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   1  // script.aculo.us dragdrop.js v1.9.0, Thu Dec 23 16:54:48 -0500 2010
   2  
   3  // Copyright (c) 2005-2010 Thomas Fuchs (http://script.aculo.us, http://mir.aculo.us)
   4  //
   5  // script.aculo.us is freely distributable under the terms of an MIT-style license.
   6  // For details, see the script.aculo.us web site: http://script.aculo.us/
   7  
   8  if(Object.isUndefined(Effect))
   9    throw("dragdrop.js requires including script.aculo.us' effects.js library");
  10  
  11  var Droppables = {
  12    drops: [],
  13  
  14    remove: function(element) {
  15      this.drops = this.drops.reject(function(d) { return d.element==$(element) });
  16    },
  17  
  18    add: function(element) {
  19      element = $(element);
  20      var options = Object.extend({
  21        greedy:     true,
  22        hoverclass: null,
  23        tree:       false
  24      }, arguments[1] || { });
  25  
  26      // cache containers
  27      if(options.containment) {
  28        options._containers = [];
  29        var containment = options.containment;
  30        if(Object.isArray(containment)) {
  31          containment.each( function(c) { options._containers.push($(c)) });
  32        } else {
  33          options._containers.push($(containment));
  34        }
  35      }
  36  
  37      if(options.accept) options.accept = [options.accept].flatten();
  38  
  39      Element.makePositioned(element); // fix IE
  40      options.element = element;
  41  
  42      this.drops.push(options);
  43    },
  44  
  45    findDeepestChild: function(drops) {
  46      deepest = drops[0];
  47  
  48      for (i = 1; i < drops.length; ++i)
  49        if (Element.isParent(drops[i].element, deepest.element))
  50          deepest = drops[i];
  51  
  52      return deepest;
  53    },
  54  
  55    isContained: function(element, drop) {
  56      var containmentNode;
  57      if(drop.tree) {
  58        containmentNode = element.treeNode;
  59      } else {
  60        containmentNode = element.parentNode;
  61      }
  62      return drop._containers.detect(function(c) { return containmentNode == c });
  63    },
  64  
  65    isAffected: function(point, element, drop) {
  66      return (
  67        (drop.element!=element) &&
  68        ((!drop._containers) ||
  69          this.isContained(element, drop)) &&
  70        ((!drop.accept) ||
  71          (Element.classNames(element).detect(
  72            function(v) { return drop.accept.include(v) } ) )) &&
  73        Position.within(drop.element, point[0], point[1]) );
  74    },
  75  
  76    deactivate: function(drop) {
  77      if(drop.hoverclass)
  78        Element.removeClassName(drop.element, drop.hoverclass);
  79      this.last_active = null;
  80    },
  81  
  82    activate: function(drop) {
  83      if(drop.hoverclass)
  84        Element.addClassName(drop.element, drop.hoverclass);
  85      this.last_active = drop;
  86    },
  87  
  88    show: function(point, element) {
  89      if(!this.drops.length) return;
  90      var drop, affected = [];
  91  
  92      this.drops.each( function(drop) {
  93        if(Droppables.isAffected(point, element, drop))
  94          affected.push(drop);
  95      });
  96  
  97      if(affected.length>0)
  98        drop = Droppables.findDeepestChild(affected);
  99  
 100      if(this.last_active && this.last_active != drop) this.deactivate(this.last_active);
 101      if (drop) {
 102        Position.within(drop.element, point[0], point[1]);
 103        if(drop.onHover)
 104          drop.onHover(element, drop.element, Position.overlap(drop.overlap, drop.element));
 105  
 106        if (drop != this.last_active) Droppables.activate(drop);
 107      }
 108    },
 109  
 110    fire: function(event, element) {
 111      if(!this.last_active) return;
 112      Position.prepare();
 113  
 114      if (this.isAffected([Event.pointerX(event), Event.pointerY(event)], element, this.last_active))
 115        if (this.last_active.onDrop) {
 116          this.last_active.onDrop(element, this.last_active.element, event);
 117          return true;
 118        }
 119    },
 120  
 121    reset: function() {
 122      if(this.last_active)
 123        this.deactivate(this.last_active);
 124    }
 125  };
 126  
 127  var Draggables = {
 128    drags: [],
 129    observers: [],
 130  
 131    register: function(draggable) {
