Defines if the "validate-change" signal gets emitted when the holder's value changes.
Creates a binding between source_property on source and target_property
on target.
Whenever the source_property is changed the target_property is
updated using the same value. For instance:
g_object_bind_property (action, "active", widget, "sensitive", 0);
Will result in the "sensitive" property of the widget #GObject instance to be updated with the same value of the "active" property of the action #GObject instance.
If flags contains %G_BINDING_BIDIRECTIONAL then the binding will be mutual:
if target_property on target changes then the source_property on source
will be updated as well.
The binding will automatically be removed when either the source or the
target instances are finalized. To remove the binding without affecting the
source and the target you can just call g_object_unref() on the returned
#GBinding instance.
Removing the binding by calling g_object_unref() on it must only be done if
the binding, source and target are only used from a single thread and it
is clear that both source and target outlive the binding. Especially it
is not safe to rely on this if the binding, source or target can be
finalized from different threads. Keep another reference to the binding and
use g_binding_unbind() instead to be on the safe side.
A #GObject can have multiple bindings.
the property on source to bind
the target #GObject
the property on target to bind
flags to pass to #GBinding
Creates a binding between source_property on source and target_property
on target, allowing you to set the transformation functions to be used by
the binding.
This function is the language bindings friendly version of g_object_bind_property_full(), using #GClosures instead of function pointers.
the property on source to bind
the target #GObject
the property on target to bind
flags to pass to #GBinding
a #GClosure wrapping the transformation function from the source to the target, or %NULL to use the default
a #GClosure wrapping the transformation function from the target to the source, or %NULL to use the default
This function is intended for #GObject implementations to re-enforce a [floating][floating-ref] object reference. Doing this is seldom required: all #GInitiallyUnowneds are created with a floating reference which usually just needs to be sunken by calling g_object_ref_sink().
Forces a holder to be invalid; to set it valid again, a new value must be assigned to it using gda_holder_set_value() or gda_holder_take_value().
holder's value is set to %NULL.
Increases the freeze count on object. If the freeze count is
non-zero, the emission of "notify" signals on object is
stopped. The signals are queued until the freeze count is decreased
to zero. Duplicate notifications are squashed so that at most one
#GObject::notify signal is emitted for each property modified while the
object is frozen.
This is necessary for accessors that modify multiple properties to prevent premature notification while the object is still being modified.
Get an "encoded" version of holder's name. The "encoding" consists in replacing non
alphanumeric character with the string "__gdaXX" where XX is the hex. representation
of the non alphanumeric char.
This method is just a wrapper around the gda_text_to_alphanum() function.
Get the value associated to a named attribute.
Attributes can have any name, but Libgda proposes some default names, see this section.
attribute name as a string
Gets a named field from the objects table of associations (see g_object_set_data()).
name of the key for that association
Get the default value held into the holder. WARNING: the default value does not need to be of
the same type as the one required by holder.
Get the ID of holder. The ID can be set using holder's "id" property
Get wether the holder can be NULL or not
Gets a property of an object.
The value can be:
In general, a copy is made of the property contents and the caller is responsible for freeing the memory by calling g_value_unset().
Note that g_object_get_property() is really intended for language bindings, g_object_get() is much more convenient for C programming.
the name of the property to get
return location for the property value
This function gets back user data pointers stored via g_object_set_qdata().
A #GQuark, naming the user data pointer
If gda_holder_set_source_model() has been used to provide a hint that holder's value
should be among the values contained in a column of a data model, then this method
returns which data model, and if col is not %NULL, then it is set to the restricting column
as well.
Otherwise, this method returns %NULL, and if col is not %NULL, then it is set to 0.
a place to store the column in the model sourcing the holder, or %NULL
Get the value held into the holder. If holder is set to use its default value
and that default value is not of the same type as holder, then %NULL is returned.
If holder is set to NULL, then the returned value is a #GDA_TYPE_NULL GValue.
If holder is invalid, then the returned value is %NULL.
