BonoboPropertyBag

BonoboPropertyBag — Implements a generic property storage interface

Synopsis




                    BonoboPropertyBagClass;
                    BonoboPropertyBag;
#define             BONOBO_PROPERTY_READABLE
#define             BONOBO_PROPERTY_WRITEABLE
#define             BONOBO_PROPERTY_WRITABLE
#define             BONOBO_PROPERTY_NO_LISTENING
#define             BONOBO_PROPERTY_NO_AUTONOTIFY
                    BonoboProperty;
void                (*BonoboPropertyGetFn)              (BonoboPropertyBag *bag,
                                                         BonoboArg *arg,
                                                         guint arg_id,
                                                         CORBA_Environment *ev,
                                                         gpointer user_data);
void                (*BonoboPropertySetFn)              (BonoboPropertyBag *bag,
                                                         const BonoboArg *arg,
                                                         guint arg_id,
                                                         CORBA_Environment *ev,
                                                         gpointer user_data);
BonoboPropertyBag*  bonobo_property_bag_new             (BonoboPropertyGetFn get_prop_cb,
                                                         BonoboPropertySetFn set_prop_cb,
                                                         gpointer user_data);
BonoboPropertyBag*  bonobo_property_bag_new_closure     (GClosure *get_prop,
                                                         GClosure *set_prop);
BonoboPropertyBag*  bonobo_property_bag_new_full        (GClosure *get_prop,
                                                         GClosure *set_prop,
                                                         BonoboEventSource *es);
BonoboPropertyBag*  bonobo_property_bag_construct       (BonoboPropertyBag *pb,
                                                         GClosure *get_prop,
                                                         GClosure *set_prop,
                                                         BonoboEventSource *es);
void                bonobo_property_bag_add             (BonoboPropertyBag *pb,
                                                         const char *name,
                                                         int idx,
                                                         BonoboArgType type,
                                                         BonoboArg *default_value,
                                                         const char *doctitle,
                                                         Bonobo_PropertyFlags flags);
void                bonobo_property_bag_add_full        (BonoboPropertyBag *pb,
                                                         const char *name,
                                                         int idx,
                                                         BonoboArgType type,
                                                         BonoboArg *default_value,
                                                         const char *doctitle,
                                                         const char *docstring,
                                                         Bonobo_PropertyFlags flags,
                                                         GClosure *get_prop,
                                                         GClosure *set_prop);
void                bonobo_property_bag_remove          (BonoboPropertyBag *pb,
                                                         const char *name);
void                bonobo_property_bag_map_params      (BonoboPropertyBag *pb,
                                                         GObject *on_instance,
                                                         const GParamSpec **pspecs,
                                                         guint n_params);
GList*              bonobo_property_bag_get_prop_list   (BonoboPropertyBag *pb);

Description

The PropertyBag is used for many things, particularly for the customization of controls. The important thing to remember about the BonoboPropertyBag implementation is that no live data is stored in the bag. ie. the Model for the properties is your code.

Consequently when someone requests a properties value, or sets a property the callbacks you supply at bag construction time are called, and the code therein must supply the property. Similarly, when a property changes value inside your object you need to notify the property bag's listeners that it has changed with a call to bonobo_event_source_notify_listeners_full.

Here is a simple example use of the property bag:

Example 11. PropertyBag Callbacks

enum {
	PROP_RUNNING,
	PROP_COLOUR
} MyArgs;

static void
get_prop (BonoboPropertyBag *bag,
	  BonoboArg         *arg,
	  guint              arg_id,
	  CORBA_Environment *ev,
	  gpointer           user_data)
{
	GtkObject *clock = user_data;

	switch (arg_id) {

	case PROP_RUNNING:
		BONOBO_ARG_SET_BOOLEAN (arg, clock->is_running);
		break;

	case PROP_COLOUR:
		BONOBO_ARG_SET_STRING (arg, clock->color);
		break;

	default:
		bonobo_exception_set (ev, ex_Bonobo_PropertyBag_NotFound);
		break;
	}
}

static void
set_prop (BonoboPropertyBag *bag,
	  const BonoboArg   *arg,
	  guint              arg_id,
	  CORBA_Environment *ev,
	  gpointer           user_data)
{
	GtkClock *clock = user_data;

	switch (arg_id) {

	case PROP_RUNNING: {
		guint i = BONOBO_ARG_GET_BOOLEAN (arg);

		if (i)
			gtk_clock_start (clock);
		else
			gtk_clock_stop (clock);
		break;
	}

	case PROP_COLOUR:
		gtk_clock_set_color (clock, BONOBO_ARG_GET_STRING (arg));

	default:
		bonobo_exception_set (ev, ex_Bonobo_PropertyBag_NotFound);
		break;
	}
}