 132      if(this.drags.length == 0) {
 133        this.eventMouseUp   = this.endDrag.bindAsEventListener(this);
 134        this.eventMouseMove = this.updateDrag.bindAsEventListener(this);
 135        this.eventKeypress  = this.keyPress.bindAsEventListener(this);
 136  
 137        Event.observe(document, "mouseup", this.eventMouseUp);
 138        Event.observe(document, "mousemove", this.eventMouseMove);
 139        Event.observe(document, "keypress", this.eventKeypress);
 140      }
 141      this.drags.push(draggable);
 142    },
 143  
 144    unregister: function(draggable) {
 145      this.drags = this.drags.reject(function(d) { return d==draggable });
 146      if(this.drags.length == 0) {
 147        Event.stopObserving(document, "mouseup", this.eventMouseUp);
 148        Event.stopObserving(document, "mousemove", this.eventMouseMove);
 149        Event.stopObserving(document, "keypress", this.eventKeypress);
 150      }
 151    },
 152  
 153    activate: function(draggable) {
 154      if(draggable.options.delay) {
 155        this._timeout = setTimeout(function() {
 156          Draggables._timeout = null;
 157          window.focus();
 158          Draggables.activeDraggable = draggable;
 159        }.bind(this), draggable.options.delay);
 160      } else {
 161        window.focus(); // allows keypress events if window isn't currently focused, fails for Safari
 162        this.activeDraggable = draggable;
 163      }
 164    },
 165  
 166    deactivate: function() {
 167      this.activeDraggable = null;
 168    },
 169  
 170    updateDrag: function(event) {
 171      if(!this.activeDraggable) return;
 172      var pointer = [Event.pointerX(event), Event.pointerY(event)];
 173      // Mozilla-based browsers fire successive mousemove events with
 174      // the same coordinates, prevent needless redrawing (moz bug?)
 175      if(this._lastPointer && (this._lastPointer.inspect() == pointer.inspect())) return;
 176      this._lastPointer = pointer;
 177  
 178      this.activeDraggable.updateDrag(event, pointer);
 179    },
 180  
 181    endDrag: function(event) {
 182      if(this._timeout) {
 183        clearTimeout(this._timeout);
 184        this._timeout = null;
 185      }
 186      if(!this.activeDraggable) return;
 187      this._lastPointer = null;
 188      this.activeDraggable.endDrag(event);
 189      this.activeDraggable = null;
 190    },
 191  
 192    keyPress: function(event) {
 193      if(this.activeDraggable)
 194        this.activeDraggable.keyPress(event);
 195    },
 196  
 197    addObserver: function(observer) {
 198      this.observers.push(observer);
 199      this._cacheObserverCallbacks();
 200    },
 201  
 202    removeObserver: function(element) {  // element instead of observer fixes mem leaks
 203      this.observers = this.observers.reject( function(o) { return o.element==element });
 204      this._cacheObserverCallbacks();
 205    },
 206  
 207    notify: function(eventName, draggable, event) {  // 'onStart', 'onEnd', 'onDrag'
 208      if(this[eventName+'Count'] > 0)
 209        this.observers.each( function(o) {
 210          if(o[eventName]) o[eventName](eventName, draggable, event);
 211        });
 212      if(draggable.options[eventName]) draggable.options[eventName](draggable, event);
 213    },
 214  
 215    _cacheObserverCallbacks: function() {
 216      ['onStart','onEnd','onDrag'].each( function(eventName) {
 217        Draggables[eventName+'Count'] = Draggables.observers.select(
 218          function(o) { return o[eventName]; }
 219        ).length;
 220      });
 221    }
 222  };
 223  
 224  /*--------------------------------------------------------------------------*/
 225  
 226  var Draggable = Class.create({
 227    initialize: function(element) {
 228      var defaults = {
 229        handle: false,
 230        reverteffect: function(element, top_offset, left_offset) {
 231          var dur = Math.sqrt(Math.abs(top_offset^2)+Math.abs(left_offset^2))*0.02;
 232          new Effect.Move(element, { x: -left_offset, y: -top_offset, duration: dur,
 233            queue: {scope:'_draggable', position:'end'}
 234          });
 235        },
 236        endeffect: function(element) {
 237          var toOpacity = Object.isNumber(element._opacity) ? element._opacity : 1.0;
 238          new Effect.Opacity(element, {duration:0.2, from:0.7, to:toOpacity,
 239            queue: {scope:'_draggable', position:'end'},
 240            afterFinish: function(){
