/**
 * jCarouselLite - jQuery plugin to navigate images/any content in a carousel style widget.
 * @requires jQuery v1.2 or above
 *
 * http://gmarwaha.com/jquery/jcarousellite/
 *
 * Copyright (c) 2007 Ganeshji Marwaha (gmarwaha.com)
 * Dual licensed under the MIT and GPL licenses:
 * http://www.opensource.org/licenses/mit-license.php
 * http://www.gnu.org/licenses/gpl.html
 *
 * Version: 1.0.1
 * Note: Requires jquery 1.2 or above from version 1.0.1
 */

/**
 * Creates a carousel-style navigation widget for images/any-content from a
 * simple HTML markup.
 * 
 * The HTML markup that is used to build the carousel can be as simple as...
 * 
 * <div class="carousel">
 * <ul>
 * <li><img src="image/1.jpg" alt="1"></li>
 * <li><img src="image/2.jpg" alt="2"></li>
 * <li><img src="image/3.jpg" alt="3"></li>
 * </ul>
 * </div>
 * 
 * As you can see, this snippet is nothing but a simple div containing an
 * unordered list of images. You don't need any special "class" attribute, or a
 * special "css" file for this plugin. I am using a class attribute just for the
 * sake of explanation here.
 * 
 * To navigate the elements of the carousel, you need some kind of navigation
 * buttons. For example, you will need a "previous" button to go backward, and a
 * "next" button to go forward. This need not be part of the carousel "div"
 * itself. It can be any element in your page. Lets assume that the following
 * elements in your document can be used as next, and prev buttons...
 * 
 * <button class="prev">&lt;&lt;</button> <button class="next">&gt;&gt;</button>
 * 
 * Now, all you need to do is call the carousel component on the div element
 * that represents it, and pass in the navigation buttons as options.
 * 
 * $(".carousel").jCarouselLite({ btnNext: ".next", btnPrev: ".prev" });
 * 
 * That's it, you would have now converted your raw div, into a magnificient
 * carousel.
 * 
 * There are quite a few other options that you can use to customize it though.
 * Each will be explained with an example below.
 * 
 * @param an
 *            options object - You can specify all the options shown below as an
 *            options object param.
 * 
 * @option btnPrev, btnNext : string - no defaults
 * @example $(".carousel").jCarouselLite({ btnNext: ".next", btnPrev: ".prev"
 *          });
 * @desc Creates a basic carousel. Clicking "btnPrev" navigates backwards and
 *       "btnNext" navigates forward.
 * 
 * @option btnGo - array - no defaults
 * @example $(".carousel").jCarouselLite({ btnNext: ".next", btnPrev: ".prev",
 *          btnGo: [".0", ".1", ".2"] });
 * @desc If you don't want next and previous buttons for navigation, instead you
 *       prefer custom navigation based on the item number within the carousel,
 *       you can use this option. Just supply an array of selectors for each
 *       element in the carousel. The index of the array represents the index of
 *       the element. What i mean is, if the first element in the array is ".0",
 *       it means that when the element represented by ".0" is clicked, the
 *       carousel will slide to the first element and so on and so forth. This
 *       feature is very powerful. For example, i made a tabbed interface out of
 *       it by making my navigation elements styled like tabs in css. As the
 *       carousel is capable of holding any content, not just images, you can
 *       have a very simple tabbed navigation in minutes without using any other
 *       plugin. The best part is that, the tab will "slide" based on the
 *       provided effect. :-)
 * 
 * @option mouseWheel : boolean - default is false
 * @example $(".carousel").jCarouselLite({ mouseWheel: true });
 * @desc The carousel can also be navigated using the mouse wheel interface of a
 *       scroll mouse instead of using buttons. To get this feature working, you
 *       have to do 2 things. First, you have to include the mouse-wheel plugin
 *       from brandon. Second, you will have to set the option "mouseWheel" to
 *       true. That's it, now you will be able to navigate your carousel using
 *       the mouse wheel. Using buttons and mouseWheel or not mutually
 *       exclusive. You can still have buttons for navigation as well. They
 *       complement each other. To use both together, just supply the options
 *       required for both as shown below.
 * @example $(".carousel").jCarouselLite({ btnNext: ".next", btnPrev: ".prev",
 *          mouseWheel: true });
 * 
 * @option auto : number - default is null, meaning autoscroll is disabled by
 *         default
 * @example $(".carousel").jCarouselLite({ auto: 800, speed: 500 });
 * @desc You can make your carousel auto-navigate itself by specfying a
 *       millisecond value in this option. The value you specify is the amount
 *       of time between 2 slides. The default is null, and that disables auto
 *       scrolling. Specify this value and magically your carousel will start
 *       auto scrolling.
 * 
 * @option speed : number - 200 is default
 * @example $(".carousel").jCarouselLite({ btnNext: ".next", btnPrev: ".prev",
 *          speed: 800 });
 * @desc Specifying a speed will slow-down or speed-up the sliding speed of your
 *       carousel. Try it out with different speeds like 800, 600, 1500 etc.
 *       Providing 0, will remove the slide effect.
 * 
 * @option easing : string - no easing effects by default.
 * @example $(".carousel").jCarouselLite({ btnNext: ".next", btnPrev: ".prev",
 *          easing: "bounceout" });
 * @desc You can specify any easing effect. Note: You need easing plugin for
 *       that. Once specified, the carousel will slide based on the provided
 *       easing effect.
 * 
 * @option vertical : boolean - default is false
 * @example $(".carousel").jCarouselLite({ btnNext: ".next", btnPrev: ".prev",
 *          vertical: true });
 * @desc Determines the direction of the carousel. true, means the carousel will
 *       display vertically. The next and prev buttons will slide the items
 *       vertically as well. The default is false, which means that the carousel
 *       will display horizontally. The next and prev items will slide the items
 *       from left-right in this case.
 * 
 * @option circular : boolean - default is true
 * @example $(".carousel").jCarouselLite({ btnNext: ".next", btnPrev: ".prev",
 *          circular: false });
 * @desc Setting it to true enables circular navigation. This means, if you
 *       click "next" after you reach the last element, you will automatically
 *       slide to the first element and vice versa. If you set circular to
 *       false, then if you click on the "next" button after you reach the last
 *       element, you will stay in the last element itself and similarly for
 *       "previous" button and first element.
 * 
 * @option visible : number - default is 3
 * @example $(".carousel").jCarouselLite({ btnNext: ".next", btnPrev: ".prev",
 *          visible: 4 });
 * @desc This specifies the number of items visible at all times within the
 *       carousel. The default is 3. You are even free to experiment with real
 *       numbers. Eg: "3.5" will have 3 items fully visible and the last item
 *       half visible. This gives you the effect of showing the user that there
 *       are more images to the right.
 * 
 * @option start : number - default is 0
 * @example $(".carousel").jCarouselLite({ btnNext: ".next", btnPrev: ".prev",
 *          start: 2 });
 * @desc You can specify from which item the carousel should start. Remember,
 *       the first item in the carousel has a start of 0, and so on.
 * 
 * @option scrool : number - default is 1
 * @example $(".carousel").jCarouselLite({ btnNext: ".next", btnPrev: ".prev",
 *          scroll: 2 });
 * @desc The number of items that should scroll/slide when you click the
 *       next/prev navigation buttons. By default, only one item is scrolled,
 *       but you may set it to any number. Eg: setting it to "2" will scroll 2
 *       items when you click the next or previous buttons.
 * 
 * @option beforeStart, afterEnd : function - callbacks
 * @example $(".carousel").jCarouselLite({ btnNext: ".next", btnPrev: ".prev",
 *          beforeStart: function(a) { alert("Before animation starts:" + a); },
 *          afterEnd: function(a) { alert("After animation ends:" + a); } });
 * @desc If you wanted to do some logic in your page before the slide starts and
 *       after the slide ends, you can register these 2 callbacks. The functions
 *       will be passed an argument that represents an array of elements that
 *       are visible at the time of callback.
 * 
 * 
 * @cat Plugins/Image Gallery
 * @author Ganeshji Marwaha/ganeshread@gmail.com
 */

