Antiscroll: cross-browser native OS X Lion scrollbars
Antiscroll fixes a fundamental problem JavaScript UI developers commonly face:
how do I customize scrollbars so that they get out of the way (for example, for
different form widgets), but retain their native scrolling properties (like OS
widge scrolling velocity, or OS specific inertia)?
Antiscroll addresses this issue by providing a cross-browser implementation of
the scrollbars popularized by OS X Lion that retains native properties.
Features
- Supports mousewheels, trackpads, other input devices natively.
- Total size is 1kb minified and gzipped.
- Doesn't magically autowrap your elements with divs (manual wrapping is necessary,
please seeindex.htmldemo) - Fade in/out controlled with CSS3 animations.
- Shows scrollbars upon hovering.
- Scrollbars are draggable.
- Size of container can be dynamically adjusted and scrollbars will adapt.
- Supports IE7+, Firefox 3+, Chrome, Safari
Demo
Please click here to see it in
action.
Installation
- Wrap scrollable content with the class
antiscroll-inner - Wrap the above with the class
antiscroll-wrap - Include the following Javascript
$(function () {
$('.antiscroll-wrap').antiscroll();
});
Configuration
You may remove automatic scrollbar hiding by passing in a key-value to the antiscroll() function like so:
$(function () {
$('.antiscroll-wrap').antiscroll({
autoHide: false
});
});
What does it look like?
Firefox 8 overflow: scroll and antiscroll on OS X
IE 9 overflow: scroll and antiscroll
How does it work?
The idea behind Antiscroll is to leverage real scrollbars, but hide them from the
view. The implementation consists of 3 steps.
1. Measure scrollbars width
In order to measure scrollbars width we use the following technique:
- Insert a div with a fixed width and measure the inner width
- Force
overflow: scroll - Measure the inner width. The difference is the scrollbar width
The caveat of this technique is precisely OS X Lion. Since the scrollbars
float on top of the content, their width is always zero but they still
overlay your content. To address this issue we add an aditional step which
consists of declaring ::-webkit-scrollbar and ::scrollbar CSS
pseudo-properties that set the width of the scrollbars to zero for modern
browsers.
2. Adjust the width of the inner element
The parent element receives overflow: hidden and the desired width and height
for the widget.
The inner .antiscroll-inner element receives the same width and height, but
the script augments this two values with the size of the scrollbars,
effectively hiding them.
The inner element is always overflow: scroll.
3. Listen on the scroll event
We attach the scroll event to the scrollable element, and we create our
scrollbars as absolutely positioned divs. We update our scrollbars based on the
detected scrollLeft and scrollTop of the element.
Credits
This technique was inspired by Facebook's chat sidebar/ticker, which also reproduces
Lion's scrollbars, but relying on setting the width of the inner container to an
arbitrarily large width, therefore allowing scrolling of a single axis
(vertical).
Scrollbar size detection based on the work of Jonathan
Sharp.
Contributors
- Alexandre Rocha Lima e marcondes @arlm
- Othree @othree
- PG Herveou @pgherveou
- Fontaine Shu @fontaineshu
Dependencies
- jQuery
- jquery-mousewheel: optional,
only needed if you want to block further scrolling when you reach the boundaries
of scrollable element.
TODO
- Automatically leverage Joe Hewitt's
scrollability as a replacement
technique if a touch-enabled browser is detected. - IE6 support
License
(The MIT License)
Copyright (c) 2011 Guillermo Rauch <guillermo@learnboost.com>
Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
'Software'), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.