 241              Draggable._dragging[element] = false
 242            }
 243          });
 244        },
 245        zindex: 1000,
 246        revert: false,
 247        quiet: false,
 248        scroll: false,
 249        scrollSensitivity: 20,
 250        scrollSpeed: 15,
 251        snap: false,  // false, or xy or [x,y] or function(x,y){ return [x,y] }
 252        delay: 0
 253      };
 254  
 255      if(!arguments[1] || Object.isUndefined(arguments[1].endeffect))
 256        Object.extend(defaults, {
 257          starteffect: function(element) {
 258            element._opacity = Element.getOpacity(element);
 259            Draggable._dragging[element] = true;
 260            new Effect.Opacity(element, {duration:0.2, from:element._opacity, to:0.7});
 261          }
 262        });
 263  
 264      var options = Object.extend(defaults, arguments[1] || { });
 265  
 266      this.element = $(element);
 267  
 268      if(options.handle && Object.isString(options.handle))
 269        this.handle = this.element.down('.'+options.handle, 0);
 270  
 271      if(!this.handle) this.handle = $(options.handle);
 272      if(!this.handle) this.handle = this.element;
 273  
 274      if(options.scroll && !options.scroll.scrollTo && !options.scroll.outerHTML) {
 275        options.scroll = $(options.scroll);
 276        this._isScrollChild = Element.childOf(this.element, options.scroll);
 277      }
 278  
 279      Element.makePositioned(this.element); // fix IE
 280  
 281      this.options  = options;
 282      this.dragging = false;
 283  
 284      this.eventMouseDown = this.initDrag.bindAsEventListener(this);
 285      Event.observe(this.handle, "mousedown", this.eventMouseDown);
 286  
 287      Draggables.register(this);
 288    },
 289  
 290    destroy: function() {
 291      Event.stopObserving(this.handle, "mousedown", this.eventMouseDown);
 292      Draggables.unregister(this);
 293    },
 294  
 295    currentDelta: function() {
 296      return([
 297        parseInt(Element.getStyle(this.element,'left') || '0'),
 298        parseInt(Element.getStyle(this.element,'top') || '0')]);
 299    },
 300  
 301    initDrag: function(event) {
 302      if(!Object.isUndefined(Draggable._dragging[this.element]) &&
 303        Draggable._dragging[this.element]) return;
 304      if(Event.isLeftClick(event)) {
 305        // abort on form elements, fixes a Firefox issue
 306        var src = Event.element(event);
 307        if((tag_name = src.tagName.toUpperCase()) && (
 308          tag_name=='INPUT' ||
 309          tag_name=='SELECT' ||
 310          tag_name=='OPTION' ||
 311          tag_name=='BUTTON' ||
 312          tag_name=='TEXTAREA')) return;
 313  
 314        var pointer = [Event.pointerX(event), Event.pointerY(event)];
 315        var pos     = this.element.cumulativeOffset();
 316        this.offset = [0,1].map( function(i) { return (pointer[i] - pos[i]) });
 317  
 318        Draggables.activate(this);
 319        Event.stop(event);
 320      }
 321    },
 322  
 323    startDrag: function(event) {
 324      this.dragging = true;
 325      if(!this.delta)
 326        this.delta = this.currentDelta();
 327  
 328      if(this.options.zindex) {
 329        this.originalZ = parseInt(Element.getStyle(this.element,'z-index') || 0);
 330        this.element.style.zIndex = this.options.zindex;
 331      }
 332  
 333      if(this.options.ghosting) {
 334        this._clone = this.element.cloneNode(true);
 335        this._originallyAbsolute = (this.element.getStyle('position') == 'absolute');
 336        if (!this._originallyAbsolute)
 337          Position.absolutize(this.element);
 338        this.element.parentNode.insertBefore(this._clone, this.element);
 339      }
 340  
 341      if(this.options.scroll) {
 342        if (this.options.scroll == window) {
 343          var where = this._getWindowScroll(this.options.scroll);
 344          this.originalScrollLeft = where.left;
 345          this.originalScrollTop = where.top;
 346        } else {
 347          this.originalScrollLeft = this.options.scroll.scrollLeft;
 348          this.originalScrollTop = this.options.scroll.scrollTop;
 349        }
 350      }
 351  
 352      Draggables.notify('onStart', this, event);
 353  
 354      if(this.options.starteffect) this.options.starteffect(this.element);
 355    },
 356  
 357    updateDrag: function(event, pointer) {
 358      if(!this.dragging) this.startDrag(event);
 359  
