class TGMenuEntry: public TObject

TGMenuBar, TGPopupMenu, TGMenuTitle and TGMenuEntry

The TGMenu.h header contains all different menu classes.

The TGMenuBar class implements a menu bar widget. It is used to
specify and provide access to common and frequently used application
actions grouped under menu titles (TGMenuTitle class). The menu bar
takes the highest-level of the menu system and it is a starting
point for many interactions. It is always visible and allows using
the keyboard equivalents. The geometry of the menu bar is
automatically set to the parent widget, i.e. the menu bar
automatically resizes itself so that it has the same width as its
parent (typically TGMainFrame). A menu bar contains one or more
popup menus and usually is placed along the top of the application
window. Any popup menu is invisible until the user invokes it by
using the mouse pointer or the keyboard.

Popup menus implemented by TGPopupMenu class are unique in that,
by convention, they are not placed with the other GUI components in
the user interfaces. Instead, a popup menu usually appears either in
a menu bar or as a context menu on the TOP of the GUI. For that
reason it needs gClient->GetDefaultRoot() as a parent to get the
pointer to the root (i.e. desktop) window. This way a popup menu
will never be embedded.
NOTE: Using gClient->GetRoot() as a parent of TGPopupMenu will not
avoid the possibility of embedding the corresponding popup menu
because the current window hierarchy can be changed by using
gClient->SetRoot() method.

As a context menus TGPopupMenu shows up after pressing the right
mouse button, over a popup-enabled component. The popup menu then
appears under the mouse pointer.

Selecting a menu item will generate the event:
kC_COMMAND, kCM_MENU, menu id, user data.