(function($) { // Compliant with jquery.noConflict()
	$.fn.jCarouselLite = function(o) {
		o = $.extend( {
			btnPrev : null,
			btnNext : null,
			btnGo : null,
			btnStartAuto : null,
			btnStopAuto : null,
			mouseWheel : false,
			autoOnStart : true,
			auto : null,

			speed : 200,
			easing : null,

			vertical : false,
			circular : true,
			visible : 3,
			start : 0,
			scroll : 1,
			fadein : null,
			fadeout : null,

			beforeStart : null,
			afterEnd : null
		}, o || {});

		return this.each(function() {
			// Returns the element collection. Chainable.

				var running = false, animCss = o.vertical ? "top" : "left", sizeCss = o.vertical ? "height"
						: "width";
				var div = $(this), ul = $("ul", div), tLi = $("li", ul), tl = tLi
						.size(), v = o.visible;
				var autoscrolling = null;

				if (o.circular) {
					ul.prepend(tLi.slice(tl - v - 1 + 1).clone()).append(
							tLi.slice(0, v).clone());
					o.start += v;
				}

				var li = $("li", ul), itemLength = li.size(), curr = o.start;
				div.css("visibility", "visible");

				li.css( {
					overflow : "hidden",
					float : o.vertical ? "none" : "left"
				});
				ul.css( {
					margin : "0",
					padding : "0",
					position : "relative",
					"list-style-type" : "none",
					"z-index" : "1"
				});
				div.css( {
					overflow : "hidden",
					position : "relative",
					"z-index" : "2",
					left : "0px"
				});

				var liSize = o.vertical ? height(li) : width(li);
				// Full li size(incl margin)-Used for animation
				var ulSize = liSize * itemLength;
				// size of full ul(total length, not just for the visible
				// items)
				var divSize = liSize * v;
				// size of entire div(total length for just the visible
				// items)

				li.css( {
					width : li.width(),
					height : li.height()
				});
				ul.css(sizeCss, ulSize + "px").css(animCss, -(curr * liSize));