 360      if(!this.options.quiet){
 361        Position.prepare();
 362        Droppables.show(pointer, this.element);
 363      }
 364  
 365      Draggables.notify('onDrag', this, event);
 366  
 367      this.draw(pointer);
 368      if(this.options.change) this.options.change(this);
 369  
 370      if(this.options.scroll) {
 371        this.stopScrolling();
 372  
 373        var p;
 374        if (this.options.scroll == window) {
 375          with(this._getWindowScroll(this.options.scroll)) { p = [ left, top, left+width, top+height ]; }
 376        } else {
 377          p = Position.page(this.options.scroll).toArray();
 378          p[0] += this.options.scroll.scrollLeft + Position.deltaX;
 379          p[1] += this.options.scroll.scrollTop + Position.deltaY;
 380          p.push(p[0]+this.options.scroll.offsetWidth);
 381          p.push(p[1]+this.options.scroll.offsetHeight);
 382        }
 383        var speed = [0,0];
 384        if(pointer[0] < (p[0]+this.options.scrollSensitivity)) speed[0] = pointer[0]-(p[0]+this.options.scrollSensitivity);
 385        if(pointer[1] < (p[1]+this.options.scrollSensitivity)) speed[1] = pointer[1]-(p[1]+this.options.scrollSensitivity);
 386        if(pointer[0] > (p[2]-this.options.scrollSensitivity)) speed[0] = pointer[0]-(p[2]-this.options.scrollSensitivity);
 387        if(pointer[1] > (p[3]-this.options.scrollSensitivity)) speed[1] = pointer[1]-(p[3]-this.options.scrollSensitivity);
 388        this.startScrolling(speed);
 389      }
 390  
 391      // fix AppleWebKit rendering
 392      if(Prototype.Browser.WebKit) window.scrollBy(0,0);
 393  
 394      Event.stop(event);
 395    },
 396  
 397    finishDrag: function(event, success) {
 398      this.dragging = false;
 399  
 400      if(this.options.quiet){
 401        Position.prepare();
 402        var pointer = [Event.pointerX(event), Event.pointerY(event)];
 403        Droppables.show(pointer, this.element);
 404      }
 405  
 406      if(this.options.ghosting) {
 407        if (!this._originallyAbsolute)
 408          Position.relativize(this.element);
 409        delete this._originallyAbsolute;
 410        Element.remove(this._clone);
 411        this._clone = null;
 412      }
 413  
 414      var dropped = false;
 415      if(success) {
 416        dropped = Droppables.fire(event, this.element);
 417        if (!dropped) dropped = false;
 418      }
 419      if(dropped && this.options.onDropped) this.options.onDropped(this.element);
 420      Draggables.notify('onEnd', this, event);
 421  
 422      var revert = this.options.revert;
 423      if(revert && Object.isFunction(revert)) revert = revert(this.element);
 424  
 425      var d = this.currentDelta();
 426      if(revert && this.options.reverteffect) {
 427        if (dropped == 0 || revert != 'failure')
 428          this.options.reverteffect(this.element,
 429            d[1]-this.delta[1], d[0]-this.delta[0]);
 430      } else {
 431        this.delta = d;
 432      }
 433  
 434      if(this.options.zindex)
 435        this.element.style.zIndex = this.originalZ;
 436  
 437      if(this.options.endeffect)
 438        this.options.endeffect(this.element);
 439  
 440      Draggables.deactivate(this);
 441      Droppables.reset();
 442    },
 443  
 444    keyPress: function(event) {
 445      if(event.keyCode!=Event.KEY_ESC) return;
 446      this.finishDrag(event, false);
 447      Event.stop(event);
 448    },
 449  
 450    endDrag: function(event) {
 451      if(!this.dragging) return;
 452      this.stopScrolling();
 453      this.finishDrag(event, true);
 454      Event.stop(event);
 455    },
 456  
 457    draw: function(point) {
 458      var pos = this.element.cumulativeOffset();
 459      if(this.options.ghosting) {
 460        var r   = Position.realOffset(this.element);
 461        pos[0] += r[0] - Position.deltaX; pos[1] += r[1] - Position.deltaY;
 462      }
 463  
 464      var d = this.currentDelta();
 465      pos[0] -= d[0]; pos[1] -= d[1];
 466  
 467      if(this.options.scroll && (this.options.scroll != window && this._isScrollChild)) {
 468        pos[0] -= this.options.scroll.scrollLeft-this.originalScrollLeft;
 469        pos[1] -= this.options.scroll.scrollTop-this.originalScrollTop;
 470      }
 471  
 472      var p = [0,1].map(function(i){
 473        return (point[i]-pos[i]-this.offset[i])
 474      }.bind(this));
 475  
 476      if(this.options.snap) {
 477        if(Object.isFunction(this.options.snap)) {
