Triggered when the current selection is cleared.
function( jsEvent, view )
A selection might be cleared for a number of reasons:
The user clicks away from the current selection (doesn’t happen when unselectAuto is
The user makes a new selection. The
unselectcallback will be fired before the new selection occurs.
The user moves forward or backward in the current view, or switches to a new view.
The unselect method is called through the API.
unselect has been triggered via the unselect method,
jsEvent will be