XWT Documentation

What it is?

XWT is a declarative UI designed for Eclipse. It is a powerful and lightweight framework. It uses XML as UI markup language.

XWT simplifies UI programming. You can create visible UI elements in the declarative XML markup with a physical separation of the UI definition from the run-time logic. An XML based declarative language is very intuitive for creating interfaces ranging from prototype to production, especially for people with a background in web design and technologies.

Overview

Getting started

Here is a simple example.

<Shell xmlns="http://www.eclipse.org/xwt/presentation"
    xmlns:x="http://www.eclipse.org/xwt">
    <Shell.layout>
       <FillLayout/>
    </Shell.layout>
    <Button text="Hello, world!">
    </Button>
</Shell>

The same UI can be developed in Java corresponding:

Shell parent = new Shell();
parent.setLayout(new FillLayout());
Button button = new Button(parent, SWT.NONE);
button.setText("Hello, world!");

To load and start a simple application, we use the class XWT:

Shell shell = XWT.load(file).getShell();
shell.pack();
shell.open();
while (!shell.isDisposed()) {
   if (!shell.getDisplay().readAndDispatch()) {
	shell.getDisplay().sleep();
   }
}

It is possible to load a UI resource under a Composite:

XWT.load(parent, uri);

Event Handling

In the previous example, we just rewrite Java code in XML. This example illustrates the separation between UI and event handling.

The appearance is defined in XWT.

<Shell xmlns="http://www.eclipse.org/xwt/presentation"
    xmlns:x="http://www.eclipse.org/xwt"
    x:Class="ui.EventHandler">
    <Shell.layout>
       <GridLayout/>
    </Shell.layout>
    <Button text="Click Me!" SelectionEvent="clickButton">
    </Button>
</Shell>

The extension attribute x:Class declares the Java class to handle all events. The Button event is handled by clickButton method in the class ui.EventHandler. The association is setup during the loading:

package ui;
import org.eclipse.swt.Event;
import org.eclipse.swt.Button;
 
public class EventHandler {
    protected void clickButton(Event event) {
        Button button = (Button )event.widget;
        button.setText("Hello, world!");
    }
}

When the button gets selected, the method clickButton is invoked to change the Button text to "Hello, world!".

Reusable Component

This tutorial will shows how to develop a reusable UI component.