Module Callbacks

GnomeVFSModuleCallback ()

void        (*GnomeVFSModuleCallback)       (gconstpointer in,
                                             gsize in_size,
                                             gpointer out,
                                             gsize out_size,
                                             gpointer callback_data);

This is the type of a callback function that gets set for a module callback.

When the callback is invoked, the user function is called with an in argument, the exact type of which depends on the specific callback. It is generally a pointer to a struct with several fields that provide information to the callback.

The out argument is used to return a values from the callback. Once again the exact type depends on the specific callback. It is generally a pointer to a pre-allocated struct with several fields that the callback function should fill in before returning.

GnomeVFSModuleCallbackResponse ()

void        (*GnomeVFSModuleCallbackResponse)
                                            (gpointer response_data);

This is the type of the response function passed to a GnomeVFSAsyncModuleCallback(). It should be called when the async callback has completed.

GnomeVFSAsyncModuleCallback ()

void        (*GnomeVFSAsyncModuleCallback)  (gconstpointer in,
                                             gsize in_size,
                                             gpointer out,
                                             gsize out_size,
                                             gpointer callback_data,
                                             GnomeVFSModuleCallbackResponse response,
                                             gpointer response_data);

This is the type of a callback function that gets set for an async module callback.

Such callbacks are useful when you are using the API and want callbacks to be handled from the main thread, for instance if they need to put up a dialog.

Like a GnomeVFSModuleCallback(), an async callback has in and out arguments for passing data into and out of the callback. However, an async callback does not need to fill in the out argument before returning. Instead, it can arrange to have the work done from a callback on the main loop, from another thread, etc. The response function should be called by whatever code finishes the work of the callback with response_data as an argument once the out argument is filled in and the callback is done.

The in and out arguments are guaranteed to remain valid until the response function is called.

gnome_vfs_module_callback_set_default ()

void        gnome_vfs_module_callback_set_default
                                            (const char *callback_name,
                                             GnomeVFSModuleCallback callback,
                                             gpointer callback_data,
                                             GDestroyNotify destroy_notify);

Set the default callback for callback_name to callback. callback will be called with callback_data on the same thread as the gnome-vfs operation that invokes it. The default value is shared for all threads, but setting it is thread-safe.

Use this function if you want to set a handler to be used by your whole application. You can use gnome_vfs_module_callback_push() to set a callback function that will temporarily override the default on the current thread instead. Or you can also use gnome_vfs_async_module_callback_set_default() to set an async callback function.

Note: destroy_notify may be called on any thread - it is not guaranteed to be called on the main thread.

gnome_vfs_module_callback_push ()

void        gnome_vfs_module_callback_push  (const char *callback_name,
                                             GnomeVFSModuleCallback callback,
                                             gpointer callback_data,
                                             GDestroyNotify destroy_notify);

Set callback as a temprary handler for callback_name. callback will be called with callback_data on the same thread as the gnome-vfs operation that invokes it. The temporary handler is set per-thread.

gnome_vfs_module_callback_pop() removes the most recently set temporary handler. The temporary handlers are treated as a first-in first-out stack.

Use this function to set a temporary callback handler for a single call or a few calls. You can use gnome_vfs_module_callback_set_default() to set a callback function that will establish a permanent global setting for all threads instead.

Note: destroy_notify may be called on any thread - it is not guaranteed to be called on the main thread.

gnome_vfs_module_callback_pop ()

void        gnome_vfs_module_callback_pop   (const char *callback_name);

Remove the temporary handler for callback_name most recently set with gnome_vfs_module_callback_push(). If another temporary handler was previously set on the same thread, it becomes the current handler. Otherwise, the default handler, if any, becomes current.

The temporary handlers are treated as a first-in first-out stack.

gnome_vfs_async_module_callback_set_default ()

void        gnome_vfs_async_module_callback_set_default
                                            (const char *callback_name,
                                             GnomeVFSAsyncModuleCallback callback,
                                             gpointer callback_data,
                                             GDestroyNotify destroy_notify);

Set the default async callback for callback_name to callback. callback will be called with callback_data from a callback on the main thread. It will be passed a response function which should be called to signal completion of the callback. The callback function itself may return in the meantime.

The default value is shared for all threads, but setting it is thread-safe.

Use this function if you want to globally set a callback handler for use with async operations.

You can use gnome_vfs_async_module_callback_push() to set an async callback function that will temporarily override the default on the current thread instead. Or you can also use gnome_vfs_module_callback_set_default() to set a regular callback function.

Note: destroy_notify may be called on any thread - it is not guaranteed to be called on the main thread.

gnome_vfs_async_module_callback_push ()

void        gnome_vfs_async_module_callback_push
                                            (const char *callback_name,
                                             GnomeVFSAsyncModuleCallback callback,
                                             gpointer callback_data,
                                             GDestroyNotify destroy_notify);

Set callback_func as a temprary async handler for callback_name. callback will be called with callback_data from a callback on the main thread. It will be passed a response function which should be called to signal completion of the callback. The callback function itself may return in the meantime.

The temporary async handler is set per-thread.

gnome_vfs_async_module_callback_pop() removes the most recently set temporary temporary handler. The temporary async handlers are treated as a first-in first-out stack.

Use this function to set a temporary async callback handler for a single call or a few calls. You can use gnome_vfs_async_module_callback_set_default() to set an async callback function that will establish a permanent global setting for all threads instead.

Note: destroy_notify may be called on any thread - it is not guaranteed to be called on the main thread.

gnome_vfs_async_module_callback_pop ()

void        gnome_vfs_async_module_callback_pop
                                            (const char *callback_name);

Remove the temporary async handler for callback_name most recently set with gnome_vfs_async_module_callback_push(). If another temporary async handler was previously set on the same thread, it becomes the current handler. Otherwise, the default async handler, if any, becomes current.

The temporary async handlers are treated as a first-in first-out stack.