Display display = this.display;
protected void checkWidget () {	Display display = this.display;	if (display == null) DND.error (SWT.ERROR_WIDGET_DISPOSED);	if (display.getThread() != Thread.currentThread ()) DND.error (SWT.ERROR_THREAD_INVALID_ACCESS);	if (display.isDisposed()) DND.error(SWT.ERROR_WIDGET_DISPOSED);}