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(gtk.info)Objects

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Objects
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Object functions
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   The GtkObject type is the root of the type hierarchy used by GTK. It
provides a minimal set of fields used to implement the actual object,
class and signal mechanisms, as well as several utility routines which
make dealing with objects easier.

   For the adventurous, see Note: Object Implementation.

 - Function: guint gtk_object_get_type (void)
     Returns the `GtkObject' type identifier.

 - Function: void gtk_object_class_add_signals (GtkObjectClass *CLASS,
          gint *SIGNALS, gint NSIGNALS)
     Adds SIGNALS to the `signals' field in the GtkObjectClass
     structure CLASS. Note: Signals.

 - Function: GtkObject* gtk_object_new (guint TYPE, ...)

 - Function: GtkObject* gtk_object_newv (guint TYPE, guint NARGS,
          GtkArg *ARGS)

 - Function: void gtk_object_ref (GtkObject *OBJECT);

 - Function: void gtk_object_unref (GtkObject *OBJECT);

 - Function: void gtk_object_getv (GtkObject *OBJECT, guint NARGS,
          GtkArg *ARGS)

 - Function: void gtk_object_set (GtkObject *OBJECT, ...)

 - Function: void gtk_object_setv (GtkObject *OBJECT, guint NARGS,
          GtkArg *ARGS)

 - Function: GtkArg* gtk_object_query_args (GtkType CLASS_TYPE, guint
          *NARGS)

 - Function: void gtk_object_add_arg_type (gchar *ARG_NAME, GtkType
          ARG_TYPE, guint ARG_ID)

 - Function: GtkType gtk_object_get_arg_type (gchar *ARG_NAME)

 - Function: void gtk_object_destroy (GtkObject *OBJECT)
     Performs checks to make sure it is alright to destroy OBJECT and
     then emits the `destroy' signal. The check which is performed is to
     make sure OBJECT is not already processing another signal. If this
     were the case then destroying the object immediately would
     undoubtedly cause problems as the other signal would not be able
     to tell the object was destroyed. The solution is that if OBJECT
     is processing another signal we mark OBJECT is needing to be
     destroyed. When we finish processing of the other signal we check
     whether the object needs to be destroyed.

   The GtkObject type provides a mechanism for associating arbitrary
amounts of data with an object. The data is associated with the object
using a character string key. The functions `gtk_object_set_data',
`gtk_object_get_data', and `gtk_object_remove_data' are the interface
to this mechanism. Two other routines, `gtk_object_set_user_data' and
`gtk_object_get_user_data', exist as convenience functions which simply
use the same mechanism.

 - Function: void gtk_object_set_data (GtkObject *OBJECT, const char
          *KEY, gpointer DATA)
     Associate DATA with KEY in the data list of OBJECT.

 - Function: gpointer gtk_object_get_data (GtkObject *OBJECT, const
          char *KEY)
     Retrieve the data associated with KEY in the data list of OBJECT.

 - Function: void gtk_object_remove_data (GtkObject *OBJECT, const char
          *KEY)
     Remove the data associated with KEY in the data list of OBJECT.

 - Function: void gtk_object_set_user_data (GtkObject *OBJECT, gpointer
          DATA)
     Sets DATA into the `user_data' field of OBJECT.

 - Function: gpointer gtk_object_get_user_data (GtkObject *OBJECT)
     Returns the `user_data' field of OBJECT.

   The GtkObject type also provides a mechanism for specifying
initialization values for fields. This general mechanism is called
object value stacks. The reason for using value stacks is that they can
simplify the life of the programmer. For instance, by default widgets
are non-visible when created. However, the "visible" value for widgets
may be specified so that widgets are made visible when created. (FIXME:
unfinished).

 - Function: void gtk_object_value_stack_new (guint OBJECT_TYPE, const
          gchar *VALUE_ID, GtkParamType VALUE_TYPE)

 - Function: void gtk_object_push_value (guint OBJECT_TYPE, const gchar
          *VALUE_ID, ...)
     Push a value on the value stack specified by OBJECT_TYPE and
     VALUE_ID. The type of value is implicitly given in the context of
     OBJECT_TYPE and VALUE_ID. (That is, it is not specified explicitly
     in the function call). Only a single extra argument is expected
     which is the data which is to be placed on the stack.

 - Function: void gtk_object_pop_value (guint OBJECT_TYPE, const gchar
          *VALUE_ID)
     Pop a value of the value stack specified by OBJECT_TYPE and
     VALUE_ID.

 - Function: gint gtk_object_peek_value (guint OBJECT_TYPE, const gchar
          *VALUE_ID, gpointer DATA)
     Peek at the value on the top of the value stack specified by
     OBJECT_TYPE and VALUE_ID. The DATA argument is interpreted as the
     location of where to place the "peeked" data. For instance, if the
     peeked data is of type `GTK_PARAM_POINTER', then DATA will be a
     pointer to a pointer. If the value stack is empty or does not
     exist or an error occurs, `gtk_object_peek_value' will return
     `FALSE'. On success it will return `TRUE'.