Java tutorial
/* * Copyright 2011 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.lists; import com.google.gwt.core.client.GWT; import com.google.gwt.core.client.RunAsyncCallback; import com.google.gwt.dom.client.Style.Unit; 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.ImageResource; import com.google.gwt.safehtml.shared.SafeHtmlBuilder; import com.google.gwt.safehtml.shared.SafeHtmlUtils; 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.ShowcaseSource; import com.google.gwt.sample.showcase.client.ShowcaseAnnotations.ShowcaseStyle; import com.google.gwt.user.client.rpc.AsyncCallback; import com.google.gwt.user.client.ui.AbstractImagePrototype; import com.google.gwt.user.client.ui.Anchor; import com.google.gwt.user.client.ui.CheckBox; import com.google.gwt.user.client.ui.HTML; import com.google.gwt.user.client.ui.HasVerticalAlignment; import com.google.gwt.user.client.ui.HorizontalPanel; import com.google.gwt.user.client.ui.Image; import com.google.gwt.user.client.ui.PopupPanel; import com.google.gwt.user.client.ui.SimplePanel; import com.google.gwt.user.client.ui.StackLayoutPanel; import com.google.gwt.user.client.ui.Tree; import com.google.gwt.user.client.ui.TreeItem; import com.google.gwt.user.client.ui.VerticalPanel; import com.google.gwt.user.client.ui.Widget; /** * Example file. */ @ShowcaseStyle({ ".gwt-DecoratedStackPanel", "html>body .gwt-DecoratedStackPanel", "* html .gwt-DecoratedStackPanel", ".cw-StackPanelHeader" }) public class CwStackLayoutPanel extends ContentWidget { /** * The constants used in this Content Widget. */ @ShowcaseSource public static interface CwConstants extends Constants { String[] cwStackLayoutPanelContacts(); String[] cwStackLayoutPanelContactsEmails(); String cwStackLayoutPanelContactsHeader(); String cwStackLayoutPanelDescription(); String[] cwStackLayoutPanelFilters(); String cwStackLayoutPanelFiltersHeader(); String[] cwStackLayoutPanelMailFolders(); String cwStackLayoutPanelMailHeader(); String cwStackLayoutPanelName(); } /** * Specifies the images that will be bundled for this example. * * We will override the leaf image used in the tree. Instead of using a blank * 16x16 image, we will use a blank 1x1 image so it does not take up any * space. Each TreeItem will use its own custom image. */ @ShowcaseSource public interface Images extends Tree.Resources { ImageResource contactsgroup(); ImageResource defaultContact(); ImageResource drafts(); ImageResource filtersgroup(); ImageResource inbox(); ImageResource mailgroup(); ImageResource sent(); ImageResource templates(); ImageResource trash(); /** * Use noimage.png, which is a blank 1x1 image. */ @Source("noimage.png") ImageResource treeLeaf(); } /** * An instance of the constants. */ @ShowcaseData private final CwConstants constants; /** * Constructor. * * @param constants the constants */ public CwStackLayoutPanel(CwConstants constants) { super(constants.cwStackLayoutPanelName(), constants.cwStackLayoutPanelDescription(), true); this.constants = constants; } /** * Initialize this example. */ @ShowcaseSource @Override public Widget onInitialize() { // Get the images. Images images = (Images) GWT.create(Images.class); // Create a new stack layout panel. StackLayoutPanel stackPanel = new StackLayoutPanel(Unit.EM); stackPanel.setPixelSize(200, 400); // Add the Mail folders. Widget mailHeader = createHeaderWidget(constants.cwStackLayoutPanelMailHeader(), images.mailgroup()); stackPanel.add(createMailItem(images), mailHeader, 4); // Add a list of filters. Widget filtersHeader = createHeaderWidget(constants.cwStackLayoutPanelFiltersHeader(), images.filtersgroup()); stackPanel.add(createFiltersItem(), filtersHeader, 4); // Add a list of contacts. Widget contactsHeader = createHeaderWidget(constants.cwStackLayoutPanelContactsHeader(), images.contactsgroup()); stackPanel.add(createContactsItem(images), contactsHeader, 4); // Return the stack panel. stackPanel.ensureDebugId("cwStackLayoutPanel"); return stackPanel; } @Override protected void asyncOnInitialize(final AsyncCallback<Widget> callback) { GWT.runAsync(CwStackLayoutPanel.class, new