Org Eclipse Swt Graphics Java by API

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.PaintEvent;
import org.eclipse.swt.events.PaintListener;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Canvas;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
public class MainClass {
  public static void main(String[] a) {
    final Display d = new Display();
    final Shell shell = new Shell(d);
    shell.setSize(250, 200);
    shell.setLayout(new FillLayout());
    // Create a canvas
    Canvas canvas = new Canvas(shell, SWT.NONE);
    canvas.addPaintListener(new PaintListener() {
      public void paintControl(PaintEvent e) {
        // Do some drawing
        Rectangle rect = ((Canvas) e.widget).getBounds();
        e.gc.setForeground(e.display.getSystemColor(SWT.COLOR_RED));
        e.gc.drawFocus(5, 5, rect.width - 10, rect.height - 10);
        e.gc.drawText("www.rntsoft.com", 5, 50, SWT.DRAW_MNEMONIC | SWT.DRAW_DELIMITER
            | SWT.DRAW_TAB | SWT.DRAW_TRANSPARENT);
      }
    });    
    
    
    shell.open();
    while (!shell.isDisposed()) {
      if (!d.readAndDispatch())
        d.sleep();
    }
    d.dispose();
  }
}