Same functionality as gda_holder_get_value() except that it returns the value as a string
(the conversion is done using dh if not %NULL, or the default data handler otherwise).
a #GdaDataHandler to use, or %NULL
Gets n_properties properties for an object.
Obtained properties will be set to values. All properties must be valid.
Warnings will be emitted and undefined behaviour may result if invalid
properties are passed in.
the names of each property to get
the values of each property to get
Checks whether object has a [floating][floating-ref] reference.
Get the validity of holder (that is, of the value held by holder)
Get the validity of holder (that is, of the value held by holder)
Locks lockable. If it is already locked by another thread, the current thread will block until it is unlocked
by the other thread.
This function can be used even if g_thread_init() has not yet been called, and, in that case, will do nothing.
Note: unlike g_mutex_lock(), this method recursive, which means a thread can lock lockable several times
(and has to unlock it as many times to actually unlock it).
Emits a "notify" signal for the property property_name on object.
When possible, eg. when signaling a property change from within the class that registered the property, you should use g_object_notify_by_pspec() instead.
Note that emission of the notify signal may be blocked with g_object_freeze_notify(). In this case, the signal emissions are queued and will be emitted (in reverse order) when g_object_thaw_notify() is called.
the name of a property installed on the class of object.
Emits a "notify" signal for the property specified by pspec on object.
This function omits the property name lookup, hence it is faster than g_object_notify().
One way to avoid using g_object_notify() from within the class that registered the properties, and using g_object_notify_by_pspec() instead, is to store the GParamSpec used with g_object_class_install_property() inside a static array, e.g.:
enum
{
PROP_0,
PROP_FOO,
PROP_LAST
};
static GParamSpec *properties[PROP_LAST];
static void
my_object_class_init (MyObjectClass *klass)
{
properties[PROP_FOO] = g_param_spec_int ("foo", "Foo", "The foo",
0, 100,
50,
G_PARAM_READWRITE);
g_object_class_install_property (gobject_class,
PROP_FOO,
properties[PROP_FOO]);
}
and then notify a change on the "foo" property with:
g_object_notify_by_pspec (self, properties[PROP_FOO]);
the #GParamSpec of a property installed on the class of object.
Increase the reference count of object, and possibly remove the
[floating][floating-ref] reference, if object has a floating reference.
In other words, if the object is floating, then this call "assumes ownership" of the floating reference, converting it to a normal reference by clearing the floating flag while leaving the reference count unchanged. If the object is not floating, then this call adds a new normal reference increasing the reference count by one.
Since GLib 2.56, the type of object will be propagated to the return type
under the same conditions as for g_object_ref().
Releases all references to other objects. This can be used to break reference cycles.
This function should only be called from object system implementations.
Set the value associated to a named attribute. The attribute string is 'stolen' by this method, and
the memory it uses will be freed using the destroy function when no longer needed (if destroy is %NULL,
then the string will not be freed at all).
Attributes can have any name, but Libgda proposes some default names, see this section.
For example one would use it as:
gda_holder_set_attribute (holder, g_strdup (my_attribute), my_value, g_free);
gda_holder_set_attribute (holder, GDA_ATTRIBUTE_NAME, my_value, NULL);
If there is already an attribute named attribute set, then its value is replaced with the new value (value is
copied), except if value is %NULL, in which case the attribute is removed.
attribute name
a #GValue, or %NULL
a function to be called when attribute is not needed anymore, or %NULL
Sets holder to change when bind_to changes (and does not make bind_to change when holder changes).
For the operation to succeed, the GType of holder and bind_to must be the same, with the exception that
any of them can have a %GDA_TYPE_NULL type (in this situation, the GType of the two #GdaHolder objects
involved is set to match the other when any of them sets its type to something different than GDA_TYPE_NULL).
If bind_to is %NULL, then holder will not be bound anymore.
Each object carries around a table of associations from strings to pointers. This function lets you set an association.
If the object already had an association with that name, the old association will be destroyed.
Internally, the key is converted to a #GQuark using g_quark_from_string().
