Upgrade to Rails 1.1.
[selectricity-live] / public / javascripts / dragdrop.js
index 63a68243b6c2d38d0b5a6e289ccd22a8cdfbeb71..a01b7be2077981531a10aad90173c0d774b7a819 100644 (file)
@@ -1,6 +1,5 @@
 // Copyright (c) 2005 Thomas Fuchs (http://script.aculo.us, http://mir.aculo.us)
-// 
-// Element.Class part Copyright (c) 2005 by Rick Olson
+//           (c) 2005 Sammi Williams (http://www.oriontransfer.co.nz, sammi@oriontransfer.co.nz)
 // 
 // See scriptaculous.js for full license.
 
@@ -10,14 +9,15 @@ var Droppables = {
   drops: [],
 
   remove: function(element) {
-    this.drops = this.drops.reject(function(d) { return d.element==element });
+    this.drops = this.drops.reject(function(d) { return d.element==$(element) });
   },
 
   add: function(element) {
     element = $(element);
     var options = Object.extend({
       greedy:     true,
-      hoverclass: null  
+      hoverclass: null,
+      tree:       false
     }, arguments[1] || {});
 
     // cache containers
@@ -31,67 +31,83 @@ var Droppables = {
         options._containers.push($(containment));
       }
     }
+    
+    if(options.accept) options.accept = [options.accept].flatten();
 
     Element.makePositioned(element); // fix IE
     options.element = element;
 
     this.drops.push(options);
   },
+  
+  findDeepestChild: function(drops) {
+    deepest = drops[0];
+      
+    for (i = 1; i < drops.length; ++i)
+      if (Element.isParent(drops[i].element, deepest.element))
+        deepest = drops[i];
+    
+    return deepest;
+  },
 
   isContained: function(element, drop) {
-    var parentNode = element.parentNode;
-    return drop._containers.detect(function(c) { return parentNode == c });
+    var containmentNode;
+    if(drop.tree) {
+      containmentNode = element.treeNode; 
+    } else {
+      containmentNode = element.parentNode;
+    }
+    return drop._containers.detect(function(c) { return containmentNode == c });
   },
-
-  isAffected: function(pX, pY, element, drop) {
+  
+  isAffected: function(point, element, drop) {
     return (
       (drop.element!=element) &&
       ((!drop._containers) ||
         this.isContained(element, drop)) &&
       ((!drop.accept) ||
-        (Element.Class.has_any(element, drop.accept))) &&
-      Position.within(drop.element, pX, pY) );
+        (Element.classNames(element).detect( 
+          function(v) { return drop.accept.include(v) } ) )) &&
+      Position.within(drop.element, point[0], point[1]) );
   },
 
   deactivate: function(drop) {
     if(drop.hoverclass)
-      Element.Class.remove(drop.element, drop.hoverclass);
+      Element.removeClassName(drop.element, drop.hoverclass);
     this.last_active = null;
   },
 
   activate: function(drop) {
-    if(this.last_active) this.deactivate(this.last_active);
     if(drop.hoverclass)
-      Element.Class.add(drop.element, drop.hoverclass);
+      Element.addClassName(drop.element, drop.hoverclass);
     this.last_active = drop;
   },
 
-  show: function(event, element) {
+  show: function(point, element) {
     if(!this.drops.length) return;
-    var pX = Event.pointerX(event);
-    var pY = Event.pointerY(event);
-    Position.prepare();
-
-    var i = this.drops.length-1; do {
-      var drop = this.drops[i];
-      if(this.isAffected(pX, pY, element, drop)) {
-        if(drop.onHover)
-           drop.onHover(element, drop.element, Position.overlap(drop.overlap, drop.element));
-        if(drop.greedy) { 
-          this.activate(drop);
-          return;
-        }
-      }
-    } while (i--);
+    var affected = [];
     
     if(this.last_active) this.deactivate(this.last_active);
+    this.drops.each( function(drop) {
+      if(Droppables.isAffected(point, element, drop))
+        affected.push(drop);
+    });
+        
+    if(affected.length>0) {
+      drop = Droppables.findDeepestChild(affected);
+      Position.within(drop.element, point[0], point[1]);
+      if(drop.onHover)
+        drop.onHover(element, drop.element, Position.overlap(drop.overlap, drop.element));
+      
+      Droppables.activate(drop);
+    }
   },
 
   fire: function(event, element) {
     if(!this.last_active) return;
     Position.prepare();
 
