SWT: A Developer's Notebook

Creating Arrow Buttons

The final style attribute that you can apply to the Button class is SWT.ARROW. SWT.ARROW buttons, as the name implies, display an arrow graphic indicating the direction in which something that will occur when the button is pressed. SWT.ARROW style buttons also need to specify an additional style that determines in which direction the arrow graphic points. Possibilities are SWT.UP, SWT.DOWN, SWT.LEFT, and SWT.RIGHT.

A common use for arrow buttons is to enable the user to increment a value in an associated text box.

How do I do that?

Example 6-2 demonstrates how to use the SWT.ARROW button style in association with a Text field to permit the user to increment a value.

Example 6-2. Using SWT arrow buttons

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.widgets.*;
public class ArrowButtonExample {    
    Display d;
    Shell s;
    ArrowButtonExample( )    {
        d = new Display( );
        s = new Shell(d);
        s.setSize(250,250);
        s.setImage(new Image(d, "c:\\icons\\JavaCup.ico"));
        s.setText("A Button Example");
        final Button b1 = new Button(s, SWT.ARROW | SWT.UP);
        b1.setBounds(100,55,20,15);
        final Button b2 = new Button(s, SWT.ARROW | SWT.DOWN);
        b2.setBounds(100,70,20,15);
        final Text t1 = new Text(s, SWT.BORDER | SWT.SINGLE | SWT.CENTER);
        t1.setBounds(80, 55, 20, 30);
        t1.setText("1");
        t1.selectAll( );
        b1.addSelectionListener(new SelectionAdapter( ) {
            public ...