This means a copy of key is kept permanently (even after object has been
finalized) — so it is recommended to only use a small, bounded set of values
for key in your program, to avoid the #GQuark storage growing unbounded.
name of the key
data to associate with that key
Sets the default value within the holder. If value is %NULL then holder won't have a
default value anymore. To set a default value to %NULL, then pass a #GValue created using
gda_value_new_null().
NOTE: the default value does not need to be of the same type as the one required by holder.
a value to set the holder's default value, or %NULL
Sets if the holder can have a NULL value. If not_null is TRUE, then that won't be allowed
TRUE if holder should not accept %NULL values
Sets a property on an object.
the name of the property to set
the value
Sets an hint that holder's values should be restricted among the values
contained in the col column of the model data model. Note that this is just a hint,
meaning this policy is not enforced by holder's implementation.
If model is %NULL, then the effect is to cancel ant previous call to gda_holder_set_source_model()
where model was not %NULL.
Sets the value within the holder. If holder is an alias for another
holder, then the value is also set for that other holder.
On success, the action of any call to gda_holder_force_invalid() is cancelled
as soon as this method is called (even if holder's value does not actually change)
If the value is not different from the one already contained within holder,
then holder is not changed and no signal is emitted.
Note1: the value argument is treated the same way if it is %NULL or if it is a #GDA_TYPE_NULL value
Note2: if holder can't accept the value value, then this method returns FALSE, and holder will be left
in an invalid state.
Note3: before the change is accepted by holder, the "validate-change" signal will be emitted (the value
of which can prevent the change from happening) which can be connected to to have a greater control
of which values holder can have, or implement some business rules.
a value to set the holder to, or %NULL
Same functionality as gda_holder_set_value() except that it uses a string representation
of the value to set, which will be converted into a GValue first (using default data handler if
dh is %NULL).
Note1: if value is %NULL or is the "NULL" string, then holder's value is set to %NULL.
Note2: if holder can't accept the value value, then this method returns FALSE, and holder will be left
in an invalid state.
a #GdaDataHandler to use, or %NULL
a value to set the holder to, as a string
Set holder's value to its default value.
Remove a specified datum from the object's data associations, without invoking the association's destroy handler.
name of the key
This function gets back user data pointers stored via
g_object_set_qdata() and removes the data from object
without invoking its destroy() function (if any was
set).
Usually, calling this function is only required to update
user data pointers with a destroy notifier, for example:
void
object_add_to_user_list (GObject *object,
const gchar *new_string)
{
// the quark, naming the object data
GQuark quark_string_list = g_quark_from_static_string ("my-string-list");
// retrieve the old string list
GList *list = g_object_steal_qdata (object, quark_string_list);
// prepend new string
list = g_list_prepend (list, g_strdup (new_string));
// this changed 'list', so we need to set it again
g_object_set_qdata_full (object, quark_string_list, list, free_string_list);
}
static void
free_string_list (gpointer data)
{
GList *node, *list = data;
for (node = list; node; node = node->next)
g_free (node->data);
g_list_free (list);
}
Using g_object_get_qdata() in the above example, instead of g_object_steal_qdata() would have left the destroy function set, and thus the partial string list would have been freed upon g_object_set_qdata_full().
A #GQuark, naming the user data pointer
Sets the const value within the holder. If holder is an alias for another
holder, then the value is also set for that other holder.
The value will not be freed, and user should take care of it, either for its freeing or for its correct value at the moment of query.
If the value is not different from the one already contained within holder,
then holder is not changed and no signal is emitted.
Note1: if holder can't accept the value value, then this method returns NULL, and holder will be left
in an invalid state.
Note2: before the change is accepted by holder, the "validate-change" signal will be emitted (the value
of which can prevent the change from happening) which can be connected to to have a greater control
of which values holder can have, or implement some business rules.
a const value to set the holder to
a boolean set with TRUE if the value changes, FALSE elsewhere.
Sets the value within the holder. If holder is an alias for another
holder, then the value is also set for that other holder.
