post][1] on [Back Alley Coder][3] about using ~~[overflow and underflow events][2]~~ [`scroll` events][2] to do event-based element resize detection; and it works great without consuming resources at all (just like any other browser originated event).
The libraries on this repository are just a ready-to-use implementation of the above, one pure javascript and the other a jQuery plugin version (just for convenience).
Libraries
=========
Pure Javascript library usage
-----------------------------
```html
<script type="text/javascript" src="detect-element-resize.js"></script>
<script type="text/javascript">
var resizeElement = document.getElementById('resizeElement'),
resizeCallback = function() {
/* do something */
};
addResizeListener(resizeElement, resizeCallback);
removeResizeListener(resizeElement, resizeCallback);
</script>
```
jQuery plugin library usage
---------------------------
```html
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="jquery.resize.js"></script>
<script type="text/javascript">
var myFunc = function() {
/* do something */
};
$('#resizeElement').resize(myFunc);
$('#resizeElement').removeResize(myFunc);
</script>
```
Compatibility
-------------
Works great on:
- Chrome
- Firefox
- IE 11 and below (tested on 11, 10, 9, 8 and 7)
Known Issues:
- On IE 10 and below: If you detach the element and re-attach it, you will need to add the resize listener again.
Doesn't work on:
- ???
Please [let me know](https://github.com/sdecima/javascript-detect-element-resize/issues) if you test these libraries on any other browser, of if you run into issues with any of the above browsers.
TODO
====
- Fix detach/re-attach issue on IE 10 and below (IE 9 and below doesn't support CSS animations so we can use those as in the rest of the browsers).
- Create minified version of the libraries.
- Add support for standard jQuery bind method on 'resize' event.
Release Notes
=============
v0.5.3
------
- Fix for when the element is inside a display:none, and for when it is detached and reattached (changed @thomassuckow and @jerjou fixes to properly use CSS animations)
- Adding /tests/ with some general QUnit tests to help test on multiple browsers
v0.5.2
------
- Adding a bower.json file (thanks @adamjcook)
- Fix style being appended to head multiple times (thanks @thomassuckow and @progman32)
- Work around a chrome bug that would show scrollbars in some cases (thanks @thomassuckow)
v0.5.1
------
- Fix for resize event on IE
v0.5
----
- It is now fully compatible with IE11.
- Rework of the libraries using the new scroll-event-based code of [Back Alley Coder][1]. For the pure javascript version I pretty much used the original code from [Back Alley Coder][1] and only had to add code to dynamically insert the styling for the resize-triggers.
v0.4.1
----
- Fix for jQuery 'resize' method overlapping.
v0.4
----
- Adds better cross-browser support, it now uses MutationObservers only on IE11.
v0.3
----
- Adds support for MutationObservers.
- Adds support for IE 11.
- Wrapped the pure javascript version of the library (to hide non-public methods).
v0.2
----
- Adds support for IE 8 and below.
v0.1
----
- Implementation based on the [works][1] of [Back Alley Coder][3].
- Adds jQuery plugin version.
References
==========
Similar libraries (but they use timers)
---------------------------------------
[jQuery-mutate](http://www.jqui.net/jquery-projects/jquery-mutate-official/)
[jQuery-resize-plugin](http://benalman.com/projects/jquery-resize-plugin/)
Don't get me wrong, these are great libraries and work as advertised, it's just that they are not easy on browser resources.
External links
--------------
[Back Alley Coder: Cross-Browser, Event-based, Element Resize Detection][1]
[Back Alley Coder: Overflow and Underflow Events][2]
[1]: http://www.backalleycoder.com/2013/03/18/cross-browser-event-based-element-resize-detection/
[2]: http://www.backalleycoder.com/2013/03/14/oft-overlooked-overflow-and-underflow-events/
[3]: http://www.backalleycoder.com/
[4]: http://www.w3.org/TR/dom/#mutation-observers
[5]: http://msdn.microsoft.com/en-us/library/ie/ms536959