[Sommaire] [Imprimer]

   1  // script.aculo.us dragdrop.js v1.7.0, Fri Jan 19 19:16:36 CET 2007
   2  
   3  // Copyright (c) 2005, 2006 Thomas Fuchs (http://script.aculo.us, http://mir.aculo.us)
   4  //           (c) 2005, 2006 Sammi Williams (http://www.oriontransfer.co.nz, sammi@oriontransfer.co.nz)
   5  // 
   6  // script.aculo.us is freely distributable under the terms of an MIT-style license.
   7  // For details, see the script.aculo.us web site: http://script.aculo.us/
   8  
   9  if(typeof Effect == 'undefined')
  10    throw("dragdrop.js requires including script.aculo.us' effects.js library");
  11  
  12  var Droppables = {
  13    drops: [],
  14  
  15    remove: function(element) {
  16      this.drops = this.drops.reject(function(d) { return d.element==$(element) });
  17    },
  18  
  19    add: function(element) {
  20      element = $(element);
  21      var options = Object.extend({
  22        greedy:     true,
  23        hoverclass: null,
  24        tree:       false
  25      }, arguments[1] || {});
  26  
  27      // cache containers
  28      if(options.containment) {
  29        options._containers = [];
  30        var containment = options.containment;
  31        if((typeof containment == 'object') && 
  32          (containment.constructor == Array)) {
  33          containment.each( function(c) { options._containers.push($(c)) });
  34        } else {
  35          options._containers.push($(containment));
  36        }
  37      }
  38      
  39      if(options.accept) options.accept = [options.accept].flatten();
  40  
  41      Element.makePositioned(element); // fix IE
  42      options.element = element;
  43  
  44      this.drops.push(options);
  45    },
  46    
  47    findDeepestChild: function(drops) {
  48      deepest = drops[0];
  49        
  50      for (i = 1; i < drops.length; ++i)
  51        if (Element.isParent(drops[i].element, deepest.element))
  52          deepest = drops[i];
  53      
  54      return deepest;
  55    },
  56  
  57    isContained: function(element, drop) {
  58      var containmentNode;
  59      if(drop.tree) {
  60        containmentNode = element.treeNode; 
  61      } else {
  62        containmentNode = element.parentNode;
  63      }
  64      return drop._containers.detect(function(c) { return containmentNode == c });
  65    },
  66    
  67    isAffected: function(point, element, drop) {
  68      return (
  69        (drop.element!=element) &&
  70        ((!drop._containers) ||
  71          this.isContained(element, drop)) &&
  72        ((!drop.accept) ||
  73          (Element.classNames(element).detect( 
  74            function(v) { return drop.accept.include(v) } ) )) &&
  75        Position.within(drop.element, point[0], point[1]) );
  76    },
  77  
  78    deactivate: function(drop) {
  79      if(drop.hoverclass)
  80        Element.removeClassName(drop.element, drop.hoverclass);
  81      this.last_active = null;
  82    },
  83  
  84    activate: function(drop) {
  85      if(drop.hoverclass)
  86        Element.addClassName(drop.element, drop.hoverclass);
  87      this.last_active = drop;
  88    },
  89  
  90    show: function(point, element) {
  91      if(!this.drops.length) return;
  92      var affected = [];
  93      
  94      if(this.last_active) this.deactivate(this.last_active);
  95      this.drops.each( function(drop) {
  96        if(Droppables.isAffected(point, element, drop))
  97          affected.push(drop);
  98      });
  99          
 100      if(affected.length>0) {
 101        drop = Droppables.findDeepestChild(affected);
 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        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    },
 118  
 119    reset: function() {
 120      if(this.last_active)
 121        this.deactivate(this.last_active);
 122    }
 123  }
 124  
 125  var Draggables = {
 126    drags: [],
 127    observers: [],
 128    
 129    register: function(draggable) {
 130      if(this.drags.length == 0) {
 131        this.eventMouseUp   = this.endDrag.bindAsEventListener(this);
