Java tutorial
/* * 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.sample.showcase.client.content.cell; import com.google.gwt.cell.client.AbstractCell; import com.google.gwt.core.client.GWT; import com.google.gwt.core.client.RunAsyncCallback; import com.google.gwt.event.dom.client.ClickEvent; import com.google.gwt.event.dom.client.ClickHandler; import com.google.gwt.i18n.client.Constants; import com.google.gwt.resources.client.ClientBundle; import com.google.gwt.resources.client.ImageResource; import com.google.gwt.safehtml.shared.SafeHtmlBuilder; import com.google.gwt.sample.showcase.client.ContentWidget; import com.google.gwt.sample.showcase.client.ShowcaseAnnotations.ShowcaseData; import com.google.gwt.sample.showcase.client.ShowcaseAnnotations.ShowcaseRaw; import com.google.gwt.sample.showcase.client.ShowcaseAnnotations.ShowcaseSource; import com.google.gwt.sample.showcase.client.content.cell.ContactDatabase.ContactInfo; import com.google.gwt.uibinder.client.UiBinder; import com.google.gwt.uibinder.client.UiField; import com.google.gwt.user.cellview.client.CellList; import com.google.gwt.user.cellview.client.HasKeyboardPagingPolicy.KeyboardPagingPolicy; import com.google.gwt.user.cellview.client.HasKeyboardSelectionPolicy.KeyboardSelectionPolicy; import com.google.gwt.user.client.rpc.AsyncCallback; import com.google.gwt.user.client.ui.AbstractImagePrototype; import com.google.gwt.user.client.ui.Button; import com.google.gwt.user.client.ui.Widget; import com.google.gwt.view.client.SelectionChangeEvent; import com.google.gwt.view.client.SingleSelectionModel; /** * Example file. */ @ShowcaseRaw({ "ContactDatabase.java", "CwCellList.ui.xml", "ContactInfoForm.java", "ShowMorePagerPanel.java", "RangeLabelPager.java" }) public class CwCellList extends ContentWidget { /** * The UiBinder interface used by this example. */ @ShowcaseSource interface Binder extends UiBinder<Widget, CwCellList> { } /** * The constants used in this Content Widget. */ @ShowcaseSource public static interface CwConstants extends Constants { String cwCellListDescription(); String cwCellListName(); } /** * The images used for this example. */ @ShowcaseSource static interface Images extends ClientBundle { ImageResource contact(); } /** * The Cell used to render a {@link ContactInfo}. */ @ShowcaseSource static class ContactCell extends AbstractCell<ContactInfo> { /** * The html of the image used for contacts. */ private final String imageHtml; public ContactCell(ImageResource image) { this.imageHtml = AbstractImagePrototype.create(image).getHTML(); } @Override public void render(Context context, ContactInfo value, SafeHtmlBuilder sb) { // Value can be null, so do a null check.. if (value == null) { return; } sb.appendHtmlConstant("<table>"); // Add the contact image. sb.appendHtmlConstant("<tr><td rowspan='3'>"); sb.appendHtmlConstant(imageHtml); sb.appendHtmlConstant("</td>"); // Add the name and address. sb.appendHtmlConstant("<td style='font-size:95%;'>"); sb.appendEscaped(value.getFullName()); sb.appendHtmlConstant("</td></tr><tr><td>"); sb.appendEscaped(value.getAddress()); sb.appendHtmlConstant("</td></tr></table>"); } } /** * The contact form used to update contacts. */ @ShowcaseData @UiField ContactInfoForm contactForm; /** * The button used to generate more contacts. */ @ShowcaseData @UiField Button generateButton; /** * The pager used to change the range of data. */ @ShowcaseData @UiField ShowMorePagerPanel pagerPanel; /** * The pager used to display the current range. */ @ShowcaseData @UiField RangeLabelPager rangeLabelPager; /** * The CellList. */ @ShowcaseData private CellList<ContactInfo> cellList; /** * Constructor. * * @param constants the constants */ public CwCellList(CwConstants constants) { super(constants.cwCellListName(), constants.cwCellListDescription(), false, "ContactDatabase.java", "CwCellList.ui.xml", "ContactInfoForm.java", "ShowMorePagerPanel.java", "RangeLabelPager.java"); } /** * Initialize this example. */ @ShowcaseSource @Override public Widget onInitialize() { Images images = GWT.create(Images.class); // Create a CellList. ContactCell contactCell = new ContactCell(images.contact()); // Set a key provider that provides a unique key for each contact. If key is // used to identify contacts when fields (such as the name and address) // change. cellList = new CellList<ContactInfo>(contactCell, ContactDatabase.ContactInfo.KEY_PROVIDER); cellList.setPageSize(30); cellList.setKeyboardPagingPolicy(KeyboardPagingPolicy.INCREASE_RANGE); cellList.setKeyboardSelectionPolicy(KeyboardSelectionPolicy.BOUND_TO_SELECTION); // Add a selection model so we can select cells. final SingleSelectionModel<ContactInfo> selectionModel = new SingleSelectionModel<ContactInfo>( ContactDatabase.ContactInfo.KEY_PROVIDER); cellList.setSelectionModel(selectionModel); selectionModel.addSelectionChangeHandler(new SelectionChangeEvent.Handler() { public void onSelectionChange(SelectionChangeEvent event) { contactForm.setContact(selectionModel.getSelectedObject()); } }); // Create the UiBinder. Binder uiBinder = GWT.create(Binder.class); Widget widget = uiBinder.createAndBindUi(this); // Add the CellList to the data provider in the database. ContactDatabase.get().addDataDisplay(cellList); // Set the cellList as the display of the pagers. This example has two // pagers. pagerPanel is a scrollable pager that extends the range when the // user scrolls to the bottom. rangeLabelPager is a pager that displays the // current range, but does not have any controls to change the range. pagerPanel.setDisplay(cellList); rangeLabelPager.setDisplay(cellList); // Handle events from the generate button. generateButton.addClickHandler(new ClickHandler() { public void onClick(ClickEvent event) { ContactDatabase.get().generateContacts(50); } }); return widget; } @Override protected void asyncOnInitialize(final AsyncCallback<Widget> callback) { GWT.runAsync(CwCellList.class, new RunAsyncCallback() { public void onFailure(Throwable caught) { callback.onFailure(caught); } public void onSuccess() { callback.onSuccess(onInitialize()); } }); } }