--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rhodecode/public/js/mergerly.js	Wed Jun 26 19:07:32 2013 +0200
@@ -0,0 +1,1460 @@
+Mgly = {};
+
+Mgly.Timer = function(){
+	var self = this;
+	self.start = function() { self.t0 = new Date().getTime(); }
+	self.stop = function() {
+		var t1 = new Date().getTime();
+		var d = t1 - self.t0;
+		self.t0 = t1;
+		return d;
+	}
+	self.start();
+}
+
+Mgly.ChangeExpression = new RegExp(/(\d+(?:,\d+)?)([acd])(\d+(?:,\d+)?)/);
+
+Mgly.DiffParser = function(diff) {
+	var changes = [];
+	var change_id = 0;
+	// parse diff
+	var diff_lines = diff.split(/\n/);
+	for (var i = 0; i < diff_lines.length; ++i) {
+		if (diff_lines[i].length == 0) continue;
+		var change = {};
+		var test = Mgly.ChangeExpression.exec(diff_lines[i]);
+		if (test == null) continue;
+		// lines are zero-based
+		var fr = test[1].split(',');
+		change['lhs-line-from'] = fr[0] - 1;
+		if (fr.length == 1) change['lhs-line-to'] = fr[0] - 1;
+		else change['lhs-line-to'] = fr[1] - 1;
+		var to = test[3].split(',');
+		change['rhs-line-from'] = to[0] - 1;
+		if (to.length == 1) change['rhs-line-to'] = to[0] - 1;
+		else change['rhs-line-to'] = to[1] - 1;
+		change['op'] = test[2];
+		changes[change_id++] = change;
+	}
+	return changes;
+}
+
+Mgly.sizeOf = function(obj) {
+	var size = 0, key;
+	for (key in obj) {
+		if (obj.hasOwnProperty(key)) size++;
+	}
+	return size;
+}
+
+Mgly.LCS = function(x, y) {
+	this.x = x.replace(/[ ]{1}/g, '\n');
+	this.y = y.replace(/[ ]{1}/g, '\n');
+}
+jQuery.extend(Mgly.LCS.prototype, {
+	clear: function() { this.ready = 0; },
+	diff: function(added, removed) {
+		var d = new Mgly.diff(this.x, this.y, retain_lines = true, ignore_ws = false);
+		var changes = Mgly.DiffParser(d.normal_form());
+		var li = 0, lj = 0;
+		for (var i = 0; i < changes.length; ++i) {
+			var change = changes[i];
+			if (change.op != 'a') {
+				// find the starting index of the line
+				li = d.lhs_lines.slice(0, change['lhs-line-from']).join(' ').length;
+				// get the index of the the span of the change
+				lj = change['lhs-line-to'] + 1;
+				// get the changed text
+				var lchange = d.lhs_lines.slice(change['lhs-line-from'], lj).join(' ');
+				if (change.op == 'd') lchange += ' ';// include the leading space
+				else if (li > 0 && change.op == 'c') li += 1; // ignore leading space if not first word
+				// output the changed index and text
+				removed(li, li + lchange.length);
+			}
+			if (change.op != 'd') {
+				// find the starting index of the line
+				li = d.rhs_lines.slice(0, change['rhs-line-from']).join(' ').length;
+				// get the index of the the span of the change
+				lj = change['rhs-line-to'] + 1;
+				// get the changed text
+				var rchange = d.rhs_lines.slice(change['rhs-line-from'], lj).join(' ');
+				if (change.op == 'a') rchange += ' ';// include the leading space
+				else if (li > 0 && change.op == 'c') li += 1; // ignore leading space if not first word
+				// output the changed index and text
+				added(li, li + rchange.length);
+			}
+		}
+	}
+});
+Mgly.diff = function(lhs, rhs, retain_lines, ignore_ws) {
+	this.diff_codes = {};
+	this.max_code = 0;
+	var lhs_lines = lhs.split('\n');
+	var rhs_lines = rhs.split('\n');
+	if (lhs.length == 0) lhs_lines = [];
+	if (rhs.length == 0) rhs_lines = [];
+
+	var lhs_data = new Object();
+	lhs_data.data = this._diff_codes(lhs_lines, ignore_ws);
+	lhs_data.modified = {};
+	lhs_data.length = Mgly.sizeOf(lhs_data.data);
+
+	var rhs_data = new Object();
+	rhs_data.data = this._diff_codes(rhs_lines, ignore_ws);
+	rhs_data.modified = {};
+	rhs_data.length = Mgly.sizeOf(rhs_data.data);
+
+	var max = (lhs_data.length + rhs_data.length + 1);
+	var vector_d = Array( 2 * max + 2 );
+	var vector_u = Array( 2 * max + 2 );
+
+	this._lcs(lhs_data, 0, lhs_data.length, rhs_data, 0, rhs_data.length, vector_u, vector_d);
+	this._optimize(lhs_data);
+	this._optimize(rhs_data);
+	this.items = this._create_diffs(lhs_data, rhs_data);
+	if (retain_lines) {
+		this.lhs_lines = lhs_lines;
+		this.rhs_lines = rhs_lines;
+	}
+};
+jQuery.extend(Mgly.diff.prototype, {
+	changes: function() { return this.items; },
+	normal_form: function() {
+		var nf = '';
+		for (var index = 0; index < this.items.length; ++index) {
+			var item = this.items[index];
+			var lhs_str = '';
+			var rhs_str = '';
+			var change = 'c';
+			if (item.lhs_deleted_count == 0 && item.rhs_inserted_count > 0) change = 'a';
+			else if (item.lhs_deleted_count > 0 && item.rhs_inserted_count == 0) change = 'd';
+
+			if (item.lhs_deleted_count == 1) lhs_str = item.lhs_start + 1;
+			else if (item.lhs_deleted_count == 0) lhs_str = item.lhs_start;
+			else lhs_str = (item.lhs_start + 1) + ',' + (item.lhs_start + item.lhs_deleted_count);
+
+			if (item.rhs_inserted_count == 1) rhs_str = item.rhs_start + 1;
+			else if (item.rhs_inserted_count == 0) rhs_str = item.rhs_start;
+			else rhs_str = (item.rhs_start + 1) + ',' + (item.rhs_start + item.rhs_inserted_count);
+			nf += lhs_str + change + rhs_str + '\n';
+			if (this.rhs_lines && this.lhs_lines) {
+				// if rhs/lhs lines have been retained, output contextual diff
+				for (var i = item.lhs_start; i < item.lhs_start + item.lhs_deleted_count; ++i) {
+					nf += '< ' + this.lhs_lines[i] + '\n';
+				}
+				if (item.rhs_inserted_count && item.lhs_deleted_count) nf += '---\n';
+				for (var i = item.rhs_start; i < item.rhs_start + item.rhs_inserted_count; ++i) {
+					nf += '> ' + this.rhs_lines[i] + '\n';
+				}
+			}
+		}
+		return nf;
+	},
+	_diff_codes: function(lines, ignore_ws) {
+		var code = this.max_code;
+		var codes = {};
+		for (var i = 0; i < lines.length; ++i) {
+			var line = lines[i];
+			if (ignore_ws) {
+				line = line.replace(/\s+/g, '');
+			}
+			var aCode = this.diff_codes[line];
+			if (aCode != undefined) {
+				codes[i] = aCode;
+			}
+			else {
+				this.max_code++;
+				this.diff_codes[line] = this.max_code;
+				codes[i] = this.max_code;
+			}
+		}
+		return codes;
+	},
+	_lcs: function(lhs, lhs_lower, lhs_upper, rhs, rhs_lower, rhs_upper, vector_u, vector_d) {
+		while ( (lhs_lower < lhs_upper) && (rhs_lower < rhs_upper) && (lhs.data[lhs_lower] == rhs.data[rhs_lower]) ) {
+			++lhs_lower;
+			++rhs_lower;
+		}
+		while ( (lhs_lower < lhs_upper) && (rhs_lower < rhs_upper) && (lhs.data[lhs_upper - 1] == rhs.data[rhs_upper - 1]) ) {
+			--lhs_upper;
+			--rhs_upper;
+		}
+		if (lhs_lower == lhs_upper) {
+			while (rhs_lower < rhs_upper) {
+				rhs.modified[ rhs_lower++ ] = true;
+			}
+		}
+		else if (rhs_lower == rhs_upper) {
+			while (lhs_lower < lhs_upper) {
+				lhs.modified[ lhs_lower++ ] = true;
+			}
+		}
+		else {
+			var sms = this._sms(lhs, lhs_lower, lhs_upper, rhs, rhs_lower, rhs_upper, vector_u, vector_d);
+			this._lcs(lhs, lhs_lower, sms.x, rhs, rhs_lower, sms.y, vector_u, vector_d);
+			this._lcs(lhs, sms.x, lhs_upper, rhs, sms.y, rhs_upper, vector_u, vector_d);
+		}
+	},
+	_sms: function(lhs, lhs_lower, lhs_upper, rhs, rhs_lower, rhs_upper, vector_u, vector_d) {
+		var max = lhs.length + rhs.length + 1;
+		var kdown = lhs_lower - rhs_lower;
+		var kup = lhs_upper - rhs_upper;
+		var delta = (lhs_upper - lhs_lower) - (rhs_upper - rhs_lower);
+		var odd = (delta & 1) != 0;
+		var offset_down = max - kdown;
+		var offset_up = max - kup;
+		var maxd = ((lhs_upper - lhs_lower + rhs_upper - rhs_lower) / 2) + 1;
+		vector_d[ offset_down + kdown + 1 ] = lhs_lower;
+		vector_u[ offset_up + kup - 1 ] = lhs_upper;
+		var ret = {x:0,y:0};
+		for (var d = 0; d <= maxd; ++d) {
+			for (var k = kdown - d; k <= kdown + d; k += 2) {
+				var x, y;
+				if (k == kdown - d) {
+					x = vector_d[ offset_down + k + 1 ];//down
+				}
+				else {
+					x = vector_d[ offset_down + k - 1 ] + 1;//right
+					if ((k < (kdown + d)) && (vector_d[ offset_down + k + 1 ] >= x)) {
+						x = vector_d[ offset_down + k + 1 ];//down
+					}
+				}
+				y = x - k;
+				// find the end of the furthest reaching forward D-path in diagonal k.