 132        this.eventMouseMove = this.updateDrag.bindAsEventListener(this);
 133        this.eventKeypress  = this.keyPress.bindAsEventListener(this);
 134        
 135        Event.observe(document, "mouseup", this.eventMouseUp);
 136        Event.observe(document, "mousemove", this.eventMouseMove);
 137        Event.observe(document, "keypress", this.eventKeypress);
 138      }
 139      this.drags.push(draggable);
 140    },
 141    
 142    unregister: function(draggable) {
 143      this.drags = this.drags.reject(function(d) { return d==draggable });
 144      if(this.drags.length == 0) {
 145        Event.stopObserving(document, "mouseup", this.eventMouseUp);
 146        Event.stopObserving(document, "mousemove", this.eventMouseMove);
 147        Event.stopObserving(document, "keypress", this.eventKeypress);
 148      }
 149    },
 150    
 151    activate: function(draggable) {
 152      if(draggable.options.delay) { 
 153        this._timeout = setTimeout(function() { 
 154          Draggables._timeout = null; 
 155          window.focus(); 
 156          Draggables.activeDraggable = draggable; 
 157        }.bind(this), draggable.options.delay); 
 158      } else {
 159        window.focus(); // allows keypress events if window isn't currently focused, fails for Safari
 160        this.activeDraggable = draggable;
 161      }
 162    },
 163    
 164    deactivate: function() {
 165      this.activeDraggable = null;
 166    },
 167    
 168    updateDrag: function(event) {
 169      if(!this.activeDraggable) return;
 170      var pointer = [Event.pointerX(event), Event.pointerY(event)];
 171      // Mozilla-based browsers fire successive mousemove events with
 172      // the same coordinates, prevent needless redrawing (moz bug?)
 173      if(this._lastPointer && (this._lastPointer.inspect() == pointer.inspect())) return;
 174      this._lastPointer = pointer;
 175      
 176      this.activeDraggable.updateDrag(event, pointer);
 177    },
 178    
 179    endDrag: function(event) {
 180      if(this._timeout) { 
 181        clearTimeout(this._timeout); 
 182        this._timeout = null; 
 183      }
 184      if(!this.activeDraggable) return;
 185      this._lastPointer = null;
 186      this.activeDraggable.endDrag(event);
 187      this.activeDraggable = null;
 188    },
 189    
 190    keyPress: function(event) {
 191      if(this.activeDraggable)
 192        this.activeDraggable.keyPress(event);
 193    },
 194    
 195    addObserver: function(observer) {
 196      this.observers.push(observer);
 197      this._cacheObserverCallbacks();
 198    },
 199    
 200    removeObserver: function(element) {  // element instead of observer fixes mem leaks
 201      this.observers = this.observers.reject( function(o) { return o.element==element });
 202      this._cacheObserverCallbacks();
 203    },
 204    
 205    notify: function(eventName, draggable, event) {  // 'onStart', 'onEnd', 'onDrag'
 206      if(this[eventName+'Count'] > 0)
 207        this.observers.each( function(o) {
 208          if(o[eventName]) o[eventName](eventName, draggable, event);
 209        });
 210      if(draggable.options[eventName]) draggable.options[eventName](draggable, event);
 211    },
 212    
 213    _cacheObserverCallbacks: function() {
 214      ['onStart','onEnd','onDrag'].each( function(eventName) {
 215        Draggables[eventName+'Count'] = Draggables.observers.select(
 216          function(o) { return o[eventName]; }
 217        ).length;
 218      });
 219    }
 220  }
 221  
 222  /*--------------------------------------------------------------------------*/
 223  
 224  var Draggable = Class.create();
 225  Draggable._dragging    = {};
 226  
 227  Draggable.prototype = {
 228    initialize: function(element) {
 229      var defaults = {
 230        handle: false,
 231        reverteffect: function(element, top_offset, left_offset) {
 232          var dur = Math.sqrt(Math.abs(top_offset^2)+Math.abs(left_offset^2))*0.02;
 233          new Effect.Move(element, { x: -left_offset, y: -top_offset, duration: dur,
