source: Dev/branches/rest-dojo-ui/client/dijit/tree/dndSource.js @ 256

define([
        "dojo/_base/array", // array.forEach array.indexOf array.map
        "dojo/_base/connect", // isCopyKey
        "dojo/_base/declare", // declare
        "dojo/dom-class", // domClass.add
        "dojo/dom-geometry", // domGeometry.position
        "dojo/_base/lang", // lang.mixin lang.hitch
        "dojo/on", // subscribe
        "dojo/touch",
        "dojo/topic",
        "dojo/dnd/Manager", // DNDManager.manager
        "./_dndSelector"
], function(array, connect, declare, domClass, domGeometry, lang, on, touch, topic, DNDManager, _dndSelector){

// module:
//              dijit/tree/dndSource
// summary:
//              Handles drag and drop operations (as a source or a target) for `dijit.Tree`

/*=====
dijit.tree.__SourceArgs = function(){
        // 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
        this.isSource = isSource;
        this.accept = accept;
        this.autoSync = autoSync;
        this.copyOnly = copyOnly;
        this.dragThreshold = dragThreshold;
        this.betweenThreshold = betweenThreshold;
}
=====*/

return declare("dijit.tree.dndSource", _dndSelector, {
        // summary:
        //              Handles drag and drop operations (as a source or a target) for `dijit.Tree`

        // isSource: [private] Boolean
        //              Can be used as a DnD source.
        isSource: true,

        // accept: String[]
        //              List of accepted types (text strings) for the Tree; defaults to
        //              ["text"]
        accept: ["text", "treeNode"],

        // copyOnly: [private] Boolean
        //              Copy items, if true, use a state of Ctrl key otherwise
        copyOnly: false,

        // dragThreshold: Number
        //              The move delay in pixels before detecting a drag; 5 by default
        dragThreshold: 5,

        // betweenThreshold: Integer
        //              Distance from upper/lower edge of node to allow drop to reorder nodes
        betweenThreshold: 0,

        constructor: function(/*dijit.Tree*/ tree, /*dijit.tree.__SourceArgs*/ params){
                // summary:
                //              a constructor of the Tree DnD Source
                // tags:
                //              private
                if(!params){ params = {}; }
                lang.mixin(this, params);
                this.isSource = typeof params.isSource == "undefined" ? true : params.isSource;
                var type = params.accept instanceof Array ? params.accept : ["text", "treeNode"];
                this.accept = null;
                if(type.length){
                        this.accept = {};
                        for(var i = 0; i < type.length; ++i){
                                this.accept[type[i]] = 1;
                        }
                }

                // class-specific variables
                this.isDragging = false;
                this.mouseDown = false;
                this.targetAnchor = null;       // DOMNode corresponding to the currently moused over TreeNode
                this.targetBox = null;  // coordinates of this.targetAnchor
                this.dropPosition = ""; // whether mouse is over/after/before this.targetAnchor
                this._lastX = 0;
                this._lastY = 0;

                // states
                this.sourceState = "";
                if(this.isSource){
                        domClass.add(this.node, "dojoDndSource");
                }
                this.targetState = "";
                if(this.accept){
                        domClass.add(this.node, "dojoDndTarget");
                }

                // set up events
                this.topics = [
                        topic.subscribe("/dnd/source/over", lang.hitch(this, "onDndSourceOver")),
                        topic.subscribe("/dnd/start", lang.hitch(this, "onDndStart")),
                        topic.subscribe("/dnd/drop", lang.hitch(this, "onDndDrop")),
                        topic.subscribe("/dnd/cancel", lang.hitch(this, "onDndCancel"))
                ];
        },

        // methods
        checkAcceptance: function(/*===== source, nodes =====*/){
                // summary:
                //              Checks if the target can accept nodes from this source
                // source: dijit.tree.dndSource
                //              The source which provides items
                // nodes: DOMNode[]
                //              Array of DOM nodes corresponding to nodes being dropped, dijitTreeRow nodes if
                //              source is a dijit.Tree.
                // tags:
                //              extension
                return true;    // Boolean
        },

        copyState: function(keyPressed){
                // summary:
                //              Returns true, if we need to copy items, false to move.
                //              It is separated to be overwritten dynamically, if needed.
                // keyPressed: Boolean
                //              The "copy" control key was pressed
                // tags:
                //              protected
                return this.copyOnly || keyPressed;     // Boolean
        },
        destroy: function(){
                // summary:
                //              Prepares the object to be garbage-collected.
                this.inherited(arguments);
                var h;
                while(h = this.topics.pop()){ h.remove(); }
                this.targetAnchor = null;
        },

        _onDragMouse: function(e){
                // summary:
                //              Helper method for processing onmousemove/onmouseover events while drag is in progress.
                //              Keeps track of current drop target.

