public async Task <bool> Unload()
{
NavigationStateStatus newStatus = NavigationStateStatus.Unloaded;
if (IsAlreadyInSameStatus(newStatus))
{
return(true);
}
bool result = await ScreenState.UnloadState();
if (result)
{
UpdateState(newStatus);
}
if (freezingState != null && freezingState.Completion.Task.Status != TaskStatus.RanToCompletion)
{
freezingState.Completion.SetResult(true);
freezingState = null;
}
// FIXME: when quit is done a double home navigation is done
// this causes that the hide/unload of the state is done twice
// because the stack is not empty, the hide state is the one creating
// the second home transition
if (Completion.Task.Status != TaskStatus.RanToCompletion && completeWhenUnload)
{
Completion.SetResult(result);
}
return(result);
}
public async Task <bool> Unfreeze()
{
NavigationStateStatus newStatus = NavigationStateStatus.Shown;
if (IsAlreadyInSameStatus(newStatus))
{
return(true);
}
bool result = await ScreenState.UnfreezeState();
if (result)
{
UpdateState(newStatus);
}
var freezingStateMemento = freezingState;
freezingState = null;
if (freezingStateMemento.Completion.Task.Status != TaskStatus.RanToCompletion)
{
freezingStateMemento.Completion.SetResult(result);
}
return(result);
}
bool IsAlreadyInSameStatus(NavigationStateStatus status)
{
if (CurrentStatus == status)
{
Log.Warning($"NavigationState has already to desired status {CurrentStatus}");
return(true);
}
return(false);
}
void UpdateState(NavigationStateStatus status)
{
Log.Verbose($"Transitioning navigation state {Name} from {CurrentStatus} to {status}");
if (Math.Abs(status - CurrentStatus) > 1 &&
!((CurrentStatus == NavigationStateStatus.Hidden && status == NavigationStateStatus.Shown) ||
(CurrentStatus == NavigationStateStatus.Shown && status == NavigationStateStatus.Hidden)))
{
Log.Warning($"Possible inconsistent status transition from {CurrentStatus} to {status}");
}
CurrentStatus = status;
}
public async Task <bool> Hide()
{
NavigationStateStatus newStatus = NavigationStateStatus.Hidden;
if (IsAlreadyInSameStatus(newStatus))
{
return(true);
}
bool result = await ScreenState.HideState();
if (result)
{
UpdateState(newStatus);
}
return(result);
}
public async Task <bool> Load(dynamic data)
{
NavigationStateStatus newStatus = NavigationStateStatus.Loaded;
if (IsAlreadyInSameStatus(newStatus))
{
return(true);
}
bool result = await ScreenState.LoadState(data);
if (result)
{
UpdateState(newStatus);
}
return(result);
}
public async Task <bool> Freeze(NavigationState freezingState)
{
NavigationStateStatus newStatus = NavigationStateStatus.Frozen;
if (IsAlreadyInSameStatus(newStatus))
{
return(true);
}
this.freezingState = freezingState;
bool result = await ScreenState.FreezeState();
if (result)
{
UpdateState(newStatus);
}
return(result);
}
