text: /* GObject - GLib Type, Object, Parameter and Signal Library
   * Copyright (C) 1998-1999, 2000-2001 Tim Janik and Red Hat, Inc.
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser 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
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser 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.
   */
  #if !defined (__GLIB_GOBJECT_H_INSIDE__) && !defined (GOBJECT_COMPILATION)
  #error "Only <glib-object.h> can be included directly."
  #endif
  
  #ifndef __G_OBJECT_H__
  #define __G_OBJECT_H__
  
  #include        <gobject/gtype.h>
  #include        <gobject/gvalue.h>
  #include        <gobject/gparam.h>
  #include        <gobject/gclosure.h>
  #include        <gobject/gsignal.h>
  
  G_BEGIN_DECLS
  
  /* --- type macros --- */
  /**
   * G_TYPE_IS_OBJECT:
   * @type: Type id to check
   * 
   * Check if the passed in type id is a %G_TYPE_OBJECT or derived from it.
   * 
   * Returns: %FALSE or %TRUE, indicating whether @type is a %G_TYPE_OBJECT.
   */
  #define G_TYPE_IS_OBJECT(type)      (G_TYPE_FUNDAMENTAL (type) == G_TYPE_OBJECT)
  /**
   * G_OBJECT:
   * @object: Object which is subject to casting.
   * 
   * Casts a #GObject or derived pointer into a (GObject*) pointer.
   * Depending on the current debugging level, this function may invoke
   * certain runtime checks to identify invalid casts.
   */
  #define G_OBJECT(object)            (G_TYPE_CHECK_INSTANCE_CAST ((object), G_TYPE_OBJECT, GObject))
  /**
   * G_OBJECT_CLASS:
   * @class: a valid #GObjectClass
   * 
   * Casts a derived #GObjectClass structure into a #GObjectClass structure.
   */
  #define G_OBJECT_CLASS(class)       (G_TYPE_CHECK_CLASS_CAST ((class), G_TYPE_OBJECT, GObjectClass))
  /**
   * G_IS_OBJECT:
   * @object: Instance to check for being a %G_TYPE_OBJECT.
   * 
   * Checks whether a valid #GTypeInstance pointer is of type %G_TYPE_OBJECT.
   */
  #define G_IS_OBJECT(object)         (G_TYPE_CHECK_INSTANCE_TYPE ((object), G_TYPE_OBJECT))
  /**
   * G_IS_OBJECT_CLASS:
   * @class: a #GObjectClass
   * 
   * Checks whether @class "is a" valid #GObjectClass structure of type
   * %G_TYPE_OBJECT or derived.
   */
  #define G_IS_OBJECT_CLASS(class)    (G_TYPE_CHECK_CLASS_TYPE ((class), G_TYPE_OBJECT))
  /**
   * G_OBJECT_GET_CLASS:
   * @object: a #GObject instance.
   * 
   * Get the class structure associated to a #GObject instance.
   *
   * Returns: pointer to object class structure.
   */
  #define G_OBJECT_GET_CLASS(object)  (G_TYPE_INSTANCE_GET_CLASS ((object), G_TYPE_OBJECT, GObjectClass))
  /**
   * G_OBJECT_TYPE:
   * @object: Object to return the type id for.
   * 
   * Get the type id of an object.
   * 
   * Returns: Type id of @object.
   */
  #define G_OBJECT_TYPE(object)       (G_TYPE_FROM_INSTANCE (object))
  /**
   * G_OBJECT_TYPE_NAME:
   * @object: Object to return the type name for.
   * 
   * Get the name of an object's type.
   * 
   * Returns: Type name of @object. The string is owned by the type system and 
   *  should not be freed.
   */
  #define G_OBJECT_TYPE_NAME(object)  (g_type_name (G_OBJECT_TYPE (object)))
  /**
   * G_OBJECT_CLASS_TYPE:
   * @class: a valid #GObjectClass
   * 
   * Get the type id of a class structure.
   * 
   * Returns: Type id of @class.
   */
  #define G_OBJECT_CLASS_TYPE(class)  (G_TYPE_FROM_CLASS (class))
  /**
   * G_OBJECT_CLASS_NAME:
   * @class: a valid #GObjectClass
   * 
   * Return the name of a class structure's type.
   * 
   * Returns: Type name of @class. The string is owned by the type system and 
   *  should not be freed.
   */
  #define G_OBJECT_CLASS_NAME(class)  (g_type_name (G_OBJECT_CLASS_TYPE (class)))
  /**
   * G_VALUE_HOLDS_OBJECT:
   * @value: a valid #GValue structure
   * 
   * Checks whether the given #GValue can hold values derived from type %G_TYPE_OBJECT.
   * 
   * Returns: %TRUE on success.
   */
  #define G_VALUE_HOLDS_OBJECT(value) (G_TYPE_CHECK_VALUE_TYPE ((value), G_TYPE_OBJECT))
  
