树 - 拖放节点 - 刷新?

时间:2011-02-11 09:11:29

标签: drag-and-drop tree smartgwt

我遇到了与smartgwt树结构相关的问题。 我正在使用来自DB的值创建一个树(名为nodesTree),并且每个节点都设置了一个名称。 例如,我有4个节点(数字是节点的名称):

1
  2
3
  4

for (TreeNode node : nodesTree.getAllNodes())
   System.out.print(node.getName());

输出:1 2 3 4

如果我在节点1下拖动节点4(与2相同的级别)

1
  2
  4
3

我希望得到节点的顺序: 1 2 4 3 但是如果我重复上面的“for”语句,输出将与上面相同:1 2 3 4。< / p>

TreeGrid.refreshFields()不起作用。

我正在使用smartgwt 2.4。

谢谢。

稍后修改

手动填充树。我正在从代码中手动将节点添加到树中,并根据我从DB收到的一些值。

Tree nodesTree = new Tree();
TreeGrid navTreeGrid = new TreeGrid();
navTreeGrid.setData(nodesTree);
navTreeGrid.setCanReorderRecords(true); 
navTreeGrid.setCanReparentNodes(true);

稍后编辑(2011年5月15日): 还有一些代码:

private static final String NAVPATH_ROOT = "/";

// Tree structure
Tree nodesTree = new Tree();
nodesTree.setRootValue(NAVPATH_ROOT);
nodesTree.setModelType(TreeModelType.PARENT);

TreeGrid navTreeGrid = new TreeGrid();
navTreeGrid.setCanReorderRecords(true);
navTreeGrid.setCanReparentNodes(true);
navTreeGrid.setData(nodesTree);

// add first node
TreeNode newNode = new TreeNode();
newNode.setName("a");
nodesTree.add(newNode, NAVPATH_ROOT);

// add the second node
newNode = new TreeNode();
newNode.setName("ab");
nodesTree.add(newNode, NAVPATH_ROOT);

// add the third node to the tree 
newNode = new TreeNode();
newNode.setName("abc");
nodesTree.add(newNode, NAVPATH_ROOT);

navTreeGrid.addDropHandler(new DropHandler()
{
   @Override
   public void onDrop(DropEvent event)
   {
      resetNodesAttributes();

    });

// I want in this method to have the order of nodes after drag&drop action was made.
// for example if I drag& drop node "abc" under "a" I want the method below to post  
// nodes in this order: a  abc  ab
public void resetNodesAttributes(){
    for (TreeNode node : nodesTree.getAllNodes()) {
       System.out.println("---:" + node.getName());
    }
}

稍后修改

我已添加DataChangedHandlerTree小部件,如下所示:

nodesTree.addDataChangedHandler(new com.smartgwt.client.widgets.tree.DataChangedHandler() 
{
   @Override
   public void onDataChanged(com.smartgwt.client.widgets.tree.DataChangedEvent dataChangedEvent) 
   {
        resetNodesAttributes();
   }
});

工作正常,但是当我拖延时例如,在节点“a”下输出节点“abc”,输出为:

a  ab  a  abc  ab  a  abc  ab

所以,似乎方法resetNodesAttributes被调用了3次 - 我不想要这个 - 我只需要调用一次。此外,节点的名称有时会发生变化,而且我不希望调用此方法。

稍后编辑(2月18日)

package de.vogella.gwt.helloworld.client;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.user.client.ui.RootPanel;
import com.smartgwt.client.types.TreeModelType;
import com.smartgwt.client.widgets.events.DropEvent;
import com.smartgwt.client.widgets.events.DropHandler;
import com.smartgwt.client.widgets.tree.Tree;
import com.smartgwt.client.widgets.tree.TreeGrid;
import com.smartgwt.client.widgets.tree.TreeNode;

public class HelloGwt implements EntryPoint {

    private static final String NAVPATH_ROOT = "/";
    Tree nodesTree = null;

    @Override
    public void onModuleLoad() {
        // Tree structure
        nodesTree = new Tree();
        nodesTree.setRootValue(NAVPATH_ROOT);
        nodesTree.setModelType(TreeModelType.PARENT);

        TreeGrid navTreeGrid = new TreeGrid();
        navTreeGrid.setCanReorderRecords(true);
        navTreeGrid.setCanReparentNodes(true);
        navTreeGrid.setData(nodesTree);

        // add first node
        TreeNode newNode = new TreeNode();
        newNode.setName("a");
        nodesTree.add(newNode, NAVPATH_ROOT);

        // add the second node
        newNode = new TreeNode();
        newNode.setName("ab");
        nodesTree.add(newNode, NAVPATH_ROOT);

        // add the third node to the tree 
        newNode = new TreeNode();
        newNode.setName("abc");
        nodesTree.add(newNode, NAVPATH_ROOT);

        navTreeGrid.addDropHandler(new DropHandler() {
            @Override
            public void onDrop(DropEvent event) {
                resetNodesAttributes(); 
            }
        });

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

    public void resetNodesAttributes() {
        // here I want to have the new order of nodes after d&d action was made
        for (TreeNode node : nodesTree.getAllNodes()) {
           System.out.println(node.getName());
        }
    }

}

1 个答案:

答案 0 :(得分:4)

将输出包裹在DeferredCommand中,您将获得正确的输出。

public class HelloGwt implements EntryPoint 
{
  public void onModuleLoad() 
  {
    Tree tree = new Tree();
    tree.setModelType(TreeModelType.PARENT);

    final TreeGrid grid = new TreeGrid();
    grid.setCanReorderRecords(true);
    grid.setCanReparentNodes(true);
    grid.setData(tree);

    tree.add(createNode("a"), tree.getRoot());
    tree.add(createNode("b"), tree.getRoot());
    tree.add(createNode("c"), tree.getRoot());

    grid.addFolderDropHandler(new FolderDropHandler(){

    public void onFolderDrop(FolderDropEvent event)
    {
      DeferredCommand.addCommand(new Command()
      {
        public void execute()
        {
          for (ListGridRecord node : grid.getRecords()) 
            System.out.println(Tree.nodeForRecord(node).getName());
        }});
      }});


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

  private TreeNode createNode(String name)
  {
    TreeNode node = new TreeNode();
    node.setName(name);
    node.setID(name);
    return node;
  }
}