Informs the editor client that the user requested a popup menu in
the given editor pane, at the location specified in the
mouseEvent. The client is responsible for building/populating
the popup menus (if necessary), and making it visible.
Parameters:
mouseEvent - the mouse event describing the location of the
popup request.
hidePopup
void hidePopup()
Informs the editor client that the popup menu (if showing) should
now be hidden. This may be in response to some user input or event.