-    if (this.isAffected(Event.pointerX(event), Event.pointerY(event), element, this.last_active))
+    if (this.isAffected([Event.pointerX(event), Event.pointerY(event)], element, this.last_active))
       if (this.last_active.onDrop) 
         this.last_active.onDrop(element, this.last_active.element, event);
   },
@@ -103,15 +119,85 @@ var Droppables = {
 }
 
 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) {
+    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.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.observers.push(observer);
+    this._cacheObserverCallbacks();
   },
-  removeObserver: function(element) {  // element instead of obsever fixes mem leaks
+  
+  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);
+      });
   },
-  notify: function(eventName, draggable) {  // 'onStart', 'onEnd'
-    this.observers.invoke(eventName, draggable);
+  
+  _cacheObserverCallbacks: function() {
+    ['onStart','onEnd','onDrag'].each( function(eventName) {
+      Draggables[eventName+'Count'] = Draggables.observers.select(
+        function(o) { return o[eventName]; }
+      ).length;
+    });
   }
 }
 
@@ -127,89 +213,144 @@ Draggable.prototype = {
       },
       reverteffect: function(element, top_offset, left_offset) {
         var dur = Math.sqrt(Math.abs(top_offset^2)+Math.abs(left_offset^2))*0.02;
-        new Effect.MoveBy(element, -top_offset, -left_offset, {duration:dur});
+        element._revert = new Effect.Move(element, { x: -left_offset, y: -top_offset, duration: dur});
       },
       endeffect: function(element) { 
-         new Effect.Opacity(element, {duration:0.2, from:0.7, to:1.0}); 
+        new Effect.Opacity(element, {duration:0.2, from:0.7, to:1.0}); 
       },
       zindex: 1000,
-      revert: false
+      revert: false,
+      scroll: false,
+      scrollSensitivity: 20,
+      scrollSpeed: 15,
+      snap: false   // false, or xy or [x,y] or function(x,y){ return [x,y] }
     }, arguments[1] || {});
 
-    this.element      = $(element);
-    if(options.handle && (typeof options.handle == 'string'))
-      this.handle = Element.Class.childrenWith(this.element, options.handle)[0];
-      
+    this.element = $(element);
+    
+    if(options.handle && (typeof options.handle == 'string')) {
+      var h = Element.childrenWithClassName(this.element, options.handle, true);
+      if(h.length>0) this.handle = h[0];
+    }
     if(!this.handle) this.handle = $(options.handle);
     if(!this.handle) this.handle = this.element;
+    
+    if(options.scroll && !options.scroll.scrollTo && !options.scroll.outerHTML)
+      options.scroll = $(options.scroll);
 
     Element.makePositioned(this.element); // fix IE    
 
-    this.offsetX      = 0;
-    this.offsetY      = 0;
-    this.originalLeft = this.currentLeft();
-    this.originalTop  = this.currentTop();
-    this.originalX    = this.element.offsetLeft;
-    this.originalY    = this.element.offsetTop;
-
-    this.options      = options;
-
-    this.active       = false;
-    this.dragging     = false;   
+    this.delta    = this.currentDelta();
+    this.options  = options;
+    this.dragging = false;   
 
-    this.eventMouseDown = this.startDrag.bindAsEventListener(this);
-    this.eventMouseUp   = this.endDrag.bindAsEventListener(this);
-    this.eventMouseMove = this.update.bindAsEventListener(this);
-    this.eventKeypress  = this.keyPress.bindAsEventListener(this);
+    this.eventMouseDown = this.initDrag.bindAsEventListener(this);
+    Event.observe(this.handle, "mousedown", this.eventMouseDown);
     
