dragdrop.js

RubyonRailsC.zip ruby on rails的源码

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

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

var SortableObserver = Class.create();
SortableObserver.prototype = {
  initialize: function(element, observer) {
    this.element   = $(element);
    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))
      this.observer(this.element)
  }
}

var Sortable = {
  sortables: new Array(),
  
  options: function(element){
    element = $(element);
    return this.sortables.detect(function(s) { return s.element == element });
  },
  
  destroy: function(element){
    element = $(element);
    this.sortables.findAll(function(s) { return s.element == element }).each(function(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 });
  },
  
  create: function(element) {
    element = $(element);
    var options = Object.extend({ 
      element:     element,
      tag:         'li',       // assumes li children, override with tag: 'tagname'
      dropOnEmpty: false,
      tree:        false,      // fixme: unimplemented
      overlap:     'vertical', // one of 'vertical', 'horizontal'
      constraint:  'vertical', // one of 'vertical', 'horizontal', false
      containment: element,    // also takes array of elements (or id's); or false
      handle:      false,      // or a CSS class
      only:        false,
      hoverclass:  null,
      ghosting:    false,
      scroll:      false,
      scrollSensitivity: 20,
      scrollSpeed: 15,
      format:      /^[^_]*_(.*)$/,
      onChange:    Prototype.emptyFunction,
      onUpdate:    Prototype.emptyFunction
    }, arguments[1] || {});

    // clear any old sortable with same element
    this.destroy(element);

    // 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 };

    if(options.starteffect)
      options_for_draggable.starteffect = options.starteffect;

    if(options.reverteffect)
      options_for_draggable.reverteffect = options.reverteffect;
    else
      if(options.ghosting) options_for_draggable.reverteffect = function(element) {
        element.style.top  = 0;
        element.style.left = 0;
      };

    if(options.endeffect)
      options_for_draggable.endeffect = options.endeffect;

    if(options.zindex)
      options_for_draggable.zindex = options.zindex;

    // build options for the droppables  
    var options_for_droppable = {
      overlap:     options.overlap,
      containment: options.containment,
      hoverclass:  options.hoverclass,
      onHover:     Sortable.onHover,
      greedy:      !options.dropOnEmpty
    }

    // fix for gecko engine
    Element.cleanWhitespace(element); 

    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});
      options.droppables.push(element);
    }

    (this.findElements(element, options) || []).each( function(e) {
      // handles are per-draggable
      var handle = options.handle ? 
        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);
      options.droppables.push(e);      
    });

    // keep reference
    this.sortables.push(options);

    // for onupdate
    Draggables.addObserver(new SortableObserver(element, options.onUpdate));

  },

  // return all suitable-for-sortable elements in a guaranteed order
  findElements: function(element, options) {
    if(!element.hasChildNodes()) return null;
    var elements = [];
    var only = options.only ? [options.only].flatten() : null;
    $A(element.childNodes).each( function(e) {
      if(e.tagName && e.tagName.toUpperCase()==options.tag.toUpperCase() &&
        (!only || (Element.classNames(e).detect(function(v) { return only.include(v) }))))
          elements.push(e);
      if(options.tree) {
        var grandchildren = this.findElements(e, options);
        if(grandchildren) elements.push(grandchildren);
      }
    });

    return (elements.length>0 ? elements.flatten() : null);
  },

  onHover: function(element, dropon, overlap) {
    if(overlap>0.5) {
      Sortable.mark(dropon, 'before');
      if(dropon.previousSibling != element) {
        var oldParentNode = element.parentNode;
        element.style.visibility = "hidden"; // fix gecko rendering
        dropon.parentNode.insertBefore(element, dropon);
        if(dropon.parentNode!=oldParentNode) 
          Sortable.options(oldParentNode).onChange(element);
        Sortable.options(dropon.parentNode).onChange(element);
      }
    } else {
      Sortable.mark(dropon, 'after');
      var nextElement = dropon.nextSibling || null;
      if(nextElement != element) {
        var oldParentNode = element.parentNode;
        element.style.visibility = "hidden"; // fix gecko rendering
        dropon.parentNode.insertBefore(element, nextElement);
        if(dropon.parentNode!=oldParentNode) 
          Sortable.options(oldParentNode).onChange(element);
        Sortable.options(dropon.parentNode).onChange(element);
      }
    }
  },

  onEmptyHover: function(element, dropon) {
    if(element.parentNode!=dropon) {
      var oldParentNode = element.parentNode;
      dropon.appendChild(element);
      Sortable.options(oldParentNode).onChange(element);
      Sortable.options(dropon).onChange(element);
    }
  },

  unmark: function() {
    if(Sortable._marker) Element.hide(Sortable._marker);
  },

  mark: function(dropon, position) {
    // mark on ghosting only
    var sortable = Sortable.options(dropon.parentNode);
    if(sortable && !sortable.ghosting) return; 

    if(!Sortable._marker) {
      Sortable._marker = $('dropmarker') || document.createElement('DIV');
      Element.hide(Sortable._marker);
      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.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);
  },

  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 name = encodeURIComponent(
      (arguments[1] && arguments[1].name) ? arguments[1].name : element.id);
    return Sortable.sequence(element, arguments[1]).map( function(item) {
      return name + "[]=" + encodeURIComponent(item);
    }).join('&');
  }
}