+				while ((x < lhs_upper) && (y < rhs_upper) && (lhs.data[x] == rhs.data[y])) {
+					x++; y++;
+				}
+				vector_d[ offset_down + k ] = x;
+				// overlap ?
+				if (odd && (kup - d < k) && (k < kup + d)) {
+					if (vector_u[offset_up + k] <= vector_d[offset_down + k]) {
+						ret.x = vector_d[offset_down + k];
+						ret.y = vector_d[offset_down + k] - k;
+						return (ret);
+					}
+				}
+			}
+			// Extend the reverse path.
+			for (var k = kup - d; k <= kup + d; k += 2) {
+				// find the only or better starting point
+				var x, y;
+				if (k == kup + d) {
+					x = vector_u[offset_up + k - 1]; // up
+				} else {
+					x = vector_u[offset_up + k + 1] - 1; // left
+					if ((k > kup - d) && (vector_u[offset_up + k - 1] < x))
+						x = vector_u[offset_up + k - 1]; // up
+				}
+				y = x - k;
+				while ((x > lhs_lower) && (y > rhs_lower) && (lhs.data[x - 1] == rhs.data[y - 1])) {
+					// diagonal
+					x--;
+					y--;
+				}
+				vector_u[offset_up + k] = x;
+				// overlap ?
+				if (!odd && (kdown - d <= k) && (k <= kdown + d)) {
+					if (vector_u[offset_up + k] <= vector_d[offset_down + k]) {
+						ret.x = vector_d[offset_down + k];
+						ret.y = vector_d[offset_down + k] - k;
+						return (ret);
+					}
+				}
+			}
+		}
+		throw "the algorithm should never come here.";
+	},
+	_optimize: function(data) {
+		var start = 0, end = 0;
+		while (start < data.length) {
+			while ((start < data.length) && (data.modified[start] == undefined || data.modified[start] == false)) {
+				start++;
+			}
+			end = start;
+			while ((end < data.length) && (data.modified[end] == true)) {
+				end++;
+			}
+			if ((end < data.length) && (data.data[start] == data.data[end])) {
+				data.modified[start] = false;
+				data.modified[end] = true;
+			}
+			else {
+				start = end;
+			}
+		}
+	},
+	_create_diffs: function(lhs_data, rhs_data) {
+		var items = [];
+		var lhs_start = 0, rhs_start = 0;
+		var lhs_line = 0, rhs_line = 0;
+
+		while (lhs_line < lhs_data.length || rhs_line < rhs_data.length) {
+			if ((lhs_line < lhs_data.length) && (!lhs_data.modified[lhs_line])
+				&& (rhs_line < rhs_data.length) && (!rhs_data.modified[rhs_line])) {
+				// equal lines
+				lhs_line++;
+				rhs_line++;
+			}
+			else {
+				// maybe deleted and/or inserted lines
+				lhs_start = lhs_line;
+				rhs_start = rhs_line;
+
+				while (lhs_line < lhs_data.length && (rhs_line >= rhs_data.length || lhs_data.modified[lhs_line]))
+					lhs_line++;
+
+				while (rhs_line < rhs_data.length && (lhs_line >= lhs_data.length || rhs_data.modified[rhs_line]))
+					rhs_line++;
+
+				if ((lhs_start < lhs_line) || (rhs_start < rhs_line)) {
+					// store a new difference-item
+					var aItem = new Object();
+					aItem.lhs_start = lhs_start;
+					aItem.rhs_start = rhs_start;
+					aItem.lhs_deleted_count = lhs_line - lhs_start;
+					aItem.rhs_inserted_count = rhs_line - rhs_start;
+					items.push(aItem);
+				}
+			}
+		}
+		return items;
+	}
+});
+
+Mgly.mergely = function(el, options) {
+	CodeMirror.defineExtension('centerOnCursor', function() {
+		var coords = this.cursorCoords(null, 'local');
+		this.scrollTo(null,
+			(coords.y + coords.yBot) / 2 - (this.getScrollerElement().clientHeight / 2));
+	});
+
+	if (el) {
+		this.init(el, options);
+	}
+};
+
+jQuery.extend(Mgly.mergely.prototype, {
+	name: 'mergely',
+	//http://jupiterjs.com/news/writing-the-perfect-jquery-plugin
+	init: function(el, options) {
+		this.settings = {
+			autoupdate: true,
+			autoresize: true,
+			rhs_margin: 'right',
+			lcs: true,
+			sidebar: true,
+			viewport: false,
+			ignorews: false,
+			fadein: 'fast',
+			editor_width: '400px',
+			editor_height: '400px',
+			resize_timeout: 500,
+			change_timeout: 150,
+			fgcolor: {a:'#4ba3fa',c:'#a3a3a3',d:'#ff7f7f'},
+			bgcolor: '#eee',
+			vpcolor: 'rgba(0, 0, 200, 0.2)',
+			lhs: function(setValue) { },
+			rhs: function(setValue) { },
+			loaded: function() { },
+			//_auto_height: function(h) { return h - 20; },
+			_auto_width: function(w) { return w; },
+			resize: function(init) {
+				var scrollbar = init ? -15 : 0;
+				var w = jQuery(el).parent().width() + scrollbar;
+				if (this.width == 'auto') {
+					w = this._auto_width(w);
+				}
+				else {
+					w = this.width;
+					this.editor_width = w;
+				}
+				if (this.height == 'auto') {
+					//h = this._auto_height(h);
+					h = jQuery(el).parent().height();
+				}
+				else {
+					h = this.height;
+					this.editor_height = h;
+				}
+				var content_width = w / 2.0 - 2 * 8 - 8;
+				var content_height = h;
+				var self = jQuery(el);
+				self.find('.mergely-column').css({ width: content_width + 'px' });
+				self.find('.mergely-column, .mergely-canvas, .mergely-margin, .mergely-column textarea, .CodeMirror-scroll, .cm-s-default').css({ height: content_height + 'px' });
+				self.find('.mergely-canvas').css({ height: content_height + 'px' });
+				self.find('.mergely-column textarea').css({ width: content_width + 'px' });
+				self.css({ width: w, height: h, clear: 'both' });
+				if (self.css('display') == 'none') {
+					if (this.fadein != false) self.fadeIn(this.fadein);
+					else self.show();
+					if (this.loaded) this.loaded();
+				}
+				if (this.resized) this.resized();
+			},
+			_debug: '', //scroll,draw,calc,diff,markup,change
+			resized: function() { }
+		};
+		var cmsettings = {
+			mode: 'text/plain',
+			readOnly: false,
+			lineWrapping: false,
+			lineNumbers: true,
+			gutters: ['merge', 'CodeMirror-linenumbers']
+		}
+		this.lhs_cmsettings = {};
+		this.rhs_cmsettings = {};
+
+		// save this element for faster queries
+		this.element = jQuery(el);
+
+		// save options if there are any
+		if (options && options.cmsettings) jQuery.extend(this.lhs_cmsettings, cmsettings, options.cmsettings, options.lhs_cmsettings);
+		if (options && options.cmsettings) jQuery.extend(this.rhs_cmsettings, cmsettings, options.cmsettings, options.rhs_cmsettings);
+		if (options) jQuery.extend(this.settings, options);
+
+		// bind if the element is destroyed
+		this.element.bind('destroyed', jQuery.proxy(this.teardown, this));
+
+		// save this instance in jQuery data
+		jQuery.data(el, this.name, this);
+
+		this._setup(el);
+	},
+	// bind events to this instance's methods
+	bind: function() {
+		var rhstx = jQuery('#' + this.id + '-rhs').get(0);
+		if (!rhstx) {
+			console.error('rhs textarea not defined - Mergely not initialized properly');
+			return;
+		}
+		var lhstx = jQuery('#' + this.id + '-lhs').get(0);
