public void removeVerifyKeyListener(EventHandler<VerifyEvent> verifyKeyListener) {
// if (fContentAssistSubjectControl != null) {
// fContentAssistSubjectControl.removeVerifyKeyListener(verifyKeyListener);
// } else
if (viewer instanceof ITextViewerExtension) {
ITextViewerExtension extension= (ITextViewerExtension) viewer;
extension.removeVerifyKeyListener(verifyKeyListener);
} else {
StyledTextArea textWidget= viewer.getTextWidget();
// if (Helper.okToUse(textWidget))
textWidget.removeEventHandler(VerifyEvent.VERIFY, verifyKeyListener);
}