Specifies the type of function passed to g_timeout_add(), g_timeout_add_full(), g_idle_add(), and g_idle_add_full().
When calling g_source_set_callback(), you may need to cast a function of a different type to this type. Use G_SOURCE_FUNC() to avoid warnings about incompatible function types.
Data passed to the function, set when the source was created with one of the above functions.
|The argument can be |
|The data is owned by the caller of the function.|