zulip/static/third/jquery-autosize/jquery.autosize.js

/** @preserve
	Autosize v1.17.7 - 2013-09-03
	Automatically adjust textarea height based on user input.
	(c) 2013 Jack Moore - http://www.jacklmoore.com/autosize
	license: http://www.opensource.org/licenses/mit-license.php
	---
	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.
*/
(function (factory) {
	if (typeof define === 'function' && define.amd) {
		// AMD. Register as an anonymous module.
		define(['jquery'], factory);
	} else {
		// Browser globals: jQuery or jQuery-like library, such as Zepto
		factory(window.jQuery || window.$);
	}
}(function ($) {
	var
	defaults = {
		className: 'autosizejs',
		append: '',
		callback: false,
		resizeDelay: 10
	},

	// 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) {
		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.
			function setWidth() {
				var style, width;

				if ('getComputedStyle' in window) {
					style = window.getComputedStyle(ta);
					width = ta.getBoundingClientRect().width;

					$.each(['paddingLeft', 'paddingRight', 'borderLeftWidth', 'borderRightWidth'], function(i,val){
						width -= parseInt(style[val],10);
					});

					mirror.style.width = width + 'px';
				}
				else {
					// window.getComputedStyle, getBoundingClientRect returning a width are unsupported and unneeded in IE8 and lower.
					mirror.style.width = Math.max($ta.width(), 0) + '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();
				}

				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();
		});
	};
}));