| /* |
| * 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.view; |
| |
| import com.google.gwt.cell.client.TextCell; |
| import com.google.gwt.core.client.EntryPoint; |
| import com.google.gwt.user.cellview.client.CellList; |
| import com.google.gwt.user.cellview.client.SimplePager; |
| import com.google.gwt.user.client.Timer; |
| import com.google.gwt.user.client.ui.RootPanel; |
| import com.google.gwt.user.client.ui.VerticalPanel; |
| import com.google.gwt.view.client.AsyncDataProvider; |
| import com.google.gwt.view.client.HasData; |
| import com.google.gwt.view.client.Range; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** |
| * Example of {@link AsyncDataProvider}. |
| */ |
| public class AsyncDataProviderExample implements EntryPoint { |
| |
| /** |
| * A custom {@link AsyncDataProvider}. |
| */ |
| private static class MyDataProvider extends AsyncDataProvider<String> { |
| /** |
| * {@link #onRangeChanged(HasData)} is called when the table requests a new |
| * range of data. You can push data back to the displays using |
| * {@link #updateRowData(int, List)}. |
| */ |
| @Override |
| protected void onRangeChanged(HasData<String> display) { |
| // Get the new range. |
| final Range range = display.getVisibleRange(); |
| |
| /* |
| * Query the data asynchronously. If you are using a database, you can |
| * make an RPC call here. We'll use a Timer to simulate a delay. |
| */ |
| new Timer() { |
| @Override |
| public void run() { |
| // We are creating fake data. Normally, the data will come from a |
| // server. |
| int start = range.getStart(); |
| int length = range.getLength(); |
| List<String> newData = new ArrayList<String>(); |
| for (int i = start; i < start + length; i++) { |
| newData.add("Item " + i); |
| } |
| |
| // Push the data to the displays. AsyncDataProvider will only update |
| // displays that are within range of the data. |
| updateRowData(start, newData); |
| } |
| }.schedule(3000); |
| } |
| } |
| |
| public void onModuleLoad() { |
| // Create a CellList. |
| CellList<String> cellList = new CellList<String>(new TextCell()); |
| |
| // Create a data provider. |
| MyDataProvider dataProvider = new MyDataProvider(); |
| |
| // Add the cellList to the dataProvider. |
| dataProvider.addDataDisplay(cellList); |
| |
| // Create paging controls. |
| SimplePager pager = new SimplePager(); |
| pager.setDisplay(cellList); |
| |
| // Add the widgets to the root panel. |
| VerticalPanel vPanel = new VerticalPanel(); |
| vPanel.add(pager); |
| vPanel.add(cellList); |
| RootPanel.get().add(vPanel); |
| } |
| } |