-    this.registerEvents();
+    Draggables.register(this);
   },
+  
   destroy: function() {
     Event.stopObserving(this.handle, "mousedown", this.eventMouseDown);
-    this.unregisterEvents();
-  },
-  registerEvents: function() {
-    Event.observe(document, "mouseup", this.eventMouseUp);
-    Event.observe(document, "mousemove", this.eventMouseMove);
-    Event.observe(document, "keypress", this.eventKeypress);
-    Event.observe(this.handle, "mousedown", this.eventMouseDown);
+    Draggables.unregister(this);
   },
-  unregisterEvents: function() {
-    //if(!this.active) return;
-    //Event.stopObserving(document, "mouseup", this.eventMouseUp);
-    //Event.stopObserving(document, "mousemove", this.eventMouseMove);
-    //Event.stopObserving(document, "keypress", this.eventKeypress);
+  
+  currentDelta: function() {
+    return([
+      parseInt(Element.getStyle(this.element,'left') || '0'),
+      parseInt(Element.getStyle(this.element,'top') || '0')]);
   },
-  currentLeft: function() {
-    return parseInt(this.element.style.left || '0');
-  },
-  currentTop: function() {
-    return parseInt(this.element.style.top || '0')
-  },
-  startDrag: function(event) {
-    if(Event.isLeftClick(event)) {
-      
+  
+  initDrag: function(event) {
+    if(Event.isLeftClick(event)) {    
       // abort on form elements, fixes a Firefox issue
       var src = Event.element(event);
       if(src.tagName && (
         src.tagName=='INPUT' ||
         src.tagName=='SELECT' ||
+        src.tagName=='OPTION' ||
         src.tagName=='BUTTON' ||
         src.tagName=='TEXTAREA')) return;
+        
+      if(this.element._revert) {
+        this.element._revert.cancel();
+        this.element._revert = null;
+      }
       
-      // this.registerEvents();
-      this.active = true;
       var pointer = [Event.pointerX(event), Event.pointerY(event)];
-      var offsets = Position.cumulativeOffset(this.element);
-      this.offsetX =  (pointer[0] - offsets[0]);
-      this.offsetY =  (pointer[1] - offsets[1]);
+      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.options.zindex) {
+      this.originalZ = parseInt(Element.getStyle(this.element,'z-index') || 0);
+      this.element.style.zIndex = this.options.zindex;
+    }
+    
+    if(this.options.ghosting) {
+      this._clone = this.element.cloneNode(true);
+      Position.absolutize(this.element);
+      this.element.parentNode.insertBefore(this._clone, this.element);
+    }
+    
+    if(this.options.scroll) {
+      if (this.options.scroll == window) {
+        var where = this._getWindowScroll(this.options.scroll);
+        this.originalScrollLeft = where.left;
+        this.originalScrollTop = where.top;
+      } else {
+        this.originalScrollLeft = this.options.scroll.scrollLeft;
+        this.originalScrollTop = this.options.scroll.scrollTop;
+      }
+    }
+    
+    Draggables.notify('onStart', this, event);
+    if(this.options.starteffect) this.options.starteffect(this.element);
+  },
+  
+  updateDrag: function(event, pointer) {
+    if(!this.dragging) this.startDrag(event);
+    Position.prepare();
+    Droppables.show(pointer, this.element);
+    Draggables.notify('onDrag', this, event);
+    this.draw(pointer);
+    if(this.options.change) this.options.change(this);
+    
+    if(this.options.scroll) {
+      this.stopScrolling();
+      
+      var p;
+      if (this.options.scroll == window) {
+        with(this._getWindowScroll(this.options.scroll)) { p = [ left, top, left+width, top+height ]; }
+      } else {
+        p = Position.page(this.options.scroll);
+        p[0] += this.options.scroll.scrollLeft;
+        p[1] += this.options.scroll.scrollTop;
+        p.push(p[0]+this.options.scroll.offsetWidth);
+        p.push(p[1]+this.options.scroll.offsetHeight);
+      }
+      var speed = [0,0];
+      if(pointer[0] < (p[0]+this.options.scrollSensitivity)) speed[0] = pointer[0]-(p[0]+this.options.scrollSensitivity);
+      if(pointer[1] < (p[1]+this.options.scrollSensitivity)) speed[1] = pointer[1]-(p[1]+this.options.scrollSensitivity);
+      if(pointer[0] > (p[2]-this.options.scrollSensitivity)) speed[0] = pointer[0]-(p[2]-this.options.scrollSensitivity);
+      if(pointer[1] > (p[3]-this.options.scrollSensitivity)) speed[1] = pointer[1]-(p[3]-this.options.scrollSensitivity);
+      this.startScrolling(speed);
+    }
+    
+    // fix AppleWebKit rendering
+    if(navigator.appVersion.indexOf('AppleWebKit')>0) window.scrollBy(0,0);
+    
+    Event.stop(event);
+  },
+  
   finishDrag: function(event, success) {
-    // this.unregisterEvents();
-
-    this.active = false;
     this.dragging = false;
 
