Groups can be nested to any depth, to create a hierarchy of items. Items are ordered within each group, with later items being displayed
above earlier items.
CanvasGroupModel is a subclass of CanvasItemModelSimple
and so inherits all of the style properties such as "stroke-color", "fill-color" and "line-width". Setting a style property on a
CanvasGroupModel will affect all children of the CanvasGroupModel (unless the
children override the property setting).
CanvasGroupModel implements the CanvasItemModel
interface, so you can use the CanvasItemModel functions such as
raise and rotate,
and the properties such as "visibility" and "pointer-events".
To get or set the properties of an existing CanvasGroupModel, use @get and
@set.
To respond to events such as mouse clicks on the group you must connect to the signal handlers of the corresponding
CanvasGroup objects. (See get_item
and item_created.)