+		if (!rhstx) {
+			console.error('lhs textarea not defined - Mergely not initialized properly');
+			return;
+		}
+		var self = this;
+		this.editor = [];
+
+		this.editor[this.id + '-lhs'] = CodeMirror.fromTextArea(lhstx, this.lhs_cmsettings);
+		this.editor[this.id + '-rhs'] = CodeMirror.fromTextArea(rhstx, this.rhs_cmsettings);
+		this.editor[this.id + '-lhs'].on('change', function(){ if (self.settings.autoupdate) self._changing(self.id + '-lhs', self.id + '-rhs'); });
+		this.editor[this.id + '-lhs'].on('scroll', function(){ self._scrolling(self.id + '-lhs'); });
+		this.editor[this.id + '-rhs'].on('change', function(){ if (self.settings.autoupdate) self._changing(self.id + '-lhs', self.id + '-rhs'); });
+		this.editor[this.id + '-rhs'].on('scroll', function(){ self._scrolling(self.id + '-rhs'); });
+
+		// resize
+		if (this.settings.autoresize) {
+			var sz_timeout1 = null;
+			var sz = function(init) {
+				//self.em_height = null; //recalculate
+				if (self.settings.resize) self.settings.resize(init);
+				self.editor[self.id + '-lhs'].refresh();
+				self.editor[self.id + '-rhs'].refresh();
+				if (self.settings.autoupdate) {
+					self._changing(self.id + '-lhs', self.id + '-rhs');
+				}
+			}
+			jQuery(window).resize(
+				function () {
+					if (sz_timeout1) clearTimeout(sz_timeout1);
+					sz_timeout1 = setTimeout(sz, self.settings.resize_timeout);
+				}
+			);
+			sz(true);
+		}
+	},
+	unbind: function() {
+		if (this.changed_timeout != null) clearTimeout(this.changed_timeout);
+		this.editor[this.id + '-lhs'].toTextArea();
+		this.editor[this.id + '-rhs'].toTextArea();
+	},
+	destroy: function() {
+		this.element.unbind('destroyed', this.teardown);
+		this.teardown();
+	},
+	teardown: function() {
+		this.unbind();
+	},
+	lhs: function(text) {
+		this.editor[this.id + '-lhs'].setValue(text);
+	},
+	rhs: function(text) {
+		this.editor[this.id + '-rhs'].setValue(text);
+	},
+	update: function() {
+		this._changing(this.id + '-lhs', this.id + '-rhs');
+	},
+	unmarkup: function() {
+		this._clear();
+	},
+	scrollTo: function(side, num) {
+		var le = this.editor[this.id + '-lhs'];
+		var re = this.editor[this.id + '-rhs'];
+		if (side == 'lhs') {
+			le.setCursor(num);
+			le.centerOnCursor();
+		}
+		else {
+			re.setCursor(num);
+			re.centerOnCursor();
+		}
+	},
+	options: function(opts) {
+		if (opts) {
+			jQuery.extend(this.settings, opts);
+			if (opts.autoresize) this.resize();
+			if (opts.autoupdate) this.update();
+			if (opts.hasOwnProperty('rhs_margin')) {
+				// dynamically swap the margin
+				if (opts.rhs_margin == 'left') {
+					this.element.find('.mergely-margin:last-child').insertAfter(
+						this.element.find('.mergely-canvas'));
+				}
+				else {
+					var target = this.element.find('.mergely-margin').last();
+					target.appendTo(target.parent());
+				}
+			}
+			if (opts.hasOwnProperty('sidebar')) {
+				// dynamically enable sidebars
+				if (opts.sidebar) {
+					jQuery(this.element).find('.mergely-margin').css({display: 'block'});
+				}
+				else {
+					jQuery(this.element).find('.mergely-margin').css({display: 'none'});
+				}
+			}
+		}
+		else {
+			return this.settings;
+		}
+	},
+	swap: function() {
+		if (this.lhs_cmsettings.readOnly || this.rhs_cmsettings.readOnly) return;
+		var le = this.editor[this.id + '-lhs'];
+		var re = this.editor[this.id + '-rhs'];
+		var tmp = re.getValue();
+		re.setValue(le.getValue());
+		le.setValue(tmp);
+	},
+	merge: function(side) {
+		var le = this.editor[this.id + '-lhs'];
+		var re = this.editor[this.id + '-rhs'];
+		if (side == 'lhs' && !this.lhs_cmsettings.readOnly) le.setValue(re.getValue());
+		else if (!this.rhs_cmsettings.readOnly) re.setValue(le.getValue());
+	},
+	get: function(side) {
+		var ed = this.editor[this.id + '-' + side];
+		var t = ed.getValue();
+		if (t == undefined) return '';
+		return t;
+	},
+	clear: function(side) {
+		if (side == 'lhs' && this.lhs_cmsettings.readOnly) return;
+		if (side == 'rhs' && this.rhs_cmsettings.readOnly) return;
+		var ed = this.editor[this.id + '-' + side];
+		ed.setValue('');
+	},
+	cm: function(side) {
+		return this.editor[this.id + '-' + side];
+	},
+	search: function(side, query, direction) {
+		var le = this.editor[this.id + '-lhs'];
+		var re = this.editor[this.id + '-rhs'];
+		var editor;
+		if (side == 'lhs') editor = le;
+		else editor = re;
+		direction = (direction == 'prev') ? 'findPrevious' : 'findNext';
+		if ((editor.getSelection().length == 0) || (this.prev_query[side] != query)) {
+			this.cursor[this.id] = editor.getSearchCursor(query, { line: 0, ch: 0 }, false);
+			this.prev_query[side] = query;
+		}
+		var cursor = this.cursor[this.id];
+
+		if (cursor[direction]()) {
+			editor.setSelection(cursor.from(), cursor.to());
+		}
+		else {
+			cursor = editor.getSearchCursor(query, { line: 0, ch: 0 }, false);
+		}
+	},
+	resize: function() {
+		this.settings.resize();
+		this._changing(this.id + '-lhs', this.id + '-rhs');
+	},
+	diff: function() {
+		var lhs = this.editor[this.id + '-lhs'].getValue();
+		var rhs = this.editor[this.id + '-rhs'].getValue();
+		var d = new Mgly.diff(lhs, rhs, retain_lines = true, ignore_ws = this.settings.ignorews);
+		return d.normal_form();
+	},
+	_setup: function(el) {
+		jQuery(this.element).hide();//hide
+		this.id = jQuery(el).attr('id');
+		var height = this.settings.editor_height;
+		var width = this.settings.editor_width;
+		this.changed_timeout = null;
+		this.chfns = {};
+		this.chfns[this.id + '-lhs'] = [];
+		this.chfns[this.id + '-rhs'] = [];
+		this.prev_query = [];
+		this.cursor = [];
+		this._skipscroll = {};
+		this.change_exp = new RegExp(/(\d+(?:,\d+)?)([acd])(\d+(?:,\d+)?)/);
+		var merge_lhs_button;
+		var merge_rhs_button;
+		if (jQuery.button != undefined) {
+			//jquery ui
+			merge_lhs_button = '<button title="Merge left"></button>';
+			merge_rhs_button = '<button title="Merge right"></button>';
+		}
+		else {
+			// homebrew
+			var style = 'opacity:0.4;width:10px;height:15px;background-color:#888;cursor:pointer;text-align:center;color:#eee;border:1px solid: #222;margin-right:5px;';
+			merge_lhs_button = '<div style="' + style + '" title="Merge left">&lt;</div>';
+			merge_rhs_button = '<div style="' + style + '" title="Merge right">&gt;</div>';
+		}
+		this.merge_rhs_button = jQuery(merge_rhs_button);
+		this.merge_lhs_button = jQuery(merge_lhs_button);
+
+		// create the textarea and canvas elements
