Java tutorial
/* * Copyright 2008 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.text; 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.event.dom.client.KeyUpEvent; import com.google.gwt.event.dom.client.KeyUpHandler; import com.google.gwt.i18n.client.Constants; import com.google.gwt.i18n.shared.AnyRtlDirectionEstimator; 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.HTML; import com.google.gwt.user.client.ui.HorizontalPanel; import com.google.gwt.user.client.ui.Label; import com.google.gwt.user.client.ui.PasswordTextBox; import com.google.gwt.user.client.ui.TextArea; import com.google.gwt.user.client.ui.TextBox; import com.google.gwt.user.client.ui.TextBoxBase; import com.google.gwt.user.client.ui.VerticalPanel; import com.google.gwt.user.client.ui.Widget; /** * Example file. */ @ShowcaseStyle(/* css style names */{ ".gwt-TextBox", ".gwt-PasswordTextBox", ".gwt-TextArea" }) public class CwBasicText extends ContentWidget { /** * The constants used in this Content Widget. */ @ShowcaseSource public static interface CwConstants extends Constants { String cwBasicTextAreaLabel(); String cwBasicTextDescription(); String cwBasicTextName(); String cwBasicTextNormalLabel(); String cwBasicTextPasswordLabel(); String cwBasicTextReadOnly(); String cwBasicTextSelected(); } /** * An instance of the constants. */ @ShowcaseData private final CwConstants constants; /** * Constructor. * * @param constants the constants */ public CwBasicText(CwConstants constants) { super(constants.cwBasicTextName(), constants.cwBasicTextDescription(), true); this.constants = constants; } /** * Initialize this example. */ @ShowcaseSource @Override public Widget onInitialize() { // Create a panel to layout the widgets VerticalPanel vpanel = new VerticalPanel(); vpanel.setSpacing(5); // Add a normal and disabled text box TextBox normalText = new TextBox(); normalText.ensureDebugId("cwBasicText-textbox"); // Set the normal text box to automatically adjust its direction according // to the input text. Use the Any-RTL heuristic, which sets an RTL direction // iff the text contains at least one RTL character. normalText.setDirectionEstimator(AnyRtlDirectionEstimator.get()); TextBox disabledText = new TextBox(); disabledText.ensureDebugId("cwBasicText-textbox-disabled"); disabledText.setText(constants.cwBasicTextReadOnly()); disabledText.setEnabled(false); vpanel.add(new HTML(constants.cwBasicTextNormalLabel())); vpanel.add(createTextExample(normalText, true)); vpanel.add(createTextExample(disabledText, false)); // Add a normal and disabled password text box PasswordTextBox normalPassword = new PasswordTextBox(); normalPassword.ensureDebugId("cwBasicText-password"); PasswordTextBox disabledPassword = new PasswordTextBox(); disabledPassword.ensureDebugId("cwBasicText-password-disabled"); disabledPassword.setText(constants.cwBasicTextReadOnly()); disabledPassword.setEnabled(false); vpanel.add(new HTML("<br><br>" + constants.cwBasicTextPasswordLabel())); vpanel.add(createTextExample(normalPassword, true)); vpanel.add(createTextExample(disabledPassword, false)); // Add a text area TextArea textArea = new TextArea(); textArea.ensureDebugId("cwBasicText-textarea"); textArea.setVisibleLines(5); vpanel.add(new HTML("<br><br>" + constants.cwBasicTextAreaLabel())); vpanel.add(createTextExample(textArea, true)); // Return the panel return vpanel; } @Override protected void asyncOnInitialize(final AsyncCallback<Widget> callback) { GWT.runAsync(CwBasicText.class, new RunAsyncCallback() { public void onFailure(Throwable caught) { callback.onFailure(caught); } public void onSuccess() { callback.onSuccess(onInitialize()); } }); } /** * Create a TextBox example that includes the text box and an optional handler * that updates a Label with the currently selected text. * * @param textBox the text box to handle * @param addSelection add handlers to update label * @return the Label that will be updated */ @ShowcaseSource private HorizontalPanel createTextExample(final TextBoxBase textBox, boolean addSelection) { // Add the text box and label to a panel HorizontalPanel hPanel = new HorizontalPanel(); hPanel.setSpacing(4); hPanel.add(textBox); // Add handlers if (addSelection) { // Create the new label final Label label = new Label(constants.cwBasicTextSelected() + ": 0, 0"); // Add a KeyUpHandler textBox.addKeyUpHandler(new KeyUpHandler() { public void onKeyUp(KeyUpEvent event) { updateSelectionLabel(textBox, label); } }); // Add a ClickHandler textBox.addClickHandler(new ClickHandler() { public void onClick(ClickEvent event) { updateSelectionLabel(textBox, label); } }); // Add the label to the box hPanel.add(label); } // Return the panel return hPanel; } /** * Update the text in one of the selection labels. * * @param textBox the text box * @param label the label to update */ @ShowcaseSource private void updateSelectionLabel(TextBoxBase textBox, Label label) { label.setText(constants.cwBasicTextSelected() + ": " + textBox.getCursorPos() + ", " + textBox.getSelectionLength()); } }