app/assets/javascripts/jquery.autosize.js
/*!
Autosize v1.18.4 - 2014-01-11
Automatically adjust textarea height based on user input.
(c) 2014 Jack Moore - http://www.jacklmoore.com/autosize
license: http://www.opensource.org/licenses/mit-license.php
*/
(function ($) {
var
defaults = {
className: 'autosizejs',
append: '',
callback: false,
resizeDelay: 10,
placeholder: true
},
// border:0 is unnecessary, but avoids a bug in Firefox on OSX
copy = '<textarea tabindex="-1" style="position:absolute; top:-999px; left:0; right:auto; bottom:auto; border:0; padding: 0; -moz-box-sizing:content-box; -webkit-box-sizing:content-box; box-sizing:content-box; word-wrap:break-word; height:0 !important; min-height:0 !important; overflow:hidden; transition:none; -webkit-transition:none; -moz-transition:none;"/>',
// line-height is conditionally included because IE7/IE8/old Opera do not return the correct value.
typographyStyles = [
'fontFamily',
'fontSize',
'fontWeight',
'fontStyle',
'letterSpacing',
'textTransform',
'wordSpacing',
'textIndent'
],
// to keep track which textarea is being mirrored when adjust() is called.
mirrored,
// the mirror element, which is used to calculate what size the mirrored element should be.
mirror = $(copy).data('autosize', true)[0];
// test that line-height can be accurately copied.
mirror.style.lineHeight = '99px';
if ($(mirror).css('lineHeight') === '99px') {
typographyStyles.push('lineHeight');
}
mirror.style.lineHeight = '';
$.fn.autosize = function (options) {
if (!this.length) {
return this;
}
options = $.extend({}, defaults, options || {});
if (mirror.parentNode !== document.body) {
$(document.body).append(mirror);
}
return this.each(function () {
var
ta = this,
$ta = $(ta),
maxHeight,
minHeight,
boxOffset = 0,
callback = $.isFunction(options.callback),
originalStyles = {
height: ta.style.height,
overflow: ta.style.overflow,
overflowY: ta.style.overflowY,
wordWrap: ta.style.wordWrap,
resize: ta.style.resize
},
timeout,
width = $ta.width();
if ($ta.data('autosize')) {
// exit if autosize has already been applied, or if the textarea is the mirror element.
return;
}
$ta.data('autosize', true);
if ($ta.css('box-sizing') === 'border-box' || $ta.css('-moz-box-sizing') === 'border-box' || $ta.css('-webkit-box-sizing') === 'border-box'){
boxOffset = $ta.outerHeight() - $ta.height();
}
// IE8 and lower return 'auto', which parses to NaN, if no min-height is set.
minHeight = Math.max(parseInt($ta.css('minHeight'), 10) - boxOffset || 0, $ta.height());
$ta.css({
overflow: 'hidden',
overflowY: 'hidden',
wordWrap: 'break-word', // horizontal overflow is hidden, so break-word is necessary for handling words longer than the textarea width
resize: ($ta.css('resize') === 'none' || $ta.css('resize') === 'vertical') ? 'none' : 'horizontal'
});
// The mirror width must exactly match the textarea width, so using getBoundingClientRect because it doesn't round the sub-pixel value.
// window.getComputedStyle, getBoundingClientRect returning a width are unsupported, but also unneeded in IE8 and lower.
function setWidth() {
var width;
var style = window.getComputedStyle ? window.getComputedStyle(ta, null) : false;
if (style) {
width = ta.getBoundingClientRect().width;
if (width === 0) {
width = parseInt(style.width,10);
}
$.each(['paddingLeft', 'paddingRight', 'borderLeftWidth', 'borderRightWidth'], function(i,val){
width -= parseInt(style[val],10);
});
} else {
width = Math.max($ta.width(), 0);
}
mirror.style.width = width + 'px';
}
function initMirror() {
var styles = {};
mirrored = ta;
mirror.className = options.className;
maxHeight = parseInt($ta.css('maxHeight'), 10);
// mirror is a duplicate textarea located off-screen that
// is automatically updated to contain the same text as the
// original textarea. mirror always has a height of 0.
