User:Avenue/Imagemap-Highlight.js

$(document).ready(function {   var //add this class to all elements created by the script. the reason is that we call the script again on //window resize, and use the class to remove all the "artefacts" we created in the previous run.		myClassName = 'imageMapHighlighterArtefacts',		liHighlightClass = 'liHighlighting', // "2d context" attributes used for highlighting.		areaHighLighting = {fillStyle: 'rgba(0,0,0,0.35)', strokeStyle: 'yellow', lineJoin: 'round', lineWidth: 2}, //every imagemap that wants highlighting, should reside in a div of this 'class':		hilightDivMarker = '.imageMapHighlighter', // specifically for wikis - redlinks tooltip adds this message		pageDoesntExistMessage = (mw && mw.config && mw.config.get('wgUserLanguage') == 'he')			? ' (הדף אינו קיים)'			: ' (page does not exist)';	function drawMarker(context, areas) { // this is where the magic is done.		function drawPoly(coords) { context.moveTo(coords.shift, coords.shift); while (coords.length) context.lineTo(coords.shift, coords.shift); }		for (var i in areas) { var coords = areas[i].coords.split(','); context.beginPath; switch (areas[i].shape) { case 'rect': drawPoly([coords[0], coords[1], coords[0], coords[3], coords[2], coords[3], coords[2], coords[1]]); break; case 'circle': context.arc(coords[0],coords[1],coords[2],0,Math.PI*2); break;//x,y,r,startAngle,endAngle case 'poly': drawPoly(coords); break; }			context.closePath; context.stroke; context.fill; }	}	function mouseAction(e) { var $this = $(this), context = $this.data('context'); var activate = e.type == 'mouseover'; $this.toggleClass(liHighlightClass, activate); context.clearRect(0, 0, context.canvas.width, context.canvas.height); if (activate) { drawMarker(context, $this.data('areas')); if ($.client.profile.name === 'msie') {	// ie9: dimwit needs to be told twice. context.clearRect(0, 0, context.canvas.width, context.canvas.height); drawMarker(context, $this.data('areas')); }		}	}	// massage the area "href" and create a human legible string to be used as the tooltip of "li" function pageOfHref(href, cssClass) { var page = href.replace(document.location.protocol + mw.config.get('wgServer') + "/wiki/", ).replace(/.*\/\//, ).replace(/_/g, ' '); page = page.replace(/#(.*)/, function(toReplace){return toReplace.replace(/\.([\dA-F]{2})/g, '%$1');}); page = decodeURIComponent(page); // used for "title" of legends - just like "normal" wiki links. if (cssClass.indexOf('new') + 1) page += pageDoesntExistMessage; return page; }	function init { appendCSS('li.' + myClassName + '{white-space:nowrap;}\n' + //css for li element					'li.' + liHighlightClass + '{background-color:yellow;}\n' + //css for highlighted li element.					'.rtl li.' + myClassName + '{float: right; margin-left: 3em;}\n' +					'.ltr li.' + myClassName + '{float: left; margin-right: 3em;}'); $(hilightDivMarker+ ' img').each(function {			var img = $(this), map = img.siblings('map:first');			if (!('area', map).length)				return;	//not an imagemap. inside "each" anonymous function, 'return' means "continue".			var w = img.width, h = img.height;			var dims = {position: 'absolute', width: w + 'px', height: h + 'px', border: 0, top:0, left:0};			var jcanvas = $(' ', {'class': myClassName})				.css(dims)				.attr({width: w, height: h});			var bgimg = $(' ', {'class': myClassName, src: img.attr('src')})				.css(dims);//completely inert image. this is what we see.			var context = $.extend(jcanvas[0].getContext("2d"), areaHighLighting); // this is where the magic is done: prepare a sandwich of the inert bgimg at the bottom, // the canvas above it, and the original, image, on top. // so canvas won't steal the mouse events. // pack them all TIGHTLY in a newly minted "relative" div, so when page chnage // (other scripts adding elements, window resize etc.), canvas and imagese remain aligned. var div = $(' ').css({position: 'relative', width: w + 'px', height: h + 'px'}); img.before(div);	// put the div just above the image, and ... div.append(bgimg)	// place the background image in the div .append(jcanvas)// and the canvas. both are "absolute", so they don't occupy space in the div .append(img);	// now yank the original image from the window and place it on top. img.fadeTo(1, 0);	// make the image transparent - we see canvas and bgimg through it. var ol = $('', {'class': myClassName}).css({clear: 'both', marginTop: '1.5em'}); // ol below image, hr below ol. original caption pushed below hr.			div.after($(' ', {'class': myClassName}).css('clear', 'both')).after(ol); var lis = {};	//collapse areas with same caption to one list item $('area', map).each(function {				var $this = $(this), text = this.title;				var li = lis[text];	// title already met? use the same li				if (!li) {			//no? create a new one.					var href = this.href, cssClass = this['class'] || '';					lis[text] = li = $('', {'class': myClassName})						.append($('', {href: href, title: pageOfHref(href, cssClass), text: text, 'class': cssClass})) 						.bind('mouseover mouseout', mouseAction)						.data('areas', [])						.data('context', context);				}				li.data('areas').push(this);	//add the area to the li				$(this).bind('mouseover mouseout', function(e) {li.trigger(e);})			}); });	}	//has at least one "imagehighlight" div, and canvas-capable browser:	if ($(hilightDivMarker).length && $(' ')[0].getContext)		init; });