-- --
-- package Copyright (c) Dmitry A. Kazakov --
-- Gtk.Handlers.References Luebeck --
-- Interface Spring, 2007 --
-- --
-- Last revision : 13:51 30 May 2014 --
-- --
-- This library is free software; you can redistribute it and/or --
-- modify it under the terms of the GNU General Public License as --
-- published by the Free Software Foundation; either version 2 of --
-- the License, or (at your option) any later version. This library --
-- is distributed in the hope that it will be useful, but WITHOUT --
-- ANY WARRANTY; without even the implied warranty of --
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU --
-- General Public License for more details. You should have --
-- received a copy of the GNU General Public License along with --
-- this library; if not, write to the Free Software Foundation, --
-- Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. --
-- --
-- As a special exception, if other files instantiate generics from --
-- this unit, or you link this unit with other files to produce an --
-- executable, this unit does not by itself cause the resulting --
-- executable to be covered by the GNU General Public License. This --
-- exception does not however invalidate any other reasons why the --
-- executable file might be covered by the GNU Public License. --
--____________________________________________________________________--
--
-- This package provides a simplified way of disconnecting the signal
-- handlers when the handler callback depends on the life time of not
-- only the object which emits the signal, but also some other object.
-- The parent package provides Object_Connect for this, but it is
-- limited to widget objects. This package allows to disconnect upon
-- finalization of any Ada object. The package declares a controlled
-- type Handler_Reference. This type can be bound to a signal handler
-- ID as returned by the Connect functions. Upon finalization of
-- Handler_Reference the callback will be disconnected. Note that that
-- differently to strong reference counting disconnection is
-- non-additive. That is when several Handler_Reference objects refer
-- to the same callback, finalization of any of them disconnects the
-- callback.
--
with Ada.Finalization;
package Gtk.Handlers.References is
--
-- Handler_Reference -- Reference to a callback handler
--
type Handler_Reference is
new Ada.Finalization.Controlled with private;
--
-- Get -- Callback identification as given by Connect
--
-- Reference - To the callback
--
-- Returns :
--
-- The callback identification
--
function Get (Reference : Handler_Reference) return Handler_ID;
--
-- Set -- Reference to callback
--
-- Reference - To be set
-- [ Handler ] - The callback identification
--
-- The parameter ID is typically the return value of a call to Connect.
-- When Reference is already set to a different callback handler the
-- latter is disconnected first. When Handler is omitted the reference
-- is reset.
--
procedure Set
( Reference : in out Handler_Reference;
Handler : Handler_ID
);
procedure Set (Reference : in out Handler_Reference);
private
type Handler_Reference is
new Ada.Finalization.Controlled with
record
ID : Gulong := Null_Handler_ID;
Closure : GClosure;
end record;
procedure Adjust (Reference : in out Handler_Reference);
procedure Finalize (Reference : in out Handler_Reference);
end Gtk.Handlers.References;