     if(this.options.ghosting) {
@@ -219,18 +360,17 @@ Draggable.prototype = {
     }
 
     if(success) Droppables.fire(event, this.element);
-    Draggables.notify('onEnd', this);
+    Draggables.notify('onEnd', this, event);
 
     var revert = this.options.revert;
     if(revert && typeof revert == 'function') revert = revert(this.element);
-
+    
+    var d = this.currentDelta();
     if(revert && this.options.reverteffect) {
       this.options.reverteffect(this.element, 
-      this.currentTop()-this.originalTop,
-      this.currentLeft()-this.originalLeft);
+        d[1]-this.delta[1], d[0]-this.delta[0]);
     } else {
-      this.originalLeft = this.currentLeft();
-      this.originalTop  = this.currentTop();
+      this.delta = d;
     }
 
     if(this.options.zindex)
@@ -239,70 +379,125 @@ Draggable.prototype = {
     if(this.options.endeffect) 
       this.options.endeffect(this.element);
 
-
+    Draggables.deactivate(this);
     Droppables.reset();
   },
+  
   keyPress: function(event) {
-    if(this.active) {
-      if(event.keyCode==Event.KEY_ESC) {
-        this.finishDrag(event, false);
-        Event.stop(event);
-      }
-    }
+    if(event.keyCode!=Event.KEY_ESC) return;
+    this.finishDrag(event, false);
+    Event.stop(event);
   },
+  
   endDrag: function(event) {
-    if(this.active && this.dragging) {
-      this.finishDrag(event, true);
-      Event.stop(event);
-    }
-    this.active = false;
-    this.dragging = false;
+    if(!this.dragging) return;
+    this.stopScrolling();
+    this.finishDrag(event, true);
+    Event.stop(event);
   },
-  draw: function(event) {
-    var pointer = [Event.pointerX(event), Event.pointerY(event)];
-    var offsets = Position.cumulativeOffset(this.element);
-    offsets[0] -= this.currentLeft();
-    offsets[1] -= this.currentTop();
+  
+  draw: function(point) {
+    var pos = Position.cumulativeOffset(this.element);
+    var d = this.currentDelta();
+    pos[0] -= d[0]; pos[1] -= d[1];
+    
+    if(this.options.scroll && (this.options.scroll != window)) {
+      pos[0] -= this.options.scroll.scrollLeft-this.originalScrollLeft;
+      pos[1] -= this.options.scroll.scrollTop-this.originalScrollTop;
+    }
+    
+    var p = [0,1].map(function(i){ 
+      return (point[i]-pos[i]-this.offset[i]) 
+    }.bind(this));
+    
+    if(this.options.snap) {
+      if(typeof this.options.snap == 'function') {
+        p = this.options.snap(p[0],p[1]);
+      } else {
+      if(this.options.snap instanceof Array) {
+        p = p.map( function(v, i) {
+          return Math.round(v/this.options.snap[i])*this.options.snap[i] }.bind(this))
+      } else {
+        p = p.map( function(v) {
+          return Math.round(v/this.options.snap)*this.options.snap }.bind(this))
+      }
+    }}
+    
     var style = this.element.style;
     if((!this.options.constraint) || (this.options.constraint=='horizontal'))
-      style.left = (pointer[0] - offsets[0] - this.offsetX) + "px";
+      style.left = p[0] + "px";
     if((!this.options.constraint) || (this.options.constraint=='vertical'))
-      style.top  = (pointer[1] - offsets[1] - this.offsetY) + "px";
+      style.top  = p[1] + "px";
     if(style.visibility=="hidden") style.visibility = ""; // fix gecko rendering
   },
-  update: function(event) {
-   if(this.active) {
-      if(!this.dragging) {
-        var style = this.element.style;
-        this.dragging = true;
