1 files changed, 162 insertions, 0 deletions
diff --git a/data/js/jquery.wheelzoom.js b/data/js/jquery.wheelzoom.js
new file mode 100644
index 000000000..85d75e56f
--- /dev/null
+++ b/data/js/jquery.wheelzoom.js
@@ -0,0 +1,162 @@
+/*!
+	Wheelzoom 2.0.1
+	license: MIT
+	http://www.jacklmoore.com/wheelzoom
+*/
+(function($){
+	var defaults = {
+		zoom: 0.10
+	};
+	var wheel;
+
+	function setSrcToBackground(img) {
+		var transparentPNG = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAACklEQVR4nGMAAQAABQABDQottAAAAABJRU5ErkJggg==";
+
+		// Explicitly set the size to the current dimensions,
+		// as the src is about to be changed to a 1x1 transparent png.
+		img.width = img.width;
+		img.height = img.height;
+
+		img.style.backgroundImage = "url('"+img.src+"')";
+		img.style.backgroundRepeat = 'no-repeat';
+		img.src = transparentPNG;
+	}
+
+	if ( document.onmousewheel !== undefined ) { // Webkit/Opera/IE
+		wheel = 'onmousewheel';
+	}
+	else if ( document.onwheel !== undefined) { // FireFox 17+
+		wheel = 'onwheel';
+	}
+
+	$.fn.wheelzoom = function(options){
+		var settings = $.extend({}, defaults, options);
+
+		if (!this[0] || !wheel || !('backgroundSize' in this[0].style)) { // do nothing in IE8 and lower
+			return this;
+		}
+
+		return this.each(function(){
+			var img = this,
+				$img = $(img);
+
+			function loaded() {
+				var width = $img.width(),
+					height = $img.height(),
+					bgWidth = width,
+					bgHeight = height,
+					bgPosX = 0,
+					bgPosY = 0;
+
+				function reset() {
+					bgWidth = width;
+					bgHeight = height;
+					bgPosX = bgPosY = 0;
+					updateBgStyle();
+				}
+
+				function updateBgStyle() {
+					if (bgPosX > 0) {
+						bgPosX = 0;
+					} else if (bgPosX < width - bgWidth) {
+						bgPosX = width - bgWidth;
+					}
+
+					if (bgPosY > 0) {
+						bgPosY = 0;
+					} else if (bgPosY < height - bgHeight) {
+						bgPosY = height - bgHeight;
+					}
+
+					img.style.backgroundSize = bgWidth+'px '+bgHeight+'px';
+					img.style.backgroundPosition = bgPosX+'px '+bgPosY+'px';
+				}
+
+				setSrcToBackground(img);
+
+				$img.css({
+					backgroundSize: width+'px '+height+'px',
+					backgroundPosition: '0 0'
+				}).bind('wheelzoom.reset', reset);
+
+				img[wheel] = function (e) {
+					var deltaY = 0;
+
+					e.preventDefault();
+
+					if (e.deltaY) { // FireFox 17+ (IE9+, Chrome 31+?)
+						deltaY = e.deltaY;
+					} else if (e.wheelDelta) {
+						deltaY = -e.wheelDelta;
+					}
+
+					// As far as I know, there is no good cross-browser way to get the cursor position relative to the event target.
+					// We have to calculate the target element's position relative to the document, and subtrack that from the
+					// cursor's position relative to the document.
+					var offsetParent = $img.offset();
+					var offsetX = e.pageX - offsetParent.left;
+					var offsetY = e.pageY - offsetParent.top;
+
+					// Record the offset between the bg edge and cursor:
+					var bgCursorX = offsetX - bgPosX;
+					var bgCursorY = offsetY - bgPosY;
+					
+					// Use the previous offset to get the percent offset between the bg edge and cursor:
+					var bgRatioX = bgCursorX/bgWidth;
+					var bgRatioY = bgCursorY/bgHeight;
+
+					// Update the bg size:
+					if (deltaY < 0) {
+						bgWidth += bgWidth*settings.zoom;
+						bgHeight += bgHeight*settings.zoom;
+					} else {
+						bgWidth -= bgWidth*settings.zoom;
+						bgHeight -= bgHeight*settings.zoom;
+					}
+
+					// Take the percent offset and apply it to the new size:
+					bgPosX = offsetX - (bgWidth * bgRatioX);
+					bgPosY = offsetY - (bgHeight * bgRatioY);
+
+					// Prevent zooming out beyond the starting size
+					if (bgWidth <= width || bgHeight <= height) {
+						reset();
+					} else {
+						updateBgStyle();
+					}
+				};
+
+				// Make the background draggable
+				img.onmousedown = function(e){
+					var last = e;
+
+					e.preventDefault();
+
+					function drag(e) {
+						e.preventDefault();
+						bgPosX += (e.pageX - last.pageX);
+						bgPosY += (e.pageY - last.pageY);
+						last = e;
+						updateBgStyle();
+					}
+
+					$(document)
+					.on('mousemove', drag)
+					.one('mouseup', function () {
+						$(document).unbind('mousemove', drag);
+					});
+				};
+			}
+
+			if (img.complete) {
+				loaded();
+			} else {
+				$img.one('load', loaded);
+			}
+
+		});
+	};
+
+	$.fn.wheelzoom.defaults = defaults;
+
+}(window.jQuery));