+		jQuery(this.element).append(jQuery('<div class="mergely-margin" style="height: ' + height + '"><canvas id="' + this.id + '-lhs-margin" width="8px" height="' + height + '"></canvas></div>'));
+		jQuery(this.element).append(jQuery('<div style="position:relative;width:' + width + '; height:' + height + '" id="' + this.id + '-editor-lhs" class="mergely-column"><textarea style="" id="' + this.id + '-lhs"></textarea></div>'));
+		jQuery(this.element).append(jQuery('<div class="mergely-canvas" style="height: ' + height + '"><canvas id="' + this.id + '-lhs-' + this.id + '-rhs-canvas" style="width:28px" width="28px" height="' + height + '"></canvas></div>'));
+		var rmargin = jQuery('<div class="mergely-margin" style="height: ' + height + '"><canvas id="' + this.id + '-rhs-margin" width="8px" height="' + height + '"></canvas></div>');
+		if (!this.settings.sidebar) {
+			jQuery(this.element).find('.mergely-margin').css({display: 'none'});
+		}
+		if (this.settings.rhs_margin == 'left') {
+			jQuery(this.element).append(rmargin);
+		}
+		jQuery(this.element).append(jQuery('<div style="width:' + width + '; height:' + height + '" id="' + this.id + '-editor-rhs" class="mergely-column"><textarea style="" id="' + this.id + '-rhs"></textarea></div>'));
+		if (this.settings.rhs_margin != 'left') {
+			jQuery(this.element).append(rmargin);
+		}
+		//codemirror
+		var cmstyle = '#' + this.id + ' .CodeMirror-gutter-text { padding: 5px 0 0 0; }' +
+			'#' + this.id + ' .CodeMirror-lines pre, ' + '#' + this.id + ' .CodeMirror-gutter-text pre { line-height: 18px; }' +
+			'.CodeMirror-linewidget { overflow: hidden; };';
+		if (this.settings.autoresize) {
+			cmstyle += this.id + ' .CodeMirror-scroll { height: 100%; overflow: auto; }';
+		}
+		jQuery('<style type="text/css">' + cmstyle + '</style>').appendTo('head');
+		this.bind();
+		if (this.settings.lhs) {
+			var setv = this.editor[this.id + '-lhs'].getDoc().setValue;
+			this.settings.lhs(setv.bind(this.editor[this.id + '-lhs'].getDoc()));
+		}
+		if (this.settings.rhs) {
+			var setv = this.editor[this.id + '-rhs'].getDoc().setValue;
+			this.settings.rhs(setv.bind(this.editor[this.id + '-rhs'].getDoc()));
+		}
+	},
+
+	_scrolling: function(editor_name) {
+		if (this._skipscroll[editor_name] === true) {
+			// scrolling one side causes the other to event - ignore it
+			this._skipscroll[editor_name] = false;
+			return;
+		}
+		var scroller = jQuery(this.editor[editor_name].getScrollerElement());
+		if (this.midway == undefined) {
+			this.midway = (scroller.height() / 2.0 + scroller.offset().top).toFixed(2);
+		}
+		// balance-line
+		var midline = this.editor[editor_name].coordsChar({left:0, top:this.midway});
+		var top_to = scroller.scrollTop();
+		var left_to = scroller.scrollLeft();
+
+		this.trace('scroll', 'side', editor_name);
+		this.trace('scroll', 'midway', this.midway);
+		this.trace('scroll', 'midline', midline);
+		this.trace('scroll', 'top_to', top_to);
+		this.trace('scroll', 'left_to', left_to);
+
+		var editor_name1 = this.id + '-lhs';
+		var editor_name2 = this.id + '-rhs';
+
+		for (var name in this.editor) {
+			if (!this.editor.hasOwnProperty(name)) continue;
+			if (editor_name == name) continue; //same editor
+			var this_side = editor_name.replace(this.id + '-', '');
+			var other_side = name.replace(this.id + '-', '');
+			var top_adjust = 0;
+
+			// find the last change that is less than or within the midway point
+			// do not move the rhs until the lhs end point is >= the rhs end point.
+			var last_change = null;
+			var force_scroll = false;
+			for (var i = 0; i < this.changes.length; ++i) {
+				var change = this.changes[i];
+				if ((midline.line >= change[this_side+'-line-from'])) {
+					last_change = change;
+					if (midline.line >= last_change[this_side+'-line-to']) {
+						if (!change.hasOwnProperty(this_side+'-y-start') ||
+							!change.hasOwnProperty(this_side+'-y-end') ||
+							!change.hasOwnProperty(other_side+'-y-start') ||
+							!change.hasOwnProperty(other_side+'-y-end')){
+							// change outside of viewport
+							force_scroll = true;
+						}
+						else {
+							top_adjust +=
+								(change[this_side+'-y-end'] - change[this_side+'-y-start']) -
+								(change[other_side+'-y-end'] - change[other_side+'-y-start']);
+						}
+					}
+				}
+			}
+
+			var vp = this.editor[name].getViewport();
+			var scroll = true;
+			if (last_change) {
+				this.trace('scroll', 'last change before midline', last_change);
+				if (midline.line >= vp.from && midline <= vp.to) {
+					scroll = false;
+				}
+			}
+			this.trace('scroll', 'scroll', scroll);
+			if (scroll || force_scroll) {
+				// scroll the other side
+				this.trace('scroll', 'scrolling other side', top_to - top_adjust);
+				var scroller = jQuery(this.editor[name].getScrollerElement());
+				this._skipscroll[name] = true;//disable next event
+				scroller.scrollTop(top_to - top_adjust).scrollLeft(left_to);
+			}
+			else this.trace('scroll', 'not scrolling other side');
+
+			if (this.settings.autoupdate) {
+				var timer = new Mgly.Timer();
+				this._calculate_offsets(editor_name1, editor_name2, this.changes);
+				this.trace('change', 'offsets time', timer.stop());
+				this._markup_changes(editor_name1, editor_name2, this.changes);
+				this.trace('change', 'markup time', timer.stop());
+				this._draw_diff(editor_name1, editor_name2, this.changes);
+				this.trace('change', 'draw time', timer.stop());
+			}
+			this.trace('scroll', 'scrolled');
+		}
+	},
+	_changing: function(editor_name1, editor_name2) {
+		this.trace('change', 'changing-timeout', this.changed_timeout);
+		var self = this;
+		if (this.changed_timeout != null) clearTimeout(this.changed_timeout);
+		this.changed_timeout = setTimeout(function(){
+			var timer = new Mgly.Timer();
+			self._changed(editor_name1, editor_name2);
+			self.trace('change', 'total time', timer.stop());
+		}, this.settings.change_timeout);
+	},
+	_changed: function(editor_name1, editor_name2) {
+		this._clear();
+		this._diff(editor_name1, editor_name2);
+	},
+	_clear: function() {
+		var self = this;
+		for (var name in this.editor) {
+			if (!this.editor.hasOwnProperty(name)) continue;
+			var editor = this.editor[name];
+			var fns = self.chfns[name];
+			// clear editor changes
+			editor.operation(function() {
+				var timer = new Mgly.Timer();
+				for (var i = 0, l = editor.lineCount(); i < l; ++i) {
+					editor.removeLineClass(i, 'background');
+				}
+				for (var i = 0; i < fns.length; ++i) {
+					//var edid = editor.getDoc().id;