Then to instantiate the property bag interface and associate it with a control perhaps we do:

Example 12. Adding a PropertyBag to a control

	BonoboPropertyBag *pb;

	pb = bonobo_property_bag_new (get_prop, set_prop, clock);
	bonobo_control_set_properties (control, pb);

	bonobo_property_bag_add (pb, "running", PROP_RUNNING,
				 BONOBO_ARG_BOOLEAN, NULL,
				 _("Whether or not the clock is running"),
				 0);

	bonobo_property_bag_add (pb, "colour", PROP_COLOUR,
				 BONOBO_ARG_STRING, NULL,
				 _("The colour of the clock face"),
				 0);

	bonobo_object_unref (BONOBO_OBJECT (pb));


And finally we need to notify listeners of changes in various properties so we could perhaps do:

Example 13. Notifying proterty bag listeners

static void
signal_handler (GtkClock *clock, BonoboPropertyBag *pb)
{
	BonoboArg *arg = bonobo_arg_new (TC_string);

	BONOBO_ARG_SET_STRING (arg, gtk_clock_get_color (clock));

	bonobo_event_source_notify_listeners_full (pb->es, 
					           "Bonobo/Property",
					           "change",
						   "colour",
					           arg, NULL);
	bonobo_arg_release (arg);
}
...
	gtk_signal_connect (GTK_OBJECT (clock), "color_changed",
			    GTK_SIGNAL_FUNC (signal_handler), pb);


See also BonoboArg.

Details

BonoboPropertyBagClass

typedef struct {
	BonoboObjectClass        parent;

	POA_Bonobo_PropertyBag__epv epv;
} BonoboPropertyBagClass;

BonoboPropertyBag

typedef struct {
	BonoboObject             parent;
	BonoboPropertyBagPrivate *priv;
	BonoboEventSource        *es;
} BonoboPropertyBag;

BONOBO_PROPERTY_READABLE

#define BONOBO_PROPERTY_READABLE      Bonobo_PROPERTY_READABLE

If this flag is set, the property allows consulting its value.

BONOBO_PROPERTY_WRITEABLE

#define BONOBO_PROPERTY_WRITEABLE     Bonobo_PROPERTY_WRITEABLE

If this flag is set, the property supports modification of its value.

BONOBO_PROPERTY_WRITABLE

#define BONOBO_PROPERTY_WRITABLE      Bonobo_PROPERTY_WRITEABLE

Misspelling of BONOBO_PROPERTY_WRITEABLE.

BONOBO_PROPERTY_NO_LISTENING

#define BONOBO_PROPERTY_NO_LISTENING  Bonobo_PROPERTY_NO_LISTENING

If this flag set, when the property changes its value its listeners will *not* be notified.

BONOBO_PROPERTY_NO_AUTONOTIFY

#define BONOBO_PROPERTY_NO_AUTONOTIFY Bonobo_PROPERTY_NO_AUTONOTIFY

If this flag set, when the property changes its value its listeners will *not* be notified.

BonoboProperty

typedef struct {
	char		      *name;
	int                    idx;
	BonoboArgType          type;
	BonoboArg             *default_value;
	char		      *doctitle;
	char		      *docstring;
	Bonobo_PropertyFlags   flags;

	BonoboPropertyPrivate *priv;
} BonoboProperty;

Structure that holds information about a property in a BonoboPropertyBag.

char *name; the canonic name of the property
int idx; unique numeric identifier of the property within the property bag
BonoboArgType type; type of value contained by this property
BonoboArg *default_value; the default value
char *doctitle; documentation string title
char *docstring; documentation string
Bonobo_PropertyFlags flags; property flags (read/write, etc.)
BonoboPropertyPrivate *priv; implementation private data

BonoboPropertyGetFn ()

void                (*BonoboPropertyGetFn)              (BonoboPropertyBag *bag,
                                                         BonoboArg *arg,
                                                         guint arg_id,
                                                         CORBA_Environment *ev,
                                                         gpointer user_data);

Property getter function.

bag : the property bag
arg : output parameter; the caller must place here the property value
arg_id : unique numeric identifier of the property within the property bag
ev : the relevant CORBA environment
user_data : user data

