/*
* Copyright 2010 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.examples.cellview;
import com.google.gwt.cell.client.TextCell;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.user.cellview.client.CellTree;
import com.google.gwt.user.client.ui.RootLayoutPanel;
import com.google.gwt.view.client.ListDataProvider;
import com.google.gwt.view.client.TreeViewModel;
/**
* Example of {@link CellTree}. This example shows a Tree consisting of strings.
*/
public class CellTreeExample implements EntryPoint {
/**
* The model that defines the nodes in the tree.
*/
private static class CustomTreeModel implements TreeViewModel {
/**
* Get the {@link NodeInfo} that provides the children of the specified
* value.
*/
public <T> NodeInfo<?> getNodeInfo(T value) {
/*
* Create some data in a data provider. Use the parent value as a prefix
* for the next level.
*/
ListDataProvider<String> dataProvider = new ListDataProvider<String>();
for (int i = 0; i < 2; i++) {
dataProvider.getList().add(value + "." + String.valueOf(i));
}
// Return a node info that pairs the data with a cell.
return new DefaultNodeInfo<String>(dataProvider, new TextCell());
}
/**
* Check if the specified value represents a leaf node. Leaf nodes cannot be
* opened.
*/
public boolean isLeaf(Object value) {
// The maximum length of a value is ten characters.
return value.toString().length() > 10;
}
}
public void onModuleLoad() {
// Create a model for the tree.
TreeViewModel model = new CustomTreeModel();
/*
* Create the tree using the model. We specify the default value of the
* hidden root node as "Item 1".
*/
CellTree tree = new CellTree(model, "Item 1");
// Add the tree to the root layout panel.
RootLayoutPanel.get().add(tree);
}
}