Context aware selection makes it possible to select the same Coin3D node
in different hierarchies (i.e. context) without ambiguity.
New/modified APIs in ViewProvider (the first two are the most crucial
APIs for context aware selection to work):
* getElementPicked(), supercedes getElement(). Given a Coin3D pick
point, this function returns a dot separated subname reference as a
path leads to the selected object.
* getDetailPath(), supercedes getDetail(). Given a subname reference,
this function returns an SoFullPath leads to the Coin3D node of the
selected object or sub-element (with SoDetail).
* (has)HiddenMarker(), check/return a special text marker for context
aware override of object visibility.
* partialRender(), render only part of the object based on given
subname references. It can render, e.g. some faces of a solid, or
some children of a container. It uses the 'secondary' extension of
SoSelectionElementAction to select which elements to render or hide.
The actually rendering functionality will be added in the following
patch.
* update()/onChanged(), modified to sync Visibility property from
DocumentObject.
* useNewSelectionModel(), modified to return the default true view
parameter. This is for test in the early stage of Link development,
probably not needed anymore.
* getBoundingBox(), a convenience function to obtain the bounding box
of a sub-object/element regardless of object's visibility. It uses
getDetailPath() and SoGetBoundingBoxAction to obtain bounding box
through Coin3D. It will be used in later sub-element box selection
functionality.
New/modified APIs in ViewProviderDocumentObject:
* getElementPicked()/getDetailPath() provides actual implementation to
support container like (sub)object selection without ambiguity. It
relies on DocumentObject::getSubObject() to walk the path.
* reattach(), called when undo deleteion
* forceUpdate()/isUpdateForced(), force update even if object is
invisible. These are used by Link to force update the visual of a
linked object regardless of its visibility.
* getLinkedViewProvider(), return the linked view provider with
hierarchy.
ViewProviderDocumentObjectPy:
* Object attribute is made writtable. Assigning it is equaivalant of
calling ViewProviderDocumentObject::attach() in Python.
