GWT - DeckPanel Widget

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Introduction

The DeckPanel widget represents a panel that displays all of its child widgets in a 'deck', where only one can be visible at a time. It is used by TabPanel.

Class declaration

Following is the declaration for com.google.gwt.user.client.ui.DeckPanel class:

public class DeckPanel
   extends ComplexPanel
      implements HasAnimation, InsertPanel.ForIsWidget

Class constructors

S.N.Constructor & Description
1DeckPanel()
Constructor for DeckPanel.

Class methods

S.N.Function name & Description
1void add(Widget w)
Adds a child widget.
2int getVisibleWidget()
Gets the index of the currently-visible widget.
3void insert(IsWidget w, int beforeIndex)
4void insert(Widget w, int beforeIndex)
Inserts a child widget before the specified index.
5boolean isAnimationEnabled()
Returns true if animations are enabled, false if not.
6boolean remove(Widget w)
Removes a child widget.
7void setAnimationEnabled(boolean enable)
Enable or disable animations.
8void showWidget(int index)
Shows the widget at the specified index.

Methods inherited

This class inherits methods from the following classes:

  • com.google.gwt.user.client.ui.UIObject

  • com.google.gwt.user.client.ui.Widget

  • com.google.gwt.user.client.ui.Panel

  • com.google.gwt.user.client.ui.ComplexPanel

  • java.lang.Object

DeckPanel Widget Example

This example will take you through simple steps to show usage of a DeckPanel Widget in GWT. Follow the following steps to update the GWT application we created in GWT - Create Application chapter:

StepDescription
1Create a project with a name HelloWorld under a package com.tutorialspoint as explained in the GWT - Create Application chapter.
2Modify HelloWorld.gwt.xml, HelloWorld.css, HelloWorld.html and HelloWorld.java as explained below. Keep rest of the files unchanged.
3Compile and run the application to verify the result of the implemented logic.

Following is the content of the modified module descriptor src/com.tutorialspoint/HelloWorld.gwt.xml.

<?xml version="1.0" encoding="UTF-8"?>
<module rename-to='helloworld'>
  <!-- Inherit the core Web Toolkit stuff.                        -->
  <inherits name='com.google.gwt.user.User'/>

  <!-- Inherit the default GWT style sheet.                       -->
  <inherits name='com.google.gwt.user.theme.clean.Clean'/>

  <!-- Specify the app entry point class.                         -->
  <entry-point class='com.tutorialspoint.client.HelloWorld'/>

  <!-- Specify the paths for translatable code                    -->
  <source path='client'/>
  <source path='shared'/>

</module>

Following is the content of the modified Style Sheet file war/HelloWorld.css.

body{
   text-align: center;
   font-family: verdana, sans-serif;
}
h1{
   font-size: 2em;
   font-weight: bold;
   color: #777777;
   margin: 40px 0px 70px;
   text-align: center;
}
.deckpanel {
  border: 1px solid #BBBBBB;
  padding: 3px;
}

Following is the content of the modified HTML host file war/HelloWorld.html.

<html>
<head>
<title>Hello World</title>
   <link rel="stylesheet" href="HelloWorld.css"/>
   <script language="javascript" src="helloworld/helloworld.nocache.js">
   </script>
</head>
<body>

<h1>DeckPanel Widget Demonstration</h1>
<div id="gwtContainer"></div>

</body>
</html>

Let us have following content of Java file src/com.tutorialspoint/HelloWorld.java which will demonstrate use of DeckPanel widget.

package com.tutorialspoint.client;


import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.DeckPanel;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.VerticalPanel;

public class HelloWorld implements EntryPoint {

   public void onModuleLoad() {
      // Create DeckPanel widget
      final DeckPanel deckPanel = new DeckPanel();
      deckPanel.setSize("300px", "120px");
      deckPanel.setStyleName("deckpanel");
      // Create lables to add to deckpanel
      Label label1 = new Label("This is first Page");
      Label label2 = new Label("This is second Page");
      Label label3 = new Label("This is third Page");
      // Add labels to deckpanel
      deckPanel.add(label1);
      deckPanel.add(label2);
      deckPanel.add(label3);
      //show first label
      deckPanel.showWidget(0);
      //create button bar
      HorizontalPanel buttonBar = new HorizontalPanel();
      buttonBar.setSpacing(5);
      
	  // create button and add click handlers
	  // show different labels on click of different buttons
	  Button button1 = new Button("Page 1");
      button1.addClickHandler(new ClickHandler() {
         @Override
         public void onClick(ClickEvent event) {
            deckPanel.showWidget(0);
         }
      });

      Button button2 = new Button("Page 2");
      button2.addClickHandler(new ClickHandler() {
	     @Override
         public void onClick(ClickEvent event) {
            deckPanel.showWidget(1);
         }
      });

      Button button3 = new Button("Page 3");
      button3.addClickHandler(new ClickHandler() {
         @Override
         public void onClick(ClickEvent event) {
            deckPanel.showWidget(2);
         }
      });

      buttonBar.add(button1);
      buttonBar.add(button2);
      buttonBar.add(button3);

      VerticalPanel vPanel = new VerticalPanel();
      vPanel.add(deckPanel);
      vPanel.add(buttonBar);

      // Add the widgets to the root panel.
      RootPanel.get().add(vPanel);
   }
}

Once you are ready with all the changes done, let us compile and run the application in development mode as we did in GWT - Create Application chapter. If everything is fine with your application, this will produce following result:

GWT DeckPanel Widget

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