/* GTK - The GIMP Toolkit * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library 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 * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the Free * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #ifndef __GTK_OBJECT_H__ #define __GTK_OBJECT_H__ #include #include #ifdef __cplusplus extern "C" { #endif /* __cplusplus */ /* GtkObject only uses the first 3 bits of the "flags" field. * They refer to the following flags. * GtkWidget uses the remaining bits. Though this is a kinda nasty * break up, it does make the size of GtkWidget smaller. */ enum { GTK_NEED_DESTROY = 1 << 0, GTK_BEING_DESTROYED = 1 << 1, GTK_IN_CALL = 1 << 2 }; /* The debugging versions of the casting macros make sure the cast is "ok" * before proceeding, but they are definately slower than their less * careful counterparts as they involve no less than 3 function calls. */ #ifdef NDEBUG #define GTK_CHECK_CAST(obj,cast_type,cast) ((cast*) obj) #define GTK_CHECK_CLASS_CAST(klass,cast_type,cast) ((cast*) klass) #else /* NDEBUG */ #define GTK_CHECK_CAST(obj,cast_type,cast) \ ((cast*) gtk_object_check_cast ((GtkObject*) obj, cast_type)) #define GTK_CHECK_CLASS_CAST(klass,cast_type,cast) \ ((cast*) gtk_object_check_class_cast ((GtkObjectClass*) klass, cast_type)) #endif /* NDEBUG */ /* Determines whether 'obj' is a type of 'otype'. */ #define GTK_CHECK_TYPE(obj,otype) (gtk_type_is_a (((GtkObject*) obj)->klass->type, otype)) /* Macro for casting a pointer to a GtkObject pointer. */ #define GTK_OBJECT(obj) GTK_CHECK_CAST (obj, gtk_object_get_type (), GtkObject) /* Macros for extracting various fields from GtkObject and * GtkObjectClass. */ #define GTK_OBJECT_CLASS(klass) GTK_CHECK_CLASS_CAST (klass, gtk_object_get_type (), GtkObjectClass) #define GTK_OBJECT_FLAGS(obj) (GTK_OBJECT (obj)->flags) #define GTK_OBJECT_NEED_DESTROY(obj) (GTK_OBJECT_FLAGS (obj) & GTK_NEED_DESTROY) #define GTK_OBJECT_BEING_DESTROYED(obj) (GTK_OBJECT_FLAGS (obj) & GTK_BEING_DESTROYED) #define GTK_OBJECT_IN_CALL(obj) (GTK_OBJECT_FLAGS (obj) & GTK_IN_CALL) #define GTK_OBJECT_DESTROY(obj) (GTK_OBJECT (obj)->klass->destroy) #define GTK_OBJECT_TYPE(obj) (GTK_OBJECT (obj)->klass->type) #define GTK_OBJECT_SIGNALS(obj) (GTK_OBJECT (obj)->klass->signals) #define GTK_OBJECT_NSIGNALS(obj) (GTK_OBJECT (obj)->klass->nsignals) /* Macro for testing whether "obj" is of type GtkObject. */ #define GTK_IS_OBJECT(obj) GTK_CHECK_TYPE (obj, gtk_object_get_type ()) /* Macros for setting and clearing bits in the "flags" field of GtkObject. */ #define GTK_OBJECT_SET_FLAGS(obj,flag) (GTK_OBJECT_FLAGS (obj) |= (flag)) #define GTK_OBJECT_UNSET_FLAGS(obj,flag) (GTK_OBJECT_FLAGS (obj) &= ~(flag)) typedef struct _GtkObjectClass GtkObjectClass; /* GtkObject is the base of the object hierarchy. It defines * the few basic items that all derived classes contain. */ struct _GtkObject { /* 32 bits of flags. GtkObject only uses 3 of these bits and * GtkWidget uses the rest. This is done because structs are * aligned on 4 or 8 byte boundaries. If bitfields were used * both here and in GtkWidget much space would be wasted. */ guint32 flags; /* 16 bit reference count. "gtk_object_destroy" actually only * destroys an object when its ref count is 0. (Decrementing * a reference count of 0 is defined as a no-op). */ guint16 ref_count; /* A pointer to the objects class. This will actually point to * the derived objects class struct (which will be derived from * GtkObjectClass). */ GtkObjectClass *klass; /* The list of signal handlers and other data * fields for this object. */ gpointer object_data; }; /* GtkObjectClass is the base of the class hierarchy. It defines * the basic necessities for the class mechanism to work. Namely, * the "type", "signals" and "nsignals" fields. */ struct _GtkObjectClass { /* The type identifier for the objects class. There is * one unique identifier per class. */ guint type; /* The signals this object class handles. "signals" is an * array of signal ID's. */ gint *signals; /* The number of signals listed in "signals". */ gint nsignals; /* The destroy function for objects. In one way ore another * this is defined for all objects. If an object class overrides * this method in order to perform class specific destruction * then it should still call it after it is finished with its * own cleanup. (See the destroy function for GtkWidget for * an example of how to do this). */ void (* destroy) (GtkObject *object); }; /* Get the type identifier for GtkObject's. */ guint gtk_object_get_type (void); /* Append "signals" to those already defined in "class". */ void gtk_object_class_add_signals (GtkObjectClass *klass, gint *signals, gint nsignals); void gtk_object_ref (GtkObject *object); void gtk_object_unref (GtkObject *object); GtkObject* gtk_object_new (guint type, ...); GtkObject* gtk_object_newv (guint type, gint nargs, GtkArg *args); void gtk_object_set (GtkObject *obj, ...); void gtk_object_setv (GtkObject *obj, gint nargs, GtkArg *args); void gtk_object_add_arg_type (const char *arg_name, GtkType arg_type); GtkType gtk_object_get_arg_type (const char *arg_name); /* Emit the "destroy" signal for "object". Normally it is * permissible to emit a signal for an object instead of * calling the corresponding convenience routine, however * "gtk_object_destroy" should be called instead of emitting * the signal manually as it checks to see if the object is * currently handling another signal emittion (very likely) * and sets the GTK_NEED_DESTROY flag which tells the object * to be destroyed when it is done handling the signal emittion. */ void gtk_object_destroy (GtkObject *object); /* Set 'data' to the "object_data" field of the object. The * data is indexed by the "key". If there is already data * associated with "key" then the new data will replace it. * If 'data' is NULL then this call is equivalent to * 'gtk_object_remove_data'. */ void gtk_object_set_data (GtkObject *object, const gchar *key, gpointer data); /* Get the data associated with "key". */ gpointer gtk_object_get_data (GtkObject *object, const gchar *key); /* Remove the data associated with "key". This call is * equivalent to 'gtk_object_set_data' where 'data' is NULL. */ void gtk_object_remove_data (GtkObject *object, const gchar *key); /* Set the "user_data" object data field of "object". It should * be noted that this is no different than calling 'gtk_object_data_add' * with a key of "user_data". It is merely provided as a convenience. */ void gtk_object_set_user_data (GtkObject *object, gpointer data); /* Get the "user_data" object data field of "object". It should * be noted that this is no different than calling 'gtk_object_data_find' * with a key of "user_data". It is merely provided as a convenience. */ gpointer gtk_object_get_user_data (GtkObject *object); GtkObject* gtk_object_check_cast (GtkObject *obj, GtkType cast_type); GtkObjectClass* gtk_object_check_class_cast (GtkObjectClass *klass, GtkType cast_type); #ifdef __cplusplus } #endif /* __cplusplus */ #endif /* __GTK_OBJECT_H__ */