Together with Plug, Socket provides the ability to embed widgets from
one process into another process in a fashion that is transparent to the
user. One process creates a Socket widget and, passes the that widget's
window ID to the other process, which then creates a Plug with that window
ID. Any widgets contained in the Plug then will appear inside the first
The socket's window ID is obtained by using socketGetId. Before using
this function, the socket must have been realized, and for hence, have been
added to its parent.
- Obtaining the window ID of a socket.
socket <- socketNew
containerAdd parent socket
-- The following call is only necessary if one of
-- the ancestors of the socket is not yet visible.
socketId <- socketGetId socket
putStrLn ("The ID of the sockets window is " ++ show socketId)
Note that if you pass the window ID of the socket to another process that
will create a plug in the socket, you must make sure that the socket widget
is not destroyed until that plug is created. Violating this rule will cause
unpredictable consequences, the most likely consequence being that the plug
will appear as a separate toplevel window. You can check if the plug has
been created by calling socketHasPlug.
If this returns True, then the plug has been successfully created inside
of the socket.
When Gtk+ is notified that the embedded window has been destroyed, then
it will destroy the socket as well. You should always, therefore, be
prepared for your sockets to be destroyed at any time when the main event
loop is running.
The communication between a Socket and a Plug follows the XEmbed
protocol. This protocol has also been implemented in other toolkits, e.g.
Qt, allowing the same level of integration when embedding a Qt widget in
Gtk+ or vice versa.