Merge pull request davist11#7 from barneyfoxuk/master

added onStick and onUnstick callbacks

jquery.stickem.js

@@ -13,7 +13,7 @@
  */
 
 ;(function($, window, document, undefined) {
-	
+
 	var Stickem = function(elem, options) {
 		this.elem = elem;
 		this.$elem = $(elem);
@@ -34,34 +34,34 @@
 
 		init: function() {
 			var _self = this;
-			
+
 			//Merge options
 			_self.config = $.extend({}, _self.defaults, _self.options, _self.metadata);
-			
+
 			_self.setWindowHeight();
 			_self.getItems();
 			_self.bindEvents();
-			
+
 			return _self;
 		},
-		
+
 		bindEvents: function() {
 			var _self = this;
-			
+
 			if(_self.items.length > 0) {
 				_self.$win.on('scroll.stickem', $.proxy(_self.handleScroll, _self));
-				
+
 				_self.$win.on('resize.stickem', $.proxy(_self.handleResize, _self));
 			}
 		},
-		
+
 		destroy: function() {
 			var _self = this;
-			
+
 			_self.$win.off('scroll.stickem');
 			_self.$win.off('resize.stickem');
 		},
-		
+
 		getItem: function(index, element) {
 			var _self = this;
 			var $this = $(element);
@@ -71,7 +71,7 @@
 				$container: $this.parents(_self.config.container),
 				isStuck: false
 			};
-			
+
 			//If the element is smaller than the window
 			if(_self.windowHeight > item.elemHeight) {
 				item.containerHeight = item.$container.outerHeight();
@@ -83,42 +83,42 @@
 					padding: {
 						bottom: parseInt(item.$container.css('padding-bottom'), 10) || 0,
 						top: parseInt(item.$container.css('padding-top'), 10) || 0
-					} 
+					}
 				};
-				
+
 				item.containerInnerHeight = item.$container.height();
 				item.containerStart = item.$container.offset().top - _self.config.offset + _self.config.start + item.containerInner.padding.top + item.containerInner.border.top;
 				item.scrollFinish = item.containerStart - _self.config.start + (item.containerInnerHeight - item.elemHeight);
-				
+
 				//If the element is smaller than the container
 				if(item.containerInnerHeight > item.elemHeight) {
 					_self.items.push(item);
 				}
 			}
 		},
-		
+
 		getItems: function() {
 			var _self = this;
-			
+
 			_self.items = [];
-			
+
 			_self.$elem.find(_self.config.item).each($.proxy(_self.getItem, _self));
 		},
-		
+
 		handleResize: function() {
 			var _self = this;
-			
+
 			_self.getItems();
 			_self.setWindowHeight();
 		},
-		
+
 		handleScroll: function() {
 			var _self = this;
 			var pos = _self.$win.scrollTop();
 
 			for(var i = 0, len = _self.items.length; i < len; i++) {
 				var item = _self.items[i];
-				
+
 				//If it's stuck, and we need to unstick it
 				if(item.isStuck && (pos < item.containerStart || pos > item.scrollFinish)) {
 					item.$elem.removeClass(_self.config.stickClass);
@@ -129,18 +129,26 @@
 					}
 
 					item.isStuck = false;
-
+
+					//if supplied fire the onUnstick callback
+					if(_self.config.onUnstick)
+						_self.config.onUnstick(item);
+
 				//If we need to stick it
 				} else if(item.isStuck === false && pos > item.containerStart && pos < item.scrollFinish) {
 						item.$elem.removeClass(_self.config.endStickClass).addClass(_self.config.stickClass);
 						item.isStuck = true;
+
+						//if supplied fire the onStick callback
+						if(_self.config.onStick)
+							_self.config.onStick(item);
 				}
 			}
 		},
-		
+
 		setWindowHeight: function() {
 			var _self = this;
-			
+
 			_self.windowHeight = _self.$win.height() - _self.config.offset;
 		}
 	};
@@ -154,7 +162,7 @@
 				new Stickem(this, options).destroy();
 			});
 		};
-		
+
 		return this.each(function() {
 			new Stickem(this, options).init();
 		});