				div.css(sizeCss, divSize + "px");
				// Width of the DIV. length of visible images

				if (o.btnPrev)
					$(o.btnPrev).click(function() {
						if (autoscrolling) {
							clearInterval(autoscrolling);
							autoscrolling = null;
						}
						if (o.fadeout) {
							div.fadeOut(o.fadeout, function() {
								go(curr - o.scroll);
							});
						} else {
							return go(curr - o.scroll);
						}
					});

				if (o.btnNext)
					$(o.btnNext).click(function() {
						if (autoscrolling) {
							clearInterval(autoscrolling);
							autoscrolling = null;
						}
						if (o.fadeout) {
							div.fadeOut(o.fadeout, function() {
								go(curr + o.scroll);
							});
						} else {
							return go(curr + o.scroll);
						}
					});

				if (o.btnGo)
					$.each(o.btnGo, function(i, val) {
						$(val).click(function() {
							if (autoscrolling) {
								clearInterval(autoscrolling);
								autoscrolling = null;
							}
							if (o.fadeout) {
								div.fadeOut(o.fadeout, function() {
									go(o.circular ? o.visible + i : i);
								});
							} else {
								return go(o.circular ? o.visible + i : i);
							}
						});
					});

				if (o.mouseWheel && div.mousewheel)
					div.mousewheel(function(e, d) {
						if (autoscrolling) {
							clearInterval(autoscrolling);
							autoscrolling = null;
						}
						return d > 0 ? go(curr - o.scroll)
								: go(curr + o.scroll);
					});

				if (o.btnStartAuto)
					$(o.btnStartAuto).click(function() {
						if (o.fadeout) {
							autoscrolling = setInterval(function() {
								div.fadeOut(o.fadeout, function() {
									go(curr + o.scroll);
								});
							}, o.auto + o.speed);

						} else {
							autoscrolling = setInterval(function() {
								go(curr + o.scroll);
							}, o.auto + o.speed);
						}
					});

				if (o.btnStopAuto)
					$(o.btnStopAuto).click(function() {
						if (autoscrolling) {
							clearInterval(autoscrolling);
							autoscrolling = null;
						}
					});

				if (o.auto)
					if (o.autoOnStart) {
						if (o.fadeout) {
							autoscrolling = setInterval(function() {
								div.fadeOut(o.fadeout, function() {
									go(curr + o.scroll);
								});
							}, o.auto + o.speed);

						} else {
							autoscrolling = setInterval(function() {
								go(curr + o.scroll);
							}, o.auto + o.speed);
						}
					}

				function vis() {
					return li.slice(curr).slice(0, v);
				}
				;

				function go(to) {
					if (!running) {
						if (o.beforeStart)
							o.beforeStart.call(this, vis());

						if (o.circular) {
							// If circular we are in first or last, then goto
							// the other end
							if (to <= o.start - v - 1) { // If first,
								// then goto last
								ul.css(animCss,
										-((itemLength - (v * 2)) * liSize)
												+ "px");
								// If "scroll" > 1, then the "to" might not
								// be equal to the condition; it can be
								// lesser depending on the number of elements.
								curr = to == o.start - v - 1 ? itemLength
										- (v * 2) - 1 : itemLength - (v * 2)
										- o.scroll;
							} else if (to >= itemLength - v + 1) {
								// If last, then goto first
								ul.css(animCss, -((v) * liSize) + "px");
								// If "scroll" > 1, then the "to" might not
								// be equal to the condition; it can be
								// greater depending on the number of elements.
								curr = to == itemLength - v + 1 ? v + 1 : v
										+ o.scroll;
							} else
								curr = to;
						} else {
							// If non-circular and to points to
							// first or last, we just return.
							if (to < 0 || to > itemLength - v)
								return;
							else
								curr = to;
						}
						// If neither overrides it, the curr will still
						// be "to" and we can proceed.
						running = true;

						ul.animate(animCss == "left" ? {
							left : -(curr * liSize)
						} : {
							top : -(curr * liSize)
						}, o.speed, o.easing, function() {
							if (o.afterEnd)
								o.afterEnd.call(this, vis(), curr);
							running = false;
							if (o.fadeout) {
								if (o.fadein) {
									div.fadeIn(o.fadein);
								} else {
									div.fadeIn(1000);
								}
							}
						});
						// Disable buttons when the carousel reaches the
						// last first, and enable when not
						if (!o.circular) {
							$(o.btnPrev + "," + o.btnNext).removeClass(
									"disabled");
							$(
									(curr - o.scroll < 0 && o.btnPrev)
											|| (curr + o.scroll > itemLength
													- v && o.btnNext) || [])
									.addClass("disabled");
						}

					}
					return false;
				}
				;
			});
	};

	function css(el, prop) {
		return parseInt($.css(el[0], prop)) || 0;
	}
	;
	function width(el) {
		return el[0].offsetWidth + css(el, 'marginLeft')
				+ css(el, 'marginRight');
	}
	;
	function height(el) {
		return el[0].offsetHeight + css(el, 'marginTop')
				+ css(el, 'marginBottom');
	}
	;

})(jQuery);