 478          p = this.options.snap(p[0],p[1],this);
 479        } else {
 480        if(Object.isArray(this.options.snap)) {
 481          p = p.map( function(v, i) {
 482            return (v/this.options.snap[i]).round()*this.options.snap[i] }.bind(this));
 483        } else {
 484          p = p.map( function(v) {
 485            return (v/this.options.snap).round()*this.options.snap }.bind(this));
 486        }
 487      }}
 488  
 489      var style = this.element.style;
 490      if((!this.options.constraint) || (this.options.constraint=='horizontal'))
 491        style.left = p[0] + "px";
 492      if((!this.options.constraint) || (this.options.constraint=='vertical'))
 493        style.top  = p[1] + "px";
 494  
 495      if(style.visibility=="hidden") style.visibility = ""; // fix gecko rendering
 496    },
 497  
 498    stopScrolling: function() {
 499      if(this.scrollInterval) {
 500        clearInterval(this.scrollInterval);
 501        this.scrollInterval = null;
 502        Draggables._lastScrollPointer = null;
 503      }
 504    },
 505  
 506    startScrolling: function(speed) {
 507      if(!(speed[0] || speed[1])) return;
 508      this.scrollSpeed = [speed[0]*this.options.scrollSpeed,speed[1]*this.options.scrollSpeed];
 509      this.lastScrolled = new Date();
 510      this.scrollInterval = setInterval(this.scroll.bind(this), 10);
 511    },
 512  
 513    scroll: function() {
 514      var current = new Date();
 515      var delta = current - this.lastScrolled;
 516      this.lastScrolled = current;
 517      if(this.options.scroll == window) {
 518        with (this._getWindowScroll(this.options.scroll)) {
 519          if (this.scrollSpeed[0] || this.scrollSpeed[1]) {
 520            var d = delta / 1000;
 521            this.options.scroll.scrollTo( left + d*this.scrollSpeed[0], top + d*this.scrollSpeed[1] );
 522          }
 523        }
 524      } else {
 525        this.options.scroll.scrollLeft += this.scrollSpeed[0] * delta / 1000;
 526        this.options.scroll.scrollTop  += this.scrollSpeed[1] * delta / 1000;
 527      }
 528  
 529      Position.prepare();
 530      Droppables.show(Draggables._lastPointer, this.element);
 531      Draggables.notify('onDrag', this);
 532      if (this._isScrollChild) {
 533        Draggables._lastScrollPointer = Draggables._lastScrollPointer || $A(Draggables._lastPointer);
 534        Draggables._lastScrollPointer[0] += this.scrollSpeed[0] * delta / 1000;
 535        Draggables._lastScrollPointer[1] += this.scrollSpeed[1] * delta / 1000;
 536        if (Draggables._lastScrollPointer[0] < 0)
 537          Draggables._lastScrollPointer[0] = 0;
 538        if (Draggables._lastScrollPointer[1] < 0)
 539          Draggables._lastScrollPointer[1] = 0;
 540        this.draw(Draggables._lastScrollPointer);
 541      }
 542  
 543      if(this.options.change) this.options.change(this);
 544    },
 545  
 546    _getWindowScroll: function(w) {
 547      var T, L, W, H;
 548      with (w.document) {
 549        if (w.document.documentElement && documentElement.scrollTop) {
 550          T = documentElement.scrollTop;
 551          L = documentElement.scrollLeft;
 552        } else if (w.document.body) {
 553          T = body.scrollTop;
 554          L = body.scrollLeft;
 555        }
 556        if (w.innerWidth) {
 557          W = w.innerWidth;
 558          H = w.innerHeight;
 559        } else if (w.document.documentElement && documentElement.clientWidth) {
 560          W = documentElement.clientWidth;
 561          H = documentElement.clientHeight;
 562        } else {
 563          W = body.offsetWidth;
 564          H = body.offsetHeight;
 565        }
 566      }
 567      return { top: T, left: L, width: W, height: H };
 568    }
 569  });
 570  
 571  Draggable._dragging = { };
 572  
 573  /*--------------------------------------------------------------------------*/
 574  
 575  var SortableObserver = Class.create({
 576    initialize: function(element, observer) {
 577      this.element   = $(element);
 578      this.observer  = observer;
 579      this.lastValue = Sortable.serialize(this.element);
 580    },
 581  
 582    onStart: function() {
 583      this.lastValue = Sortable.serialize(this.element);
 584    },
 585  
 586    onEnd: function() {
 587      Sortable.unmark();
 588      if(this.lastValue != Sortable.serialize(this.element))
 589        this.observer(this.element)
 590    }
 591  });
 592  