-        
-        if(Element.getStyle(this.element,'position')=='') 
-          style.position = "relative";
-        
-        if(this.options.zindex) {
-          this.originalZ = parseInt(Element.getStyle(this.element,'z-index') || 0);
-          style.zIndex = this.options.zindex;
-        }
-
-        if(this.options.ghosting) {
-          this._clone = this.element.cloneNode(true);
-          Position.absolutize(this.element);
-          this.element.parentNode.insertBefore(this._clone, this.element);
+  
+  stopScrolling: function() {
+    if(this.scrollInterval) {
+      clearInterval(this.scrollInterval);
+      this.scrollInterval = null;
+      Draggables._lastScrollPointer = null;
+    }
+  },
+  
+  startScrolling: function(speed) {
+    this.scrollSpeed = [speed[0]*this.options.scrollSpeed,speed[1]*this.options.scrollSpeed];
+    this.lastScrolled = new Date();
+    this.scrollInterval = setInterval(this.scroll.bind(this), 10);
+  },
+  
+  scroll: function() {
+    var current = new Date();
+    var delta = current - this.lastScrolled;
+    this.lastScrolled = current;
+    if(this.options.scroll == window) {
+      with (this._getWindowScroll(this.options.scroll)) {
+        if (this.scrollSpeed[0] || this.scrollSpeed[1]) {
+          var d = delta / 1000;
+          this.options.scroll.scrollTo( left + d*this.scrollSpeed[0], top + d*this.scrollSpeed[1] );
         }
-
-        Draggables.notify('onStart', this);
-        if(this.options.starteffect) this.options.starteffect(this.element);
       }
-
-      Droppables.show(event, this.element);
-      this.draw(event);
-      if(this.options.change) this.options.change(this);
-
-      // fix AppleWebKit rendering
-      if(navigator.appVersion.indexOf('AppleWebKit')>0) window.scrollBy(0,0); 
-
-      Event.stop(event);
-   }
+    } else {
+      this.options.scroll.scrollLeft += this.scrollSpeed[0] * delta / 1000;
+      this.options.scroll.scrollTop  += this.scrollSpeed[1] * delta / 1000;
+    }
+    
+    Position.prepare();
+    Droppables.show(Draggables._lastPointer, this.element);
+    Draggables.notify('onDrag', this);
+    Draggables._lastScrollPointer = Draggables._lastScrollPointer || $A(Draggables._lastPointer);
+    Draggables._lastScrollPointer[0] += this.scrollSpeed[0] * delta / 1000;
+    Draggables._lastScrollPointer[1] += this.scrollSpeed[1] * delta / 1000;
+    if (Draggables._lastScrollPointer[0] < 0)
+      Draggables._lastScrollPointer[0] = 0;
+    if (Draggables._lastScrollPointer[1] < 0)
+      Draggables._lastScrollPointer[1] = 0;
+    this.draw(Draggables._lastScrollPointer);
+    
+    if(this.options.change) this.options.change(this);
+  },
+  
+  _getWindowScroll: function(w) {
+    var T, L, W, H;
+    with (w.document) {
+      if (w.document.documentElement && documentElement.scrollTop) {
+        T = documentElement.scrollTop;
+        L = documentElement.scrollLeft;
+      } else if (w.document.body) {
+        T = body.scrollTop;
+        L = body.scrollLeft;
+      }
+      if (w.innerWidth) {
+        W = w.innerWidth;
+        H = w.innerHeight;
+      } else if (w.document.documentElement && documentElement.clientWidth) {
+        W = documentElement.clientWidth;
+        H = documentElement.clientHeight;
+      } else {
+        W = body.offsetWidth;
+        H = body.offsetHeight
+      }
+    }
+    return { top: T, left: L, width: W, height: H };
   }
 }
 
