// script.aculo.us dragdrop.js v1.8.0, Tue Nov 06 15:01:40 +0300 2007

// Copyright (c) 2005-2007 Thomas Fuchs (http://script.aculo.us, http://mir.aculo.us)
//           (c) 2005-2007 Sammi Williams (http://www.oriontransfer.co.nz, sammi@oriontransfer.co.nz)
// 
// 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/
//
// Modified by Tero Marttila to strip unused code

var Draggables = {
  drags: [],
  observers: [],
  
  register: function(draggable) {
    if(this.drags.length == 0) {
      this.eventMouseUp   = this.endDrag.bindAsEventListener(this);
      this.eventMouseMove = this.updateDrag.bindAsEventListener(this);
      this.eventKeypress  = this.keyPress.bindAsEventListener(this);
      
      Event.observe(document, "mouseup", this.eventMouseUp);
      Event.observe(document, "mousemove", this.eventMouseMove);
      Event.observe(document, "keypress", this.eventKeypress);
    }
    this.drags.push(draggable);
  },
  
  unregister: function(draggable) {
    this.drags = this.drags.reject(function(d) { return d==draggable });
    if(this.drags.length == 0) {
      Event.stopObserving(document, "mouseup", this.eventMouseUp);
      Event.stopObserving(document, "mousemove", this.eventMouseMove);
      Event.stopObserving(document, "keypress", this.eventKeypress);
    }
  },
  
  activate: function(draggable) {
    if(draggable.options.delay) { 
      this._timeout = setTimeout(function() { 
        Draggables._timeout = null; 
        window.focus(); 
        Draggables.activeDraggable = draggable; 
      }.bind(this), draggable.options.delay); 
    } else {
      window.focus(); // allows keypress events if window isn't currently focused, fails for Safari
      this.activeDraggable = draggable;
    }
  },
  
  deactivate: function() {
    this.activeDraggable = null;
  },
  
  updateDrag: function(event) {
    if(!this.activeDraggable) return;
    var pointer = [Event.pointerX(event), Event.pointerY(event)];
    // Mozilla-based browsers fire successive mousemove events with
    // the same coordinates, prevent needless redrawing (moz bug?)
    if(this._lastPointer && (this._lastPointer.inspect() == pointer.inspect())) return;
    this._lastPointer = pointer;
    
    this.activeDraggable.updateDrag(event, pointer);
  },
  
  endDrag: function(event) {
    if(this._timeout) { 
      clearTimeout(this._timeout); 
      this._timeout = null; 
    }
    if(!this.activeDraggable) return;
    this._lastPointer = null;
    this.activeDraggable.endDrag(event);
    this.activeDraggable = null;
  },
  
  keyPress: function(event) {
    if(this.activeDraggable)
      this.activeDraggable.keyPress(event);
  },
  
  addObserver: function(observer) {
    this.observers.push(observer);
    this._cacheObserverCallbacks();
  },
  
  removeObserver: function(element) {  // element instead of observer fixes mem leaks
    this.observers = this.observers.reject( function(o) { return o.element==element });
    this._cacheObserverCallbacks();
  },
  
  notify: function(eventName, draggable, event) {  // 'onStart', 'onEnd', 'onDrag'
    if(this[eventName+'Count'] > 0)
      this.observers.each( function(o) {
        if(o[eventName]) o[eventName](eventName, draggable, event);
      });
    if(draggable.options[eventName]) draggable.options[eventName](draggable, event);
  },
  
  _cacheObserverCallbacks: function() {
    ['onStart','onEnd','onDrag'].each( function(eventName) {
      Draggables[eventName+'Count'] = Draggables.observers.select(
        function(o) { return o[eventName]; }
      ).length;
    });
  }
}

