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126 | -- --
-- package Copyright (c) Dmitry A. Kazakov --
-- GLib.Object.Strong_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 generic package provides a easier way of using GTK references.
-- It provides a controlled type Strong_Reference encapsulating GTK+
-- reference. When set to an object it calls to Ref. When finalized it
-- calls to Unref. Strong_Reference can be used to prevent a GTK+
-- object from premature destruction. You can use Strong_Reference when
-- you don't want to derive your widget from a widget container but
-- wish it acted as a container. The type is non-limited, and can be
-- put into widget records.
--
with Ada.Finalization;
generic
type Object_Type is new GObject_Record with private;
package GLib.Object.Strong_References is
--
-- Strong_Reference -- Strong reference to an object
--
type Strong_Reference is
new Ada.Finalization.Controlled with private;
--
-- Adjust -- Assignment
--
-- Reference - Being copied
--
-- When overridden, it must be called from the override.
--
procedure Adjust (Reference : in out Strong_Reference);
--
-- Finalize -- Destruction
--
-- Reference - To destroy
--
-- A derived type is responsible to call to Finalize if it overrides
-- this procedure.
--
procedure Finalize (Reference : in out Strong_Reference);
--
-- Get -- Get the referenced object
--
-- Reference - Object reference
--
-- Returns :
--
-- A pointer to the object, or null, if the reference is invalid
--
function Get (Reference : Strong_Reference)
return access Object_Type'Class;
--
-- Invalidate -- Reset reference
--
-- Reference - Object reference
--
-- The reference becomes invalid. As a result the referenced object can
-- be destroyed.
--
procedure Invalidate (Reference : in out Strong_Reference);
--
-- Is_Invalid -- Check if the reference points to an object
--
-- Reference - Object reference
--
-- Returns :
--
-- True if the reference is valid
--
function Is_Valid (Reference : Strong_Reference) return Boolean;
--
-- Ref -- Get a reference to the object
--
-- Object - The object to reference
--
-- Returns :
--
-- A strong reference to the object
--
function Ref (Object : not null access Object_Type'Class)
return Strong_Reference;
--
-- Set -- To another object
--
-- Reference - Object reference
-- Object - The object to reference
--
-- Nothing happens if Object is already referenced by Reference.
--
procedure Set
( Reference : in out Strong_Reference;
Object : access Object_Type'Class
);
private
pragma Inline (Get, Invalidate, Is_Valid, Ref, Set);
type Object_Ptr is access all Object_Type'Class;
type Strong_Reference is new Ada.Finalization.Controlled with record
Object : Object_Ptr;
end record;
end GLib.Object.Strong_References;
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