Bonobo API Reference Manual
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BonoboPersistStream

Name

BonoboPersistStream -- Interface for anything that can save / load itself from a Bonobo stream.

Synopsis



struct      BonoboPersistStream;
void        (*BonoboPersistStreamIOFn)      (BonoboPersistStream *ps,
                                             const Bonobo_Stream stream,
                                             Bonobo_Persist_ContentType type,
                                             void *closure,
                                             CORBA_Environment *ev);
CORBA_long  (*BonoboPersistStreamMaxFn)     (BonoboPersistStream *ps,
                                             void *closure,
                                             CORBA_Environment *ev);
Bonobo_Persist_ContentTypeList* (*BonoboPersistStreamTypesFn)
                                            (BonoboPersistStream *ps,
                                             void *closure,
                                             CORBA_Environment *ev);
typedef     BonoboPersistStreamClass;
void        bonobo_persist_stream_set_dirty (BonoboPersistStream *ps,
                                             gboolean dirty);
BonoboPersistStream* bonobo_persist_stream_new
                                            (BonoboPersistStreamIOFn load_fn,
                                             BonoboPersistStreamIOFn save_fn,
                                             BonoboPersistStreamMaxFn max_fn,
                                             BonoboPersistStreamTypesFn types_fn,
                                             void *closure);
BonoboPersistStream* bonobo_persist_stream_construct
                                            (BonoboPersistStream *ps,
                                             BonoboPersistStreamIOFn load_fn,
                                             BonoboPersistStreamIOFn save_fn,
                                             BonoboPersistStreamMaxFn max_fn,
                                             BonoboPersistStreamTypesFn types_fn,
                                             void *closure);

Object Hierarchy


  GtkObject
   +----BonoboObject
         +----BonoboXObject
               +----BonoboPersist
                     +----BonoboPersistStream

Description

The PersistStream interface is the interface to use for all new components that are able to load and save themselves to a stream. It should be associated with any BonoboEmbeddable for use by the container in creating a compound document.

This interface works by connecting callbacks to the methods, in a somewhat 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. Implementing the PersistStream callbacks

static void
load_from_stream (BonoboPersistStream        *ps,
                  const Bonobo_Stream         stream,
                  Bonobo_Persist_ContentType  type,
                  void                       *closure,
                  CORBA_Environment          *ev)
{
	EogImageData *image_data = closure;

	g_warning ("Load content from stream of type 's'", type);
}

static gint
save_to_stream (BonoboPersistStream        *ps,
                const Bonobo_Stream         stream,
                Bonobo_Persist_ContentType  type,
                void                       *closure,
                CORBA_Environment          *ev)
{
	EogImageData *image_data = closure;

	g_warning ("Save content to stream with type 's'", type);
}

static Bonobo_Persist_ContentTypeList *
get_supported_types (BonoboPersistStream *ps,
                     void                *closure,
                     CORBA_Environment   *ev)
{
	return bonobo_persist_generate_content_types (
		2, "text/plain", "text/html");
}
Having implemented the callbacks we then have to register them and aggregate the interface to our object:

Example 2. Aggregating a new PersistStream

EogImageData *
eog_image_data_construct (EogImageData *image_data)
{
	BonoboObject        *retval;
	BonoboPersistStream *ps;

	ps = bonobo_persist_stream_new (
		load_from_stream, save_to_stream,
		get_supported_types, NULL,
		image_data);

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

	bonobo_object_add_interface (BONOBO_OBJECT (image_data),
				     BONOBO_OBJECT (ps));

	return image_data;
}

Details

struct BonoboPersistStream

struct BonoboPersistStream;

BonoboPersistStreamIOFn ()

void        (*BonoboPersistStreamIOFn)      (BonoboPersistStream *ps,
                                             const Bonobo_Stream stream,
                                             Bonobo_Persist_ContentType type,
                                             void *closure,
                                             CORBA_Environment *ev);

ps :

stream :

type :

closure :

ev :

BonoboPersistStreamMaxFn ()

CORBA_long  (*BonoboPersistStreamMaxFn)     (BonoboPersistStream *ps,
                                             void *closure,
                                             CORBA_Environment *ev);

ps :

closure :

ev :

Returns :

BonoboPersistStreamTypesFn ()

Bonobo_Persist_ContentTypeList* (*BonoboPersistStreamTypesFn)
                                            (BonoboPersistStream *ps,
                                             void *closure,
                                             CORBA_Environment *ev);

ps :

closure :

ev :

Returns :

BonoboPersistStreamClass

typedef struct {
	BonoboPersistClass parent_class;

	POA_Bonobo_PersistStream__epv epv;

	/* methods */
	void       (*load)         (BonoboPersistStream        *ps,
				    Bonobo_Stream              stream,
				    Bonobo_Persist_ContentType type,
				    CORBA_Environment          *ev);
	void       (*save)         (BonoboPersistStream        *ps,
				    Bonobo_Stream              stream,
				    Bonobo_Persist_ContentType type,
				    CORBA_Environment          *ev);
	CORBA_long (*get_size_max) (BonoboPersistStream *ps,
				    CORBA_Environment   *ev);
	Bonobo_Persist_ContentTypeList * (*get_content_types) (BonoboPersistStream *ps,
							       CORBA_Environment   *ev);

} BonoboPersistStreamClass;

bonobo_persist_stream_set_dirty ()

void        bonobo_persist_stream_set_dirty (BonoboPersistStream *ps,
                                             gboolean dirty);

This routine sets the dirty bit for the PersistStream object.

ps :

A BonoboPersistStream object

dirty :

A boolean value representing whether the object is dirty or not

bonobo_persist_stream_new ()

BonoboPersistStream* bonobo_persist_stream_new
                                            (BonoboPersistStreamIOFn load_fn,
                                             BonoboPersistStreamIOFn save_fn,
                                             BonoboPersistStreamMaxFn max_fn,
                                             BonoboPersistStreamTypesFn types_fn,
                                             void *closure);

Creates a new BonoboPersistStream object. The various operations for the object are performed by the provided callback functions, which are passed closure when they are invoked. If any callback is NULL, the corresponding operation is performed by the class load and save routines.

load_fn :

Loading routine

save_fn :

Saving routine

max_fn :

get_max_size routine

types_fn :

get_content_types routine

closure :

Data passed to IO routines.

Returns :

the newly-created BonoboPersistStream object.

bonobo_persist_stream_construct ()

BonoboPersistStream* bonobo_persist_stream_construct
                                            (BonoboPersistStream *ps,
                                             BonoboPersistStreamIOFn load_fn,
                                             BonoboPersistStreamIOFn save_fn,
                                             BonoboPersistStreamMaxFn max_fn,
                                             BonoboPersistStreamTypesFn types_fn,
                                             void *closure);

Initializes the BonoboPersistStream object. The load and save operations for the object are performed by the provided load_fn and save_fn callback functions, which are passed closure when they are invoked. If either load_fn or save_fn is NULL, the corresponding operation is performed by the class load and save routines.

ps :

A BonoboPersistStream object

load_fn :

Loading routine

save_fn :

Saving routine

max_fn :

types_fn :

closure :

Data passed to IO routines.

Returns :

The initialized BonoboPersistStream object.



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