Как добавить корневой узел TreePanel в другой TreePanel с помощью перетаскивания?

Question

Я хочу добавить корневой узел одного дерева в другое дерево с помощью перетаскивания. Пример я использую для этой задачи по следующему адресу:

http://gwt-ext.com/demo/#twoTrees

Пожалуйста, помогите мне как можно скорее.

Answer 1

В той же ссылке. код указан.

public class TwoTreesSample implements EntryPoint { 

    public void onModuleLoad() { 
     Panel panel = new Panel(); 
     panel.setBorder(false); 
     panel.setPaddings(15); 

     //create form for nody drop style 
     FormPanel formPanel = new FormPanel(); 
     formPanel.setBorder(false); 
     formPanel.setHideLabels(true); 

     FieldSet fieldSet = new FieldSet("Drop style"); 
     fieldSet.setWidth(420); 
     formPanel.add(fieldSet); 

     final Radio moveRadio = new Radio(); 
     moveRadio.setName("dropstyle"); 
     moveRadio.setBoxLabel("Move"); 
     moveRadio.setChecked(true); 
     fieldSet.add(moveRadio); 

     final Radio copyRadio = new Radio(); 
     copyRadio.setName("dropstyle"); 
     copyRadio.setBoxLabel("Copy"); 
     fieldSet.add(copyRadio); 

     //create source countries tree 
     final TreePanel treePanel = new TreePanel(); 
     treePanel.setTitle("Countries"); 
     treePanel.setAnimate(true); 
     treePanel.setEnableDD(true); 
     treePanel.setContainerScroll(true); 
     treePanel.setRootVisible(true); 
     treePanel.setWidth(200); 
     treePanel.setHeight(400); 
     treePanel.setSelectionModel(new MultiSelectionModel()); 

     final XMLTreeLoader loader = new XMLTreeLoader(); 
     loader.setDataUrl("data/countries-grouped.xml"); 
     loader.setMethod(Connection.GET); 
     loader.setRootTag("countries"); 
     loader.setFolderTitleMapping("@title"); 
     loader.setFolderTag("continent"); 
     loader.setLeafTitleMapping("@title"); 
     loader.setLeafTag("country"); 
     loader.setQtipMapping("@qtip"); 
     loader.setIconMapping("@icon"); 

     AsyncTreeNode root = new AsyncTreeNode("Countries", loader); 
     treePanel.setRootNode(root); 
     root.expand(); 
     treePanel.expandAll(); 

     //create target vacation tree 
     final TreePanel tripTreePanel = new TreePanel(); 
     tripTreePanel.setTitle("Trip Planner"); 
     tripTreePanel.setAnimate(true); 
     tripTreePanel.setEnableDD(true); 
     tripTreePanel.setContainerScroll(true); 
     tripTreePanel.setRootVisible(true); 
     tripTreePanel.setWidth(200); 
     tripTreePanel.setHeight(400); 

     final XMLTreeLoader tripLoader = new XMLTreeLoader(); 
     tripLoader.setDataUrl("data/trip.xml"); 
     tripLoader.setMethod(Connection.GET); 
     tripLoader.setRootTag("vacations"); 
     tripLoader.setFolderIdMapping("@title"); 
     tripLoader.setFolderTag("trip"); 
     tripLoader.setQtipMapping("@qtip"); 
     tripLoader.setIconMapping("@icon"); 
     tripLoader.setAttributeMappings(new String[]{"@trip"}); 

     final AsyncTreeNode tripRoot = new AsyncTreeNode("Places to Visit", tripLoader); 

     tripTreePanel.setRootNode(tripRoot); 

     //add trip tree listener that handles move/copy logic 
     tripTreePanel.addListener(new TreePanelListenerAdapter() { 
      public void onRender(Component component) { 
       tripRoot.expand(); 
       tripTreePanel.expandAll(); 
      } 

      public boolean doBeforeNodeDrop(TreePanel treePanel, TreeNode target, DragData dragData, 
              String point, DragDrop source, TreeNode dropNode, 
              DropNodeCallback dropDropNodeCallback) { 
       if ("true".equals(target.getAttribute("trip"))) { 
        if (copyRadio.getValue()) { 
         TreeNode copyNode = dropNode.cloneNode(); 
         Node[] children = copyNode.getChildNodes(); 
         for (int i = 0; i < children.length; i++) { 
          Node child = children[i]; 
          copyNode.removeChild(child); 
         } 
         dropDropNodeCallback.setDropNode(copyNode); 
        } 
       } 
       return true; 
      } 
     }); 

     Panel horizontalPanel = new Panel(); 
     horizontalPanel.setLayout(new HorizontalLayout(20)); 
     horizontalPanel.add(treePanel); 
     horizontalPanel.add(tripTreePanel); 

     Panel verticalPanel = new Panel(); 
     verticalPanel.setLayout(new VerticalLayout(15)); 

     verticalPanel.add(formPanel); 
     verticalPanel.add(horizontalPanel); 

     panel.add(verticalPanel); 

     RootPanel.get().add(panel); 
    } 
}