  /* --- type macros --- */
  /**
   * G_TYPE_INITIALLY_UNOWNED:
   * 
   * The type for #GInitiallyUnowned.
   */
  #define G_TYPE_INITIALLY_UNOWNED	      (g_initially_unowned_get_type())
  /**
   * G_INITIALLY_UNOWNED:
   * @object: Object which is subject to casting.
   * 
   * Casts a #GInitiallyUnowned or derived pointer into a (GInitiallyUnowned*) 
   * pointer. Depending on the current debugging level, this function may invoke
   * certain runtime checks to identify invalid casts.
   */
  #define G_INITIALLY_UNOWNED(object)           (G_TYPE_CHECK_INSTANCE_CAST ((object), G_TYPE_INITIALLY_UNOWNED, GInitiallyUnowned))
  /**
   * G_INITIALLY_UNOWNED_CLASS:
   * @class: a valid #GInitiallyUnownedClass
   * 
   * Casts a derived #GInitiallyUnownedClass structure into a
   * #GInitiallyUnownedClass structure.
   */
  #define G_INITIALLY_UNOWNED_CLASS(class)      (G_TYPE_CHECK_CLASS_CAST ((class), G_TYPE_INITIALLY_UNOWNED, GInitiallyUnownedClass))
  /**
   * G_IS_INITIALLY_UNOWNED:
   * @object: Instance to check for being a %G_TYPE_INITIALLY_UNOWNED.
   * 
   * Checks whether a valid #GTypeInstance pointer is of type %G_TYPE_INITIALLY_UNOWNED.
   */
  #define G_IS_INITIALLY_UNOWNED(object)        (G_TYPE_CHECK_INSTANCE_TYPE ((object), G_TYPE_INITIALLY_UNOWNED))
  /**
   * G_IS_INITIALLY_UNOWNED_CLASS:
   * @class: a #GInitiallyUnownedClass
   * 
   * Checks whether @class "is a" valid #GInitiallyUnownedClass structure of type
   * %G_TYPE_INITIALLY_UNOWNED or derived.
   */
  #define G_IS_INITIALLY_UNOWNED_CLASS(class)   (G_TYPE_CHECK_CLASS_TYPE ((class), G_TYPE_INITIALLY_UNOWNED))
  /**
   * G_INITIALLY_UNOWNED_GET_CLASS:
   * @object: a #GInitiallyUnowned instance.
   * 
   * Get the class structure associated to a #GInitiallyUnowned instance.
   *
   * Returns: pointer to object class structure.
   */
  #define G_INITIALLY_UNOWNED_GET_CLASS(object) (G_TYPE_INSTANCE_GET_CLASS ((object), G_TYPE_INITIALLY_UNOWNED, GInitiallyUnownedClass))
  /* GInitiallyUnowned ia a GObject with initially floating reference count */
  