 234            queue: {scope:'_draggable', position:'end'}
 235          });
 236        },
 237        endeffect: function(element) {
 238          var toOpacity = typeof element._opacity == 'number' ? element._opacity : 1.0;
 239          new Effect.Opacity(element, {duration:0.2, from:0.7, to:toOpacity, 
 240            queue: {scope:'_draggable', position:'end'},
 241            afterFinish: function(){ 
 242              Draggable._dragging[element] = false 
 243            }
 244          }); 
 245        },
 246        zindex: 1000,
 247        revert: 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] || typeof arguments[1].endeffect == 'undefined')
 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 && (typeof options.handle == 'string'))
 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.delta    = this.currentDelta();
 282      this.options  = options;
 283      this.dragging = false;   
 284  
 285      this.eventMouseDown = this.initDrag.bindAsEventListener(this);
 286      Event.observe(this.handle, "mousedown", this.eventMouseDown);
 287      
 288      Draggables.register(this);
 289    },
 290    
 291    destroy: function() {
 292      Event.stopObserving(this.handle, "mousedown", this.eventMouseDown);
 293      Draggables.unregister(this);
 294    },
 295    
 296    currentDelta: function() {
 297      return([
 298        parseInt(Element.getStyle(this.element,'left') || '0'),
 299        parseInt(Element.getStyle(this.element,'top') || '0')]);
 300    },
 301    
 302    initDrag: function(event) {
 303      if(typeof Draggable._dragging[this.element] != 'undefined' &&
 304        Draggable._dragging[this.element]) return;
 305      if(Event.isLeftClick(event)) {    
 306        // abort on form elements, fixes a Firefox issue
 307        var src = Event.element(event);
 308        if((tag_name = src.tagName.toUpperCase()) && (
 309          tag_name=='INPUT' ||
 310          tag_name=='SELECT' ||
 311          tag_name=='OPTION' ||
 312          tag_name=='BUTTON' ||
 313          tag_name=='TEXTAREA')) return;
 314          
 315        var pointer = [Event.pointerX(event), Event.pointerY(event)];
 316        var pos     = Position.cumulativeOffset(this.element);
 317        this.offset = [0,1].map( function(i) { return (pointer[i] - pos[i]) });
 318        
 319        Draggables.activate(this);
 320        Event.stop(event);
 321      }
 322    },
 323    
 324    startDrag: function(event) {
 325      this.dragging = true;
 326      
 327      if(this.options.zindex) {
 328        this.originalZ = parseInt(Element.getStyle(this.element,'z-index') || 0);
 329        this.element.style.zIndex = this.options.zindex;
 330      }
 331      
 332      if(this.options.ghosting) {
 333        this._clone = this.element.cloneNode(true);
 334        Position.absolutize(this.element);
 335        this.element.parentNode.insertBefore(this._clone, this.element);
 336      }
 337      
 338      if(this.options.scroll) {
 339        if (this.options.scroll == window) {
 340          var where = this._getWindowScroll(this.options.scroll);
 341          this.originalScrollLeft = where.left;
 342          this.originalScrollTop = where.top;
 343        } else {
 344          this.originalScrollLeft = this.options.scroll.scrollLeft;
 345          this.originalScrollTop = this.options.scroll.scrollTop;
 346        }
 347      }
 348      
 349      Draggables.notify('onStart', this, event);
 350          
 351      if(this.options.starteffect) this.options.starteffect(this.element);
 352    },
 353    
 354    updateDrag: function(event, pointer) {
 355      if(!this.dragging) this.startDrag(event);
 356      Position.prepare();
 357      Droppables.show(pointer, this.element);
 358      Draggables.notify('onDrag', this, event);
 359      
 360      this.draw(pointer);
 361      if(this.options.change) this.options.change(this);
 362      
 363      if(this.options.scroll) {
 364        this.stopScrolling();
 365        
 366        var p;
 367        if (this.options.scroll == window) {
