// script.aculo.us slider.js v1.7.0, Fri Jan 19 19:16:36 CET 2007

// Copyright (c) 2005, 2006 Marty Haught, Thomas Fuchs
//
// script.aculo.us is freely distributable under the terms of an MIT-style license.
// For details, see the script.aculo.us web site: http://script.aculo.us/

if(!Control) var Control = {};
Control.Slider = Class.create();

// options:
//  axis: 'vertical', or 'horizontal' (default)
//
// callbacks:
//  onChange(value)
//  onSlide(value)
Control.Slider.prototype = {
	initialize: function(handle, track, options) {
		var slider = this;

		if(handle instanceof Array) {
			this.handles = handle.collect( function(e) { return $(e) });
		} else {
			this.handles = [$(handle)];
		}

		this.track   = $(track);
		this.options = options || {};

		this.axis      = this.options.axis || 'horizontal';
		this.increment = this.options.increment || 1;
		this.step      = parseInt(this.options.step || '1');
		this.range     = this.options.range || $R(0,1);

		this.value  = 0; // assure backwards compat
		this.values = this.handles.map( function() { return 0 });
		this.spans  = this.options.spans ? this.options.spans.map(function(s){ return $(s) }) : false;
		this.options.startSpan = $(this.options.startSpan || null);
		this.options.endSpan   = $(this.options.endSpan || null);

		this.restricted = this.options.restricted || false;

		this.maximum = this.options.maximum || this.range.end;
		this.minimum = this.options.minimum || this.range.start;

		// Will be used to align the handle onto the track, if necessary
		this.alignX = parseInt(this.options.alignX || '0');
		this.alignY = parseInt(this.options.alignY || '0');

		this.trackLength = this.maximumOffset() - this.minimumOffset();

		this.handleLength = this.isVertical() ?
			(this.handles[0].offsetHeight != 0 ?
				this.handles[0].offsetHeight : this.handles[0].style.height.replace(/px$/,"")) :
			(this.handles[0].offsetWidth != 0 ? this.handles[0].offsetWidth :
				this.handles[0].style.width.replace(/px$/,""));

		this.active   = false;
		this.dragging = false;
		this.disabled = false;

		if(this.options.disabled) this.setDisabled();

		// Allowed values array
		this.allowedValues = this.options.values ? this.options.values.sortBy(Prototype.K) : false;
		if(this.allowedValues) {
			this.minimum = this.allowedValues.min();
			this.maximum = this.allowedValues.max();
		}

		this.eventMouseDown = this.startDrag.bindAsEventListener(this);
		this.eventMouseUp   = this.endDrag.bindAsEventListener(this);
		this.eventMouseMove = this.update.bindAsEventListener(this);

		// Initialize handles in reverse (make sure first handle is active)
		this.handles.each( function(h,i) {
			i = slider.handles.length-1-i;
			slider.setValue(parseFloat(
				(slider.options.sliderValue instanceof Array ?
					slider.options.sliderValue[i] : slider.options.sliderValue) ||
				slider.range.start), i);
			Element.makePositioned(h); // fix IE
			Event.observe(h, "mousedown", slider.eventMouseDown);
		});

		Event.observe(this.track, "mousedown", this.eventMouseDown);
		Event.observe(document, "mouseup", this.eventMouseUp);
		Event.observe(document, "mousemove", this.eventMouseMove);

		this.initialized = true;
	},
	dispose: function() {
		var slider = this;
		Event.stopObserving(this.track, "mousedown", this.eventMouseDown);
		Event.stopObserving(document, "mouseup", this.eventMouseUp);
		Event.stopObserving(document, "mousemove", this.eventMouseMove);
		this.handles.each( function(h) {
			Event.stopObserving(h, "mousedown", slider.eventMouseDown);
		});
	},
	setDisabled: function(){
		this.disabled = true;
	},
	setEnabled: function(){
		this.disabled = false;
	},
	getNearestValue: function(value){
		if(this.allowedValues){
			if(value >= this.allowedValues.max()) return(this.allowedValues.max());
			if(value <= this.allowedValues.min()) return(this.allowedValues.min());

			var offset = Math.abs(this.allowedValues[0] - value);
			var newValue = this.allowedValues[0];
			this.allowedValues.each( function(v) {
				var currentOffset = Math.abs(v - value);
				if(currentOffset <= offset){
					newValue = v;
					offset = currentOffset;
				}
			});
			return newValue;
		}
		if(value > this.range.end) return this.range.end;
		if(value < this.range.start) return this.range.start;
		return value;
	},
	setValue: function(sliderValue, handleIdx){
		if(!this.active) {
			this.activeHandleIdx = handleIdx || 0;
			this.activeHandle    = this.handles[this.activeHandleIdx];
			this.updateStyles();
		}
		handleIdx = handleIdx || this.activeHandleIdx || 0;
		if(this.initialized && this.restricted) {
			if((handleIdx>0) && (sliderValue<this.values[handleIdx-1]))
				sliderValue = this.values[handleIdx-1];
			if((handleIdx < (this.handles.length-1)) && (sliderValue>this.values[handleIdx+1]))
				sliderValue = this.values[handleIdx+1];
		}
		sliderValue = this.getNearestValue(sliderValue);
		this.values[handleIdx] = sliderValue;
		this.value = this.values[0]; // assure backwards compat