@@ -315,9 +510,11 @@ SortableObserver.prototype = {
     this.observer  = observer;
     this.lastValue = Sortable.serialize(this.element);
   },
+  
   onStart: function() {
     this.lastValue = Sortable.serialize(this.element);
   },
+  
   onEnd: function() {
     Sortable.unmark();
     if(this.lastValue != Sortable.serialize(this.element))
@@ -326,27 +523,41 @@ SortableObserver.prototype = {
 }
 
 var Sortable = {
-  sortables: new Array(),
-  options: function(element){
-    element = $(element);
-    return this.sortables.detect(function(s) { return s.element == element });
+  sortables: {},
+  
+  _findRootElement: function(element) {
+    while (element.tagName != "BODY") {  
+      if(element.id && Sortable.sortables[element.id]) return element;
+      element = element.parentNode;
+    }
   },
+
+  options: function(element) {
+    element = Sortable._findRootElement($(element));
+    if(!element) return;
+    return Sortable.sortables[element.id];
+  },
+  
   destroy: function(element){
-    element = $(element);
-    this.sortables.findAll(function(s) { return s.element == element }).each(function(s){
+    var s = Sortable.options(element);
+    
+    if(s) {
       Draggables.removeObserver(s.element);
       s.droppables.each(function(d){ Droppables.remove(d) });
       s.draggables.invoke('destroy');
-    });
-    this.sortables = this.sortables.reject(function(s) { return s.element == element });
+      
+      delete Sortable.sortables[s.element.id];
+    }
   },
+
   create: function(element) {
     element = $(element);
     var options = Object.extend({ 
       element:     element,
       tag:         'li',       // assumes li children, override with tag: 'tagname'
       dropOnEmpty: false,
-      tree:        false,      // fixme: unimplemented
+      tree:        false,
+      treeTag:     'ul',
       overlap:     'vertical', // one of 'vertical', 'horizontal'
       constraint:  'vertical', // one of 'vertical', 'horizontal', false
       containment: element,    // also takes array of elements (or id's); or false
@@ -354,7 +565,10 @@ var Sortable = {
       only:        false,
       hoverclass:  null,
       ghosting:    false,
-      format:      null,
+      scroll:      false,
+      scrollSensitivity: 20,
+      scrollSpeed: 15,
+      format:      /^[^_]*_(.*)$/,
       onChange:    Prototype.emptyFunction,
       onUpdate:    Prototype.emptyFunction
     }, arguments[1] || {});
@@ -365,6 +579,9 @@ var Sortable = {
     // build options for the draggables
     var options_for_draggable = {
       revert:      true,
+      scroll:      options.scroll,
+      scrollSpeed: options.scrollSpeed,
+      scrollSensitivity: options.scrollSensitivity,
       ghosting:    options.ghosting,
       constraint:  options.constraint,
       handle:      options.handle };
@@ -390,9 +607,17 @@ var Sortable = {
     var options_for_droppable = {
       overlap:     options.overlap,
       containment: options.containment,
+      tree:        options.tree,
       hoverclass:  options.hoverclass,
-      onHover:     Sortable.onHover,
-      greedy:      !options.dropOnEmpty
+      onHover:     Sortable.onHover
+      //greedy:      !options.dropOnEmpty
+    }
+    
+    var options_for_tree = {
+      onHover:      Sortable.onEmptyHover,
+      overlap:      options.overlap,
+      containment:  options.containment,
+      hoverclass:   options.hoverclass
     }
 
     // fix for gecko engine
@@ -401,27 +626,33 @@ var Sortable = {
     options.draggables = [];
     options.droppables = [];
 
-    // make it so
-
     // drop on empty handling
-    if(options.dropOnEmpty) {
-      Droppables.add(element,
-        {containment: options.containment, onHover: Sortable.onEmptyHover, greedy: false});
+    if(options.dropOnEmpty || options.tree) {
+      Droppables.add(element, options_for_tree);
       options.droppables.push(element);
     }
 
     (this.findElements(element, options) || []).each( function(e) {
       // handles are per-draggable
       var handle = options.handle ? 
-        Element.Class.childrenWith(e, options.handle)[0] : e;    
+        Element.childrenWithClassName(e, options.handle)[0] : e;    
       options.draggables.push(
         new Draggable(e, Object.extend(options_for_draggable, { handle: handle })));
       Droppables.add(e, options_for_droppable);
+      if(options.tree) e.treeNode = element;
       options.droppables.push(e);      
     });
+    
+    if(options.tree) {
+      (Sortable.findTreeElements(element, options) || []).each( function(e) {
+        Droppables.add(e, options_for_tree);
+        e.treeNode = element;
+        options.droppables.push(e);
+      });
+    }
 
     // keep reference
-    this.sortables.push(options);
+    this.sortables[element.id] = options;
 
     // for onupdate
     Draggables.addObserver(new SortableObserver(element, options.onUpdate));
@@ -430,23 +661,21 @@ var Sortable = {
 