+					var change = fns[i];
+					//if (change.doc.id != edid) continue;
+					if (change.lines.length) {
+						self.trace('change', 'clear text', change.lines[0].text);
+					}
+					change.clear();
+				}
+				editor.clearGutter('merge');
+				self.trace('change', 'clear time', timer.stop());
+			});
+		}
+		self.chfns[name] = [];
+
+		var ex = this._draw_info(this.id + '-lhs', this.id + '-rhs');
+		var ctx_lhs = ex.clhs.get(0).getContext('2d');
+		var ctx_rhs = ex.crhs.get(0).getContext('2d');
+		var ctx = ex.dcanvas.getContext('2d');
+
+		ctx_lhs.beginPath();
+		ctx_lhs.fillStyle = this.settings.bgcolor;
+		ctx_lhs.strokeStyle = '#888';
+		ctx_lhs.fillRect(0, 0, 6.5, ex.visible_page_height);
+		ctx_lhs.strokeRect(0, 0, 6.5, ex.visible_page_height);
+
+		ctx_rhs.beginPath();
+		ctx_rhs.fillStyle = this.settings.bgcolor;
+		ctx_rhs.strokeStyle = '#888';
+		ctx_rhs.fillRect(0, 0, 6.5, ex.visible_page_height);
+		ctx_rhs.strokeRect(0, 0, 6.5, ex.visible_page_height);
+
+		ctx.beginPath();
+		ctx.fillStyle = '#fff';
+		ctx.fillRect(0, 0, this.draw_mid_width, ex.visible_page_height);
+	},
+	_diff: function(editor_name1, editor_name2) {
+		var lhs = this.editor[editor_name1].getValue();
+		var rhs = this.editor[editor_name2].getValue();
+		var timer = new Mgly.Timer();
+		var d = new Mgly.diff(lhs, rhs, false, this.settings.ignorews);
+		this.trace('change', 'diff time', timer.stop());
+		this.changes = Mgly.DiffParser(d.normal_form());
+		this.trace('change', 'parse time', timer.stop());
+		this._calculate_offsets(editor_name1, editor_name2, this.changes);
+		this.trace('change', 'offsets time', timer.stop());
+		this._markup_changes(editor_name1, editor_name2, this.changes);
+		this.trace('change', 'markup time', timer.stop());
+		this._draw_diff(editor_name1, editor_name2, this.changes);
+		this.trace('change', 'draw time', timer.stop());
+	},
+	_parse_diff: function (editor_name1, editor_name2, diff) {
+		this.trace('diff', 'diff results:\n', diff);
+		var changes = [];
+		var change_id = 0;
+		// parse diff
+		var diff_lines = diff.split(/\n/);
+		for (var i = 0; i < diff_lines.length; ++i) {
+			if (diff_lines[i].length == 0) continue;
+			var change = {};
+			var test = this.change_exp.exec(diff_lines[i]);
+			if (test == null) continue;
+			// lines are zero-based
+			var fr = test[1].split(',');
+			change['lhs-line-from'] = fr[0] - 1;
+			if (fr.length == 1) change['lhs-line-to'] = fr[0] - 1;
+			else change['lhs-line-to'] = fr[1] - 1;
+			var to = test[3].split(',');
+			change['rhs-line-from'] = to[0] - 1;
+			if (to.length == 1) change['rhs-line-to'] = to[0] - 1;
+			else change['rhs-line-to'] = to[1] - 1;
+			// TODO: optimize for changes that are adds/removes
+			if (change['lhs-line-from'] < 0) change['lhs-line-from'] = 0;
+			if (change['lhs-line-to'] < 0) change['lhs-line-to'] = 0;
+			if (change['rhs-line-from'] < 0) change['rhs-line-from'] = 0;
+			if (change['rhs-line-to'] < 0) change['rhs-line-to'] = 0;
+			change['op'] = test[2];
+			changes[change_id++] = change;
+			this.trace('diff', 'change', change);
+		}
+		return changes;
+	},
+	_get_viewport: function(editor_name1, editor_name2) {
+		var lhsvp = this.editor[editor_name1].getViewport();
+		var rhsvp = this.editor[editor_name2].getViewport();
+		return {from: Math.min(lhsvp.from, rhsvp.from), to: Math.max(lhsvp.to, rhsvp.to)};
+	},
+	_is_change_in_view: function(vp, change) {
+		if (!this.settings.viewport) return true;
+		if ((change['lhs-line-from'] < vp.from && change['lhs-line-to'] < vp.to) ||
+			(change['lhs-line-from'] > vp.from && change['lhs-line-to'] > vp.to) ||
+			(change['rhs-line-from'] < vp.from && change['rhs-line-to'] < vp.to) ||
+			(change['rhs-line-from'] > vp.from && change['rhs-line-to'] > vp.to)) {
+			// if the change is outside the viewport, skip
+			return false;
+		}
+		return true;
+	},
+	_calculate_offsets: function (editor_name1, editor_name2, changes) {
+		if (this.em_height == null) {
+			// this is the distance from the top of the screen
+			var topnode = jQuery('#' + this.id + ' .CodeMirror-measure').first();
+			var top_offset = topnode.offset().top - 4;
+			if (!top_offset) return;//try again
+			this.draw_top_offset = 0.5 - top_offset;
+			this.em_height = this.editor[editor_name1].defaultTextHeight();
+			if (!this.em_height) {
+				console.warn('Failed to calculate offsets, using 18 by default');
+				this.em_height = 18;
+			}
+			this.draw_lhs_min = 0.5;
+			var c = jQuery('#' + editor_name1 + '-' + editor_name2 + '-canvas');
+			if (!c.length) {
+				console.error('failed to find canvas', '#' + editor_name1 + '-' + editor_name2 + '-canvas');
+			}
+			if (!c.width()) {
+				console.error('canvas width is 0');
+				return;
+			}
+			this.draw_mid_width = jQuery('#' + editor_name1 + '-' + editor_name2 + '-canvas').width();
+			this.draw_rhs_max = this.draw_mid_width - 0.5; //24.5;
+			this.draw_lhs_width = 5;
+			this.draw_rhs_width = 5;
+			this.trace('calc', 'change offsets calculated', {top_offset: top_offset, lhs_min: this.draw_lhs_min, rhs_max: this.draw_rhs_max, lhs_width: this.draw_lhs_width, rhs_width: this.draw_rhs_width});
+		}
+		var lhschc = this.editor[editor_name1].charCoords({line: 0});
+		var rhschc = this.editor[editor_name2].charCoords({line: 0});
+		var vp = this._get_viewport(editor_name1, editor_name2);
+
+		for (var i = 0; i < changes.length; ++i) {
+			var change = changes[i];
+
+			if (!this.settings.sidebar && !this._is_change_in_view(vp, change)) {
+				// if the change is outside the viewport, skip
+				delete change['lhs-y-start'];
+				delete change['lhs-y-end'];
+				delete change['rhs-y-start'];
+				delete change['rhs-y-end'];
+				continue;
+			}
+			var llf = change['lhs-line-from'] >= 0 ? change['lhs-line-from'] : 0;
+			var llt = change['lhs-line-to'] >= 0 ? change['lhs-line-to'] : 0;
+			var rlf = change['rhs-line-from'] >= 0 ? change['rhs-line-from'] : 0;
+			var rlt = change['rhs-line-to'] >= 0 ? change['rhs-line-to'] : 0;
+
+			var ls, le, rs, re;
+			if (this.editor[editor_name1].getOption('lineWrapping') || this.editor[editor_name1].getOption('lineWrapping')) {
+				// If using line-wrapping, we must get the height of the line
+				var tls = this.editor[editor_name1].cursorCoords({line: llf, ch: 0}, 'page');
+				var lhssh = this.editor[editor_name1].getLineHandle(llf);
+				ls = { top: tls.top, bottom: tls.top + lhssh.height };
+
+				var tle = this.editor[editor_name1].cursorCoords({line: llt, ch: 0}, 'page');
