Bonobo API Reference Manual
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BonoboPersistFile

Name

BonoboPersistFile -- Interface for anything that can save / load itself from a file.

Synopsis



struct      BonoboPersistFile;
int         (*BonoboPersistFileIOFn)        (BonoboPersistFile *pf,
                                             const CORBA_char *filename,
                                             CORBA_Environment *ev,
                                             void *closure);
typedef     BonoboPersistFileClass;
void        bonobo_persist_file_set_dirty   (BonoboPersistFile *ps,
                                             gboolean dirty);
BonoboPersistFile* bonobo_persist_file_new  (BonoboPersistFileIOFn load_fn,
                                             BonoboPersistFileIOFn save_fn,
                                             void *closure);
BonoboPersistFile* bonobo_persist_file_construct
                                            (BonoboPersistFile *ps,
                                             BonoboPersistFileIOFn load_fn,
                                             BonoboPersistFileIOFn save_fn,
                                             void *closure);

Object Hierarchy


  GtkObject
   +----BonoboObject
         +----BonoboXObject
               +----BonoboPersist
                     +----BonoboPersistFile

Description

The PersistFile interface is a useful interface for Bonoboizing legacy applications, however, for new / correct applications it is far preferable to implement the BonoboPersistStream interface, since this will not only result in a nice clean to your application architecture, but also allow the transparent use of local, remote, and synthetic streams.

This interface works by connecting callbacks to the methods, in a pretty deprecated fashion, it is probably better nowadays to simply sub-class the BonoboXObject and override the epv methods. Either way, after all the caveats here is an example use:

Example 1. Persist file implementation

static gint
load_from_file (BonoboPersistFile *pf,
                const CORBA_char  *filename,
		CORBA_Environment *ev,
                void              *closure)
{
	EogImageData *image_data = closure;

	g_warning ("Load from 's'", filename);

	return 0; /* Return 0 on success */
}

static gint
save_to_file (BonoboPersistFile *pf,
              const CORBA_char  *filename,
              CORBA_Environment *ev,
              void              *closure)
{
	EogImageData *image_data = closure;

	g_warning ("Save to 's'", filename);

	return 0; /* Return 0 on success */
}
Having implemented the callbacks we then have to register them and aggregate the interface to our object:

Example 2. Aggregating a new PersistFile

EogImageData *
eog_image_data_construct (EogImageData *image_data)
{
	BonoboObject        *retval;
	BonoboPersistFile   *file;

	file = bonobo_persist_file_new (
		load_from_file, save_to_file, image_data);

	if (file == NULL) {
		bonobo_object_unref (BONOBO_OBJECT (image_data));
		return NULL;
	}

	bonobo_object_add_interface (BONOBO_OBJECT (image_data),
				     BONOBO_OBJECT (file));

	return image_data;
}
Note again, that you should be writing a BonoboPersistStream interface, however if you have already done this you might like to just have hooks through so that old apps can use the PersistFile interface:

Example 3. Chaining to a PersistStream implementation

static gint
load_from_file (BonoboPersistFile *pf,
                const CORBA_char  *filename,
		CORBA_Environment *ev,
                void              *closure)
{
	Bonobo_PersistStream ps = closure;
	BonoboStream *stream;
	
	stream = bonobo_stream_open (
		BONOBO_IO_DRIVER_FS,
		filename, Bonobo_STORAGE_READ,
		0);

	if (!stream)
		return 0;

	.. extract content type from file ...

	Bonobo_PersistStream_load (ps, type, ev);

	return 0; /* Return 0 on success */
}

static gint
save_to_file (BonoboPersistFile *pf,
              const CORBA_char  *filename,
              CORBA_Environment *ev,
              void              *closure)
{
	Bonobo_PersistStream ps = closure;
	BonoboStream *stream;
	
	stream = bonobo_stream_open (
		BONOBO_IO_DRIVER_FS,
		filename, Bonobo_STORAGE_WRITE | Bonobo_STORAGE_CREATE,
		S_IRUSR | S_IWUSR | S_IRGRP);

	if (!stream)
		return 0;

	.. work out content type we want to save ...

	Bonobo_PersistStream_save (ps, type, ev);

	return 0; /* Return 0 on success */
}
The mime type data can be extracted from gnome-vfs or gnome-mime.

Details

struct BonoboPersistFile

struct BonoboPersistFile;

BonoboPersistFileIOFn ()

int         (*BonoboPersistFileIOFn)        (BonoboPersistFile *pf,
                                             const CORBA_char *filename,
                                             CORBA_Environment *ev,
                                             void *closure);

pf :

filename :

ev :

closure :

Returns :

BonoboPersistFileClass

typedef struct {
	BonoboPersistClass parent_class;

	POA_Bonobo_PersistFile__epv epv;

	/* methods */
	int   (*load)             (BonoboPersistFile *ps,
				   const CORBA_char  *filename,
				   CORBA_Environment *ev);

	int   (*save)             (BonoboPersistFile *ps,
				   const CORBA_char  *filename,
				   CORBA_Environment *ev);

	char *(*get_current_file) (BonoboPersistFile *ps,
				   CORBA_Environment *ev);

} BonoboPersistFileClass;

bonobo_persist_file_set_dirty ()

void        bonobo_persist_file_set_dirty   (BonoboPersistFile *ps,
                                             gboolean dirty);

ps :

dirty :

bonobo_persist_file_new ()

BonoboPersistFile* bonobo_persist_file_new  (BonoboPersistFileIOFn load_fn,
                                             BonoboPersistFileIOFn save_fn,
                                             void *closure);

Creates a BonoboPersistFile object. The load_fn and save_fn parameters might be NULL. If this is the case, the load and save operations are performed by the class load and save methods

load_fn :

Loading routine

save_fn :

Saving routine

closure :

Data passed to IO routines.

Returns :

bonobo_persist_file_construct ()

BonoboPersistFile* bonobo_persist_file_construct
                                            (BonoboPersistFile *ps,
                                             BonoboPersistFileIOFn load_fn,
                                             BonoboPersistFileIOFn save_fn,
                                             void *closure);

Initializes the BonoboPersistFile object. The load_fn and save_fn parameters might be NULL. If this is the case, the load and save operations are performed by the class load and save methods

ps :

load_fn :

Loading routine

save_fn :

Saving routine

closure :

Data passed to IO routines.

Returns :

See Also

BonoboPersistStream, BonoboPersist



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