   // return all suitable-for-sortable elements in a guaranteed order
   findElements: function(element, options) {
-    if(!element.hasChildNodes()) return null;
-    var elements = [];
-    $A(element.childNodes).each( function(e) {
-      if(e.tagName && e.tagName==options.tag.toUpperCase() &&
-        (!options.only || (Element.Class.has(e, options.only))))
-          elements.push(e);
-      if(options.tree) {
-        var grandchildren = this.findElements(e, options);
-        if(grandchildren) elements.push(grandchildren);
-      }
-    });
-
-    return (elements.length>0 ? elements.flatten() : null);
+    return Element.findChildren(
+      element, options.only, options.tree ? true : false, options.tag);
+  },
+  
+  findTreeElements: function(element, options) {
+    return Element.findChildren(
+      element, options.only, options.tree ? true : false, options.treeTag);
   },
 
   onHover: function(element, dropon, overlap) {
-    if(overlap>0.5) {
+    if(Element.isParent(dropon, element)) return;
+
+    if(overlap > .33 && overlap < .66 && Sortable.options(dropon).tree) {
+      return;
+    } else if(overlap>0.5) {
       Sortable.mark(dropon, 'before');
       if(dropon.previousSibling != element) {
         var oldParentNode = element.parentNode;
@@ -469,13 +698,37 @@ var Sortable = {
       }
     }
   },
-
-  onEmptyHover: function(element, dropon) {
-    if(element.parentNode!=dropon) {
-      var oldParentNode = element.parentNode;
-      dropon.appendChild(element);
+  
+  onEmptyHover: function(element, dropon, overlap) {
+    var oldParentNode = element.parentNode;
+    var droponOptions = Sortable.options(dropon);
+        
+    if(!Element.isParent(dropon, element)) {
+      var index;
+      
+      var children = Sortable.findElements(dropon, {tag: droponOptions.tag});
+      var child = null;
+            
+      if(children) {
+        var offset = Element.offsetSize(dropon, droponOptions.overlap) * (1.0 - overlap);
+        
+        for (index = 0; index < children.length; index += 1) {
+          if (offset - Element.offsetSize (children[index], droponOptions.overlap) >= 0) {
+            offset -= Element.offsetSize (children[index], droponOptions.overlap);
+          } else if (offset - (Element.offsetSize (children[index], droponOptions.overlap) / 2) >= 0) {
+            child = index + 1 < children.length ? children[index + 1] : null;
+            break;
+          } else {
+            child = children[index];
+            break;
+          }
+        }
+      }
+      
+      dropon.insertBefore(element, child);
+      
       Sortable.options(oldParentNode).onChange(element);
-      Sortable.options(dropon).onChange(element);
+      droponOptions.onChange(element);
     }
   },
 
@@ -491,29 +744,170 @@ var Sortable = {
     if(!Sortable._marker) {
       Sortable._marker = $('dropmarker') || document.createElement('DIV');
       Element.hide(Sortable._marker);
-      Element.Class.add(Sortable._marker, 'dropmarker');
+      Element.addClassName(Sortable._marker, 'dropmarker');
       Sortable._marker.style.position = 'absolute';
       document.getElementsByTagName("body").item(0).appendChild(Sortable._marker);
     }    
     var offsets = Position.cumulativeOffset(dropon);
-    Sortable._marker.style.top  = offsets[1] + 'px';
-    if(position=='after') Sortable._marker.style.top = (offsets[1]+dropon.clientHeight) + 'px';
     Sortable._marker.style.left = offsets[0] + 'px';
+    Sortable._marker.style.top = offsets[1] + 'px';
+    
+    if(position=='after')
+      if(sortable.overlap == 'horizontal') 
+        Sortable._marker.style.left = (offsets[0]+dropon.clientWidth) + 'px';
+      else
+        Sortable._marker.style.top = (offsets[1]+dropon.clientHeight) + 'px';
+    
     Element.show(Sortable._marker);
   },
+  
+  _tree: function(element, options, parent) {
+    var children = Sortable.findElements(element, options) || [];
+  
+    for (var i = 0; i < children.length; ++i) {
+      var match = children[i].id.match(options.format);
+
+      if (!match) continue;
+      
+      var child = {
+        id: encodeURIComponent(match ? match[1] : null),
+        element: element,
+        parent: parent,
+        children: new Array,
+        position: parent.children.length,
+        container: Sortable._findChildrenElement(children[i], options.treeTag.toUpperCase())
+      }
+      
+      /* Get the element containing the children and recurse over it */
+      if (child.container)
+        this._tree(child.container, options, child)
+      
+      parent.children.push (child);
+    }
+
+    return parent; 
+  },
 