 368          with(this._getWindowScroll(this.options.scroll)) { p = [ left, top, left+width, top+height ]; }
 369        } else {
 370          p = Position.page(this.options.scroll);
 371          p[0] += this.options.scroll.scrollLeft + Position.deltaX;
 372          p[1] += this.options.scroll.scrollTop + Position.deltaY;
 373          p.push(p[0]+this.options.scroll.offsetWidth);
 374          p.push(p[1]+this.options.scroll.offsetHeight);
 375        }
 376        var speed = [0,0];
 377        if(pointer[0] < (p[0]+this.options.scrollSensitivity)) speed[0] = pointer[0]-(p[0]+this.options.scrollSensitivity);
 378        if(pointer[1] < (p[1]+this.options.scrollSensitivity)) speed[1] = pointer[1]-(p[1]+this.options.scrollSensitivity);
 379        if(pointer[0] > (p[2]-this.options.scrollSensitivity)) speed[0] = pointer[0]-(p[2]-this.options.scrollSensitivity);
 380        if(pointer[1] > (p[3]-this.options.scrollSensitivity)) speed[1] = pointer[1]-(p[3]-this.options.scrollSensitivity);
 381        this.startScrolling(speed);
 382      }
 383      
 384      // fix AppleWebKit rendering
 385      if(navigator.appVersion.indexOf('AppleWebKit')>0) window.scrollBy(0,0);
 386      
 387      Event.stop(event);
 388    },
 389    
 390    finishDrag: function(event, success) {
 391      this.dragging = false;
 392  
 393      if(this.options.ghosting) {
 394        Position.relativize(this.element);
 395        Element.remove(this._clone);
 396        this._clone = null;
 397      }
 398  
 399      if(success) Droppables.fire(event, this.element);
 400      Draggables.notify('onEnd', this, event);
 401  
 402      var revert = this.options.revert;
 403      if(revert && typeof revert == 'function') revert = revert(this.element);
 404      
 405      var d = this.currentDelta();
 406      if(revert && this.options.reverteffect) {
 407        this.options.reverteffect(this.element, 
 408          d[1]-this.delta[1], d[0]-this.delta[0]);
 409      } else {
 410        this.delta = d;
 411      }
 412  
 413      if(this.options.zindex)
 414        this.element.style.zIndex = this.originalZ;
 415  
 416      if(this.options.endeffect) 
 417        this.options.endeffect(this.element);
 418        
 419      Draggables.deactivate(this);
 420      Droppables.reset();
 421    },
 422    
 423    keyPress: function(event) {
 424      if(event.keyCode!=Event.KEY_ESC) return;
 425      this.finishDrag(event, false);
 426      Event.stop(event);
 427    },
 428    
 429    endDrag: function(event) {
 430      if(!this.dragging) return;
 431      this.stopScrolling();
 432      this.finishDrag(event, true);
 433      Event.stop(event);
 434    },
 435    
 436    draw: function(point) {
 437      var pos = Position.cumulativeOffset(this.element);
 438      if(this.options.ghosting) {
 439        var r   = Position.realOffset(this.element);
 440        pos[0] += r[0] - Position.deltaX; pos[1] += r[1] - Position.deltaY;
 441      }
 442      
 443      var d = this.currentDelta();
 444      pos[0] -= d[0]; pos[1] -= d[1];
 445      
 446      if(this.options.scroll && (this.options.scroll != window && this._isScrollChild)) {
 447        pos[0] -= this.options.scroll.scrollLeft-this.originalScrollLeft;
 448        pos[1] -= this.options.scroll.scrollTop-this.originalScrollTop;
 449      }
 450      
 451      var p = [0,1].map(function(i){ 
 452        return (point[i]-pos[i]-this.offset[i]) 
 453      }.bind(this));
 454      
 455      if(this.options.snap) {
 456        if(typeof this.options.snap == 'function') {
 457          p = this.options.snap(p[0],p[1],this);
 458        } else {
 459        if(this.options.snap instanceof Array) {
 460          p = p.map( function(v, i) {
 461            return Math.round(v/this.options.snap[i])*this.options.snap[i] }.bind(this))
 462        } else {
 463          p = p.map( function(v) {
 464            return Math.round(v/this.options.snap)*this.options.snap }.bind(this))
 465        }
 466      }}
 467      
 468      var style = this.element.style;