 593  var Sortable = {
 594    SERIALIZE_RULE: /^[^_\-](?:[A-Za-z0-9\-\_]*)[_](.*)$/,
 595  
 596    sortables: { },
 597  
 598    _findRootElement: function(element) {
 599      while (element.tagName.toUpperCase() != "BODY") {
 600        if(element.id && Sortable.sortables[element.id]) return element;
 601        element = element.parentNode;
 602      }
 603    },
 604  
 605    options: function(element) {
 606      element = Sortable._findRootElement($(element));
 607      if(!element) return;
 608      return Sortable.sortables[element.id];
 609    },
 610  
 611    destroy: function(element){
 612      element = $(element);
 613      var s = Sortable.sortables[element.id];
 614  
 615      if(s) {
 616        Draggables.removeObserver(s.element);
 617        s.droppables.each(function(d){ Droppables.remove(d) });
 618        s.draggables.invoke('destroy');
 619  
 620        delete Sortable.sortables[s.element.id];
 621      }
 622    },
 623  
 624    create: function(element) {
 625      element = $(element);
 626      var options = Object.extend({
 627        element:     element,
 628        tag:         'li',       // assumes li children, override with tag: 'tagname'
 629        dropOnEmpty: false,
 630        tree:        false,
 631        treeTag:     'ul',
 632        overlap:     'vertical', // one of 'vertical', 'horizontal'
 633        constraint:  'vertical', // one of 'vertical', 'horizontal', false
 634        containment: element,    // also takes array of elements (or id's); or false
 635        handle:      false,      // or a CSS class
 636        only:        false,
 637        delay:       0,
 638        hoverclass:  null,
 639        ghosting:    false,
 640        quiet:       false,
 641        scroll:      false,
 642        scrollSensitivity: 20,
 643        scrollSpeed: 15,
 644        format:      this.SERIALIZE_RULE,
 645  
 646        // these take arrays of elements or ids and can be
 647        // used for better initialization performance
 648        elements:    false,
 649        handles:     false,
 650  
 651        onChange:    Prototype.emptyFunction,
 652        onUpdate:    Prototype.emptyFunction
 653      }, arguments[1] || { });
 654  
 655      // clear any old sortable with same element
 656      this.destroy(element);
 657  
 658      // build options for the draggables
 659      var options_for_draggable = {
 660        revert:      true,
 661        quiet:       options.quiet,
 662        scroll:      options.scroll,
 663        scrollSpeed: options.scrollSpeed,
 664        scrollSensitivity: options.scrollSensitivity,
 665        delay:       options.delay,
 666        ghosting:    options.ghosting,
 667        constraint:  options.constraint,
 668        handle:      options.handle };
 669  
 670      if(options.starteffect)
 671        options_for_draggable.starteffect = options.starteffect;
 672  
 673      if(options.reverteffect)
 674        options_for_draggable.reverteffect = options.reverteffect;
 675      else
 676        if(options.ghosting) options_for_draggable.reverteffect = function(element) {
 677          element.style.top  = 0;
 678          element.style.left = 0;
 679        };
 680  
 681      if(options.endeffect)
 682        options_for_draggable.endeffect = options.endeffect;
 683  
 684      if(options.zindex)
 685        options_for_draggable.zindex = options.zindex;
 686  
 687      // build options for the droppables
 688      var options_for_droppable = {
 689        overlap:     options.overlap,
 690        containment: options.containment,
 691        tree:        options.tree,
 692        hoverclass:  options.hoverclass,
 693        onHover:     Sortable.onHover
 694      };
 695  
 696      var options_for_tree = {
 697        onHover:      Sortable.onEmptyHover,
 698        overlap:      options.overlap,
 699        containment:  options.containment,
 700        hoverclass:   options.hoverclass
 701      };
 702  
 703      // fix for gecko engine
 704      Element.cleanWhitespace(element);
 705  
 706      options.draggables = [];
 707      options.droppables = [];
 708  
 709      // drop on empty handling
 710      if(options.dropOnEmpty || options.tree) {
 711        Droppables.add(element, options_for_tree);
 712        options.droppables.push(element);
 713      }
 714  
 715      (options.elements || this.findElements(element, options) || []).each( function(e,i) {
 716        var handle = options.handles ? $(options.handles[i]) :
