GWT - VerticalPanel Widget

Introduction

The VerticalPanel widget represents a panel that lays all of its widgets out in a single vertical row.

Class Declaration

Following is the declaration for com.google.gwt.user.client.ui.VerticalPanel class −

public class VerticalPanel
   extends CellPanel
      implements HasAlignment, InsertPanel.ForIsWidget

Class Constructors

Sr.No.	Constructor & Description
1	VerticalPanel() Constructor for empty vertical Panel.

Class Methods

Sr.No.	Function name & Description
1	void add(Widget w) Adds a child widget.
2	Has Horizontal Alignment. Horizontal Alignment Constant get Horizontal Alignment() Gets the horizontal alignment.
3	HasVerticalAlignment.VerticalAlignmentConstant getVerticalAlignment() Gets the vertical alignment.
4	void insert(IsWidget w, int beforeIndex)
5	void insert(Widget w, int beforeIndex) Inserts a child widget before the specified index.
6	protected void onEnsureDebugId(java.lang.String baseID) Affected Elements: -# = the cell at the given index.
7	boolean remove(Widget w) Removes a child widget.
8	void set Horizontal Alignment (Has Horizontal Alignment.Horizontal Alignment Constant align) Sets the default horizontal alignment to be used for widgets added to this panel.
9	void set Vertical Alignment (Has Vertical Alignment.Vertical Alignment Constant align) Sets the default vertical alignment to be used for widgets added to this panel.

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
com.google.gwt.user.client.ui.CellPanel
java.lang.Object

VerticalPanel Widget Example

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

Step	Description
1	Create a project with a name HelloWorld under a package com.tutorialspoint as explained in the GWT - Create Application chapter.
2	Modify HelloWorld.gwt.xml, HelloWorld.css, HelloWorld.html and HelloWorld.java as explained below. Keep rest of the files unchanged.
3	Compile 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;
}

.gwt-CheckBox {
   margin: 10px;	
}

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>VerticalPanel 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 VerticalPanel widget.

package com.tutorialspoint.client;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.user.client.ui.CheckBox;
import com.google.gwt.user.client.ui.DecoratorPanel;
import com.google.gwt.user.client.ui.VerticalPanel;
import com.google.gwt.user.client.ui.RootPanel;

public class HelloWorld implements EntryPoint {

   public void onModuleLoad() {
      // Create a vertical panel			
      VerticalPanel verticalPanel = new VerticalPanel();

      // Add CheckBoxes to vertical Panel
      for(int i = 1;  i <= 10; i++){
         CheckBox checkBox = new CheckBox("Item" + i);
         verticalPanel.add(checkBox);
      }

      DecoratorPanel decoratorPanel = new DecoratorPanel();
      decoratorPanel.add(verticalPanel);

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

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_layout_panels.htm