dataviewer: reset metadata if url is None
If url is None then the tomwer.gui.visualization.dataviewer.ImageStack._reconsWidget
should be cleared (look for # FIXME: add a function to clear the metadata widget)
note for beginners
The 'SliceStack._viewer' has a clearSliceMetadata
that should do the job.
By the way we can also note that the setCurrentUrl
function signature is wrong because this function handle the case url
is None. The parent class signature is also different and allows None
value