  
  /* --- typedefs & structures --- */
  typedef struct _GObject                  GObject;
  typedef struct _GObjectClass             GObjectClass;
  typedef struct _GObject                  GInitiallyUnowned;
  typedef struct _GObjectClass             GInitiallyUnownedClass;
  typedef struct _GObjectConstructParam    GObjectConstructParam;
  /**
   * GObjectGetPropertyFunc:
   * @object: a #GObject
   * @property_id: the numeric id under which the property was registered with
   *  g_object_class_install_property().
   * @value: a #GValue to return the property value in
   * @pspec: the #GParamSpec describing the property
   * 
   * The type of the @get_property function of #GObjectClass. 
   */
  typedef void (*GObjectGetPropertyFunc)  (GObject      *object,
                                           guint         property_id,
                                           GValue       *value,
                                           GParamSpec   *pspec);
  /**
   * GObjectSetPropertyFunc:
   * @object: a #GObject
   * @property_id: the numeric id under which the property was registered with
   *  g_object_class_install_property().
   * @value: the new value for the property
   * @pspec: the #GParamSpec describing the property
   * 
   * The type of the @set_property function of #GObjectClass. 
   */
  typedef void (*GObjectSetPropertyFunc)  (GObject      *object,
                                           guint         property_id,
                                           const GValue *value,
                                           GParamSpec   *pspec);
  /**
   * GObjectFinalizeFunc:
   * @object: the #GObject being finalized
   * 
   * The type of the @finalize function of #GObjectClass.
   */
  typedef void (*GObjectFinalizeFunc)     (GObject      *object);
  /**
   * GWeakNotify:
   * @data: data that was provided when the weak reference was established
   * @where_the_object_was: the object being finalized
   * 
   * A #GWeakNotify function can be added to an object as a callback that gets
   * triggered when the object is finalized. Since the object is already being
   * finalized when the #GWeakNotify is called, there's not much you could do 
   * with the object, apart from e.g. using its address as hash-index or the like. 
   */
  typedef void (*GWeakNotify)		(gpointer      data,
  					 GObject      *where_the_object_was);
  /**
   * GObject:
   * 
   * All the fields in the <structname>GObject</structname> structure are private 
   * to the #GObject implementation and should never be accessed directly.
   */
  struct  _GObject
  {
    GTypeInstance  g_type_instance;
    
    /*< private >*/
    volatile guint ref_count;
    GData         *qdata;
  };
  /**
   * GObjectClass:
   * @g_type_class: the parent class
   * @constructor: the @constructor function is called by g_object_new () to 
   *  complete the object initialization after all the construction properties are
   *  set. The first thing a @constructor implementation must do is chain up to the
   *  @constructor of the parent class. Overriding @constructor should be rarely 
   *  needed, e.g. to handle construct properties, or to implement singletons.
   * @set_property: the generic setter for all properties of this type. Should be
   *  overridden for every type with properties. Implementations of @set_property
   *  don't need to emit property change notification explicitly, this is handled
   *  by the type system.
   * @get_property: the generic getter for all properties of this type. Should be
   *  overridden for every type with properties.
   * @dispose: the @dispose function is supposed to drop all references to other 
   *  objects, but keep the instance otherwise intact, so that client method 
   *  invocations still work. It may be run multiple times (due to reference 
   *  loops). Before returning, @dispose should chain up to the @dispose method 
   *  of the parent class.
   * @finalize: instance finalization function, should finish the finalization of 
   *  the instance begun in @dispose and chain up to the @finalize method of the 
   *  parent class.
   * @dispatch_properties_changed: emits property change notification for a bunch
   *  of properties. Overriding @dispatch_properties_changed should be rarely 
   *  needed.
   * @notify: the class closure for the notify signal
   * @constructed: the @constructed function is called by g_object_new() as the
   *  final step of the object creation process.  At the point of the call, all
   *  construction properties have been set on the object.  The purpose of this
   *  call is to allow for object initialisation steps that can only be performed
   *  after construction properties have been set.  @constructed implementors
   *  should chain up to the @constructed call of their parent class to allow it
   *  to complete its initialisation.
   * 
   * The class structure for the <structname>GObject</structname> type.
   * 
   * <example>
   * <title>Implementing singletons using a constructor</title>
   * <programlisting>
   * static MySingleton *the_singleton = NULL;
   * 
   * static GObject*
   * my_singleton_constructor (GType                  type,
   *                           guint                  n_construct_params,
   *                           GObjectConstructParam *construct_params)
   * {
   *   GObject *object;
   *   
   *   if (!the_singleton)
   *     {
   *       object = G_OBJECT_CLASS (parent_class)->constructor (type,
   *                                                            n_construct_params,
   *                                                            construct_params);
   *       the_singleton = MY_SINGLETON (object);
   *     }
   *   else
   *     object = g_object_ref (G_OBJECT (the_singleton));
   * 
   *   return object;
   * }
   * </programlisting></example>
   */
  struct  _GObjectClass
  {
    GTypeClass   g_type_class;
  