-  serialize: function(element) {
+  /* Finds the first element of the given tag type within a parent element.
+    Used for finding the first LI[ST] within a L[IST]I[TEM].*/
+  _findChildrenElement: function (element, containerTag) {
+    if (element && element.hasChildNodes)
+      for (var i = 0; i < element.childNodes.length; ++i)
+        if (element.childNodes[i].tagName == containerTag)
+          return element.childNodes[i];
+  
+    return null;
+  },
+
+  tree: function(element) {
     element = $(element);
     var sortableOptions = this.options(element);
     var options = Object.extend({
-      tag:  sortableOptions.tag,
+      tag: sortableOptions.tag,
+      treeTag: sortableOptions.treeTag,
       only: sortableOptions.only,
       name: element.id,
-      format: sortableOptions.format || /^[^_]*_(.*)$/
+      format: sortableOptions.format
     }, arguments[1] || {});
-    return $(this.findElements(element, options) || []).collect( function(item) {
-      return (encodeURIComponent(options.name) + "[]=" + 
-              encodeURIComponent(item.id.match(options.format) ? item.id.match(options.format)[1] : ''));
-    }).join("&");
+    
+    var root = {
+      id: null,
+      parent: null,
+      children: new Array,
+      container: element,
+      position: 0
+    }
+    
+    return Sortable._tree (element, options, root);
+  },
+
+  /* Construct a [i] index for a particular node */
+  _constructIndex: function(node) {
+    var index = '';
+    do {
+      if (node.id) index = '[' + node.position + ']' + index;
+    } while ((node = node.parent) != null);
+    return index;
+  },
+
+  sequence: function(element) {
+    element = $(element);
+    var options = Object.extend(this.options(element), arguments[1] || {});
+    
+    return $(this.findElements(element, options) || []).map( function(item) {
+      return item.id.match(options.format) ? item.id.match(options.format)[1] : '';
+    });
+  },
+
+  setSequence: function(element, new_sequence) {
+    element = $(element);
+    var options = Object.extend(this.options(element), arguments[2] || {});
+    
+    var nodeMap = {};
+    this.findElements(element, options).each( function(n) {
+        if (n.id.match(options.format))
+            nodeMap[n.id.match(options.format)[1]] = [n, n.parentNode];
+        n.parentNode.removeChild(n);
+    });
+   
+    new_sequence.each(function(ident) {
+      var n = nodeMap[ident];
+      if (n) {
+        n[1].appendChild(n[0]);
+        delete nodeMap[ident];
+      }
+    });
+  },
+  
+  serialize: function(element) {
+    element = $(element);
+    var options = Object.extend(Sortable.options(element), arguments[1] || {});
+    var name = encodeURIComponent(
+      (arguments[1] && arguments[1].name) ? arguments[1].name : element.id);
+    
+    if (options.tree) {
+      return Sortable.tree(element, arguments[1]).children.map( function (item) {
+        return [name + Sortable._constructIndex(item) + "=" + 
+                encodeURIComponent(item.id)].concat(item.children.map(arguments.callee));
+      }).flatten().join('&');
+    } else {
+      return Sortable.sequence(element, arguments[1]).map( function(item) {
+        return name + "[]=" + encodeURIComponent(item);
+      }).join('&');
+    }
   }
+}
+
+/* Returns true if child is contained within element */
+Element.isParent = function(child, element) {
+  if (!child.parentNode || child == element) return false;
+
+  if (child.parentNode == element) return true;
+
+  return Element.isParent(child.parentNode, element);
+}
+
+Element.findChildren = function(element, only, recursive, tagName) {    
+  if(!element.hasChildNodes()) return null;
+  tagName = tagName.toUpperCase();
+  if(only) only = [only].flatten();
+  var elements = [];
+  $A(element.childNodes).each( function(e) {
+    if(e.tagName && e.tagName.toUpperCase()==tagName &&
+      (!only || (Element.classNames(e).detect(function(v) { return only.include(v) }))))
+        elements.push(e);
+    if(recursive) {
+      var grandchildren = Element.findChildren(e, only, recursive, tagName);
+      if(grandchildren) elements.push(grandchildren);
+    }
+  });
+
+  return (elements.length>0 ? elements.flatten() : []);
+}
+
+Element.offsetSize = function (element, type) {
+  if (type == 'vertical' || type == 'height')
+    return element.offsetHeight;
+  else
+    return element.offsetWidth;
 }
\ No newline at end of file

Benjamin Mako Hill || Want to submit a patch?