/*
---
name: Scrollbar
description: A simple Apple-style productbrowser, that extends Slider using a container with Fx.Scroll.
 
version: 0.9.7
copyright: Enrique Erne (http://mild.ch)
license: MIT License
authors:
- Enrique Erne
 
requires:
core/1.2.4: [Class, Element.Event, Element.Dimensions, Fx.Tween, Fx.Transitions, Selectors]
more/1.2.4.4: [Fx.Scroll, Slider]
 
provides: ScrollBar
...
*/
 
var ScrollBar = new Class({
 
Extends: Slider,
 
options: {
scroll: {
wheelStops: false/*
onStart: $empty,
onComplete: $empty*/
},
slider: {
mode: 'horizontal',
wheel: true/*
onChange: $empty(intStep),
onComplete: $empty(strStep)*/
},
knob: {/*
onStart: $empty*/
}
},
 
initialize: function(scroller, slider, knob, options){
this.knob = document.id(knob).set('tween', options.knob);
this.slider = document.id(slider);
this.scroller = document.id(scroller);
this.scrollElement = this.scroller.getFirst();
this.parent(this.slider, this.knob, $extend(this.options.slider, options.slider));
this.steps = this.scrollElement.getSize()[this.axis] - this.scroller.getSize()[this.axis];
this.scroll = new Fx.Scroll(this.scroller, $extend(this.options.scroll, options.scroll));
this.scroller.addEvent('mousewheel', function(event){
this.element.fireEvent('mousewheel', event);
}.bind(this));
this.ratio = this.steps / (this.slider.getSize()[this.axis] - this.knob.getSize()[this.axis]);
},
 
move2: function(amount){
this.set(this.knob.getPosition(this.slider)[this.axis] + amount);
},
 
set: function(position){
if($type(position) === 'element') position = position.getPosition(this.scrollElement)[this.axis] / this.ratio;
position = position.limit(-this.options.offset, this.full -this.options.offset);
this.move(position * this.ratio);
this.knob.tween(this.property, position).get('tween').chain(function(){
this.fireEvent('complete', Math.round(position * this.ratio) + '');
}.bind(this));
},
 
move: function(position){
var to = $chk(position) ? position : this.step;
if (this.options.mode === 'vertical') this.scroll.cancel().start(0, to);
else this.scroll.cancel().start(to, 0);
},
 
draggedKnob: function(){
this.parent();
if (this.options.mode === 'vertical') this.scroll.cancel().set(0, this.step);
else this.scroll.cancel().set(this.step);
},
 
clickedElement: function(event){
if (event.target === this.knob){
this.knob.get('tween').cancel();
return;
}
var position = event.page[this.axis] - this.element.getPosition()[this.axis] - this.half;
position = position.limit(-this.options.offset, this.full -this.options.offset);
this.set(position);
},
 
scrolledElement: function(event){
var mode = (this.options.mode == 'horizontal') ? (event.wheel < 0) : (event.wheel > 0);
this.move2(mode ? -this.stepSize * 100 : this.stepSize * 100);
event.stop();
}
 
});