GWT - Anchor Widget

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Introduction

The Anchor widget that represents a simple <a> element.

Class declaration

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

public class Anchor
   extends FocusWidget
      implements HasHorizontalAlignment, HasName,
	     HasHTML, HasWordWrap, HasDirection

CSS style rules

Following default CSS Style rule will be applied to all the Image widget. You can override it as per your requirements.

.gwt-Anchor { }

Class constructors

S.N.Constructor & Description
1Anchor()
Creates an empty anchor.
2protected Anchor(Element element)
This constructor may be used by subclasses to explicitly use an existing element.
3Anchor(java.lang.String text)
Creates an anchor for scripting.
4Anchor(java.lang.String text, boolean asHtml)
Creates an anchor for scripting.
5Anchor(java.lang.String text, boolean asHTML, java.lang.String href)
Creates an anchor with its text and href (target URL) specified.
6Anchor(java.lang.String text, boolean asHtml, java.lang.String href, java.lang.String target)
Creates a source anchor (link to URI).
7Anchor(java.lang.String text, java.lang.String href)
Creates an anchor with its text and href (target URL) specified.
8Anchor(java.lang.String text, java.lang.String href, java.lang.String target)
Creates a source anchor with a frame target.

Class methods

S.N.Function name & Description
1HasDirection.Direction getDirection()
Gets the directionality of the widget.
2HasHorizontalAlignment.HorizontalAlignmentConstant getHorizontalAlignment()
Gets the horizontal alignment.
3java.lang.String getHref()
Gets the anchor's href (the url to which it links).
4java.lang.String getHTML()
Gets this object's contents as HTML.
5java.lang.String getName()
Gets the widget's name.
6int getTabIndex()
Gets the widget's position in the tab index.
7java.lang.String getTarget()
Gets the anchor's target frame (the frame in which navigation will occur when the link is selected).
8java.lang.String getText()
Gets this object's text.
9boolean getWordWrap()
Gets whether word-wrapping is enabled.
10void setAccessKey(char key)
Sets the widget's 'access key'.
11void setFocus(boolean focused)
Explicitly focus/unfocus this widget.
12void setHorizontalAlignment(HasHorizontalAlignment.HorizontalAlignmentConstant align)
Sets the horizontal alignment.
13void setHref(java.lang.String href)
Sets the anchor's href (the url to which it links).
14void setHTML(java.lang.String html)
Sets this object's contents via HTML.
15void setName(java.lang.String name)
Sets the widget's name.
16void setTabIndex(int index)
Sets the widget's position in the tab index.
17void setText(java.lang.String text)
Sets this object's text.
18void setWordWrap(boolean wrap)
Sets whether word-wrapping is enabled.
19static Anchor wrap(Element element)
Creates an Anchor widget that wraps an existing <a> element.

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.FocusWidget

Anchor Widget Example

This example will take you through simple steps to show usage of a Anchor 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;
}

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>Anchor 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 Anchor widget.

package com.tutorialspoint.client;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.user.client.ui.Anchor;
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 a Anchor widget, 
      // pass text as TutorialsPoint  
      // set asHtml as false, 
      // href as www.tutorialspoint.com, 
      // target as _blank
      Anchor anchor = new Anchor("TutorialsPoint",
                                 false,
                                 "http://www.tutorialspoint.com",
                                 "_blank");
      // Add anchor to the root panel.
      VerticalPanel panel = new VerticalPanel();
      panel.add(anchor);

      RootPanel.get("gwtContainer").add(panel);
   }	
}

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 Anchor Widget

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