import org.eclipse.swt.graphics.GC; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; public class PaintWindowGCShell { public static void main(String[] args) { Display display = new Display(); Shell shell = new Shell(display); shell.open(); GC gc = new GC(shell); gc.setLineWidth(4); gc.drawRectangle(20, 20, 100, 100); gc.dispose(); while (!shell.isDisposed()) { if (!display.readAndDispatch()) display.sleep(); } display.dispose(); } }