public void setText (String value) {
	checkWidget ();
	if (value == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
	if (value.equals (super.getText ())) return;					/* same value */
	super.setText (value);
	GC gc = new GC (parent);
	computeDisplayText (gc);
	gc.dispose ();
	if (parent.drawCount <= 0 && parent.getHeaderVisible ()) {
		/* don't damage the header's drawn borders */
		parent.header.redraw (getX (), 1, width - 2, parent.getHeaderHeight () - 3, false);
	}
}