+				var lhseh = this.editor[editor_name1].getLineHandle(llt);
+				le = { top: tle.top, bottom: tle.top + lhseh.height };
+
+				var tls = this.editor[editor_name2].cursorCoords({line: rlf, ch: 0}, 'page');
+				var rhssh = this.editor[editor_name2].getLineHandle(rlf);
+				rs = { top: tls.top, bottom: tls.top + rhssh.height };
+
+				var tle = this.editor[editor_name2].cursorCoords({line: rlt, ch: 0}, 'page');
+				var rhseh = this.editor[editor_name2].getLineHandle(rlt);
+				re = { top: tle.top, bottom: tle.top + rhseh.height };
+			}
+			else {
+				// If not using line-wrapping, we can calculate the line position
+				ls = {
+					top: lhschc.top + llf * this.em_height,
+					bottom: lhschc.bottom + llf * this.em_height + 2
+				};
+				le = {
+					top: lhschc.top + llt * this.em_height,
+					bottom: lhschc.bottom + llt * this.em_height + 2
+				};
+				rs = {
+					top: rhschc.top + rlf * this.em_height,
+					bottom: rhschc.bottom + rlf * this.em_height + 2
+				};
+				re = {
+					top: rhschc.top + rlt * this.em_height,
+					bottom: rhschc.bottom + rlt * this.em_height + 2
+				};
+			}
+
+			if (change['op'] == 'a') {
+				// adds (right), normally start from the end of the lhs,
+				// except for the case when the start of the rhs is 0
+				if (rlf > 0) {
+					ls.top = ls.bottom;
+					ls.bottom += this.em_height;
+					le = ls;
+				}
+			}
+			else if (change['op'] == 'd') {
+				// deletes (left) normally finish from the end of the rhs,
+				// except for the case when the start of the lhs is 0
+				if (llf > 0) {
+					rs.top = rs.bottom;
+					rs.bottom += this.em_height;
+					re = rs;
+				}
+			}
+			change['lhs-y-start'] = this.draw_top_offset + ls.top;
+			if (change['op'] == 'c' || change['op'] == 'd') {
+				change['lhs-y-end'] = this.draw_top_offset + le.bottom;
+			}
+			else {
+				change['lhs-y-end'] = this.draw_top_offset + le.top;
+			}
+			change['rhs-y-start'] = this.draw_top_offset + rs.top;
+			if (change['op'] == 'c' || change['op'] == 'a') {
+				change['rhs-y-end'] = this.draw_top_offset + re.bottom;
+			}
+			else {
+				change['rhs-y-end'] = this.draw_top_offset + re.top;
+			}
+			this.trace('calc', 'change calculated', i, change);
+		}
+		return changes;
+	},
+	_markup_changes: function (editor_name1, editor_name2, changes) {
+		jQuery('.merge-button').remove(); // clear
+
+		var self = this;
+		var led = this.editor[editor_name1];
+		var red = this.editor[editor_name2];
+
+		var timer = new Mgly.Timer();
+		led.operation(function() {
+			for (var i = 0; i < changes.length; ++i) {
+				var change = changes[i];
+				var llf = change['lhs-line-from'] >= 0 ? change['lhs-line-from'] : 0;
+				var llt = change['lhs-line-to'] >= 0 ? change['lhs-line-to'] : 0;
+				var rlf = change['rhs-line-from'] >= 0 ? change['rhs-line-from'] : 0;
+				var rlt = change['rhs-line-to'] >= 0 ? change['rhs-line-to'] : 0;
+
+				var clazz = ['mergely', 'lhs', change['op'], 'cid-' + i];
+				led.addLineClass(llf, 'background', 'start');
+				led.addLineClass(llt, 'background', 'end');
+
+				if (llf == 0 && llt == 0 && rlf == 0) {
+					led.addLineClass(llf, 'background', clazz.join(' '));
+					led.addLineClass(llf, 'background', 'first');
+				}
+				else {
+					// apply change for each line in-between the changed lines
+					for (var j = llf; j <= llt; ++j) {
+						led.addLineClass(j, 'background', clazz.join(' '));
+						led.addLineClass(j, 'background', clazz.join(' '));
+					}
+				}
+
+				if (!red.getOption('readOnly')) {
+					// add widgets to lhs, if rhs is not read only
+					var rhs_button = self.merge_rhs_button.clone();
+					if (rhs_button.button) {
+						//jquery-ui support
+						rhs_button.button({icons: {primary: 'ui-icon-triangle-1-e'}, text: false});
+					}
+					rhs_button.addClass('merge-button');
+					rhs_button.attr('id', 'merge-rhs-' + i);
+					led.setGutterMarker(llf, 'merge', rhs_button.get(0));
+				}
+			}
+		});
+
+		var vp = this._get_viewport(editor_name1, editor_name2);
+
+		this.trace('change', 'markup lhs-editor time', timer.stop());
+		red.operation(function() {
+			for (var i = 0; i < changes.length; ++i) {
+				var change = changes[i];
+				var llf = change['lhs-line-from'] >= 0 ? change['lhs-line-from'] : 0;
+				var llt = change['lhs-line-to'] >= 0 ? change['lhs-line-to'] : 0;
+				var rlf = change['rhs-line-from'] >= 0 ? change['rhs-line-from'] : 0;
+				var rlt = change['rhs-line-to'] >= 0 ? change['rhs-line-to'] : 0;
+
+				if (!self._is_change_in_view(vp, change)) {
+					// if the change is outside the viewport, skip
+					continue;
+				}
+
+				var clazz = ['mergely', 'rhs', change['op'], 'cid-' + i];
+				red.addLineClass(rlf, 'background', 'start');
+				red.addLineClass(rlt, 'background', 'end');
+
+				if (rlf == 0 && rlt == 0 && llf == 0) {
+					red.addLineClass(rlf, 'background', clazz.join(' '));
+					red.addLineClass(rlf, 'background', 'first');
+				}
+				else {
+					// apply change for each line in-between the changed lines
+					for (var j = rlf; j <= rlt; ++j) {
+						red.addLineClass(j, 'background', clazz.join(' '));
+						red.addLineClass(j, 'background', clazz.join(' '));
+					}
+				}
+
+				if (!led.getOption('readOnly')) {
+					// add widgets to rhs, if lhs is not read only
+					var lhs_button = self.merge_lhs_button.clone();
+					if (lhs_button.button) {
+						//jquery-ui support
+						lhs_button.button({icons: {primary: 'ui-icon-triangle-1-w'}, text: false});
+					}
+					lhs_button.addClass('merge-button');
+					lhs_button.attr('id', 'merge-lhs-' + i);
+					red.setGutterMarker(rlf, 'merge', lhs_button.get(0));
+				}
+			}
+		});
+		this.trace('change', 'markup rhs-editor time', timer.stop());
+
+		// mark text deleted, LCS changes
+		var marktext = [];
+		for (var i = 0; this.settings.lcs && i < changes.length; ++i) {
+			var change = changes[i];
+			var llf = change['lhs-line-from'] >= 0 ? change['lhs-line-from'] : 0;
+			var llt = change['lhs-line-to'] >= 0 ? change['lhs-line-to'] : 0;
+			var rlf = change['rhs-line-from'] >= 0 ? change['rhs-line-from'] : 0;
+			var rlt = change['rhs-line-to'] >= 0 ? change['rhs-line-to'] : 0;
+
+			if (!this._is_change_in_view(vp, change)) {
+				// if the change is outside the viewport, skip
+				continue;
+			}
+			if (change['op'] == 'd') {
+				// apply delete to cross-out (left-hand side only)
+				var from = llf;
+				var to = llt;
+				var to_ln = led.lineInfo(to);
+				if (to_ln) {
+					marktext.push([led, {line:from, ch:0}, {line:to, ch:to_ln.text.length}, {className: 'mergely ch d lhs'}]);
