/// <summary>
/// Restores the original projection and render transform of
/// the targeted framework elements.
/// </summary>
private static void RestoreProjectionsAndTransforms()
{
if (_featheringTargets == null || !_pendingRestore)
{
return;
}
foreach (WeakReference r in _featheringTargets)
{
FrameworkElement element = r.Target as FrameworkElement;
if (element == null)
{
continue;
}
Projection projection = TurnstileFeatherEffect.GetOriginalProjection(element);
Transform transform = TurnstileFeatherEffect.GetOriginalRenderTransform(element);
element.Projection = projection;
element.RenderTransform = transform;
}
_pendingRestore = false;
}
/// <summary>
/// Unsubscribes an element from the private manager.
/// </summary>
/// <param name="target">The framework element.</param>
private static void UnsubscribeFrameworkElement(FrameworkElement target)
{
// If element is subscribed, unsubscribe.
if (TurnstileFeatherEffect.GetIsSubscribed(target))
{
TurnstileFeatherEffect.SetParentPage(target, null);
TurnstileFeatherEffect.SetIsSubscribed(target, false);
}
}
/// <summary>
/// Adds a set of animations corresponding to the
/// turnstile feather effect.
/// </summary>
/// <param name="storyboard">
/// The storyboard where the animations
/// will be added.</param>
/// <param name="beginTime">
/// The time at which the storyboard should begin.</param>
/// <param name="mode">
/// The mode of the turnstile feather effect.
/// </param>
internal static void ComposeStoryboard(Storyboard storyboard, TimeSpan?beginTime, TurnstileFeatherTransitionMode mode)
{
RestoreProjectionsAndTransforms();
_featheringTargets = GetTargetsToAnimate();
if (_featheringTargets == null)
{
return;
}
_pendingRestore = true;
switch (mode)
{
case TurnstileFeatherTransitionMode.ForwardIn:
ComposeForwardInStoryboard(storyboard);
break;
case TurnstileFeatherTransitionMode.ForwardOut:
ComposeForwardOutStoryboard(storyboard);
break;
case TurnstileFeatherTransitionMode.BackwardIn:
ComposeBackwardInStoryboard(storyboard);
break;
case TurnstileFeatherTransitionMode.BackwardOut:
ComposeBackwardOutStoryboard(storyboard);
break;
default:
break;
}
storyboard.BeginTime = beginTime;
storyboard.Completed += (s, e) =>
{
foreach (WeakReference r in _featheringTargets)
{
FrameworkElement element = (FrameworkElement)r.Target;
double originalOpacity = TurnstileFeatherEffect.GetOriginalOpacity(element);
element.Opacity = originalOpacity;
}
RestoreProjectionsAndTransforms();
};
}
/// <summary>
/// Subscribes an element to the private managers.
/// </summary>
/// <param name="target">The framework element.</param>
private static void SubscribeFrameworkElement(FrameworkElement target)
{
if (!TurnstileFeatherEffect.GetIsSubscribed(target))
{
// Find the parent page.
PhoneApplicationPage page = target.GetParentByType <PhoneApplicationPage>();
if (page == null)
{
return;
}
TurnstileFeatherEffect.SetParentPage(target, page);
TurnstileFeatherEffect.SetIsSubscribed(target, true);
}
}
/// <summary>
/// Adds a set of animations corresponding to the
/// turnstile feather backward in effect.
/// </summary>
/// <param name="storyboard">
/// The storyboard where the animations
/// will be added.
/// </param>
private static void ComposeBackwardInStoryboard(Storyboard storyboard)
{
int counter = 0;
PhoneApplicationFrame root = Application.Current.RootVisual as PhoneApplicationFrame;
foreach (WeakReference r in _featheringTargets)
{
FrameworkElement element = (FrameworkElement)r.Target;
double originalOpacity = element.Opacity;
TurnstileFeatherEffect.SetOriginalOpacity(element, originalOpacity);
// Hide the element until the storyboard is begun.