 469      if((!this.options.constraint) || (this.options.constraint=='horizontal'))
 470        style.left = p[0] + "px";
 471      if((!this.options.constraint) || (this.options.constraint=='vertical'))
 472        style.top  = p[1] + "px";
 473      
 474      if(style.visibility=="hidden") style.visibility = ""; // fix gecko rendering
 475    },
 476    
 477    stopScrolling: function() {
 478      if(this.scrollInterval) {
 479        clearInterval(this.scrollInterval);
 480        this.scrollInterval = null;
 481        Draggables._lastScrollPointer = null;
 482      }
 483    },
 484    
 485    startScrolling: function(speed) {
 486      if(!(speed[0] || speed[1])) return;
 487      this.scrollSpeed = [speed[0]*this.options.scrollSpeed,speed[1]*this.options.scrollSpeed];
 488      this.lastScrolled = new Date();
 489      this.scrollInterval = setInterval(this.scroll.bind(this), 10);
 490    },
 491    
 492    scroll: function() {
 493      var current = new Date();
 494      var delta = current - this.lastScrolled;
 495      this.lastScrolled = current;
 496      if(this.options.scroll == window) {
 497        with (this._getWindowScroll(this.options.scroll)) {
 498          if (this.scrollSpeed[0] || this.scrollSpeed[1]) {
 499            var d = delta / 1000;
 500            this.options.scroll.scrollTo( left + d*this.scrollSpeed[0], top + d*this.scrollSpeed[1] );
 501          }
 502        }
 503      } else {
 504        this.options.scroll.scrollLeft += this.scrollSpeed[0] * delta / 1000;
 505        this.options.scroll.scrollTop  += this.scrollSpeed[1] * delta / 1000;
 506      }
 507      
 508      Position.prepare();
 509      Droppables.show(Draggables._lastPointer, this.element);
 510      Draggables.notify('onDrag', this);
 511      if (this._isScrollChild) {
 512        Draggables._lastScrollPointer = Draggables._lastScrollPointer || $A(Draggables._lastPointer);
 513        Draggables._lastScrollPointer[0] += this.scrollSpeed[0] * delta / 1000;
 514        Draggables._lastScrollPointer[1] += this.scrollSpeed[1] * delta / 1000;
 515        if (Draggables._lastScrollPointer[0] < 0)
 516          Draggables._lastScrollPointer[0] = 0;
 517        if (Draggables._lastScrollPointer[1] < 0)
 518          Draggables._lastScrollPointer[1] = 0;
 519        this.draw(Draggables._lastScrollPointer);
 520      }
 521      
 522      if(this.options.change) this.options.change(this);
 523    },
 524    
 525    _getWindowScroll: function(w) {
 526      var T, L, W, H;
 527      with (w.document) {
 528        if (w.document.documentElement && documentElement.scrollTop) {
 529          T = documentElement.scrollTop;
 530          L = documentElement.scrollLeft;
 531        } else if (w.document.body) {
 532          T = body.scrollTop;
 533          L = body.scrollLeft;
 534        }
 535        if (w.innerWidth) {
 536          W = w.innerWidth;
 537          H = w.innerHeight;
 538        } else if (w.document.documentElement && documentElement.clientWidth) {
 539          W = documentElement.clientWidth;
 540          H = documentElement.clientHeight;
 541        } else {
 542          W = body.offsetWidth;
 543          H = body.offsetHeight
 544        }
 545      }
 546      return { top: T, left: L, width: W, height: H };
 547    }
 548  }
 549  
 550  /*--------------------------------------------------------------------------*/
 551  
 552  var SortableObserver = Class.create();
 553  SortableObserver.prototype = {
 554    initialize: function(element, observer) {
 555      this.element   = $(element);
 556      this.observer  = observer;
 557      this.lastValue = Sortable.serialize(this.element);
 558    },
 559    
 560    onStart: function() {
 561      this.lastValue = Sortable.serialize(this.element);
 562    },
 563    
 564    onEnd: function() {
 565      Sortable.unmark();
 566      if(this.lastValue != Sortable.serialize(this.element))
 567        this.observer(this.element)
 568    }
 569  }
 570  
 571  var Sortable = {
 572    SERIALIZE_RULE: /^[^_\-](?:[A-Za-z0-9\-\_]*)[_](.*)$/,
 573    
 574    sortables: {},
 575    
