source: Dev/trunk/src/client/dijit/tree/_dndContainer.js

define([
        "dojo/aspect", // aspect.after
        "dojo/_base/declare", // declare
        "dojo/dom-class", // domClass.add domClass.remove domClass.replace
        "dojo/_base/lang", // lang.mixin lang.hitch
        "dojo/on",
        "dojo/touch"
], function(aspect, declare, domClass, lang, on, touch){

        // module:
        //              dijit/tree/_dndContainer

        /*=====
         var __Args = {
         // summary:
         //             A dict of parameters for Tree source configuration.
         // isSource: Boolean?
         //             Can be used as a DnD source. Defaults to true.
         // accept: String[]
         //             List of accepted types (text strings) for a target; defaults to
         //             ["text", "treeNode"]
         // copyOnly: Boolean?
         //             Copy items, if true, use a state of Ctrl key otherwise,
         // dragThreshold: Number
         //             The move delay in pixels before detecting a drag; 0 by default
         // betweenThreshold: Integer
         //             Distance from upper/lower edge of node to allow drop to reorder nodes
         };
         =====*/

        return declare("dijit.tree._dndContainer", null, {

                // summary:
                //              This is a base class for `dijit/tree/_dndSelector`, and isn't meant to be used directly.
                //              It's modeled after `dojo/dnd/Container`.
                // tags:
                //              protected

                /*=====
                 // current: TreeNode
                 //             The currently hovered TreeNode.  Not set to anything for keyboard operation.  (TODO: change?)
                 current: null,
                 =====*/

                constructor: function(tree, params){
                        // summary:
                        //              A constructor of the Container
                        // tree: Node
                        //              Node or node's id to build the container on
                        // params: __Args
                        //              A dict of parameters, which gets mixed into the object
                        // tags:
                        //              private
                        this.tree = tree;
                        this.node = tree.domNode;       // TODO: rename; it's not a TreeNode but the whole Tree
                        lang.mixin(this, params);

                        // states
                        this.containerState = "";
                        domClass.add(this.node, "dojoDndContainer");

                        // set up events
                        this.events = [
                                // Mouse (or touch) enter/leave on Tree itself
                                on(this.node, touch.enter, lang.hitch(this, "onOverEvent")),
                                on(this.node, touch.leave, lang.hitch(this, "onOutEvent")),

                                // switching between TreeNodes
                                aspect.after(this.tree, "_onNodeMouseEnter", lang.hitch(this, "onMouseOver"), true),
                                aspect.after(this.tree, "_onNodeMouseLeave", lang.hitch(this, "onMouseOut"), true),

                                // cancel text selection and text dragging
                                on(this.node, "dragstart, selectstart", function(evt){
                                        evt.preventDefault();
                                })
                        ];
                },

                destroy: function(){
                        // summary:
                        //              Prepares this object to be garbage-collected

                        var h;
                        while(h = this.events.pop()){
                                h.remove();
                        }

                        // this.clearItems();
                        this.node = this.parent = null;
                },

                // mouse events
                onMouseOver: function(widget /*===== , evt =====*/){
                        // summary:
                        //              Called when mouse is moved over a TreeNode
                        // widget: TreeNode
                        // evt: Event
                        // tags:
                        //              protected
                        this.current = widget;
                },

                onMouseOut: function(/*===== widget, evt =====*/){
                        // summary:
                        //              Called when mouse is moved away from a TreeNode
                        // widget: TreeNode
                        // evt: Event
                        // tags:
                        //              protected
                        this.current = null;
                },

                _changeState: function(type, newState){
                        // summary:
                        //              Changes a named state to new state value
                        // type: String
                        //              A name of the state to change
                        // newState: String
                        //              new state
                        var prefix = "dojoDnd" + type;
                        var state = type.toLowerCase() + "State";
                        //domClass.replace(this.node, prefix + newState, prefix + this[state]);
                        domClass.replace(this.node, prefix + newState, prefix + this[state]);
                        this[state] = newState;
                },

                _addItemClass: function(node, type){
                        // summary:
                        //              Adds a class with prefix "dojoDndItem"
                        // node: Node
                        //              A node
                        // type: String
                        //              A variable suffix for a class name
                        domClass.add(node, "dojoDndItem" + type);
                },

                _removeItemClass: function(node, type){
                        // summary:
                        //              Removes a class with prefix "dojoDndItem"
                        // node: Node
                        //              A node
                        // type: String
                        //              A variable suffix for a class name
                        domClass.remove(node, "dojoDndItem" + type);
                },

                onOverEvent: function(){
                        // summary:
                        //              This function is called once, when mouse is over our container
                        // tags:
                        //              protected
                        this._changeState("Container", "Over");
                },

                onOutEvent: function(){
                        // summary:
                        //              This function is called once, when mouse is out of our container
                        // tags:
                        //              protected
                        this._changeState("Container", "");
                }
        });
});