docs: def _on_wheel_event(self, event):
          """
          Increments or decrements editor fonts settings on mouse wheel event
          if ctrl modifier is on.
  
          :param event: wheel event
          :type event: QWheelEvent
          """
          try:
              delta = event.angleDelta().y()
          except AttributeError:
              # PyQt4/PySide
              delta = event.delta()
          if int(event.modifiers()) & QtCore.Qt.ControlModifier > 0:
              if delta < self.prev_delta:
                  self.editor.zoom_out()
                  event.accept()
              else:
                  self.editor.zoom_in()
                  event.accept()