How to use

copyMarkedRegion

method

in

org.eclipse.jface.text.TextViewer

case CUT:
  if (!fTextWidget.isTextSelected())
    copyMarkedRegion(true);
  else
    wrapCompoundChange(() -> fTextWidget.cut());
case COPY:
  if (!fTextWidget.isTextSelected())
    copyMarkedRegion(false);
  else
    fTextWidget.copy();

case CUT:
  if (!fTextWidget.isTextSelected())
    copyMarkedRegion(true);
  else
    wrapCompoundChange(new Runnable() {
case COPY:
  if (!fTextWidget.isTextSelected())
    copyMarkedRegion(false);
  else
    fTextWidget.copy();