                var m = DNDManager.manager(),
                        oldTarget = this.targetAnchor,                  // the TreeNode corresponding to TreeNode mouse was previously over
                        newTarget = this.current,                               // TreeNode corresponding to TreeNode mouse is currently over
                        oldDropPosition = this.dropPosition;    // the previous drop position (over/before/after)

                // calculate if user is indicating to drop the dragged node before, after, or over
                // (i.e., to become a child of) the target node
                var newDropPosition = "Over";
                if(newTarget && this.betweenThreshold > 0){
                        // If mouse is over a new TreeNode, then get new TreeNode's position and size
                        if(!this.targetBox || oldTarget != newTarget){
                                this.targetBox = domGeometry.position(newTarget.rowNode, true);
                        }
                        if((e.pageY - this.targetBox.y) <= this.betweenThreshold){
                                newDropPosition = "Before";
                        }else if((e.pageY - this.targetBox.y) >= (this.targetBox.h - this.betweenThreshold)){
                                newDropPosition = "After";
                        }
                }

                if(newTarget != oldTarget || newDropPosition != oldDropPosition){
                        if(oldTarget){
                                this._removeItemClass(oldTarget.rowNode, oldDropPosition);
                        }
                        if(newTarget){
                                this._addItemClass(newTarget.rowNode, newDropPosition);
                        }

                        // Check if it's ok to drop the dragged node on/before/after the target node.
                        if(!newTarget){
                                m.canDrop(false);
                        }else if(newTarget == this.tree.rootNode && newDropPosition != "Over"){
                                // Can't drop before or after tree's root node; the dropped node would just disappear (at least visually)
                                m.canDrop(false);
                        }else{
                                // Guard against dropping onto yourself (TODO: guard against dropping onto your descendant, #7140)
                                var model = this.tree.model,
                                        sameId = false;
                                if(m.source == this){
                                        for(var dragId in this.selection){
                                                var dragNode = this.selection[dragId];
                                                if(dragNode.item === newTarget.item){
                                                        sameId = true;
                                                        break;
                                                }
                                        }
                                }
                                if(sameId){
                                        m.canDrop(false);
                                }else if(this.checkItemAcceptance(newTarget.rowNode, m.source, newDropPosition.toLowerCase())
                                                && !this._isParentChildDrop(m.source, newTarget.rowNode)){
                                        m.canDrop(true);
                                }else{
                                        m.canDrop(false);
                                }
                        }

                        this.targetAnchor = newTarget;
                        this.dropPosition = newDropPosition;
                }
        },

        onMouseMove: function(e){
                // summary:
                //              Called for any onmousemove/ontouchmove events over the Tree
                // e: Event
                //              onmousemouse/ontouchmove event
                // tags:
                //              private
                if(this.isDragging && this.targetState == "Disabled"){ return; }
                this.inherited(arguments);
                var m = DNDManager.manager();
                if(this.isDragging){
                        this._onDragMouse(e);
                }else{
                        if(this.mouseDown && this.isSource &&
                                 (Math.abs(e.pageX-this._lastX)>=this.dragThreshold || Math.abs(e.pageY-this._lastY)>=this.dragThreshold)){
                                var nodes = this.getSelectedTreeNodes();
                                if(nodes.length){
                                        if(nodes.length > 1){
                                                //filter out all selected items which has one of their ancestor selected as well
                                                var seen = this.selection, i = 0, r = [], n, p;
                                                nextitem: while((n = nodes[i++])){
                                                        for(p = n.getParent(); p && p !== this.tree; p = p.getParent()){
                                                                if(seen[p.id]){ //parent is already selected, skip this node
                                                                        continue nextitem;
                                                                }
                                                        }
                                                        //this node does not have any ancestors selected, add it
                                                        r.push(n);
                                                }
                                                nodes = r;
                                        }
                                        nodes = array.map(nodes, function(n){return n.domNode});
                                        m.startDrag(this, nodes, this.copyState(connect.isCopyKey(e)));
                                }
                        }
                }
        },

        onMouseDown: function(e){
                // summary:
                //              Event processor for onmousedown/ontouchstart
                // e: Event
                //              onmousedown/ontouchend event
                // tags:
                //              private
                this.mouseDown = true;
                this.mouseButton = e.button;
                this._lastX = e.pageX;
                this._lastY = e.pageY;
                this.inherited(arguments);
        },

        onMouseUp: function(e){
                // summary:
                //              Event processor for onmouseup/ontouchend
                // e: Event
                //              onmouseup/ontouchend event
                // tags:
                //              private
                if(this.mouseDown){
                        this.mouseDown = false;
                        this.inherited(arguments);
                }
        },