    /*< private >*/
    GSList      *construct_properties;
  
    /*< public >*/
    /* seldom overidden */
    GObject*   (*constructor)     (GType                  type,
                                   guint                  n_construct_properties,
                                   GObjectConstructParam *construct_properties);
    /* overridable methods */
    void       (*set_property)		(GObject        *object,
                                           guint           property_id,
                                           const GValue   *value,
                                           GParamSpec     *pspec);
    void       (*get_property)		(GObject        *object,
                                           guint           property_id,
                                           GValue         *value,
                                           GParamSpec     *pspec);
    void       (*dispose)			(GObject        *object);
    void       (*finalize)		(GObject        *object);
    /* seldom overidden */
    void       (*dispatch_properties_changed) (GObject      *object,
  					     guint	   n_pspecs,
  					     GParamSpec  **pspecs);
    /* signals */
    void	     (*notify)			(GObject	*object,
  					 GParamSpec	*pspec);
  
    /* called when done constructing */
    void	     (*constructed)		(GObject	*object);
  
    /*< private >*/
    gsize		flags;
  
    /* padding */
    gpointer	pdummy[6];
  };
  /**
   * GObjectConstructParam:
   * @pspec: the #GParamSpec of the construct parameter
   * @value: the value to set the parameter to
   * 
   * The <structname>GObjectConstructParam</structname> struct is an auxiliary 
   * structure used to hand #GParamSpec/#GValue pairs to the @constructor of
   * a #GObjectClass.
   */
  struct _GObjectConstructParam
  {
    GParamSpec *pspec;
    GValue     *value;
  };
  
  /**
   * GInitiallyUnowned:
   * 
   * All the fields in the <structname>GInitiallyUnowned</structname> structure 
   * are private to the #GInitiallyUnowned implementation and should never be 
   * accessed directly.
   */
  /**
   * GInitiallyUnownedClass:
   * 
   * The class structure for the <structname>GInitiallyUnowned</structname> type.
   */
  
  
  /* --- prototypes --- */
  GType       g_initially_unowned_get_type      (void);
  void        g_object_class_install_property   (GObjectClass   *oclass,
  					       guint           property_id,
  					       GParamSpec     *pspec);
  GParamSpec* g_object_class_find_property      (GObjectClass   *oclass,
  					       const gchar    *property_name);
  GParamSpec**g_object_class_list_properties    (GObjectClass   *oclass,
  					       guint	      *n_properties);
  void        g_object_class_override_property  (GObjectClass   *oclass,
  					       guint           property_id,
  					       const gchar    *name);
  void        g_object_class_install_properties (GObjectClass   *oclass,
                                                 guint           n_pspecs,
                                                 GParamSpec    **pspecs);
  
  void        g_object_interface_install_property (gpointer     g_iface,
  						 GParamSpec  *pspec);
  GParamSpec* g_object_interface_find_property    (gpointer     g_iface,
  						 const gchar *property_name);
  GParamSpec**g_object_interface_list_properties  (gpointer     g_iface,
  						 guint       *n_properties_p);
  
