if ((parent.style & SWT.VIRTUAL) != 0) cached = true;
public void setBackground (Color value) {	checkWidget ();	if (value != null && value.isDisposed ()) {		SWT.error (SWT.ERROR_INVALID_ARGUMENT);	}	if (background == value) return;	if (background != null && background.equals (value)) return;	background = value;	redrawItem ();}