// This gives a cross-browser supported way getting the actual
// height of the text, through the scrollTop property.
$.each(typographyStyles, function(i,val){
styles[val] = $ta.css(val);
});
$(mirror).css(styles);
setWidth();
// Chrome-specific fix:
// When the textarea y-overflow is hidden, Chrome doesn't reflow the text to account for the space
// made available by removing the scrollbar. This workaround triggers the reflow for Chrome.
if (window.chrome) {
var width = ta.style.width;
ta.style.width = '0px';
var ignore = ta.offsetWidth;
ta.style.width = width;
}
}
// Using mainly bare JS in this function because it is going
// to fire very often while typing, and needs to very efficient.
function adjust() {
var height, original;
if (mirrored !== ta) {
initMirror();
} else {
setWidth();
}
if (!ta.value && options.placeholder) {
// If the textarea is empty, copy the placeholder text into
// the mirror control and use that for sizing so that we
// don't end up with placeholder getting trimmed.
mirror.value = ($(ta).attr("placeholder") || '') + options.append;
} else {
mirror.value = ta.value + options.append;
}
mirror.style.overflowY = ta.style.overflowY;
original = parseInt(ta.style.height,10);
// Setting scrollTop to zero is needed in IE8 and lower for the next step to be accurately applied
mirror.scrollTop = 0;
mirror.scrollTop = 9e4;
// Using scrollTop rather than scrollHeight because scrollHeight is non-standard and includes padding.
height = mirror.scrollTop;
if (maxHeight && height > maxHeight) {
ta.style.overflowY = 'scroll';
height = maxHeight;
} else {
ta.style.overflowY = 'hidden';
if (height < minHeight) {
height = minHeight;
}
}
height += boxOffset;
if (original !== height) {
ta.style.height = height + 'px';
if (callback) {
options.callback.call(ta,ta);
}
}
}
function resize () {
clearTimeout(timeout);
timeout = setTimeout(function(){
var newWidth = $ta.width();
if (newWidth !== width) {
width = newWidth;
adjust();
}
}, parseInt(options.resizeDelay,10));
}
if ('onpropertychange' in ta) {
if ('oninput' in ta) {
// Detects IE9. IE9 does not fire onpropertychange or oninput for deletions,
// so binding to onkeyup to catch most of those occasions. There is no way that I
// know of to detect something like 'cut' in IE9.
$ta.on('input.autosize keyup.autosize', adjust);
} else {
// IE7 / IE8
$ta.on('propertychange.autosize', function(){
if(event.propertyName === 'value'){
adjust();
}
});
}
} else {
// Modern Browsers
$ta.on('input.autosize', adjust);
}
// Set options.resizeDelay to false if using fixed-width textarea elements.
// Uses a timeout and width check to reduce the amount of times adjust needs to be called after window resize.
if (options.resizeDelay !== false) {
$(window).on('resize.autosize', resize);
}
// Event for manual triggering if needed.
// Should only be needed when the value of the textarea is changed through JavaScript rather than user input.
$ta.on('autosize.resize', adjust);
// Event for manual triggering that also forces the styles to update as well.
// Should only be needed if one of typography styles of the textarea change, and the textarea is already the target of the adjust method.
$ta.on('autosize.resizeIncludeStyle', function() {
mirrored = null;
adjust();
});
$ta.on('autosize.destroy', function(){
mirrored = null;
clearTimeout(timeout);
$(window).off('resize', resize);
$ta
.off('autosize')
.off('.autosize')
.css(originalStyles)
.removeData('autosize');
});
// Call adjust in case the textarea already contains text.
adjust();
});
};
}(window.jQuery || window.$)); // jQuery or jQuery-like library, such as Zepto