		this.handles[handleIdx].style[this.isVertical() ? 'top' : 'left'] =
			this.translateToPx(sliderValue);

		this.drawSpans();
		if(!this.dragging || !this.event) this.updateFinished();
	},
	setValueBy: function(delta, handleIdx) {
		this.setValue(this.values[handleIdx || this.activeHandleIdx || 0] + delta,
			handleIdx || this.activeHandleIdx || 0);
	},
	translateToPx: function(value) {
		return Math.round(
			((this.trackLength-this.handleLength)/(this.range.end-this.range.start)) * (value - this.range.start)) + "px";
	},
	translateToValue: function(offset) {
		return ((offset/(this.trackLength-this.handleLength) * (this.range.end-this.range.start)) + this.range.start);
	},
	getRange: function(range) {
		var v = this.values.sortBy(Prototype.K);
		range = range || 0;
		return $R(v[range],v[range+1]);
	},
	minimumOffset: function(){
		return(this.isVertical() ? this.alignY : this.alignX);
	},
	maximumOffset: function(){
		return(this.isVertical() ?
			(this.track.offsetHeight != 0 ? this.track.offsetHeight :
				this.track.style.height.replace(/px$/,"")) - this.alignY :
			(this.track.offsetWidth != 0 ? this.track.offsetWidth :
				this.track.style.width.replace(/px$/,"")) - this.alignY);
	},
	isVertical:	function(){
		return (this.axis == 'vertical');
	},
	drawSpans: function() {
		var slider = this;
		if(this.spans)
			$R(0, this.spans.length-1).each(function(r) { slider.setSpan(slider.spans[r], slider.getRange(r)) });
		if(this.options.startSpan)
			this.setSpan(this.options.startSpan,
				$R(0, this.values.length>1 ? this.getRange(0).min() : this.value ));
		if(this.options.endSpan)
			this.setSpan(this.options.endSpan,
				$R(this.values.length>1 ? this.getRange(this.spans.length-1).max() : this.value, this.maximum));
	},
	setSpan: function(span, range) {
		if(this.isVertical()) {
			span.style.top = this.translateToPx(range.start);
			span.style.height = this.translateToPx(range.end - range.start + this.range.start);
		} else {
			span.style.left = this.translateToPx(range.start);
			span.style.width = this.translateToPx(range.end - range.start + this.range.start);
		}
	},
	updateStyles: function() {
		this.handles.each( function(h){ Element.removeClassName(h, 'selected') });
		Element.addClassName(this.activeHandle, 'selected');
	},
	startDrag: function(event) {
		if(Event.isLeftClick(event)) {
			if(!this.disabled){
				this.active = true;

				var handle   = Event.element(event);
				var pointer  = [Event.pointerX(event), Event.pointerY(event)];
				var track    = handle;
				if(track==this.track) {
					var offsets = Position.cumulativeOffset(this.track);
					this.event = event;
					this.setValue(this.translateToValue(
						(this.isVertical() ? pointer[1]-offsets[1] : pointer[0]-offsets[0])-(this.handleLength/2)
					));
					var offsets  = Position.cumulativeOffset(this.activeHandle);
					this.offsetX = (pointer[0] - offsets[0]);
					this.offsetY = (pointer[1] - offsets[1]);
				} else {
					// find the handle (prevents issues with Safari)
					while((this.handles.indexOf(handle) == -1) && handle.parentNode)
						handle = handle.parentNode;

					if(this.handles.indexOf(handle)!=-1) {
						this.activeHandle    = handle;
						this.activeHandleIdx = this.handles.indexOf(this.activeHandle);
						this.updateStyles();

						var offsets  = Position.cumulativeOffset(this.activeHandle);
						this.offsetX = (pointer[0] - offsets[0]);
						this.offsetY = (pointer[1] - offsets[1]);
					}
				}
			}
			Event.stop(event);
		}
	},
	update: function(event) {
		if(this.active) {
			if(!this.dragging) this.dragging = true;
			this.draw(event);
			// fix AppleWebKit rendering
			if(navigator.appVersion.indexOf('AppleWebKit')>0) window.scrollBy(0,0);
			Event.stop(event);
		}
	},
	draw: function(event) {
		var pointer = [Event.pointerX(event), Event.pointerY(event)];
		var offsets = Position.cumulativeOffset(this.track);
		pointer[0] -= this.offsetX + offsets[0];
		pointer[1] -= this.offsetY + offsets[1];
		this.event = event;
		this.setValue(this.translateToValue( this.isVertical() ? pointer[1] : pointer[0] ));
		if(this.initialized && this.options.onSlide)
			this.options.onSlide(this.values.length>1 ? this.values : this.value, this);
	},
	endDrag: function(event) {
		if(this.active && this.dragging) {
			this.finishDrag(event, true);
			Event.stop(event);
		}
		this.active = false;
		this.dragging = false;
	},
	finishDrag: function(event, success) {
		this.active = false;
		this.dragging = false;
		this.updateFinished();
	},
	updateFinished: function() {
		if(this.initialized && this.options.onChange)
			this.options.onChange(this.values.length>1 ? this.values : this.value, this);
		this.event = null;
	}
}