private void OnJournalOwnershipPropertyChanged(JournalOwnership newValue)
{
// NavigationService.InvalidateJournalNavigationScope() will be called (recursively)
// when making an ownership change and will throw if there is a navigation in progress.
switch (_journalOwnership/*previous value*/)
{
case JournalOwnership.Automatic:
switch (newValue)
{
case JournalOwnership.OwnsJournal:
SwitchToOwnJournal();
break;
case JournalOwnership.UsesParentJournal:
SwitchToParentJournal();
break;
}
break;
case JournalOwnership.OwnsJournal:
Debug.Assert(_ownJournalScope != null);
switch (newValue)
{
case JournalOwnership.Automatic:
Debug.Fail("UsesOwnJournal->Automatic transition should be blocked by CoerceJournalOwnership().");
break;
case JournalOwnership.UsesParentJournal:
SwitchToParentJournal();
break;
}
break;
case JournalOwnership.UsesParentJournal:
Debug.Assert(_ownJournalScope == null);
switch (newValue)
{
case JournalOwnership.Automatic:
// The effective journal ownership is not going to change unless the
// frame is reparented (or, more unlikely, the parent's journal becomes
// unavailable). This invalidation is done only so that the next
// navigation causes a switch to UsesParentJournal, to be consistent
// with the initial transition from Automatic.
_navigationService.InvalidateJournalNavigationScope();
break;
case JournalOwnership.OwnsJournal:
SwitchToOwnJournal();
break;
}
break;
}
_journalOwnership = newValue;
}
public static T JournalOwnership <T>(this T source, JournalOwnership value) where T : Frame
{
source.JournalOwnership = value;
return(source);
}
