GWT - HorizantalPanel Widget

Advertisements


Introduction

The HorizantalPanel widget represents a panel that lays all of its widgets out in a single horizontal column.

Class declaration

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

public class HorizontalPanel
   extends CellPanel
      implements HasAlignment, InsertPanel.ForIsWidget

Class constructors

S.N.Constructor & Description
1HorizontalPanel()
Constructor for empty horizontal Panel.

Class methods

S.N.Function name & Description
1void add(Widget w)
Adds a child widget.
2HasHorizontalAlignment.HorizontalAlignmentConstant getHorizontalAlignment()
Gets the horizontal alignment.
3HasVerticalAlignment.VerticalAlignmentConstant getVerticalAlignment()
Gets the vertical alignment.
4void insert(IsWidget w, int beforeIndex)
5void insert(Widget w, int beforeIndex)
Inserts a child widget before the specified index.
6protected void onEnsureDebugId(java.lang.String baseID)
Affected Elements: -# = the cell at the given index.
7boolean remove(Widget w)
Removes a child widget.
8void setHorizontalAlignment(HasHorizontalAlignment.HorizontalAlignmentConstant align)
Sets the default horizontal alignment to be used for widgets added to this panel.
9void setVerticalAlignment(HasVerticalAlignment.VerticalAlignmentConstant 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

HorizontalPanel Widget Example

This example will take you through simple steps to show usage of a HorizontalPanel 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;
}
.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>HorizontalPanel 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 HorizontalPanel 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.HorizontalPanel;
import com.google.gwt.user.client.ui.RootPanel;

public class HelloWorld implements EntryPoint {

   public void onModuleLoad() {
      // Create a horizontal panel			
      HorizontalPanel horizontalPanel = new HorizontalPanel();

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

      DecoratorPanel decoratorPanel = new DecoratorPanel();
      decoratorPanel.setWidth("500");
      decoratorPanel.add(horizontalPanel);

      // 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 HorizontalPanel Widget

Advertisements
Advertisements