nodebb/public/vendor/autosize.js

/*!
	Autosize 2.0.0
	license: MIT
	http://www.jacklmoore.com/autosize
*/
'use strict';
/*globals define*/
(function (root, factory) {
	if (typeof define === 'function' && define.amd) {
		// AMD. Register as an anonymous module.
		define('autosize', factory);
	} else if (typeof exports === 'object') {
		// Node. Does not work with strict CommonJS, but
		// only CommonJS-like environments that support module.exports,
		// like Node.
		module.exports = factory();
	} else {
		// Browser globals (root is window)
		root.autosize = factory();
  }
}(this, function () {
	function main(ta) {
		if (!ta || !ta.nodeName || ta.nodeName !== 'TEXTAREA' || ta.hasAttribute('data-autosize-on')) { return; }

		var maxHeight;
		var heightOffset;
		var amountOfCR;

		function init() {
			var style = window.getComputedStyle(ta, null);

			if (style.resize === 'vertical') {
				ta.style.resize = 'none';
			} else if (style.resize === 'both') {
				ta.style.resize = 'horizontal';
			}

			// horizontal overflow is hidden, so break-word is necessary for handling words longer than the textarea width
			ta.style.wordWrap = 'break-word';

			// Chrome/Safari-specific fix:
			// When the textarea y-overflow is hidden, Chrome/Safari doesn't reflow the text to account for the space
			// made available by removing the scrollbar. This workaround will cause the text to reflow.
			var width = ta.style.width;
			ta.style.width = '0px';
			// Force reflow:
			/* jshint ignore:start */
			ta.offsetWidth;
			/* jshint ignore:end */
			ta.style.width = width;

			maxHeight = style.maxHeight !== 'none' ? parseFloat(style.maxHeight) : false;
			
			if (style.boxSizing === 'content-box') {
				heightOffset = -(parseFloat(style.paddingTop)+parseFloat(style.paddingBottom));
			} else {
				heightOffset = parseFloat(style.borderTopWidth)+parseFloat(style.borderBottomWidth);
			}

			amountOfCR = (ta.value.match(/\n/g) || []).length;
			adjust();
		}

		function adjust() {
			var startHeight = ta.style.height;
			var htmlTop = document.documentElement.scrollTop;
			var bodyTop = document.body.scrollTop;

			var newAmountOfCR = (ta.value.match(/\n/g) || []).length;
			if (newAmountOfCR === amountOfCR) {
				return;
			}

			amountOfCR = newAmountOfCR;
			
			ta.style.height = 'auto';

			var endHeight = ta.scrollHeight+heightOffset;

			if (maxHeight !== false && maxHeight < endHeight) {
				endHeight = maxHeight;
				if (ta.style.overflowY !== 'scroll') {
					ta.style.overflowY = 'scroll';
				}
			} else if (ta.style.overflowY !== 'hidden') {
				ta.style.overflowY = 'hidden';
			}

			ta.style.height = endHeight+'px';

			// prevents scroll-position jumping
			document.documentElement.scrollTop = htmlTop;
			document.body.scrollTop = bodyTop;

			if (startHeight !== ta.style.height) {
				var evt = document.createEvent('Event');
				evt.initEvent('autosize.resized', true, false);
				ta.dispatchEvent(evt);
			}
		}

		// IE9 does not fire onpropertychange or oninput for deletions,
		// so binding to onkeyup to catch most of those events.
		// There is no way that I know of to detect something like 'cut' in IE9.
		if ('onpropertychange' in ta && 'oninput' in ta) {
			ta.addEventListener('keyup', adjust);
		}

		window.addEventListener('resize', adjust);
		ta.addEventListener('input', adjust);

		ta.addEventListener('autosize.update', adjust);

		ta.addEventListener('autosize.destroy', function(style){
			window.removeEventListener('resize', adjust);
			ta.removeEventListener('input', adjust);
			ta.removeEventListener('keyup', adjust);
			ta.removeEventListener('autosize.destroy');

			Object.keys(style).forEach(function(key){
				ta.style[key] = style[key];
			});

			ta.removeAttribute('data-autosize-on');
		}.bind(ta, {
			height: ta.style.height,
			overflow: ta.style.overflow,
			overflowY: ta.style.overflowY,
			wordWrap: ta.style.wordWrap,
			resize: ta.style.resize
		}));

		ta.setAttribute('data-autosize-on', true);
		ta.style.overflow = 'hidden';
		ta.style.overflowY = 'hidden';

		init();		
	}

	// Do nothing in IE8 or lower
	if (typeof window.getComputedStyle !== 'function') {
		return function(elements) {
			return elements;
		};
	} else {
		return function(elements) {
			if (elements && elements.length) {
				Array.prototype.forEach.call(elements, main);
			} else if (elements && elements.nodeName) {
				main(elements);
			}
			return elements;
		};
	}
}));