-----------------------------------------------------------------------
-- GtkAda - Ada95 binding for Gtk+/Gnome --
-- --
-- Copyright (C) 1998-2000 E. Briot, J. Brobecker and A. Charlet --
-- Copyright (C) 2000-2003 ACT-Europe --
-- --
-- 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 is the base class of the widget hierarchy.
-- Everything in GtkAda inherits from this class Gtk_Object, except for a few
-- structures in the Gdk.* packages (low-level drawing routines).
--
-- This class provides a set of handful features that you can choose to reuse
-- in your applications:
--
-- - Reference counting: an object is not deleted while there exists at least
-- one reference to it. Although GtkAda mostly takes care of that aspect
-- transparently, you might need in some obscure cases to increment or
-- decrement the reference counting for a widget manually, so that it is not
-- removed from memory while you still need it.
--
-- - User data: any number of data can be attached to a Gtk_Object or one of
-- its children. Theses data are referenced by a String, in a hash-table.
-- GtkAda itself uses this feature to provide an easy conversion between C
-- and Ada widgets.
-- Although you might prefer to have a completely object-oriented
-- application (and thus associate data through class inheritance), it
-- might be convenient to directly attach some data to your objects.
--
-- - It also contains the basic structures and subprograms required for signal
-- emission. This is of course used to implement the signal mechanism in
-- GtkAda itself, but can also be used to implement a Model/View/Controller
-- framework.
--
-- Note that a lot of functions provided in the C interface are not provided
-- here. They are used to emulate an object-oriented language in C, which can
-- of course be done much more conveniently in Ada. Therefore most of these
-- functions are not needed.
--
-- Here is a brief explanation on how the reference counting and destruction
-- process work. You should not have to understand all this to use GtkAda, but
-- it might help anyway.
--
-- When an object (descendant of Gtk.Object) is created, it has initially a
-- ref_count of 1. A flag is set to say the object is "floating". See the
-- Flags functions in this package for how to retrieve the status of this
-- flag.
--
-- When the object gets a parent (ie Gtk.Widget.Set_Parent is called, possibly
-- from other subprograms like Gtk.Container.Add, Gtk.Box.Pack_Start, ...),
-- the ref_count of the object is incremented to 2.
-- If the object was still "floating", it is also "sinked", ie its ref_count
-- is decremented to 1, and the "floating" flag is cleared.
--
-- The same behavior as above happens when the object is registered as a
-- top-level widget (i.e. we know it won't have any parent).
--
-- Thus the normal life cycle of an object is to have a ref_count to 1, and
-- not be a "floating" object.
--
-- When the object is destroyed, the following happens:
-- A temporary reference to the object is created (call to Ref), and
-- ref_count to 2.
-- The object is shutdown:
-- It is removed from its parent (if any), and its ref_count is
-- decremented to 1.
-- The "destroy" signal is emitted, the user's handlers are called,
-- and then all the handlers connected to the object are destroyed.
-- The object is unref-ed. If its ref_count goes down to 0 (normal case),
-- the memory used by the object and its user_data is freed.
--
--
-- 1.3.11
with Glib.Object;
with Glib.Properties;
with Gtkada.Types;
package Gtk.Object is
type Gtk_Object_Record is new Glib.Object.GObject_Record with private;
type Gtk_Object is access all Gtk_Object_Record'Class;
procedure Sink (Object : access Gtk_Object_Record);
-- Sink the object.
-- If the object is floating (does not have a parent yet), it is unref-ed
-- once and the floating flag is cleared.
procedure Destroy (Object : access Gtk_Object_Record);
-- Destroy the object.
-- This emits a "destroy" signal, calls all your handlers, and then
-- unconnects them all. The object is then unref-ed, and if its reference
-- count goes down to 0, the memory associated with the object and its
-- user data is freed.
-- Note that when you destroy handlers are called, the user_data is still
-- available.
function Get_Type return Gtk.Gtk_Type;
-- Return the internal value associated with a Gtk_Object internally.
pragma Import (C, Get_Type, "gtk_object_get_type");
function Get_Type (Object : access Gtk_Object_Record) return Gtk_Type;
-- This function is now obsolete, and is temporarily kept for backward
-- compatibility only. Use Glib.Object.Get_Type instead.