  GType       g_object_get_type                 (void) G_GNUC_CONST;
  gpointer    g_object_new                      (GType           object_type,
  					       const gchar    *first_property_name,
  					       ...);
  gpointer    g_object_newv		      (GType           object_type,
  					       guint	       n_parameters,
  					       GParameter     *parameters);
  GObject*    g_object_new_valist               (GType           object_type,
  					       const gchar    *first_property_name,
  					       va_list         var_args);
  void	    g_object_set                      (gpointer	       object,
  					       const gchar    *first_property_name,
  					       ...) G_GNUC_NULL_TERMINATED;
  void        g_object_get                      (gpointer        object,
  					       const gchar    *first_property_name,
  					       ...) G_GNUC_NULL_TERMINATED;
  gpointer    g_object_connect                  (gpointer	       object,
  					       const gchar    *signal_spec,
  					       ...) G_GNUC_NULL_TERMINATED;
  void	    g_object_disconnect               (gpointer	       object,
  					       const gchar    *signal_spec,
  					       ...) G_GNUC_NULL_TERMINATED;
  void        g_object_set_valist               (GObject        *object,
  					       const gchar    *first_property_name,
  					       va_list         var_args);
  void        g_object_get_valist               (GObject        *object,
  					       const gchar    *first_property_name,
  					       va_list         var_args);
  void        g_object_set_property             (GObject        *object,
  					       const gchar    *property_name,
  					       const GValue   *value);
  void        g_object_get_property             (GObject        *object,
  					       const gchar    *property_name,
  					       GValue         *value);
  void        g_object_freeze_notify            (GObject        *object);
  void        g_object_notify                   (GObject        *object,
  					       const gchar    *property_name);
  void        g_object_notify_by_pspec          (GObject        *object,
  					       GParamSpec     *pspec);
  void        g_object_thaw_notify              (GObject        *object);
  gboolean    g_object_is_floating    	      (gpointer        object);
  gpointer    g_object_ref_sink       	      (gpointer	       object);
  gpointer    g_object_ref                      (gpointer        object);
  void        g_object_unref                    (gpointer        object);
  void	    g_object_weak_ref		      (GObject	      *object,
  					       GWeakNotify     notify,
  					       gpointer	       data);
  void	    g_object_weak_unref		      (GObject	      *object,
  					       GWeakNotify     notify,
  					       gpointer	       data);
  void        g_object_add_weak_pointer         (GObject        *object, 
                                                 gpointer       *weak_pointer_location);
  void        g_object_remove_weak_pointer      (GObject        *object, 
                                                 gpointer       *weak_pointer_location);
  
  /**
   * GToggleNotify:
   * @data: Callback data passed to g_object_add_toggle_ref()
   * @object: The object on which g_object_add_toggle_ref() was called.
   * @is_last_ref: %TRUE if the toggle reference is now the
   *  last reference to the object. %FALSE if the toggle
   *  reference was the last reference and there are now other
   *  references.
   * 
   * A callback function used for notification when the state
   * of a toggle reference changes. See g_object_add_toggle_ref().
   */
  typedef void (*GToggleNotify) (gpointer      data,
  			       GObject      *object,
  			       gboolean      is_last_ref);
  
  void g_object_add_toggle_ref    (GObject       *object,
  				 GToggleNotify  notify,
  				 gpointer       data);
  void g_object_remove_toggle_ref (GObject       *object,
  				 GToggleNotify  notify,
  				 gpointer       data);
  
