autosize.js

/*!
	Autosize 3.0.17
	license: MIT
	http://www.jacklmoore.com/autosize
*/
(function (global, factory) {
	if (typeof define === 'function' && define.amd) {
		define(['exports', 'module'], factory);
	} else if (typeof exports !== 'undefined' && typeof module !== 'undefined') {
		factory(exports, module);
	} else {
		var mod = {
			exports: {}
		};
		factory(mod.exports, mod);
		global.autosize = mod.exports;
	}
})(this, function (exports, module) {
	'use strict';

	var set = typeof Set === 'function' ? new Set() : (function () {
		var list = [];

		return {
			has: function has(key) {
				return Boolean(list.indexOf(key) > -1);
			},
			add: function add(key) {
				list.push(key);
			},
			'delete': function _delete(key) {
				list.splice(list.indexOf(key), 1);
			} };
	})();

	var createEvent = function createEvent(name) {
		return new Event(name);
	};
	try {
		new Event('test');
	} catch (e) {
		// IE does not support `new Event()`
		createEvent = function (name) {
			var evt = document.createEvent('Event');
			evt.initEvent(name, true, false);
			return evt;
		};
	}

	function assign(ta) {
		if (!ta || !ta.nodeName || ta.nodeName !== 'TEXTAREA' || set.has(ta)) return;

		var heightOffset = null;
		var clientWidth = ta.clientWidth;
		var cachedHeight = null;

		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';
			}

			if (style.boxSizing === 'content-box') {
				heightOffset = -(parseFloat(style.paddingTop) + parseFloat(style.paddingBottom));
			} else {
				heightOffset = parseFloat(style.borderTopWidth) + parseFloat(style.borderBottomWidth);
			}
			// Fix when a textarea is not on document body and heightOffset is Not a Number
			if (isNaN(heightOffset)) {
				heightOffset = 0;
			}

			update();
		}

		function changeOverflow(value) {
			{
				// Chrome/Safari-specific fix:
				// When the textarea y-overflow is hidden, Chrome/Safari do not reflow the text to account for the space
				// made available by removing the scrollbar. The following forces the necessary text reflow.
				var width = ta.style.width;
				ta.style.width = '0px';
				// Force reflow:
				/* jshint ignore:start */
				ta.offsetWidth;
				/* jshint ignore:end */
				ta.style.width = width;
			}

			ta.style.overflowY = value;

			resize();
		}

		function getParentOverflows(el) {
			var arr = [];

			while (el && el.parentNode && el.parentNode instanceof Element) {
				if (el.parentNode.scrollTop) {
					arr.push({
						node: el.parentNode,
						scrollTop: el.parentNode.scrollTop });
				}
				el = el.parentNode;
			}

			return arr;
		}

		function resize() {
			var originalHeight = ta.style.height;
			var overflows = getParentOverflows(ta);
			var docTop = document.documentElement && document.documentElement.scrollTop; // Needed for Mobile IE (ticket #240)

			ta.style.height = 'auto';

			var endHeight = ta.scrollHeight + heightOffset;

			if (ta.scrollHeight === 0) {
				// If the scrollHeight is 0, then the element probably has display:none or is detached from the DOM.
				ta.style.height = originalHeight;
				return;
			}

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

			// used to check if an update is actually necessary on window.resize
			clientWidth = ta.clientWidth;

			// prevents scroll-position jumping
			overflows.forEach(function (el) {
				el.node.scrollTop = el.scrollTop;
			});

			if (docTop) {
				document.documentElement.scrollTop = docTop;
			}
		}

		function update() {
			resize();

			var computed = window.getComputedStyle(ta, null);
			var computedHeight = Math.round(parseFloat(computed.height));
			var styleHeight = Math.round(parseFloat(ta.style.height));

			// The computed height not matching the height set via resize indicates that
			// the max-height has been exceeded, in which case the overflow should be set to visible.
			if (computedHeight !== styleHeight) {
				if (computed.overflowY !== 'visible') {
					changeOverflow('visible');
				}
			} else {
				// Normally keep overflow set to hidden, to avoid flash of scrollbar as the textarea expands.
				if (computed.overflowY !== 'hidden') {
					changeOverflow('hidden');
				}
			}

			if (cachedHeight !== computedHeight) {
				cachedHeight = computedHeight;
				var evt = createEvent('autosize:resized');
				ta.dispatchEvent(evt);
			}
		}

		var pageResize = function pageResize() {
			if (ta.clientWidth !== clientWidth) {
				update();
			}
		};

		var destroy = (function (style) {
			window.removeEventListener('resize', pageResize, false);
			ta.removeEventListener('input', update, false);
			ta.removeEventListener('keyup', update, false);
			ta.removeEventListener('autosize:destroy', destroy, false);
			ta.removeEventListener('autosize:update', update, false);
			set['delete'](ta);

			Object.keys(style).forEach(function (key) {
				ta.style[key] = style[key];
			});
		}).bind(ta, {
			height: ta.style.height,
			resize: ta.style.resize,
			overflowY: ta.style.overflowY,
			overflowX: ta.style.overflowX,
			wordWrap: ta.style.wordWrap });

		ta.addEventListener('autosize:destroy', destroy, false);

		// 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', update, false);
		}

		window.addEventListener('resize', pageResize, false);
		ta.addEventListener('input', update, false);
		ta.addEventListener('autosize:update', update, false);
		set.add(ta);
		ta.style.overflowX = 'hidden';
		ta.style.wordWrap = 'break-word';

		init();
	}

	function destroy(ta) {
		if (!(ta && ta.nodeName && ta.nodeName === 'TEXTAREA')) return;
		var evt = createEvent('autosize:destroy');
		ta.dispatchEvent(evt);
	}

	function update(ta) {
		if (!(ta && ta.nodeName && ta.nodeName === 'TEXTAREA')) return;
		var evt = createEvent('autosize:update');
		ta.dispatchEvent(evt);
	}

	var autosize = null;

	// Do nothing in Node.js environment and IE8 (or lower)
	if (typeof window === 'undefined' || typeof window.getComputedStyle !== 'function') {
		autosize = function (el) {
			return el;
		};
		autosize.destroy = function (el) {
			return el;
		};
		autosize.update = function (el) {
			return el;
		};
	} else {
		autosize = function (el, options) {
			if (el) {
				Array.prototype.forEach.call(el.length ? el : [el], function (x) {
					return assign(x, options);
				});
			}
			return el;
		};
		autosize.destroy = function (el) {
			if (el) {
				Array.prototype.forEach.call(el.length ? el : [el], destroy);
			}
			return el;
		};
		autosize.update = function (el) {
			if (el) {
				Array.prototype.forEach.call(el.length ? el : [el], update);
			}
			return el;
		};
	}

	module.exports = autosize;
});