[vtk-developers] Heads up changes to interactors and widgets....

[Will Schroeder]

I wanted to give VTK folks a heads up relative to some changes I will 
be checking in the next day or two. I have added some methods in 
vtkObject: GrabFocus(vtkCommand*) and ReleaseFocus() that allow a 
particular observer/command to gain total control over the stream of 
events. That is, when the focus is grabbed by a vtkCommand on a 
particular object, only events registered by that command/observer 
are processed.

(My primary motivation for this is to avoid widget/interactor 
contention when a widget starts a sequence of events and then the 
interactor starts intercepting/responding to events before the widget 
has completed processing its expected sequence of interaction events.)

While the testing says everything is fine, if there are any problems 
it manifests in the form of an unresponsive 
vtkRenderWindowInteractor. (I only saw this once when I forgot a 
ReleaseFocus() in one of the interactor styles :-)) Please let me 
know if you ever see this happen.

Will