BonoboPropertySetFn ()

void                (*BonoboPropertySetFn)              (BonoboPropertyBag *bag,
                                                         const BonoboArg *arg,
                                                         guint arg_id,
                                                         CORBA_Environment *ev,
                                                         gpointer user_data);

Property setter function.

bag : the property bag
arg : the new property value to be set
arg_id : unique numeric identifier of the property within the property bag
ev : the relevant CORBA environment
user_data : user data

bonobo_property_bag_new ()

BonoboPropertyBag*  bonobo_property_bag_new             (BonoboPropertyGetFn get_prop_cb,
                                                         BonoboPropertySetFn set_prop_cb,
                                                         gpointer user_data);

Creates a new property bag with the specified callbacks.

get_prop_cb : the property get callback
set_prop_cb : the property set callback
user_data : user data for the callbacks
Returns : A new BonoboPropertyBag object.

bonobo_property_bag_new_closure ()

BonoboPropertyBag*  bonobo_property_bag_new_closure     (GClosure *get_prop,
                                                         GClosure *set_prop);

Creates a new property bag with the specified callbacks.

get_prop : the property get closure
set_prop : the property set closure
Returns : A new BonoboPropertyBag object.

bonobo_property_bag_new_full ()

BonoboPropertyBag*  bonobo_property_bag_new_full        (GClosure *get_prop,
                                                         GClosure *set_prop,
                                                         BonoboEventSource *es);

Creates a new property bag with the specified callbacks.

get_prop : the property get closure
set_prop : the property set closure
es : an event source to aggregate
Returns : A new BonoboPropertyBag object.

bonobo_property_bag_construct ()

BonoboPropertyBag*  bonobo_property_bag_construct       (BonoboPropertyBag *pb,
                                                         GClosure *get_prop,
                                                         GClosure *set_prop,
                                                         BonoboEventSource *es);

Constructor, only for use in wrappers and object derivation, please refer to the bonobo_property_bag_new for normal use.

This function returns pb, or NULL in case of error. If it returns NULL, the passed in pb is unrefed.

pb : BonoboPropertyBag to construct
get_prop : the property get closure
set_prop : the property set closure
es : an event source to aggregate
Returns : BonoboPropertyBag pointer or NULL.

bonobo_property_bag_add ()

void                bonobo_property_bag_add             (BonoboPropertyBag *pb,
                                                         const char *name,
                                                         int idx,
                                                         BonoboArgType type,
                                                         BonoboArg *default_value,
                                                         const char *doctitle,
                                                         Bonobo_PropertyFlags flags);

Adds a property to the property bag.

pb : property bag to add to
name : name of new property
idx : integer index for fast callback switch statement
type : the CORBA type eg. TC_long
default_value : the default value or NULL
doctitle : the translated documentation string
flags : various flags

bonobo_property_bag_add_full ()

void                bonobo_property_bag_add_full        (BonoboPropertyBag *pb,
                                                         const char *name,
                                                         int idx,
                                                         BonoboArgType type,
                                                         BonoboArg *default_value,
                                                         const char *doctitle,
                                                         const char *docstring,
                                                         Bonobo_PropertyFlags flags,
                                                         GClosure *get_prop,
                                                         GClosure *set_prop);

This adds a property to pb at the full tilt of complexity.

pb : property bag to add to
name : name of new property
idx : integer index for fast callback switch statement
type : the CORBA type eg. TC_long
default_value : the default value or NULL
doctitle : the translated documentation title
docstring : the translated documentation string
flags : various flags
get_prop : a per property get callback
set_prop : a per property set callback

bonobo_property_bag_remove ()

void                bonobo_property_bag_remove          (BonoboPropertyBag *pb,
                                                         const char *name);

removes the property with name from b.

pb : the property bag
name : name of property to remove.

bonobo_property_bag_map_params ()

void                bonobo_property_bag_map_params      (BonoboPropertyBag *pb,
                                                         GObject *on_instance,
                                                         const GParamSpec **pspecs,
                                                         guint n_params);

pb :
on_instance :
pspecs :
n_params :

bonobo_property_bag_get_prop_list ()

GList*              bonobo_property_bag_get_prop_list   (BonoboPropertyBag *pb);

pb : A BonoboPropertyBag.
Returns : a GList of BonoboProperty structures. This function is private and should only be used internally, or in a PropertyBag persistence implementation. You should not touch the BonoboProperty structure unless you know what you're doing.