public void redrawCaret(boolean focus)
    {
        drawUnfocusedCaret(false);
        setCaretsSize(focus ? (!isInserting) : isInserting);
        if (isInserting && upANibble != 0) {
            upANibble = 0;
            refreshCaretsPosition();
            if (focus) setFocus();
        } else {
            drawUnfocusedCaret(true);
        }
//        if (focus) notifyListeners(SWT.Modify, null);
    }
redraw the caret with respect of Inserting/Overwriting mode
plugins/org.jkiss.dbeaver.ui.editors.hex/src/org/jkiss/dbeaver/ui/editors/binary/HexEditControl.java