+				}
+			}
+			else if (change['op'] == 'c') {
+				// apply LCS changes to each line
+				for (var j = llf, k = rlf, p = 0;
+					 ((j >= 0) && (j <= llt)) || ((k >= 0) && (k <= rlt));
+					 ++j, ++k) {
+					if (k + p > rlt) {
+						// lhs continues past rhs, mark lhs as deleted
+						var lhs_line = led.getLine( j );
+						marktext.push([led, {line:j, ch:0}, {line:j, ch:lhs_line.length}, {className: 'mergely ch d lhs'}]);
+						continue;
+					}
+					if (j + p > llt) {
+						// rhs continues past lhs, mark rhs as added
+						var rhs_line = red.getLine( k );
+						marktext.push([red, {line:k, ch:0}, {line:k, ch:rhs_line.length}, {className: 'mergely ch a rhs'}]);
+						continue;
+					}
+					var lhs_line = led.getLine( j );
+					var rhs_line = red.getLine( k );
+					var lhs_start = { line: -1, ch: -1 };
+					var lhs_stop = { line: -1, ch: -1 };
+					var rhs_start = { line: -1, ch: -1 };
+					var rhs_stop = { line: -1, ch: -1 };
+
+					var lcs = new Mgly.LCS(lhs_line, rhs_line);
+					lcs.diff(
+						function (from, to) {//added
+							marktext.push([red, {line:k, ch:from}, {line:k, ch:to}, {className: 'mergely ch a rhs'}]);
+						},
+						removed = function (from, to) {//removed
+							marktext.push([led, {line:j, ch:from}, {line:j, ch:to}, {className: 'mergely ch d lhs'}]);
+						}
+					);
+				}
+			}
+		}
+		this.trace('change', 'LCS marktext time', timer.stop());
+
+		// mark changes outside closure
+		led.operation(function() {
+			// apply lhs markup
+			for (var i = 0; i < marktext.length; ++i) {
+				var m = marktext[i];
+				if (m[0].doc.id != led.getDoc().id) continue;
+				self.chfns[self.id + '-lhs'].push(m[0].markText(m[1], m[2], m[3]));
+			}
+		});
+		red.operation(function() {
+			// apply lhs markup
+			for (var i = 0; i < marktext.length; ++i) {
+				var m = marktext[i];
+				if (m[0].doc.id != red.getDoc().id) continue;
+				self.chfns[self.id + '-rhs'].push(m[0].markText(m[1], m[2], m[3]));
+			}
+		});
+		this.trace('change', 'LCS markup time', timer.stop());
+
+		// merge buttons
+		var ed = {lhs:led, rhs:red};
+		jQuery('.merge-button').on('click', function(ev){
+			// side of mouseenter
+			var side = 'rhs';
+			var oside = 'lhs';
+			var parent = jQuery(this).parents('#' + self.id + '-editor-lhs');
+			if (parent.length) {
+				side = 'lhs';
+				oside = 'rhs';
+			}
+			var pos = ed[side].coordsChar({left:ev.pageX, top:ev.pageY});
+
+			// get the change id
+			var cid = null;
+			var info = ed[side].lineInfo(pos.line);
+			jQuery.each(info.bgClass.split(' '), function(i, clazz) {
+				if (clazz.indexOf('cid-') == 0) {
+					cid = parseInt(clazz.split('-')[1], 10);
+					return false;
+				}
+			});
+			var change = self.changes[cid];
+
+			var line = {lhs: ed['lhs'].lineInfo(llt), rhs: ed['rhs'].lineInfo(rlt)};
+
+			var text = ed[side].getRange(
+				CodeMirror.Pos(change[side + '-line-from'], 0),
+				CodeMirror.Pos(change[side + '-line-to'] + 1, 0));
+
+			if (change['op'] == 'c') {
+				ed[oside].replaceRange(text,
+					CodeMirror.Pos(change[oside + '-line-from'], 0),
+					CodeMirror.Pos(change[oside + '-line-to'] + 1, 0));
+			}
+			else if (side == 'rhs') {
+				if (change['op'] == 'a') {
+					ed[oside].replaceRange(text,
+						CodeMirror.Pos(change[oside + '-line-from'] + 1, 0),
+						CodeMirror.Pos(change[oside + '-line-to'] + 1, 0));
+				}
+				else {// 'd'
+					var from = parseInt(change[oside + '-line-from']);
+					var to = parseInt(change[oside + '-line-to']);
+					for (var i = to; i >= from; --i) {
+						ed[oside].removeLine(i);
+					}
+				}
+			}
+			else if (side == 'lhs') {
+				if (change['op'] == 'a') {
+					var from = parseInt(change[oside + '-line-from']);
+					var to = parseInt(change[oside + '-line-to']);
+					for (var i = to; i >= from; --i) {
+						ed[oside].removeLine(i);
+					}
+				}
+				else {// 'd'
+					ed[oside].replaceRange( text,
+						CodeMirror.Pos(change[oside + '-line-from'] + 1, 0));
+				}
+			}
+			//reset
+			ed['lhs'].setValue(ed['lhs'].getValue());
+			ed['rhs'].setValue(ed['rhs'].getValue());
+			return false;
+		});
+		this.trace('change', 'markup buttons time', timer.stop());
+	},
+	_draw_info: function(editor_name1, editor_name2) {
+		var visible_page_height = jQuery(this.editor[editor_name1].getScrollerElement()).height();
+		var gutter_height = jQuery(this.editor[editor_name1].getScrollerElement()).children(':first-child').height();
+		var dcanvas = document.getElementById(editor_name1 + '-' + editor_name2 + '-canvas');
+		if (dcanvas == undefined) throw 'Failed to find: ' + editor_name1 + '-' + editor_name2 + '-canvas';
+		var clhs = jQuery('#' + this.id + '-lhs-margin');
+		var crhs = jQuery('#' + this.id + '-rhs-margin');
+		return {
+			visible_page_height: visible_page_height,
+			gutter_height: gutter_height,
+			visible_page_ratio: (visible_page_height / gutter_height),
+			margin_ratio: (visible_page_height / gutter_height),
+			lhs_scroller: jQuery(this.editor[editor_name1].getScrollerElement()),
+			rhs_scroller: jQuery(this.editor[editor_name2].getScrollerElement()),
+			lhs_lines: this.editor[editor_name1].lineCount(),
+			rhs_lines: this.editor[editor_name2].lineCount(),
+			dcanvas: dcanvas,
+			clhs: clhs,
+			crhs: crhs,
+			lhs_xyoffset: jQuery(clhs).offset(),
+			rhs_xyoffset: jQuery(crhs).offset()
+		};
+	},
+	_draw_diff: function(editor_name1, editor_name2, changes) {
+		var ex = this._draw_info(editor_name1, editor_name2);
+		var mcanvas_lhs = ex.clhs.get(0);
+		var mcanvas_rhs = ex.crhs.get(0);
+		var ctx = ex.dcanvas.getContext('2d');
+		var ctx_lhs = mcanvas_lhs.getContext('2d');
+		var ctx_rhs = mcanvas_rhs.getContext('2d');
+
+		this.trace('draw', 'visible_page_height', ex.visible_page_height);
+		this.trace('draw', 'gutter_height', ex.gutter_height);
+		this.trace('draw', 'visible_page_ratio', ex.visible_page_ratio);
+		this.trace('draw', 'lhs-scroller-top', ex.lhs_scroller.scrollTop());
+		this.trace('draw', 'rhs-scroller-top', ex.rhs_scroller.scrollTop());
+
+		jQuery.each(jQuery.find('#' + this.id + ' canvas'), function () {
+			jQuery(this).get(0).height = ex.visible_page_height;
+		});
+
+		ex.clhs.unbind('click');
+		ex.crhs.unbind('click');
+
+		ctx_lhs.beginPath();
+		ctx_lhs.fillStyle = this.settings.bgcolor;
+		ctx_lhs.strokeStyle = '#888';
+		ctx_lhs.fillRect(0, 0, 6.5, ex.visible_page_height);
+		ctx_lhs.strokeRect(0, 0, 6.5, ex.visible_page_height);
+
+		ctx_rhs.beginPath();
