public void setToolTipText (String string) {
	checkWidget ();
	if (toolTipText == string) return;
	if (toolTipText != null && toolTipText.equals (string)) return;
	toolTipText = string;
	if (parent.toolTipShell == null) return; /* tooltip not currently showing */
	if (((Integer) parent.toolTipShell.getData ()).intValue () != getIndex ()) return;	/* tooltip showing for different column */
	parent.headerUpdateToolTip (getX () + (width / 2));	/* update the tooltip text */
}