package test;

import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.RowLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;

public class DemoFocus {

	public static void main(String[] args) {

		Display display = new Display();
		Shell shell = new Shell(display);
		shell.setLayout(new RowLayout());

		Composite composite = new Composite(shell, SWT.NONE);
		composite.setLayout(new RowLayout());

		final Text text = new Text(composite, SWT.NONE);
		text.setText("Text 1");
		
		text.addListener(SWT.FocusOut, new Listener () {
			public void handleEvent (Event event) {
				if (text.getText().equals("")) {
					System.out.println("You must provide a value for text 1");
					event.doit = false;
					text.forceFocus();
				}
			}			
		});
		/* does not work either
		text.addFocusListener(new FocusAdapter() {
			public void focusLost(FocusEvent event) {
				if (text.getText().equals("")) {
					System.out.println("FOCUSLISTENER You must provide a value for text 1");
					text.forceFocus();
				}				
			}
		});
		*/

		Text text2 = new Text(composite, SWT.NONE);
		text2.setText("Text 2");
		
		shell.pack();
		shell.open();

		while (!shell.isDisposed()) {
			if (!display.readAndDispatch()) {
				display.sleep ();
			}
		}

		display.dispose();
	}
}

text.addListener(SWT.FocusOut, new Listener () {
			public void handleEvent (Event event) {
				if (text.getText().equals("")) {
					System.out.println("You must provide a value for text 1");
					event.doit = false;
					composite.getDisplay().asyncExec(new Runnable() {
					    public void run() {
					    	text.forceFocus();
					    }
					});
					
				}
			}			
		});