/*--------------------------------------------------------------------------*/

var Draggable = Class.create({
  initialize: function(element) {
    var defaults = {
      handle: false,
      zindex: 1000,
      quiet: false,
      delay: 0
    };
    
    var options = Object.extend(defaults, arguments[1] || { });

    this.element = $(element);
    
    if(options.handle && Object.isString(options.handle))
      this.handle = this.element.down('.'+options.handle, 0);
    
    if(!this.handle) this.handle = $(options.handle);
    if(!this.handle) this.handle = this.element;
    
    Element.makePositioned(this.element); // fix IE    

    this.options  = options;
    this.dragging = false;   

    this.eventMouseDown = this.initDrag.bindAsEventListener(this);
    Event.observe(this.handle, "mousedown", this.eventMouseDown);
    
    Draggables.register(this);
  },
  
  destroy: function() {
    Event.stopObserving(this.handle, "mousedown", this.eventMouseDown);
    Draggables.unregister(this);
  },
  
  currentDelta: function() {
    return([
      parseInt(Element.getStyle(this.element,'left') || '0'),
      parseInt(Element.getStyle(this.element,'top') || '0')]);
  },
  
  initDrag: function(event) {
    if(!Object.isUndefined(Draggable._dragging[this.element]) &&
      Draggable._dragging[this.element]) return;
    if(Event.isLeftClick(event)) {    
      // abort on form elements, fixes a Firefox issue
      var src = Event.element(event);
      if((tag_name = src.tagName.toUpperCase()) && (
        tag_name=='INPUT' ||
        tag_name=='SELECT' ||
        tag_name=='OPTION' ||
        tag_name=='BUTTON' ||
        tag_name=='TEXTAREA')) return;
        
      var pointer = [Event.pointerX(event), Event.pointerY(event)];
      var pos     = Position.cumulativeOffset(this.element);
      this.offset = [0,1].map( function(i) { return (pointer[i] - pos[i]) });
      
      Draggables.activate(this);
      Event.stop(event);
    }
  },
  
  startDrag: function(event) {
    this.dragging = true;
    if(!this.delta)
      this.delta = this.currentDelta();
    
    if(this.options.zindex) {
      this.originalZ = parseInt(Element.getStyle(this.element,'z-index') || 0);
      this.element.style.zIndex = this.options.zindex;
    }
    
    Draggables.notify('onStart', this, event);
  },
  
  updateDrag: function(event, pointer) {
    if(!this.dragging) this.startDrag(event);
    
    Draggables.notify('onDrag', this, event);
    
    this.draw(pointer);
    if(this.options.change) this.options.change(this);
    
    // fix AppleWebKit rendering
    if(Prototype.Browser.WebKit) window.scrollBy(0,0);
    
    Event.stop(event);
  },
  
  finishDrag: function(event, success) {
    this.dragging = false;
    
    Draggables.notify('onEnd', this, event);

    var d = this.currentDelta();
    this.delta = d;

    if(this.options.zindex)
      this.element.style.zIndex = this.originalZ;

    Draggables.deactivate(this);
  },
  
  keyPress: function(event) {
    if(event.keyCode!=Event.KEY_ESC) return;
    this.finishDrag(event, false);
    Event.stop(event);
  },
  
  endDrag: function(event) {
    if(!this.dragging) return;
    this.finishDrag(event, true);
    Event.stop(event);
  },
  
  draw: function(point) {
    var pos = Position.cumulativeOffset(this.element);
    
    var d = this.currentDelta();
    pos[0] -= d[0]; pos[1] -= d[1];
    
    var p = [0,1].map(function(i){ 
      return (point[i]-pos[i]-this.offset[i]) 
    }.bind(this));
    
    var style = this.element.style;
    if((!this.options.constraint) || (this.options.constraint=='horizontal'))
      style.left = p[0] + "px";
    if((!this.options.constraint) || (this.options.constraint=='vertical'))
      style.top  = p[1] + "px";
    
    if(style.visibility=="hidden") style.visibility = ""; // fix gecko rendering
  },
   
});

Draggable._dragging = { };