        onMouseOut: function(){
                // summary:
                //              Event processor for when mouse is moved away from a TreeNode
                // tags:
                //              private
                this.inherited(arguments);
                this._unmarkTargetAnchor();
        },

        checkItemAcceptance: function(/*===== target, source, position =====*/){
                // summary:
                //              Stub function to be overridden if one wants to check for the ability to drop at the node/item level
                // description:
                //              In the base case, this is called to check if target can become a child of source.
                //              When betweenThreshold is set, position="before" or "after" means that we
                //              are asking if the source node can be dropped before/after the target node.
                // target: DOMNode
                //              The dijitTreeRoot DOM node inside of the TreeNode that we are dropping on to
                //              Use dijit.getEnclosingWidget(target) to get the TreeNode.
                // source: dijit.tree.dndSource
                //              The (set of) nodes we are dropping
                // position: String
                //              "over", "before", or "after"
                // tags:
                //              extension
                return true;
        },

        // topic event processors
        onDndSourceOver: function(source){
                // summary:
                //              Topic event processor for /dnd/source/over, called when detected a current source.
                // source: Object
                //              The dijit.tree.dndSource / dojo.dnd.Source which has the mouse over it
                // tags:
                //              private
                if(this != source){
                        this.mouseDown = false;
                        this._unmarkTargetAnchor();
                }else if(this.isDragging){
                        var m = DNDManager.manager();
                        m.canDrop(false);
                }
        },
        onDndStart: function(source, nodes, copy){
                // summary:
                //              Topic event processor for /dnd/start, called to initiate the DnD operation
                // source: Object
                //              The dijit.tree.dndSource / dojo.dnd.Source which is providing the items
                // nodes: DomNode[]
                //              The list of transferred items, dndTreeNode nodes if dragging from a Tree
                // copy: Boolean
                //              Copy items, if true, move items otherwise
                // tags:
                //              private

                if(this.isSource){
                        this._changeState("Source", this == source ? (copy ? "Copied" : "Moved") : "");
                }
                var accepted = this.checkAcceptance(source, nodes);

                this._changeState("Target", accepted ? "" : "Disabled");

                if(this == source){
                        DNDManager.manager().overSource(this);
                }

                this.isDragging = true;
        },

        itemCreator: function(nodes /*===== , target, source =====*/){
                // summary:
                //              Returns objects passed to `Tree.model.newItem()` based on DnD nodes
                //              dropped onto the tree.   Developer must override this method to enable
                //              dropping from external sources onto this Tree, unless the Tree.model's items
                //              happen to look like {id: 123, name: "Apple" } with no other attributes.
                // description:
                //              For each node in nodes[], which came from source, create a hash of name/value
                //              pairs to be passed to Tree.model.newItem().  Returns array of those hashes.
                // nodes: DomNode[]
                // target: DomNode
                // source: dojo.dnd.Source
                // returns: Object[]
                //              Array of name/value hashes for each new item to be added to the Tree, like:
                // |    [
                // |            { id: 123, label: "apple", foo: "bar" },
                // |            { id: 456, label: "pear", zaz: "bam" }
                // |    ]
                // tags:
                //              extension

                // TODO: for 2.0 refactor so itemCreator() is called once per drag node, and
                // make signature itemCreator(sourceItem, node, target) (or similar).

                return array.map(nodes, function(node){
                        return {
                                "id": node.id,
                                "name": node.textContent || node.innerText || ""
                        };
                }); // Object[]
        },

        onDndDrop: function(source, nodes, copy){
                // summary:
                //              Topic event processor for /dnd/drop, called to finish the DnD operation.
                // description:
                //              Updates data store items according to where node was dragged from and dropped
                //              to.   The tree will then respond to those data store updates and redraw itself.
                // source: Object
                //              The dijit.tree.dndSource / dojo.dnd.Source which is providing the items
                // nodes: DomNode[]
                //              The list of transferred items, dndTreeNode nodes if dragging from a Tree
                // copy: Boolean
                //              Copy items, if true, move items otherwise
                // tags:
                //              protected
                if(this.containerState == "Over"){
                        var tree = this.tree,
                                model = tree.model,
                                target = this.targetAnchor;

                        this.isDragging = false;

                        // Compute the new parent item
                        var newParentItem;
                        var insertIndex;
                        newParentItem = (target && target.item) || tree.item;
                        if(this.dropPosition == "Before" || this.dropPosition == "After"){
                                // TODO: if there is no parent item then disallow the drop.
                                // Actually this should be checked during onMouseMove too, to make the drag icon red.
                                newParentItem = (target.getParent() && target.getParent().item) || tree.item;
                                // Compute the insert index for reordering
                                insertIndex = target.getIndexInParent();
                                if(this.dropPosition == "After"){
                                        insertIndex = target.getIndexInParent() + 1;
                                }
                        }else{
                                newParentItem = (target && target.item) || tree.item;
                        }

