CwBasicText.java example

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google-web-toolkit-svnmirror-master
/*
 * 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());
  }
}