BUG #14283. Fix change events fired by vtkControlPointsItem.
This commit consolidates the logic between all vtkControlPointsItem subclasses to consistently notify rest of the world that the control points were modified. Previously, commit 1509669d tried to do the same with vtkControlPointsItem::PointsModifiedEvent, however vtkCompositeControlPointsItem wasn't firing those consistently resulting in the BUG #14283. While attempting to fix that, I noticed that vtkControlPointsItem has StartChanges()/EndChanges() methods that could be used for a similar purpose: notify the world that control points are being changed. Hence, remved the PointsModifiedEvent, instead fixing the code to consistently use StartChanges()/EndChanges() calls. Fixed StartChanges/EndChanges to fire the event on the vtkControlPointsItem (along with tranfer function, as it was previously) and added logic to avoid duplicable firing of events due nested calls to StartChanges/EndChanges. Change-Id: I144e775cbdfbc9c1334cfc2b02609b37dda8cae7
Showing with 67 additions and 14 deletions