private void TargetElement_PreviewLostKeyboardFocus(object sender, KeyboardFocusChangedEventArgs e)
{
log.DebugFormat("Losing keyboard focus: {0}, from {1}, to {2}", sender, e.OldFocus, e.NewFocus);
DependencyObject oldFocus = e.OldFocus as DependencyObject;
DependencyObject newFocus = e.NewFocus as DependencyObject;
if (oldFocus != null & newFocus != null)
{
if (TargetElement.IsAncestorOf(oldFocus) && TargetElement.IsAncestorOf(newFocus))
{
// Focus moved within the container.
return;
}
}
log.Debug("Saving state on UI service providers");
var statePersistentServices = UIServiceProvider.GetAllServices <IStatePersistency>(TargetElement);
foreach (var service in statePersistentServices)
{
service.SaveCurrentState();
}
}
private void TargetElement_PreviewGotKeyboardFocus(object sender, KeyboardFocusChangedEventArgs e)
{
log.DebugFormat("Regaining keyboard focus: {0}, from {1}, to {2}", sender, e.OldFocus, e.NewFocus);
//if (isUpdatingFocus.IsSet)
// return;
if (isFirstFocus)
{
isFirstFocus = false;
log.Debug("Got focus for the first time.");
UpdateFocus();
return;
}
if (isRestoringState.IsSet)
{
return;
}
using (isRestoringState.Set())
{
DependencyObject oldFocus = e.OldFocus as DependencyObject;
if (oldFocus == null)
{
log.Debug("Old focus is null. Not restoring focus.");
return;
}
DependencyObject newFocus = e.NewFocus as DependencyObject;
if (newFocus != null)
{
if (TargetElement.IsAncestorOf(oldFocus) && TargetElement.IsAncestorOf(newFocus))
{
log.DebugFormat("Focus changed within the same element");
// Focus moved within the container.
return;
}
}
log.Debug("Restoring state on UI service providers");
var statePersistentServices = UIServiceProvider.GetAllServices <IStatePersistency>(TargetElement);
foreach (var service in statePersistentServices)
{
service.RestoreState();
}
}
}