-- ???
-----------
-- Flags --
-----------
-- Each object is associated with a set of flags, that reports the state
-- of the object.
-- The following flags are known by all objects:
--
-- - "Destroyed":
-- Set if the object is marked as destroyed (if its reference count is
-- not yet 0, the memory has not been freed, but you should not use it
-- anyway).
--
-- - "Floating":
-- The object has no parent yet, since it was just created. Its
-- reference count is still 1 (as it was initially). This flag is
-- cleared as soon as Set_Parent is called on the widget or the widget
-- is qualified as a toplevel widget (see
-- Gtk.Container.Register_Toplevel).
In_Destruction : constant := 2 ** 0;
Floating : constant := 2 ** 1;
Reserved_1 : constant := 2 ** 2;
Reserved_2 : constant := 2 ** 3;
function Flags (Object : access Gtk_Object_Record) return Guint32;
-- Return the flags that are set for the object, as a binary mask.
procedure Set_Flags (Object : access Gtk_Object_Record; Flags : Guint32);
-- Set some specific flags for the object.
-- Flags is a mask that will be added to the current flags of the object.
procedure Unset_Flags (Object : access Gtk_Object_Record; Flags : Guint32);
-- Unset some specific flags for the object.
-- Flags is a mask that will be deleted from the current flags of the
-- object.
function Flag_Is_Set
(Object : access Gtk_Object_Record; Flag : Guint32) return Boolean;
-- Return True if the specific flag Flag is set for the object.
function In_Destruction_Is_Set
(Object : access Gtk_Object_Record'Class) return Boolean;
-- Test if the Destroyed flag is set for the object.
--
function Destroyed_Is_Set (Object : access Gtk_Object_Record'Class)
return Boolean renames In_Destruction_Is_Set;
-- backward compatibility only
--
function Floating_Is_Set
(Object : access Gtk_Object_Record'Class) return Boolean;
-- Test if the Floating flag is set for the object.
--------------------------
-- Creating new widgets --
--------------------------
--
-- The following definitions are only provided for better backward
-- compatibility. You should use Glib.Object directly.
subtype GObject_Class is Glib.Object.GObject_Class;
Uninitialized_Class : GObject_Class renames
Glib.Object.Uninitialized_Class;
subtype Signal_Parameter_Types is Glib.Object.Signal_Parameter_Types;
Null_Parameter_Types : Signal_Parameter_Types renames
Glib.Object.Null_Parameter_Types;
procedure Initialize_Class_Record
(Object : access GObject_Record'Class;
Signals : Gtkada.Types.Chars_Ptr_Array;
Class_Record : in out GObject_Class;
Type_Name : String;
Parameters : Signal_Parameter_Types := Null_Parameter_Types)
renames Glib.Object.Initialize_Class_Record;
--
---------------
-- User Data --
---------------
-- It is possible to associate your own specific data with an existing
-- object. See the documentation in Glib.Object.
-- The declaration below has been kept for compatibility reasons.
generic
package User_Data renames Glib.Object.User_Data;
----------------
-- Properties --
----------------
--
-- The following properties are defined for this widget. See
-- Glib.Properties for more information on properties.
--
-- - Name: User_Data_Property
-- Type: Pointer
-- Flags: read-write
-- Descr: Anonymous User Data Pointer
-- See also: User_Data.Set, using the default Id "user_data"
--
--
User_Data_Property : constant Glib.Properties.Property_Address;
-------------
-- Signals --
-------------
--
-- The following new signals are defined for this widget:
--
-- - "destroy"
-- procedure Handler (Object : access Gtk_Object_Record'Class);
--
-- Raised when the object is about to be destroyed. The "destroyed"
-- flag has been set on the object first. Handlers should not keep
-- a reference on the object.
-- Note that when your destroy handlers are called, the user_data is
-- still available.
-- The default implementation destroys all the handlers.
--
private
type Gtk_Object_Record is new Glib.Object.GObject_Record with null record;
User_Data_Property : constant Glib.Properties.Property_Address :=
Glib.Properties.Build ("user_data");
pragma Inline (Floating_Is_Set);
pragma Inline (In_Destruction_Is_Set);
end Gtk.Object;