RunAsyncCallback() { public void onFailure(Throwable caught) { callback.onFailure(caught); } public void onSuccess() { callback.onSuccess(onInitialize()); } }); } /** * Add a {@link TreeItem} to a root item. * * @param root the root {@link TreeItem} * @param image the icon for the new child item * @param label the label for the child icon */ @ShowcaseSource private void addItem(TreeItem root, ImageResource image, String label) { SafeHtmlBuilder sb = new SafeHtmlBuilder(); sb.append(SafeHtmlUtils.fromTrustedString(AbstractImagePrototype.create(image).getHTML())); sb.appendEscaped(" ").appendEscaped(label); root.addItem(sb.toSafeHtml()); } /** * Create the list of Contacts. * * @param images the {@link Images} used in the Contacts * @return the list of contacts */ @ShowcaseSource private Widget createContactsItem(Images images) { // Create a popup to show the contact info when a contact is clicked HorizontalPanel contactPopupContainer = new HorizontalPanel(); contactPopupContainer.setSpacing(5); contactPopupContainer.add(new Image(images.defaultContact())); final HTML contactInfo = new HTML(); contactPopupContainer.add(contactInfo); final PopupPanel contactPopup = new PopupPanel(true, false); contactPopup.setWidget(contactPopupContainer); // Create the list of contacts VerticalPanel contactsPanel = new VerticalPanel(); contactsPanel.setSpacing(4); String[] contactNames = constants.cwStackLayoutPanelContacts(); String[] contactEmails = constants.cwStackLayoutPanelContactsEmails(); for (int i = 0; i < contactNames.length; i++) { final String contactName = contactNames[i]; final String contactEmail = contactEmails[i]; final Anchor contactLink = new Anchor(contactName); contactsPanel.add(contactLink); // Open the contact info popup when the user clicks a contact contactLink.addClickHandler(new ClickHandler() { public void onClick(ClickEvent event) { // Set the info about the contact SafeHtmlBuilder sb = new SafeHtmlBuilder(); sb.appendEscaped(contactName); sb.appendHtmlConstant("<br><i>"); sb.appendEscaped(contactEmail); sb.appendHtmlConstant("</i>"); contactInfo.setHTML(sb.toSafeHtml()); // Show the popup of contact info int left = contactLink.getAbsoluteLeft() + 14; int top = contactLink.getAbsoluteTop() + 14; contactPopup.setPopupPosition(left, top); contactPopup.show(); } }); } return new SimplePanel(contactsPanel); } /** * Create the list of filters for the Filters item. * * @return the list of filters */ @ShowcaseSource private Widget createFiltersItem() { VerticalPanel filtersPanel = new VerticalPanel(); filtersPanel.setSpacing(4); for (String filter : constants.cwStackLayoutPanelFilters()) { filtersPanel.add(new CheckBox(filter)); } return new SimplePanel(filtersPanel); } /** * Create a widget to display in the header that includes an image and some * text. * * @param text the header text * @param image the {@link ImageResource} to add next to the header * @return the header widget */ @ShowcaseSource private Widget createHeaderWidget(String text, ImageResource image) { // Add the image and text to a horizontal panel HorizontalPanel hPanel = new HorizontalPanel(); hPanel.setHeight("100%"); hPanel.setSpacing(0); hPanel.setVerticalAlignment(HasVerticalAlignment.ALIGN_MIDDLE); hPanel.add(new Image(image)); HTML headerText = new HTML(text); headerText.setStyleName("cw-StackPanelHeader"); hPanel.add(headerText); return new SimplePanel(hPanel); } /** * Create the {@link Tree} of Mail options. * * @param images the {@link Images} used in the Mail options * @return the {@link Tree} of mail options */ @ShowcaseSource private Widget createMailItem(Images images) { Tree mailPanel = new Tree(images); TreeItem mailPanelRoot = mailPanel.addItem("foo@example.com"); String[] mailFolders = constants.cwStackLayoutPanelMailFolders(); addItem(mailPanelRoot, images.inbox(), mailFolders[0]); addItem(mailPanelRoot, images.drafts(), mailFolders[1]); addItem(mailPanelRoot, images.templates(), mailFolders[2]); addItem(mailPanelRoot, images.sent(), mailFolders[3]); addItem(mailPanelRoot, images.trash(), mailFolders[4]); mailPanelRoot.setState(true); return mailPanel; } }