The sequence of commands describing the clip path of the item, specified
as a string using the same syntax
as in the
the parent model.
data used by the canvas item for viewing the model.
Adds a child at the given stack position.
the child to add.
the position of the child, or -1 to place it last (at the top of the stacking order).
Animates a model from its current position to the given offsets, scale and rotation.
the final x coordinate.
the final y coordinate.
the final scale.
the final rotation. This can be negative to rotate anticlockwise, and can also be greater than 360 to rotate a number of times.
if the x,
y,
scale
and degrees
values are absolute, or relative to the current transform. Note that absolute animations only work if the model currently has a simple transform. If the model has a shear or some other complicated transform it may result in strange animations.
the duration of the animation, in milliseconds (1/1000ths of a second).
the time between each animation step, in milliseconds.
specifies what happens when the animation finishes.
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
Attempts to find the given child with the container's stack.
the child to find.
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().
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.
Gets the child at the given stack position.
the position of a child in the container's stack.
Gets a child property of child
.
a child #GooCanvasItemModel.
the name of the child property to get.
a location to return the value.
Gets a named field from the objects table of associations (see g_object_set_data()).
name of the key for that association
Gets the number of children of the container.
Gets the parent of the given model.
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
This function can be used to get the position, scale and rotation of an item model, providing that the model has a simple transformation matrix (e.g. set with goo_canvas_item_model_set_simple_transform(), or using a combination of simple translate, scale and rotate operations). If the model has a complex transformation matrix the results will be incorrect.
returns the x coordinate of the origin of the model's coordinate space.
returns the y coordinate of the origin of the model's coordinate space.
returns the scale of the model.
returns the clockwise rotation of the model, in degrees (0-360).
Gets the model's style. If the model doesn't have its own style it will return its parent's style.
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
Tests to see if the given item model is a container.
Checks whether object
has a [floating][floating-ref] reference.
Lowers a model in the stacking order.
the item model to lower model
below, or %NULL to lower model
to the bottom of the stack.
Moves a child to a new stack position.
the current position of the child.
the new position of the child.
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
.
Raises a model in the stacking order.
the item model to raise model
above, or %NULL to raise model
to the top of the stack.
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().
Removes a model from its parent. If the model is in a canvas it will be removed.
This would normally also result in the model being freed.
Removes the child at the given position.
the position of the child to remove.
Rotates the model's coordinate system by the given amount, about the given origin.
the clockwise angle of rotation.
the x coordinate of the origin of the rotation.
the y coordinate of the origin of the rotation.
Releases all references to other objects. This can be used to break reference cycles.
This function should only be called from object system implementations.
Scales the model's coordinate system by the given amounts.
the amount to scale the horizontal axis.
the amount to scale the vertical axis.
Sets a child property of child
.
a child #GooCanvasItemModel.
the name of the child property to set.
the value to set the property to.
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
This function is only intended to be used when implementing new canvas item models (specifically container models such as #GooCanvasGroupModel). It sets the parent of the child model.
the new parent item model.
Sets a property on an object.
the name of the property to set
the value
A convenience function to set the item model's transformation matrix.
the x coordinate of the origin of the model's coordinate space.
the y coordinate of the origin of the model's coordinate space.
the scale of the model.
the clockwise rotation of the model, in degrees.
Sets the model's style, by copying the properties from the given style.
a style.
Skews the model's coordinate system along the x axis by the given amount, about the given origin.
the skew angle.
the x coordinate of the origin of the skew transform.
the y coordinate of the origin of the skew transform.
Skews the model's coordinate system along the y axis by the given amount, about the given origin.
the skew angle.
the x coordinate of the origin of the skew transform.
the y coordinate of the origin of the skew transform.
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
Stops any current animation for the given model, leaving it at its current position.
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.
Translates the origin of the model's coordinate system by the given amounts.
the amount to move the origin in the horizontal direction.
the amount to move the origin in the vertical direction.
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.
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
#GooCanvasItemModelSimple is used as a base class for the standard canvas item models. It can also be used as the base class for new custom canvas item models.
It provides default implementations for many of the #GooCanvasItemModel methods.
Subclasses of #GooCanvasItemModelSimple only need to implement the create_item() method of the #GooCanvasItemModel interface, to create the default canvas item to view the item model.