// script.aculo.us slider.js v1.8.2, Tue Nov 18 18:30:58 +0100 2008 

// Copyright (c) 2005-2008 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 = { };

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

            if (Object.isArray(handle)) {
                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(
                            (Object.isArray(slider.options.sliderValue) ?
                                slider.options.sliderValue[i] : slider.options.sliderValue) ||
                            slider.range.start), i);
                    h.makePositioned().observe("mousedown", slider.eventMouseDown);
                });

            this.track.observe("mousedown", this.eventMouseDown);
            document.observe("mouseup", this.eventMouseUp);
            $(this.track.parentNode.parentNode).observe("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(this.track.parentNode.parentNode, "mousemove", this.eventMouseMove);
            this.handles.each( function(h) {
                    Event.stopObserving(h, "mousedown", slider.eventMouseDown);
                });
        },
        setDisabled: function(){
            this.disabled = true;
            this.track.parentNode.className = this.track.parentNode.className + ' disabled';
        },
        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.alignX);
        },
        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) || event.button === 0) {
                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);
                if (Prototype.Browser.WebKit) 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;
        }
    });