element.Opacity = 0.0;
if (!TryAttachProjectionAndTransform(root, element))
{
continue;
}
DoubleAnimation doubleAnimation = new DoubleAnimation()
{
Duration = TimeSpan.FromMilliseconds(BackwardInFeatheringDuration),
From = BackwardInFeatheringAngle,
To = 0.0,
BeginTime = TimeSpan.FromMilliseconds(BackwardInFeatheringDelay * counter),
EasingFunction = TurnstileFeatheringExponentialEaseOut
};
Storyboard.SetTarget(doubleAnimation, element);
Storyboard.SetTargetProperty(doubleAnimation, RotationYPropertyPath);
storyboard.Children.Add(doubleAnimation);
doubleAnimation = new DoubleAnimation()
{
Duration = TimeSpan.Zero,
From = 0.0,
To = originalOpacity,
BeginTime = TimeSpan.FromMilliseconds(BackwardInFeatheringDelay * counter)
};
Storyboard.SetTarget(doubleAnimation, element);
Storyboard.SetTargetProperty(doubleAnimation, OpacityPropertyPath);
storyboard.Children.Add(doubleAnimation);
counter++;
}
}
/// <summary>
/// Prepares a framework element to be feathered by adding a plane projection
/// and a composite transform to it.
/// </summary>
/// <param name="root">The root visual.</param>
/// <param name="element">The framework element.</param>
private static bool TryAttachProjectionAndTransform(PhoneApplicationFrame root, FrameworkElement element)
{
GeneralTransform generalTransform;
try
{
generalTransform = element.TransformToVisual(root);
}
catch (ArgumentException)
{
return(false);
}
Point coordinates = generalTransform.Transform(Origin);
double y = coordinates.Y + element.ActualHeight / 2.0;
double offset = (root.ActualHeight / 2.0) - y;
// Cache original projection and transform.
TurnstileFeatherEffect.SetOriginalProjection(element, element.Projection);
TurnstileFeatherEffect.SetOriginalRenderTransform(element, element.RenderTransform);
// Attach projection.
PlaneProjection projection = new PlaneProjection();
projection.GlobalOffsetY = offset * -1.0;
projection.CenterOfRotationX = FeatheringCenterOfRotationX;
element.Projection = projection;
// Attach transform.
Transform originalTransform = element.RenderTransform;
TranslateTransform translateTransform = new TranslateTransform();
translateTransform.Y = offset;
TransformGroup transformGroup = new TransformGroup();
transformGroup.Children.Add(originalTransform);
transformGroup.Children.Add(translateTransform);
element.RenderTransform = transformGroup;
return(true);
}
/// <summary>
/// Subscribes an element to the private manager.
/// </summary>
/// <param name="obj">The event sender.</param>
/// <param name="e">The event arguments.</param>
private static void OnFeatheringIndexPropertyChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
{
FrameworkElement target = obj as FrameworkElement;
if (target == null)
{
string message = string.Format(CultureInfo.InvariantCulture, "The dependency object must be of the type {0}.", typeof(FrameworkElement));
throw new InvalidOperationException(message);
}
CheckForTypePermission(target);
int index = (int)e.NewValue;
if (index < 0)
{
// Dettach event handlers.
if (TurnstileFeatherEffect.GetHasEventsAttached(target))
{
target.SizeChanged -= Target_SizeChanged;
target.Unloaded -= Target_Unloaded;
TurnstileFeatherEffect.SetHasEventsAttached(target, false);
}
UnsubscribeFrameworkElement(target);
}
else
{
// Attach event handlers.
if (!TurnstileFeatherEffect.GetHasEventsAttached(target))
{
target.SizeChanged += Target_SizeChanged;
target.Unloaded += Target_Unloaded;
TurnstileFeatherEffect.SetHasEventsAttached(target, true);
}
SubscribeFrameworkElement(target);
}
}
/// <summary>
/// Composes the
/// <see cref="M:System.Windows.Media.Animation.Storyboard"/>
/// and mirrors
/// <see cref="M:System.Windows.Media.Animation.Storyboard.Begin"/>.
/// </summary>
public override void Begin()
{
TurnstileFeatherEffect.ComposeStoryboard(Storyboard, _beginTime, _mode);
base.Begin();
}
