There should be a way to block signals from mitk::SliceNavigationController.
We have a custom viewer based on QmitkStdMultiWidget. The logic of changing the window layout or the geometry is more complex than that of the original QmitkStdMultiWidget. It involves construction a geometry for the slice navigation controllers, setting their positions, etc.
Currently, several events are generated during this process, which results that other plugins who listen to the slice change events, get notified about slice changes when the viewer is in an inconsistent state, because the geometry is being set at the moment.
The solution would be to block the signals of the SNCs while the geometry is being set, and send out the notifications when the viewer is in a consistent state again.
I am going to propose a patch through a github pull request.