 576    _findRootElement: function(element) {
 577      while (element.tagName.toUpperCase() != "BODY") {  
 578        if(element.id && Sortable.sortables[element.id]) return element;
 579        element = element.parentNode;
 580      }
 581    },
 582  
 583    options: function(element) {
 584      element = Sortable._findRootElement($(element));
 585      if(!element) return;
 586      return Sortable.sortables[element.id];
 587    },
 588    
 589    destroy: function(element){
 590      var s = Sortable.options(element);
 591      
 592      if(s) {
 593        Draggables.removeObserver(s.element);
 594        s.droppables.each(function(d){ Droppables.remove(d) });
 595        s.draggables.invoke('destroy');
 596        
 597        delete Sortable.sortables[s.element.id];
 598      }
 599    },
 600  
 601    create: function(element) {
 602      element = $(element);
 603      var options = Object.extend({ 
 604        element:     element,
 605        tag:         'li',       // assumes li children, override with tag: 'tagname'
 606        dropOnEmpty: false,
 607        tree:        false,
 608        treeTag:     'ul',
 609        overlap:     'vertical', // one of 'vertical', 'horizontal'
 610        constraint:  'vertical', // one of 'vertical', 'horizontal', false
 611        containment: element,    // also takes array of elements (or id's); or false
 612        handle:      false,      // or a CSS class
 613        only:        false,
 614        delay:       0,
 615        hoverclass:  null,
 616        ghosting:    false,
 617        scroll:      false,
 618        scrollSensitivity: 20,
 619        scrollSpeed: 15,
 620        format:      this.SERIALIZE_RULE,
 621        onChange:    Prototype.emptyFunction,
 622        onUpdate:    Prototype.emptyFunction
 623      }, arguments[1] || {});
 624  
 625      // clear any old sortable with same element
 626      this.destroy(element);
 627  
 628      // build options for the draggables
 629      var options_for_draggable = {
 630        revert:      true,
 631        scroll:      options.scroll,
 632        scrollSpeed: options.scrollSpeed,
 633        scrollSensitivity: options.scrollSensitivity,
 634        delay:       options.delay,
 635        ghosting:    options.ghosting,
 636        constraint:  options.constraint,
 637        handle:      options.handle };
 638  
 639      if(options.starteffect)
 640        options_for_draggable.starteffect = options.starteffect;
 641  
 642      if(options.reverteffect)
 643        options_for_draggable.reverteffect = options.reverteffect;
 644      else
 645        if(options.ghosting) options_for_draggable.reverteffect = function(element) {
 646          element.style.top  = 0;
 647          element.style.left = 0;
 648        };
 649  
 650      if(options.endeffect)
 651        options_for_draggable.endeffect = options.endeffect;
 652  
 653      if(options.zindex)
 654        options_for_draggable.zindex = options.zindex;
 655  
 656      // build options for the droppables  
 657      var options_for_droppable = {
 658        overlap:     options.overlap,
 659        containment: options.containment,
 660        tree:        options.tree,
 661        hoverclass:  options.hoverclass,
 662        onHover:     Sortable.onHover
 663      }
 664      
 665      var options_for_tree = {
 666        onHover:      Sortable.onEmptyHover,
 667        overlap:      options.overlap,
 668        containment:  options.containment,
 669        hoverclass:   options.hoverclass
 670      }
 671  
 672      // fix for gecko engine
 673      Element.cleanWhitespace(element); 
 674  
 675      options.draggables = [];
 676      options.droppables = [];
 677  
 678      // drop on empty handling
 679      if(options.dropOnEmpty || options.tree) {
 680        Droppables.add(element, options_for_tree);
 681        options.droppables.push(element);
 682      }
 683  
 684      (this.findElements(element, options) || []).each( function(e) {
 685        // handles are per-draggable
 686        var handle = options.handle ? 