                        // If necessary, use this variable to hold array of hashes to pass to model.newItem()
                        // (one entry in the array for each dragged node).
                        var newItemsParams;

                        array.forEach(nodes, function(node, idx){
                                // dojo.dnd.Item representing the thing being dropped.
                                // Don't confuse the use of item here (meaning a DnD item) with the
                                // uses below where item means dojo.data item.
                                var sourceItem = source.getItem(node.id);

                                // Information that's available if the source is another Tree
                                // (possibly but not necessarily this tree, possibly but not
                                // necessarily the same model as this Tree)
                                if(array.indexOf(sourceItem.type, "treeNode") != -1){
                                        var childTreeNode = sourceItem.data,
                                                childItem = childTreeNode.item,
                                                oldParentItem = childTreeNode.getParent().item;
                                }

                                if(source == this){
                                        // This is a node from my own tree, and we are moving it, not copying.
                                        // Remove item from old parent's children attribute.
                                        // TODO: dijit.tree.dndSelector should implement deleteSelectedNodes()
                                        // and this code should go there.

                                        if(typeof insertIndex == "number"){
                                                if(newParentItem == oldParentItem && childTreeNode.getIndexInParent() < insertIndex){
                                                        insertIndex -= 1;
                                                }
                                        }
                                        model.pasteItem(childItem, oldParentItem, newParentItem, copy, insertIndex);
                                }else if(model.isItem(childItem)){
                                        // Item from same model
                                        // (maybe we should only do this branch if the source is a tree?)
                                        model.pasteItem(childItem, oldParentItem, newParentItem, copy, insertIndex);
                                }else{
                                        // Get the hash to pass to model.newItem().  A single call to
                                        // itemCreator() returns an array of hashes, one for each drag source node.
                                        if(!newItemsParams){
                                                newItemsParams = this.itemCreator(nodes, target.rowNode, source);
                                        }

                                        // Create new item in the tree, based on the drag source.
                                        model.newItem(newItemsParams[idx], newParentItem, insertIndex);
                                }
                        }, this);

                        // Expand the target node (if it's currently collapsed) so the user can see
                        // where their node was dropped.   In particular since that node is still selected.
                        this.tree._expandNode(target);
                }
                this.onDndCancel();
        },

        onDndCancel: function(){
                // summary:
                //              Topic event processor for /dnd/cancel, called to cancel the DnD operation
                // tags:
                //              private
                this._unmarkTargetAnchor();
                this.isDragging = false;
                this.mouseDown = false;
                delete this.mouseButton;
                this._changeState("Source", "");
                this._changeState("Target", "");
        },

        // When focus moves in/out of the entire Tree
        onOverEvent: function(){
                // summary:
                //              This method is called when mouse is moved over our container (like onmouseenter)
                // tags:
                //              private
                this.inherited(arguments);
                DNDManager.manager().overSource(this);
        },
        onOutEvent: function(){
                // summary:
                //              This method is called when mouse is moved out of our container (like onmouseleave)
                // tags:
                //              private
                this._unmarkTargetAnchor();
                var m = DNDManager.manager();
                if(this.isDragging){
                        m.canDrop(false);
                }
                m.outSource(this);

                this.inherited(arguments);
        },

        _isParentChildDrop: function(source, targetRow){
                // summary:
                //              Checks whether the dragged items are parent rows in the tree which are being
                //              dragged into their own children.
                //
                // source:
                //              The DragSource object.
                //
                // targetRow:
                //              The tree row onto which the dragged nodes are being dropped.
                //
                // tags:
                //              private

                // If the dragged object is not coming from the tree this widget belongs to,
                // it cannot be invalid.
                if(!source.tree || source.tree != this.tree){
                        return false;
                }


                var root = source.tree.domNode;
                var ids = source.selection;

                var node = targetRow.parentNode;

                // Iterate up the DOM hierarchy from the target drop row,
                // checking of any of the dragged nodes have the same ID.
                while(node != root && !ids[node.id]){
                        node = node.parentNode;
                }

                return node.id && ids[node.id];
        },

        _unmarkTargetAnchor: function(){
                // summary:
                //              Removes hover class of the current target anchor
                // tags:
                //              private
                if(!this.targetAnchor){ return; }
                this._removeItemClass(this.targetAnchor.rowNode, this.dropPosition);
                this.targetAnchor = null;
                this.targetBox = null;
                this.dropPosition = null;
        },

        _markDndStatus: function(copy){
                // summary:
                //              Changes source's state based on "copy" status
                this._changeState("Source", copy ? "Copied" : "Moved");
        }
});

});