docs: def show(self, fromQtmacs: bool=False):
          """
          Overloaded ``show()`` function to avoid calling it
          accidentally.
  
          This method is a (weak) security mechanism to prevent
          programmers from using the ``show`` method as originally
          intended by Qt, ie. to show a window. In Qtmacs, applets can
          only be made visible with either ``qteMakeAppletActive`` or by
          replacing another window in the layout with eg
          ``qteReplaceWindowInLayout``. Using the Qt native ``show()``
          method messes with the Qtmacs layout engine and can lead to
          unexpected visual results and more serious errors.
  
          This method should only be used by ``QtmacsMain`` to implement
          the layout but not by any applets or macros, unless it is for
          a widget not under the control of Qtmacs (probably a bad
          idea).
  
          The user should call the ``qteNewApplet`` method to create and
          show a applet.
  
          |Args|
  
          * ``fromQtmacs`` (**bool**): if **True** then the original
            ``show()`` method is called
  
          |Returns|
  
          * **None**
  
          |Raises|
  
          * **QtmacsArgumentError** if at least one argument has an invalid type.
          """
          if not fromQtmacs:
              # Log a warning message if someone tries to call the
              # native show() method.
              msg = 'show() command for applet <b>{}</b> ignored. '
              msg += ' Use qteNewApplet instead.'.format(self.qteAppletID())
              self.qteLogger.warning(msg)
          else:
              # Sanity check: the parent of this applet *must* be a
              # ``QtmacsLayoutSplitter`` as otherwise it cannot be
              # shown.
              sig_ = self.parent()._qteAdmin.widgetSignature
              if sig_ != '__QtmacsLayoutSplitter__':
                  msg = 'show() command for applet <b>{}</b> ignored'
                  msg = msg.format(self.qteAppletID())
                  msg += ' because its parent is not a '
                  msg += 'QtmacsLayoutSplitter --> Bug.'
                  return
  
              # Before the applet is actually shown update the
              # ``parentWindow`` reference in the admin structure. To
              # obtain this reference, query the parent of this very
              # applet (which is a QtmacsSplitter instance) for its
              # parent window since both must necessarily be shown in
              # the same window and thus have the same parent window.
              self._qteAdmin.parentWindow = self.parent().qteParentWindow()
  
              # Update the Qtmacs internal visibility flag (used in the
              # focus manager to ensure that Qt and Qtmacs agree on
              # which applets are visible and which are not) and then
              # tell Qt to make the applet visible once the event loop
              # regains control.
              self._qteAdmin.isVisible = True
              QtGui.QWidget.show(self)