Delete an attached data pointer from an object.

Parameters:

obj	The object to delete the data pointer from
key	The string key the data was stored under

Returns:

The original data pointer stored at key on obj

This will remove the stored data pointer from obj stored under key and return this same pointer, if actually there was data there, or NULL, if nothing was stored under that key.

Example:

 int *my_data;
 extern Evas_Object *obj;

 my_data = evas_object_data_del(obj, "name_of_my_data");

Since :

2.3.1

Examples:

glview_example_01.c.

Return an attached data pointer on an Evas object by its given string key.

Parameters:

obj	The object to which the data was attached
key	The string key the data was stored under

Returns:

The data pointer stored, or NULL if none was stored

This function will return the data pointer attached to the object obj, stored using the string key key. If the object is valid and a data pointer was stored under the given key, that pointer will be returned. If this is not the case, NULL will be returned, signifying an invalid object or a non-existent key. It is possible that a NULL pointer was stored given that key, but this situation is non-sensical and thus can be considered an error as well. NULL pointers are never stored as this is the return value if an error occurs.

Example:

 int *my_data;
 extern Evas_Object *obj;

 my_data = evas_object_data_get(obj, "name_of_my_data");
 if (my_data) printf("Data stored was %p\n", my_data);
 else printf("No data was stored on the object\n");

Since :

2.3.1

Examples:

ecore_imf_example.c, evas-smart-interface.c, evas-smart-object.c, glview_example_01.c, prefs_example_01.c, and prefs_example_02.c.

Set an attached data pointer to an object with a given string key.

Parameters:

obj	The object to attach the data pointer to
key	The string key for the data to access it
data	The pointer to the data to be attached

This attaches the pointer data to the object obj, given the access string key. This pointer will stay "hooked" to the object until a new pointer with the same string key is attached with evas_object_data_set() or it is deleted with evas_object_data_del(). On deletion of the object obj, the pointers will not be accessible from the object anymore.

You can find the pointer attached under a string key using evas_object_data_get(). It is the job of the calling application to free any data pointed to by data when it is no longer required.

If data is NULL, the old value stored at key will be removed but no new value will be stored. This is synonymous with calling evas_object_data_del() with obj and key.

Note:

This function is very handy when you have data associated specifically to an Evas object, being of use only when dealing with it. Than you don't have the burden to a pointer to it elsewhere, using this family of functions.

Example:

 int *my_data;
 extern Evas_Object *obj;

 my_data = malloc(500);
 evas_object_data_set(obj, "name_of_data", my_data);
 printf("The data that was attached was %p\n", evas_object_data_get(obj, "name_of_data"));

Since :

2.3.1

Examples:

ecore_imf_example.c, evas-smart-interface.c, evas-smart-object.c, glview_example_01.c, prefs_example_01.c, prefs_example_02.c, and web_example_02.c.