 687          $(e).down('.'+options.handle,0) : e;    
 688        options.draggables.push(
 689          new Draggable(e, Object.extend(options_for_draggable, { handle: handle })));
 690        Droppables.add(e, options_for_droppable);
 691        if(options.tree) e.treeNode = element;
 692        options.droppables.push(e);      
 693      });
 694      
 695      if(options.tree) {
 696        (Sortable.findTreeElements(element, options) || []).each( function(e) {
 697          Droppables.add(e, options_for_tree);
 698          e.treeNode = element;
 699          options.droppables.push(e);
 700        });
 701      }
 702  
 703      // keep reference
 704      this.sortables[element.id] = options;
 705  
 706      // for onupdate
 707      Draggables.addObserver(new SortableObserver(element, options.onUpdate));
 708  
 709    },
 710  
 711    // return all suitable-for-sortable elements in a guaranteed order
 712    findElements: function(element, options) {
 713      return Element.findChildren(
 714        element, options.only, options.tree ? true : false, options.tag);
 715    },
 716    
 717    findTreeElements: function(element, options) {
 718      return Element.findChildren(
 719        element, options.only, options.tree ? true : false, options.treeTag);
 720    },
 721  
 722    onHover: function(element, dropon, overlap) {
 723      if(Element.isParent(dropon, element)) return;
 724  
 725      if(overlap > .33 && overlap < .66 && Sortable.options(dropon).tree) {
 726        return;
 727      } else if(overlap>0.5) {
 728        Sortable.mark(dropon, 'before');
 729        if(dropon.previousSibling != element) {
 730          var oldParentNode = element.parentNode;
 731          element.style.visibility = "hidden"; // fix gecko rendering
 732          dropon.parentNode.insertBefore(element, dropon);
 733          if(dropon.parentNode!=oldParentNode) 
 734            Sortable.options(oldParentNode).onChange(element);
 735          Sortable.options(dropon.parentNode).onChange(element);
 736        }
 737      } else {
 738        Sortable.mark(dropon, 'after');
 739        var nextElement = dropon.nextSibling || null;
 740        if(nextElement != element) {
 741          var oldParentNode = element.parentNode;
 742          element.style.visibility = "hidden"; // fix gecko rendering
 743          dropon.parentNode.insertBefore(element, nextElement);
 744          if(dropon.parentNode!=oldParentNode) 
 745            Sortable.options(oldParentNode).onChange(element);
 746          Sortable.options(dropon.parentNode).onChange(element);
 747        }
 748      }
 749    },
 750    
 751    onEmptyHover: function(element, dropon, overlap) {
 752      var oldParentNode = element.parentNode;
 753      var droponOptions = Sortable.options(dropon);
 754          
 755      if(!Element.isParent(dropon, element)) {
 756        var index;
 757        
 758        var children = Sortable.findElements(dropon, {tag: droponOptions.tag, only: droponOptions.only});
 759        var child = null;
 760              
 761        if(children) {
 762          var offset = Element.offsetSize(dropon, droponOptions.overlap) * (1.0 - overlap);
 763          
 764          for (index = 0; index < children.length; index += 1) {
 765            if (offset - Element.offsetSize (children[index], droponOptions.overlap) >= 0) {
 766              offset -= Element.offsetSize (children[index], droponOptions.overlap);
 767            } else if (offset - (Element.offsetSize (children[index], droponOptions.overlap) / 2) >= 0) {
 768              child = index + 1 < children.length ? children[index + 1] : null;
 769              break;
 770            } else {
 771              child = children[index];
 772              break;
 773            }
 774          }
 775        }
 776        
 777        dropon.insertBefore(element, child);
 778        
 779        Sortable.options(oldParentNode).onChange(element);
 780        droponOptions.onChange(element);
 781      }
 782    },
 783  
 784    unmark: function() {
 785      if(Sortable._marker) Sortable._marker.hide();
 786    },
 787  
 788    mark: function(dropon, position) {
 789      // mark on ghosting only
 790      var sortable = Sortable.options(dropon.parentNode);
 791      if(sortable && !sortable.ghosting) return; 
 792  
 793      if(!Sortable._marker) {
 794        Sortable._marker = 
 795          ($('dropmarker') || Element.extend(document.createElement('DIV'))).