On success, the action of any call to gda_holder_force_invalid() is cancelled
as soon as this method is called (even if holder's value does not actually change).
If the value is not different from the one already contained within holder,
then holder is not changed and no signal is emitted.
Note1: if holder can't accept the value value, then this method returns FALSE, and holder will be left
in an invalid state.
Note2: before the change is accepted by holder, the "validate-change" signal will be emitted (the value
of which can prevent the change from happening) which can be connected to to have a greater control
of which values holder can have, or implement some business rules.
Note3: if user previously set this holder with gda_holder_take_static_value () the GValue
stored internally will be forgiven and replaced by the value. User should then
take care of the 'old' static GValue.
a value to set the holder to
Reverts the effect of a previous call to
g_object_freeze_notify(). The freeze count is decreased on object
and when it reaches zero, queued "notify" signals are emitted.
Duplicate notifications for each property are squashed so that at most one #GObject::notify signal is emitted for each property, in the reverse order in which they have been queued.
It is an error to call this function when the freeze count is zero.
Tries to lock lockable. If it is already locked by another thread, then it immediately returns FALSE, otherwise
it locks lockable.
This function can be used even if g_thread_init() has not yet been called, and, in that case, will do nothing.
Note: unlike g_mutex_lock(), this method recursive, which means a thread can lock lockable several times
(and has to unlock it as many times to actually unlock it).
Unlocks lockable. This method should not be called if the current does not already holds a lock on lockable (having
used gda_lockable_lock() or gda_lockable_trylock()).
This function can be used even if g_thread_init() has not yet been called, and, in that case, will do nothing.
Decreases the reference count of object. When its reference count
drops to 0, the object is finalized (i.e. its memory is freed).
If the pointer to the #GObject may be reused in future (for example, if it is an instance variable of another object), it is recommended to clear the pointer to %NULL rather than retain a dangling pointer to a potentially invalid #GObject instance. Use g_clear_object() for this.
Tells if holder's current value is the default one.
This function essentially limits the life time of the closure to
the life time of the object. That is, when the object is finalized,
the closure is invalidated by calling g_closure_invalidate() on
it, in order to prevent invocations of the closure with a finalized
(nonexisting) object. Also, g_object_ref() and g_object_unref() are
added as marshal guards to the closure, to ensure that an extra
reference count is held on object during invocation of the
closure. Usually, this function will be called on closures that
use this object as closure data.
#GClosure to watch
Find the #GParamSpec with the given name for an
interface. Generally, the interface vtable passed in as g_iface
will be the default vtable from g_type_default_interface_ref(), or,
if you know the interface has already been loaded,
g_type_default_interface_peek().
any interface vtable for the interface, or the default vtable for the interface
name of a property to look up.
Add a property to an interface; this is only useful for interfaces that are added to GObject-derived types. Adding a property to an interface forces all objects classes with that interface to have a compatible property. The compatible property could be a newly created #GParamSpec, but normally g_object_class_override_property() will be used so that the object class only needs to provide an implementation and inherits the property description, default value, bounds, and so forth from the interface property.
This function is meant to be called from the interface's default
vtable initialization function (the class_init member of
#GTypeInfo.) It must not be called after after class_init has
been called for any object types implementing this interface.
If pspec is a floating reference, it will be consumed.
any interface vtable for the interface, or the default vtable for the interface.
the #GParamSpec for the new property
Lists the properties of an interface.Generally, the interface
vtable passed in as g_iface will be the default vtable from
g_type_default_interface_ref(), or, if you know the interface has
already been loaded, g_type_default_interface_peek().
any interface vtable for the interface, or the default vtable for the interface
Creates a new instance of a #GObject subtype and sets its properties.
Construction parameters (see %G_PARAM_CONSTRUCT, %G_PARAM_CONSTRUCT_ONLY) which are not explicitly specified are set to their default values.
the type id of the #GObject subtype to instantiate
an array of #GParameter
Creates a new holder of type
type