Eclipse Cookbook

8.9. Creating Composite Widgets

Problem

To create your own custom widget, you need to create a widget that contains other widgets.

Solution

Use a container widget such as a composite widget to create an object from the Composite class. Then add widgets to the composite object as you would to a Shell object.

Discussion

A number of widgets, such as composite widgets, are designed to hold other widgets, which enables you to build composite widgets. Example 8-7 displays a composite widget (CompositeApp at this book’s site). In this case, we’ll display the same labels that we displayed using a grid layout, but in a shell in a composite widget instead. First, we create a composite widget and install a grid layout in it:

final Composite composite = new Composite(shell, SWT.NONE);
GridLayout gridLayout = new GridLayout( );
gridLayout.numColumns = 4;
composite.setLayout(gridLayout);

Now treat the composite widget as a container, just like a shell, and add the label widgets to it, as shown in Example 8-7.

Example 8-7. Using composite widgets

package org.cookbook.ch08; import org.eclipse.swt.*; import org.eclipse.swt.layout.*; import org.eclipse.swt.widgets.*; public class CompositeClass { public static void main (String [] args) { Display display = new Display ( ); final Shell shell = new Shell (display); shell.setSize(300, 300); shell.setLayout(new RowLayout( )); shell.setText("Composite Example"); final Composite composite = new Composite(shell, SWT.NONE); GridLayout gridLayout = new GridLayout( ...