+		ctx_rhs.fillStyle = this.settings.bgcolor;
+		ctx_rhs.strokeStyle = '#888';
+		ctx_rhs.fillRect(0, 0, 6.5, ex.visible_page_height);
+		ctx_rhs.strokeRect(0, 0, 6.5, ex.visible_page_height);
+
+		var vp = this._get_viewport(editor_name1, editor_name2);
+		for (var i = 0; i < changes.length; ++i) {
+			var change = changes[i];
+
+			this.trace('draw', change);
+			// margin indicators
+			var lhs_y_start = ((change['lhs-y-start'] + ex.lhs_scroller.scrollTop()) * ex.visible_page_ratio);
+			var lhs_y_end = ((change['lhs-y-end'] + ex.lhs_scroller.scrollTop()) * ex.visible_page_ratio) + 1;
+			var rhs_y_start = ((change['rhs-y-start'] + ex.rhs_scroller.scrollTop()) * ex.visible_page_ratio);
+			var rhs_y_end = ((change['rhs-y-end'] + ex.rhs_scroller.scrollTop()) * ex.visible_page_ratio) + 1;
+			this.trace('draw', 'marker calculated', lhs_y_start, lhs_y_end, rhs_y_start, rhs_y_end);
+
+			ctx_lhs.beginPath();
+			ctx_lhs.fillStyle = this.settings.fgcolor[change['op']];
+			ctx_lhs.strokeStyle = '#000';
+			ctx_lhs.lineWidth = 1.0;
+			ctx_lhs.fillRect(1.5, lhs_y_start, 4.5, Math.max(lhs_y_end - lhs_y_start, 5));
+			ctx_lhs.strokeRect(1.5, lhs_y_start, 4.5, Math.max(lhs_y_end - lhs_y_start, 5));
+
+			ctx_rhs.beginPath();
+			ctx_rhs.fillStyle = this.settings.fgcolor[change['op']];
+			ctx_rhs.strokeStyle = '#000';
+			ctx_rhs.lineWidth = 1.0;
+			ctx_rhs.fillRect(1.5, rhs_y_start, 4.5, Math.max(rhs_y_end - rhs_y_start, 5));
+			ctx_rhs.strokeRect(1.5, rhs_y_start, 4.5, Math.max(rhs_y_end - rhs_y_start, 5));
+
+			if (!this._is_change_in_view(vp, change)) {
+				continue;
+			}
+
+			lhs_y_start = change['lhs-y-start'];
+			lhs_y_end = change['lhs-y-end'];
+			rhs_y_start = change['rhs-y-start'];
+			rhs_y_end = change['rhs-y-end'];
+
+			var radius = 3;
+
+			// draw left box
+			ctx.beginPath();
+			ctx.strokeStyle = this.settings.fgcolor[change['op']];
+			ctx.lineWidth = 1;
+
+			var rectWidth = this.draw_lhs_width;
+			var rectHeight = lhs_y_end - lhs_y_start - 1;
+			var rectX = this.draw_lhs_min;
+			var rectY = lhs_y_start;
+			// top and top top-right corner
+
+			// draw left box
+			ctx.moveTo(rectX, rectY);
+			if (navigator.appName == 'Microsoft Internet Explorer') {
+				// IE arcs look awful
+				ctx.lineTo(this.draw_lhs_min + this.draw_lhs_width, lhs_y_start);
+				ctx.lineTo(this.draw_lhs_min + this.draw_lhs_width, lhs_y_end + 1);
+				ctx.lineTo(this.draw_lhs_min, lhs_y_end + 1);
+			}
+			else {
+				if (rectHeight <= 0) {
+					ctx.lineTo(rectX + rectWidth, rectY);
+				}
+				else {
+					ctx.arcTo(rectX + rectWidth, rectY, rectX + rectWidth, rectY + radius, radius);
+					ctx.arcTo(rectX + rectWidth, rectY + rectHeight, rectX + rectWidth - radius, rectY + rectHeight, radius);
+				}
+				// bottom line
+				ctx.lineTo(rectX, rectY + rectHeight);
+			}
+			ctx.stroke();
+
+			rectWidth = this.draw_rhs_width;
+			rectHeight = rhs_y_end - rhs_y_start - 1;
+			rectX = this.draw_rhs_max;
+			rectY = rhs_y_start;
+
+			// draw right box
+			ctx.moveTo(rectX, rectY);
+			if (navigator.appName == 'Microsoft Internet Explorer') {
+				ctx.lineTo(this.draw_rhs_max - this.draw_rhs_width, rhs_y_start);
+				ctx.lineTo(this.draw_rhs_max - this.draw_rhs_width, rhs_y_end + 1);
+				ctx.lineTo(this.draw_rhs_max, rhs_y_end + 1);
+			}
+			else {
+				if (rectHeight <= 0) {
+					ctx.lineTo(rectX - rectWidth, rectY);
+				}
+				else {
+					ctx.arcTo(rectX - rectWidth, rectY, rectX - rectWidth, rectY + radius, radius);
+					ctx.arcTo(rectX - rectWidth, rectY + rectHeight, rectX - radius, rectY + rectHeight, radius);
+				}
+				ctx.lineTo(rectX, rectY + rectHeight);
+			}
+			ctx.stroke();
+
+			// connect boxes
+			var cx = this.draw_lhs_min + this.draw_lhs_width;
+			var cy = lhs_y_start + (lhs_y_end + 1 - lhs_y_start) / 2.0;
+			var dx = this.draw_rhs_max - this.draw_rhs_width;
+			var dy = rhs_y_start + (rhs_y_end + 1 - rhs_y_start) / 2.0;
+			ctx.moveTo(cx, cy);
+			if (cy == dy) {
+				ctx.lineTo(dx, dy);
+			}
+			else {
+				// fancy!
+				ctx.bezierCurveTo(
+					cx + 12, cy - 3, // control-1 X,Y
+					dx - 12, dy - 3, // control-2 X,Y
+					dx, dy);
+			}
+			ctx.stroke();
+		}
+
+		// visible window feedback
+		ctx_lhs.fillStyle = this.settings.vpcolor;
+		ctx_rhs.fillStyle = this.settings.vpcolor;
+
+		var lto = ex.clhs.height() * ex.visible_page_ratio;
+		var lfrom = (ex.lhs_scroller.scrollTop() / ex.gutter_height) * ex.clhs.height();
+		var rto = ex.crhs.height() * ex.visible_page_ratio;
+		var rfrom = (ex.rhs_scroller.scrollTop() / ex.gutter_height) * ex.crhs.height();
+		this.trace('draw', 'cls.height', ex.clhs.height());
+		this.trace('draw', 'lhs_scroller.scrollTop()', ex.lhs_scroller.scrollTop());
+		this.trace('draw', 'gutter_height', ex.gutter_height);
+		this.trace('draw', 'visible_page_ratio', ex.visible_page_ratio);
+		this.trace('draw', 'lhs from', lfrom, 'lhs to', lto);
+		this.trace('draw', 'rhs from', rfrom, 'rhs to', rto);
+
+		ctx_lhs.fillRect(1.5, lfrom, 4.5, lto);
+		ctx_rhs.fillRect(1.5, rfrom, 4.5, rto);
+
+		ex.clhs.click(function (ev) {
+			var y = ev.pageY - ex.lhs_xyoffset.top - (lto / 2);
+			var sto = Math.max(0, (y / mcanvas_lhs.height) * ex.lhs_scroller.get(0).scrollHeight);
+			ex.lhs_scroller.scrollTop(sto);
+		});
+		ex.crhs.click(function (ev) {
+			var y = ev.pageY - ex.rhs_xyoffset.top - (rto / 2);
+			var sto = Math.max(0, (y / mcanvas_rhs.height) * ex.rhs_scroller.get(0).scrollHeight);
+			ex.rhs_scroller.scrollTop(sto);
+		});
+	},
+	trace: function(name) {
+		if(this.settings._debug.indexOf(name) >= 0) {
+			arguments[0] = name+':';
+			console.log([].slice.apply(arguments));
+		}
+	}
+});
+
+jQuery.pluginMaker = function(plugin) {
+	// add the plugin function as a jQuery plugin
+	jQuery.fn[plugin.prototype.name] = function(options) {
+		// get the arguments
+		var args = jQuery.makeArray(arguments),
+		after = args.slice(1);
+		var rc = undefined;
+		this.each(function() {
+			// see if we have an instance
+			var instance = jQuery.data(this, plugin.prototype.name);
+			if (instance) {
+				// call a method on the instance
+				if (typeof options == "string") {
+					rc = instance[options].apply(instance, after);
+				} else if (instance.update) {
+					// call update on the instance
+					return instance.update.apply(instance, args);
+				}
+			} else {
+				// create the plugin
+				new plugin(this, options);
+			}
+		});
+		if (rc != undefined) return rc;
+	};
+};
+
+// make the mergely widget
+jQuery.pluginMaker(Mgly.mergely);