  gpointer    g_object_get_qdata                (GObject        *object,
  					       GQuark          quark);
  void        g_object_set_qdata                (GObject        *object,
  					       GQuark          quark,
  					       gpointer        data);
  void        g_object_set_qdata_full           (GObject        *object,
  					       GQuark          quark,
  					       gpointer        data,
  					       GDestroyNotify  destroy);
  gpointer    g_object_steal_qdata              (GObject        *object,
  					       GQuark          quark);
  gpointer    g_object_get_data                 (GObject        *object,
  					       const gchar    *key);
  void        g_object_set_data                 (GObject        *object,
  					       const gchar    *key,
  					       gpointer        data);
  void        g_object_set_data_full            (GObject        *object,
  					       const gchar    *key,
  					       gpointer        data,
  					       GDestroyNotify  destroy);
  gpointer    g_object_steal_data               (GObject        *object,
  					       const gchar    *key);
  void        g_object_watch_closure            (GObject        *object,
  					       GClosure       *closure);
  GClosure*   g_cclosure_new_object             (GCallback       callback_func,
  					       GObject	      *object);
  GClosure*   g_cclosure_new_object_swap        (GCallback       callback_func,
  					       GObject	      *object);
  GClosure*   g_closure_new_object              (guint           sizeof_closure,
  					       GObject        *object);
  void        g_value_set_object                (GValue         *value,
  					       gpointer        v_object);
  gpointer    g_value_get_object                (const GValue   *value);
  gpointer    g_value_dup_object                (const GValue   *value);
  gulong	    g_signal_connect_object           (gpointer	       instance,
  					       const gchar    *detailed_signal,
  					       GCallback       c_handler,
  					       gpointer	       gobject,
  					       GConnectFlags   connect_flags);
  
  /*< protected >*/
  void        g_object_force_floating           (GObject        *object);
  void        g_object_run_dispose	      (GObject	      *object);
  
  
  void        g_value_take_object               (GValue         *value,
  					       gpointer        v_object);
  GLIB_DEPRECATED_FOR(g_value_take_object)
  void        g_value_set_object_take_ownership (GValue         *value,
                                                 gpointer        v_object);
  
  GLIB_DEPRECATED
  gsize	    g_object_compat_control	      (gsize	       what,
  					       gpointer	       data);
  
  /* --- implementation macros --- */
  #define G_OBJECT_WARN_INVALID_PSPEC(object, pname, property_id, pspec) \
  G_STMT_START { \
    GObject *_object = (GObject*) (object); \
    GParamSpec *_pspec = (GParamSpec*) (pspec); \
    guint _property_id = (property_id); \
    g_warning ("%s: invalid %s id %u for \"%s\" of type `%s' in `%s'", \
               G_STRLOC, \
               (pname), \
               _property_id, \
               _pspec->name, \
               g_type_name (G_PARAM_SPEC_TYPE (_pspec)), \
               G_OBJECT_TYPE_NAME (_object)); \
  } G_STMT_END
  /**
   * G_OBJECT_WARN_INVALID_PROPERTY_ID:
   * @object: the #GObject on which set_property() or get_property() was called
   * @property_id: the numeric id of the property
   * @pspec: the #GParamSpec of the property
   * 
   * This macro should be used to emit a standard warning about unexpected 
   * properties in set_property() and get_property() implementations.
   */
  #define G_OBJECT_WARN_INVALID_PROPERTY_ID(object, property_id, pspec) \
      G_OBJECT_WARN_INVALID_PSPEC ((object), "property", (property_id), (pspec))
  
  void    g_clear_object (volatile GObject **object_ptr);
  #define g_clear_object(object_ptr) \
    G_STMT_START {                                                             \
      /* Only one access, please */                                            \
      gpointer *_p = (gpointer) (object_ptr);                                  \
      gpointer _o;                                                             \
                                                                               \
      do                                                                       \
        _o = g_atomic_pointer_get (_p);                                        \
      while G_UNLIKELY (!g_atomic_pointer_compare_and_exchange (_p, _o, NULL));\
                                                                               \
      if (_o)                                                                  \
        g_object_unref (_o);                                                   \
    } G_STMT_END
  
  typedef struct {
      /*<private>*/
      union { gpointer p; } priv;
  } GWeakRef;
  
  void     g_weak_ref_init       (GWeakRef *weak_ref,
                                  gpointer  object);
  void     g_weak_ref_clear      (GWeakRef *weak_ref);
  gpointer g_weak_ref_get        (GWeakRef *weak_ref);
  void     g_weak_ref_set        (GWeakRef *weak_ref,
                                  gpointer  object);
  
  G_END_DECLS
  
  #endif /* __G_OBJECT_H__ */
  