 717          (options.handle ? $(e).select('.' + options.handle)[0] : e);
 718        options.draggables.push(
 719          new Draggable(e, Object.extend(options_for_draggable, { handle: handle })));
 720        Droppables.add(e, options_for_droppable);
 721        if(options.tree) e.treeNode = element;
 722        options.droppables.push(e);
 723      });
 724  
 725      if(options.tree) {
 726        (Sortable.findTreeElements(element, options) || []).each( function(e) {
 727          Droppables.add(e, options_for_tree);
 728          e.treeNode = element;
 729          options.droppables.push(e);
 730        });
 731      }
 732  
 733      // keep reference
 734      this.sortables[element.identify()] = options;
 735  
 736      // for onupdate
 737      Draggables.addObserver(new SortableObserver(element, options.onUpdate));
 738  
 739    },
 740  
 741    // return all suitable-for-sortable elements in a guaranteed order
 742    findElements: function(element, options) {
 743      return Element.findChildren(
 744        element, options.only, options.tree ? true : false, options.tag);
 745    },
 746  
 747    findTreeElements: function(element, options) {
 748      return Element.findChildren(
 749        element, options.only, options.tree ? true : false, options.treeTag);
 750    },
 751  
 752    onHover: function(element, dropon, overlap) {
 753      if(Element.isParent(dropon, element)) return;
 754  
 755      if(overlap > .33 && overlap < .66 && Sortable.options(dropon).tree) {
 756        return;
 757      } else if(overlap>0.5) {
 758        Sortable.mark(dropon, 'before');
 759        if(dropon.previousSibling != element) {
 760          var oldParentNode = element.parentNode;
 761          element.style.visibility = "hidden"; // fix gecko rendering
 762          dropon.parentNode.insertBefore(element, dropon);
 763          if(dropon.parentNode!=oldParentNode)
 764            Sortable.options(oldParentNode).onChange(element);
 765          Sortable.options(dropon.parentNode).onChange(element);
 766        }
 767      } else {
 768        Sortable.mark(dropon, 'after');
 769        var nextElement = dropon.nextSibling || null;
 770        if(nextElement != element) {
 771          var oldParentNode = element.parentNode;
 772          element.style.visibility = "hidden"; // fix gecko rendering
 773          dropon.parentNode.insertBefore(element, nextElement);
 774          if(dropon.parentNode!=oldParentNode)
 775            Sortable.options(oldParentNode).onChange(element);
 776          Sortable.options(dropon.parentNode).onChange(element);
 777        }
 778      }
 779    },
 780  
 781    onEmptyHover: function(element, dropon, overlap) {
 782      var oldParentNode = element.parentNode;
 783      var droponOptions = Sortable.options(dropon);
 784  
 785      if(!Element.isParent(dropon, element)) {
 786        var index;
 787  
 788        var children = Sortable.findElements(dropon, {tag: droponOptions.tag, only: droponOptions.only});
 789        var child = null;
 790  
 791        if(children) {
 792          var offset = Element.offsetSize(dropon, droponOptions.overlap) * (1.0 - overlap);
 793  
 794          for (index = 0; index < children.length; index += 1) {
 795            if (offset - Element.offsetSize (children[index], droponOptions.overlap) >= 0) {
 796              offset -= Element.offsetSize (children[index], droponOptions.overlap);
 797            } else if (offset - (Element.offsetSize (children[index], droponOptions.overlap) / 2) >= 0) {
 798              child = index + 1 < children.length ? children[index + 1] : null;
 799              break;
 800            } else {
 801              child = children[index];
 802              break;
 803            }
 804          }
 805        }
 806  
 807        dropon.insertBefore(element, child);
 808  
 809        Sortable.options(oldParentNode).onChange(element);
 810        droponOptions.onChange(element);
 811      }
 812    },
 813  
 814    unmark: function() {
 815      if(Sortable._marker) Sortable._marker.hide();
 816    },
 817  
 818    mark: function(dropon, position) {
 819      // mark on ghosting only
 820      var sortable = Sortable.options(dropon.parentNode);
 821      if(sortable && !sortable.ghosting) return;
 822  
 823      if(!Sortable._marker) {
 824        Sortable._marker =
 825          ($('dropmarker') || Element.extend(document.createElement('DIV'))).
