/// <summary>
/// Creates a TranslateTransform and associates it with the given element, returning
/// a Storyboard which will animate the TranslateTransform with a SineEase function
/// </summary>
private static Storyboard GetAnimation(FrameworkElement element, bool fromRight)
{
double from = fromRight ? 80 : -80;
Storyboard sb;
double delay = (ListAnimation.GetAnimationLevel(element)) * 0.1 + 0.1;
TranslateTransform trans = new TranslateTransform()
{
X = from
};
element.RenderTransform = trans;
sb = new Storyboard();
sb.BeginTime = TimeSpan.FromSeconds(delay);
DoubleAnimation db = new DoubleAnimation();
db.To = 0;
db.From = from;
db.EasingFunction = new SineEase();
sb.Duration = db.Duration = TimeSpan.FromSeconds(0.8);
sb.Children.Add(db);
Storyboard.SetTarget(db, trans);
Storyboard.SetTargetProperty(db, new PropertyPath("X"));
return(sb);
}
private static void OnIsPivotAnimatedChanged(DependencyObject d, DependencyPropertyChangedEventArgs args)
{
ItemsControl list = d as ItemsControl;
list.Loaded += (s2, e2) =>
{
// locate the pivot control that this list is within
Pivot pivot = list.Ancestors <Pivot>().Single() as Pivot;
// and its index within the pivot
int pivotIndex = pivot.Items.IndexOf(list.Ancestors <PivotItem>().Single());
bool selectionChanged = false;
pivot.SelectionChanged += (s3, e3) =>
{
selectionChanged = true;
};
// handle manipulation events which occur when the user
// moves between pivot items
pivot.ManipulationCompleted += (s, e) =>
{
if (!selectionChanged)
{
return;
}
selectionChanged = false;
if (pivotIndex != pivot.SelectedIndex)
{
return;
}
// determine which direction this tab will be scrolling in from
bool fromRight = e.TotalManipulation.Translation.X <= 0;
// locate the stack panel that hosts the items
VirtualizingStackPanel vsp = list.Descendants <VirtualizingStackPanel>().First() as VirtualizingStackPanel;
// iterate over each of the items in view
int firstVisibleItem = (int)vsp.VerticalOffset;
int visibleItemCount = (int)vsp.ViewportHeight;
for (int index = firstVisibleItem; index <= firstVisibleItem + visibleItemCount; index++)
{
// find all the item that have the AnimationLevel attached property set
var lbi = list.ItemContainerGenerator.ContainerFromIndex(index);
if (lbi == null)
{
continue;
}
vsp.Dispatcher.BeginInvoke(() =>
{
var animationTargets = lbi.Descendants().Where(p => ListAnimation.GetAnimationLevel(p) > -1);
foreach (FrameworkElement target in animationTargets)
{
// trigger the required animation
GetAnimation(target, fromRight).Begin();
}
});
}
;
};
};
}
