private void ValidateListener(IVisualStateListener listener)
{
if (string.Equals(VisualStateName, listener.VisualStateName) == false)
{
throw new ArgumentOutOfRangeException(nameof(listener));
}
}
public void DetachListener(IVisualStateListener listener)
{
ValidateListener(listener);
_listeners.Remove(listener);
if (_isActive)
{
listener.LeaveState(false);
}
}
public void AttachListener(IVisualStateListener listener)
{
ValidateListener(listener);
_listeners.Add(listener);
if (_isActive)
{
listener.EnterState(false);
}
}
public WeakVisualStateListener(IVisualStateListener listener)
{
VisualStateName = listener.VisualStateName;
_weakReference = new WeakReference(listener);
}
public void DetachListener(IVisualStateListener listener)
{
EnsureLayoutUpdatedHandler();
GetListenerCollection(listener.VisualStateName, false)?.DetachListener(listener);
}
public void AttachListener(IVisualStateListener listener)
{
EnsureLayoutUpdatedHandler();
GetListenerCollection(listener.VisualStateName, true).AttachListener(listener);
}
private static bool IsAliveListener(IVisualStateListener listener)
{
var weakListener = listener as IWeakReference;
return(weakListener == null || weakListener.IsAlive);
}