 826            hide().addClassName('dropmarker').setStyle({position:'absolute'});
 827        document.getElementsByTagName("body").item(0).appendChild(Sortable._marker);
 828      }
 829      var offsets = dropon.cumulativeOffset();
 830      Sortable._marker.setStyle({left: offsets[0]+'px', top: offsets[1] + 'px'});
 831  
 832      if(position=='after')
 833        if(sortable.overlap == 'horizontal')
 834          Sortable._marker.setStyle({left: (offsets[0]+dropon.clientWidth) + 'px'});
 835        else
 836          Sortable._marker.setStyle({top: (offsets[1]+dropon.clientHeight) + 'px'});
 837  
 838      Sortable._marker.show();
 839    },
 840  
 841    _tree: function(element, options, parent) {
 842      var children = Sortable.findElements(element, options) || [];
 843  
 844      for (var i = 0; i < children.length; ++i) {
 845        var match = children[i].id.match(options.format);
 846  
 847        if (!match) continue;
 848  
 849        var child = {
 850          id: encodeURIComponent(match ? match[1] : null),
 851          element: element,
 852          parent: parent,
 853          children: [],
 854          position: parent.children.length,
 855          container: $(children[i]).down(options.treeTag)
 856        };
 857  
 858        /* Get the element containing the children and recurse over it */
 859        if (child.container)
 860          this._tree(child.container, options, child);
 861  
 862        parent.children.push (child);
 863      }
 864  
 865      return parent;
 866    },
 867  
 868    tree: function(element) {
 869      element = $(element);
 870      var sortableOptions = this.options(element);
 871      var options = Object.extend({
 872        tag: sortableOptions.tag,
 873        treeTag: sortableOptions.treeTag,
 874        only: sortableOptions.only,
 875        name: element.id,
 876        format: sortableOptions.format
 877      }, arguments[1] || { });
 878  
 879      var root = {
 880        id: null,
 881        parent: null,
 882        children: [],
 883        container: element,
 884        position: 0
 885      };
 886  
 887      return Sortable._tree(element, options, root);
 888    },
 889  
 890    /* Construct a [i] index for a particular node */
 891    _constructIndex: function(node) {
 892      var index = '';
 893      do {
 894        if (node.id) index = '[' + node.position + ']' + index;
 895      } while ((node = node.parent) != null);
 896      return index;
 897    },
 898  
 899    sequence: function(element) {
 900      element = $(element);
 901      var options = Object.extend(this.options(element), arguments[1] || { });
 902  
 903      return $(this.findElements(element, options) || []).map( function(item) {
 904        return item.id.match(options.format) ? item.id.match(options.format)[1] : '';
 905      });
 906    },
 907  
 908    setSequence: function(element, new_sequence) {
 909      element = $(element);
 910      var options = Object.extend(this.options(element), arguments[2] || { });
 911  
 912      var nodeMap = { };
 913      this.findElements(element, options).each( function(n) {
 914          if (n.id.match(options.format))
 915              nodeMap[n.id.match(options.format)[1]] = [n, n.parentNode];
 916          n.parentNode.removeChild(n);
 917      });
 918  
 919      new_sequence.each(function(ident) {
 920        var n = nodeMap[ident];
 921        if (n) {
 922          n[1].appendChild(n[0]);
 923          delete nodeMap[ident];
 924        }
 925      });
 926    },
 927  
 928    serialize: function(element) {
 929      element = $(element);
 930      var options = Object.extend(Sortable.options(element), arguments[1] || { });
 931      var name = encodeURIComponent(
 932        (arguments[1] && arguments[1].name) ? arguments[1].name : element.id);
 933  
 934      if (options.tree) {
 935        return Sortable.tree(element, arguments[1]).children.map( function (item) {
 936          return [name + Sortable._constructIndex(item) + "[id]=" +
 937                  encodeURIComponent(item.id)].concat(item.children.map(arguments.callee));
 938        }).flatten().join('&');
 939      } else {
 940        return Sortable.sequence(element, arguments[1]).map( function(item) {
 941          return name + "[]=" + encodeURIComponent(item);
 942        }).join('&');
 943      }
 944    }
 945  };
 946  
 947  // Returns true if child is contained within element
 948  Element.isParent = function(child, element) {
 949    if (!child.parentNode || child == element) return false;
 950    if (child.parentNode == element) return true;
 951    return Element.isParent(child.parentNode, element);
 952  };
 953  
 954  Element.findChildren = function(element, only, recursive, tagName) {
 955    if(!element.hasChildNodes()) return null;
 956    tagName = tagName.toUpperCase();
 957    if(only) only = [only].flatten();
 958    var elements = [];
 959    $A(element.childNodes).each( function(e) {
 960      if(e.tagName && e.tagName.toUpperCase()==tagName &&
 961        (!only || (Element.classNames(e).detect(function(v) { return only.include(v) }))))
 962          elements.push(e);
 963      if(recursive) {
 964        var grandchildren = Element.findChildren(e, only, recursive, tagName);
 965        if(grandchildren) elements.push(grandchildren);
 966      }
 967    });
 968  
 969    return (elements.length>0 ? elements.flatten() : []);
 970  };
 971  
 972  Element.offsetSize = function (element, type) {
 973    return element['offset' + ((type=='vertical' || type=='height') ? 'Height' : 'Width')];
 974  };