 796            hide().addClassName('dropmarker').setStyle({position:'absolute'});
 797        document.getElementsByTagName("body").item(0).appendChild(Sortable._marker);
 798      }    
 799      var offsets = Position.cumulativeOffset(dropon);
 800      Sortable._marker.setStyle({left: offsets[0]+'px', top: offsets[1] + 'px'});
 801      
 802      if(position=='after')
 803        if(sortable.overlap == 'horizontal') 
 804          Sortable._marker.setStyle({left: (offsets[0]+dropon.clientWidth) + 'px'});
 805        else
 806          Sortable._marker.setStyle({top: (offsets[1]+dropon.clientHeight) + 'px'});
 807      
 808      Sortable._marker.show();
 809    },
 810    
 811    _tree: function(element, options, parent) {
 812      var children = Sortable.findElements(element, options) || [];
 813    
 814      for (var i = 0; i < children.length; ++i) {
 815        var match = children[i].id.match(options.format);
 816  
 817        if (!match) continue;
 818        
 819        var child = {
 820          id: encodeURIComponent(match ? match[1] : null),
 821          element: element,
 822          parent: parent,
 823          children: [],
 824          position: parent.children.length,
 825          container: $(children[i]).down(options.treeTag)
 826        }
 827        
 828        /* Get the element containing the children and recurse over it */
 829        if (child.container)
 830          this._tree(child.container, options, child)
 831        
 832        parent.children.push (child);
 833      }
 834  
 835      return parent; 
 836    },
 837  
 838    tree: function(element) {
 839      element = $(element);
 840      var sortableOptions = this.options(element);
 841      var options = Object.extend({
 842        tag: sortableOptions.tag,
 843        treeTag: sortableOptions.treeTag,
 844        only: sortableOptions.only,
 845        name: element.id,
 846        format: sortableOptions.format
 847      }, arguments[1] || {});
 848      
 849      var root = {
 850        id: null,
 851        parent: null,
 852        children: [],
 853        container: element,
 854        position: 0
 855      }
 856      
 857      return Sortable._tree(element, options, root);
 858    },
 859  
 860    /* Construct a [i] index for a particular node */
 861    _constructIndex: function(node) {
 862      var index = '';
 863      do {
 864        if (node.id) index = '[' + node.position + ']' + index;
 865      } while ((node = node.parent) != null);
 866      return index;
 867    },
 868  
 869    sequence: function(element) {
 870      element = $(element);
 871      var options = Object.extend(this.options(element), arguments[1] || {});
 872      
 873      return $(this.findElements(element, options) || []).map( function(item) {
 874        return item.id.match(options.format) ? item.id.match(options.format)[1] : '';
 875      });
 876    },
 877  
 878    setSequence: function(element, new_sequence) {
 879      element = $(element);
 880      var options = Object.extend(this.options(element), arguments[2] || {});
 881      
 882      var nodeMap = {};
 883      this.findElements(element, options).each( function(n) {
 884          if (n.id.match(options.format))
 885              nodeMap[n.id.match(options.format)[1]] = [n, n.parentNode];
 886          n.parentNode.removeChild(n);
 887      });
 888     
 889      new_sequence.each(function(ident) {
 890        var n = nodeMap[ident];
 891        if (n) {
 892          n[1].appendChild(n[0]);
 893          delete nodeMap[ident];
 894        }
 895      });
 896    },
 897    
 898    serialize: function(element) {
 899      element = $(element);
 900      var options = Object.extend(Sortable.options(element), arguments[1] || {});
 901      var name = encodeURIComponent(
 902        (arguments[1] && arguments[1].name) ? arguments[1].name : element.id);
 903      
 904      if (options.tree) {
 905        return Sortable.tree(element, arguments[1]).children.map( function (item) {
 906          return [name + Sortable._constructIndex(item) + "[id]=" + 
 907                  encodeURIComponent(item.id)].concat(item.children.map(arguments.callee));
 908        }).flatten().join('&');
 909      } else {
 910        return Sortable.sequence(element, arguments[1]).map( function(item) {
 911          return name + "[]=" + encodeURIComponent(item);
 912        }).join('&');
 913      }
 914    }
 915  }
 916  
 917  // Returns true if child is contained within element
 918  Element.isParent = function(child, element) {
 919    if (!child.parentNode || child == element) return false;
 920    if (child.parentNode == element) return true;
 921    return Element.isParent(child.parentNode, element);
 922  }
 923  
 924  Element.findChildren = function(element, only, recursive, tagName) {    
 925    if(!element.hasChildNodes()) return null;
 926    tagName = tagName.toUpperCase();
 927    if(only) only = [only].flatten();
 928    var elements = [];
 929    $A(element.childNodes).each( function(e) {
 930      if(e.tagName && e.tagName.toUpperCase()==tagName &&
 931        (!only || (Element.classNames(e).detect(function(v) { return only.include(v) }))))
 932          elements.push(e);
 933      if(recursive) {
 934        var grandchildren = Element.findChildren(e, only, recursive, tagName);
 935        if(grandchildren) elements.push(grandchildren);
 936      }
 937    });
 938  
 939    return (elements.length>0 ? elements.flatten() : []);
 940  }
 941  
 942  Element.offsetSize = function (element, type) {
 943    return element['offset' + ((type=='vertical' || type=='height') ? 'Height' : 'Width')];
 944  }