protected override void OnContentChanged(object oldContent, object newContent)
{
UIElement oldElement = oldContent as UIElement;
UIElement newElement = newContent as UIElement;
// Try to force ClientArea to be realized
//this.ApplyTemplate();
// Require the appropriate template parts plus a new element to
// transition to.
if (_clientArea == null)
{
return;
}
_oldPresenter = _newPresenter;
_newPresenter = GetNewPresenter();
_clientArea.Children.Insert(0, _newPresenter);
SetOpacity(_newPresenter, 0);
_newPresenter.Visibility = Visibility.Visible;
_newPresenter.Content = newElement;
if (_oldPresenter != null)
{
_oldPresenter.GetVisual();
lock (_presenters)
_presenters.Enqueue(_oldPresenter);
SetOpacity(_oldPresenter, 1);
_oldPresenter.Visibility = Visibility.Visible;
_oldPresenter.IsHitTestVisible = false;
if (oldElement != null)
{
_oldPresenter.Content = oldElement;
}
}
// If we're not playing transitions, get in and out in a flash.
if (SkipTransition)
{
SkipTransition = false;
{
Sb_Completed(null, null);
if (_oldPresenter != null)
{
_clientArea.Children.Remove(_oldPresenter);
_oldPresenter.Content = null;
_oldPresenter = null;
}
SetOpacity(_newPresenter, 1);
}
return;
}
if (oldElement == null)
{
SetOpacity(_newPresenter, 1);
}
else
{
if (AnimationEngine == NavigationAnimationEngine.Composition)
{
SetOpacity(_newPresenter, 1);
// Create a composition scoped batch. This will track when the transition completes
Compositor comp = _oldPresenter.GetVisual().Compositor;
CompositionScopedBatch batch = _currentBatch = comp.CreateScopedBatch(CompositionBatchTypes.Animation);
batch.Completed += Batch_Completed;
// Create a start the transition
CompositionStoryboard group = _currentGroup = GenerateCompositionTransition(_isForwardNavigation ? NavigationMode.New : NavigationMode.Back, _oldPresenter, _newPresenter);
group.Start();
// Seal the batch
batch.End();
}
else
{
Storyboard sb = _currentTransition = GenerateStoryboardTransition(_isForwardNavigation ? NavigationMode.New : NavigationMode.Back, _oldPresenter, _newPresenter);
sb.Completed += Sb_Completed;
var a = Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Low, () =>
{
sb.Begin();
});
}
}
}