Name
BonoboPersistStream -- Interface for anything that can save / load itself from a Bonobo stream.
Synopsis
#define BONOBO_PERSIST_STREAM_TYPE
struct BonoboPersistStreamPrivate;
struct BonoboPersistStream;
void (*BonoboPersistStreamIOFn) (BonoboPersistStream *ps,
const Bonobo_Stream stream,
Bonobo_Persist_ContentType type,
void *closure,
CORBA_Environment *ev);
Bonobo_Persist_ContentTypeList* (*BonoboPersistStreamTypesFn)
(BonoboPersistStream *ps,
void *closure,
CORBA_Environment *ev);
typedef BonoboPersistStreamClass;
BonoboPersistStream* bonobo_persist_stream_new
(BonoboPersistStreamIOFn load_fn,
BonoboPersistStreamIOFn save_fn,
BonoboPersistStreamTypesFn types_fn,
const gchar *iid,
void *closure);
BonoboPersistStream* bonobo_persist_stream_construct
(BonoboPersistStream *ps,
BonoboPersistStreamIOFn load_fn,
BonoboPersistStreamIOFn save_fn,
BonoboPersistStreamTypesFn types_fn,
const gchar *iid,
void *closure);
|
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_generateoops
The requested page could not be found. Please use
your browsers 'back' button or the above home button to return to the
Greenstone Digital Library.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
BONOBO_PERSIST_STREAM_TYPE
#define BONOBO_PERSIST_STREAM_TYPE BONOBO_TYPE_PERSIST_STREAM /* deprecated, you should use BONOBO_TYPE_PERSIST_STREAM */ |
struct BonoboPersistStreamPrivate
struct BonoboPersistStreamPrivate; |
struct BonoboPersistStream
struct BonoboPersistStream {
BonoboPersist persist;
gboolean is_dirty;
/*
* For the sample routines, NULL if we use the
* methods from the class
*/
BonoboPersistStreamIOFn save_fn;
BonoboPersistStreamIOFn load_fn;
BonoboPersistStreamTypesFn types_fn;
void *closure;
BonoboPersistStreamPrivate *priv;
}; |
BonoboPersistStreamIOFn ()
void (*BonoboPersistStreamIOFn) (BonoboPersistStream *ps,
const Bonobo_Stream stream,
Bonobo_Persist_ContentType type,
void *closure,
CORBA_Environment *ev); |
BonoboPersistStreamTypesFn ()
Bonobo_Persist_ContentTypeList* (*BonoboPersistStreamTypesFn)
(BonoboPersistStream *ps,
void *closure,
CORBA_Environment *ev); |
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);
Bonobo_Persist_ContentTypeList * (*getoops
The requested page could not be found. Please use
your browsers 'back' button or the above home button to return to the
Greenstone Digital Library.types) (BonoboPersistStream *ps,
CORBA_Environment *ev);
} BonoboPersistStreamClass; |
bonobo_persist_stream_new ()
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.
bonobo_persist_stream_construct ()
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.