为ExtJS 4 系列树添加可将节点拖动到叶子节点上的功能，可配置

为ExtJS 4 系列树添加可将节点拖动到叶子节点上的功能，可配置。

使用方法：将以下代码复制，新建立一js文件后，将其引用在ext核心js后即可。 

使用时，通过allowLeafInserts属性进行叶子节点是否可拖动的配置，默认值为true。 

啊啊啊啊…………又通宵了…… 

  1 /*以下改动为是：给树添加允许为叶子节点添加子节点功能 --by lihong 2012/2/24
  2 通过TreeViewDragDrop的allowLeafInserts为true或false进行配置 
  3 例：
  4 //    Ext.define('myTree', {
  5 //        extend: 'Ext.tree.Panel',
  6 //        viewConfig: {
  7 //            plugins: {
  8 //                ptype: 'treeviewdragdrop',
  9 //                allowLeafInserts : true
 10 //            }
 11 //        }
 12 //    }
 13 //*/    
 14 Ext.override(Ext.tree.ViewDropZone, {
 15     getPosition: function (e, node) {
 16         var view = this.view,
 17         record = view.getRecord(node),
 18         y = e.getPageY(),
 19         noAppend = record.isLeaf(),
 20         noBelow = false,
 21         region = Ext.fly(node).getRegion(),
 22         fragment;
 23 
 24         if (record.isRoot()) {
 25             return 'append';
 26         }
 27 
 28         if (this.appendOnly) {
 29             return noAppend ? false : 'append';
 30         }
 31         if (!this.allowParentInsert) {
 32             //leehom modify begin
 33             noBelow = this.allowLeafInserts || (record.hasChildNodes() && record.isExpanded());
 34             //leehom modify end
 35         }
 36 
 37         fragment = (region.bottom - region.top) / (noAppend ? 2 : 3);
 38         if (y >= region.top && y < (region.top + fragment)) {
 39             return 'before';
 40         }
 41         else if (!noBelow && (noAppend || (y >= (region.bottom - fragment) && y <= region.bottom))) {
 42             return 'after';
 43         }
 44         else {
 45             return 'append';
 46         }
 47     },
 48     handleNodeDrop: function (data, targetNode, position) {
 49         var me = this,
 50         view = me.view,
 51         parentNode = targetNode.parentNode,
 52         store = view.getStore(),
 53         recordDomNodes = [],
 54         records, i, len,
 55         insertionMethod, argList,
 56         needTargetExpand,
 57         transferData,
 58         processDrop;
 59         if (data.copy) {
 60             records = data.records;
 61             data.records = [];
 62             for (i = 0, len = records.length; i < len; i++) {
 63                 data.records.push(Ext.apply({}, records[i].data));
 64             }
 65         }
 66         me.cancelExpand();
 67         if (position == 'before') {
 68             insertionMethod = parentNode.insertBefore;
 69             argList = [null, targetNode];
 70             targetNode = parentNode;
 71         }
 72         else if (position == 'after') {
 73             if (targetNode.nextSibling) {
 74                 insertionMethod = parentNode.insertBefore;
 75                 argList = [null, targetNode.nextSibling];
 76             }
 77             else {
 78                 insertionMethod = parentNode.appendChild;
 79                 argList = [null];
 80             }
 81             targetNode = parentNode;
 82         }
 83         else {
 84             //leehom add begin
 85             if (this.allowLeafInserts) {
 86                 if (targetNode.get('leaf')) {
 87                     targetNode.set('leaf', false);
 88                     targetNode.set('expanded', true);
 89                 }
 90             }
 91             //leehom add end
 92             if (!targetNode.isExpanded()) {
 93                 needTargetExpand = true;
 94             }
 95             insertionMethod = targetNode.appendChild;
 96             argList = [null];
 97         }
 98 
 99         transferData = function () {
100             var node;
101             for (i = 0, len = data.records.length; i < len; i++) {
102                 argList[0] = data.records[i];
103                 node = insertionMethod.apply(targetNode, argList);
104 
105                 if (Ext.enableFx && me.dropHighlight) {
106                     recordDomNodes.push(view.getNode(node));
107                 }
108             }
109             if (Ext.enableFx && me.dropHighlight) {
110                 Ext.Array.forEach(recordDomNodes, function (n) {
111                     if (n) {
112                         Ext.fly(n.firstChild ? n.firstChild : n).highlight(me.dropHighlightColor);
113                     }
114                 });
115             }
116         };
117         if (needTargetExpand) {
118             targetNode.expand(false, transferData);
119         }
120         else {
121             transferData();
122         }
123     }
124 });
125 
126 
127 Ext.override(Ext.tree.plugin.TreeViewDragDrop, {
128     allowLeafInserts: true,
129 
130     onViewRender: function (view) {
131         var me = this;
132         if (me.enableDrag) {
133             me.dragZone = Ext.create('Ext.tree.ViewDragZone', {
134                 view: view,
135                 allowLeafInserts: me.allowLeafInserts,
136                 ddGroup: me.dragGroup || me.ddGroup,
137                 dragText: me.dragText,
138                 repairHighlightColor: me.nodeHighlightColor,
139                 repairHighlight: me.nodeHighlightOnRepair
140             });
141         }
142 
143         if (me.enableDrop) {
144             me.dropZone = Ext.create('Ext.tree.ViewDropZone', {
145                 view: view,
146                 ddGroup: me.dropGroup || me.ddGroup,
147                 allowContainerDrops: me.allowContainerDrops,
148                 appendOnly: me.appendOnly,
149                 allowLeafInserts: me.allowLeafInserts,
150                 allowParentInserts: me.allowParentInserts,
151                 expandDelay: me.expandDelay,
152                 dropHighlightColor: me.nodeHighlightColor,
153                 dropHighlight: me.nodeHighlightOnDrop
154             });
155         }
156     }
157 });
158 ////////////////树叶子节点改动结束//////////////////////////////////////////////////////////