private void ConfigureAnimations(Visual photoVisual, Visual infoVisual, SpriteVisual shadowVisual)
{
// Create a drop shadow to be animated by the manipulation
var shadow = _compositor.CreateDropShadow();
shadowVisual.Shadow = shadow;
_props.InsertScalar("progress", 0);
// Create an animation that tracks the progress of the manipulation and stores it in a the PropertySet _props
var trackerNode = _tracker.GetReference();
_props.StartAnimation("progress", trackerNode.Position.Y / trackerNode.MaxPosition.Y);
// Create an animation that scales up the infoVisual based on the manipulation progress
var propSetProgress = _props.GetReference().GetScalarProperty("progress");
infoVisual.StartAnimation("Scale", EF.Vector3(1, 1, 1) * EF.Lerp(1, 1.2f, propSetProgress));
// Create an animation that changes the offset of the photoVisual and shadowVisual based on the manipulation progress
var photoOffsetExp = -120f * _props.GetReference().GetScalarProperty("Progress");
photoVisual.StartAnimation("offset.y", photoOffsetExp);
shadowVisual.StartAnimation("offset.y", photoOffsetExp);
// Create an animation that fades in the info visual based on the manipulation progress
infoVisual.StartAnimation("opacity", EF.Lerp(0, 1, _props.GetReference().GetScalarProperty("Progress")));
shadow.StartAnimation("blurradius", EF.Lerp(1, 50, _props.GetReference().GetScalarProperty("Progress")));
}
private void SetupExpressionAnimationsForCard()
{
_cardVisual = VisualExtensions.GetVisual(Card);
_cardVisual.RelativeSizeAdjustment = Vector2.One;
_cardVisual.CenterPoint = new Vector3(Card.RenderSize.ToVector2() / 2, 0.0f);
var initialPositionY = (float)ActualHeight;
_cardVisual.Offset = new Vector3(0.0f, initialPositionY, 0.0f);
_progress.InsertScalar("Progress", 0);
var progressExpressionNode = _progress.GetReference().GetScalarProperty("Progress");
// Scale the card visual based on the progress.
_cardVisual.StartAnimation("Scale", EF.Vector3(1.0f, 1.0f, 1.0f) * EF.Lerp(0.6f, 1.0f, progressExpressionNode));
// Fade in the card visual based on the progress.
_cardVisual.StartAnimation("Opacity", EF.Lerp(0.0f, 1.0f, progressExpressionNode));
// Move the card visual based on the progress.
var offset = initialPositionY * (1.0f - progressExpressionNode);
_cardVisual.StartAnimation("Offset.Y", offset);
}
private void Page_Loaded(object sender, RoutedEventArgs e)
{
// Retrieve the ScrollViewer that the GridView is using internally
var scrollViewer = gridView.GetFirstDescendantOfType <ScrollViewer>();
// Update the ZIndex of the header container so that the header is above the items when scrolling
var headerPresenter = (UIElement)VisualTreeHelper.GetParent((UIElement)gridView.Header);
var headerContainer = (UIElement)VisualTreeHelper.GetParent(headerPresenter);
Canvas.SetZIndex((UIElement)headerContainer, 1);
// Get the PropertySet that contains the scroll values from the ScrollViewer
_scrollerPropertySet = ElementCompositionPreview.GetScrollViewerManipulationPropertySet(scrollViewer);
_compositor = _scrollerPropertySet.Compositor;
// Create a PropertySet that has values to be referenced in the ExpressionAnimations below
_props = _compositor.CreatePropertySet();
_props.InsertScalar("progress", 0);
_props.InsertScalar("clampSize", 150);
_props.InsertScalar("scaleFactor", 0.7f);
// Get references to our property sets for use with ExpressionNodes
var scrollingProperties = _scrollerPropertySet.GetSpecializedReference <ManipulationPropertySetReferenceNode>();
var props = _props.GetReference();
var progressNode = props.GetScalarProperty("progress");
var clampSizeNode = props.GetScalarProperty("clampSize");
var scaleFactorNode = props.GetScalarProperty("scaleFactor");
// Create a blur effect to be animated based on scroll position
var blurEffect = new GaussianBlurEffect()
{
Name = "blur",
BlurAmount = 0.0f,
BorderMode = EffectBorderMode.Hard,
Optimization = EffectOptimization.Balanced,
Source = new CompositionEffectSourceParameter("source")
};
var blurBrush = _compositor.CreateEffectFactory(
blurEffect,
new[] { "blur.BlurAmount" })
.CreateBrush();
blurBrush.SetSourceParameter("source", _compositor.CreateBackdropBrush());
// Create a Visual for applying the blur effect
_blurredBackgroundImageVisual = _compositor.CreateSpriteVisual();
_blurredBackgroundImageVisual.Brush = blurBrush;
_blurredBackgroundImageVisual.Size = new Vector2((float)OverlayRectangle.ActualWidth, (float)OverlayRectangle.ActualHeight);
// Insert the blur visual at the right point in the Visual Tree
ElementCompositionPreview.SetElementChildVisual(OverlayRectangle, _blurredBackgroundImageVisual);
// Create and start an ExpressionAnimation to track scroll progress over the desired distance
ExpressionNode progressAnimation = EF.Clamp(-scrollingProperties.Translation.Y / clampSizeNode, 0, 1);
_props.StartAnimation("progress", progressAnimation);
// Create and start an ExpressionAnimation to animate blur radius between 0 and 15 based on progress
ExpressionNode blurAnimation = EF.Lerp(0, 15, progressNode);
_blurredBackgroundImageVisual.Brush.Properties.StartAnimation("blur.BlurAmount", blurAnimation);
// Get the backing visual for the header so that its properties can be animated
Visual headerVisual = ElementCompositionPreview.GetElementVisual(Header);
// Create and start an ExpressionAnimation to clamp the header's offset to keep it onscreen
ExpressionNode headerTranslationAnimation = EF.Conditional(progressNode < 1, 0, -scrollingProperties.Translation.Y - clampSizeNode);
headerVisual.StartAnimation("Offset.Y", headerTranslationAnimation);
// Create and start an ExpressionAnimation to scale the header during overpan
ExpressionNode headerScaleAnimation = EF.Lerp(1, 1.25f, EF.Clamp(scrollingProperties.Translation.Y / 50, 0, 1));
headerVisual.StartAnimation("Scale.X", headerScaleAnimation);
headerVisual.StartAnimation("Scale.Y", headerScaleAnimation);
//Set the header's CenterPoint to ensure the overpan scale looks as desired
headerVisual.CenterPoint = new Vector3((float)(Header.ActualWidth / 2), (float)Header.ActualHeight, 0);
// Get the backing visual for the photo in the header so that its properties can be animated
Visual photoVisual = ElementCompositionPreview.GetElementVisual(BackgroundRectangle);
// Create and start an ExpressionAnimation to opacity fade out the image behind the header
ExpressionNode imageOpacityAnimation = 1 - progressNode;
photoVisual.StartAnimation("opacity", imageOpacityAnimation);
// Get the backing visual for the profile picture visual so that its properties can be animated
Visual profileVisual = ElementCompositionPreview.GetElementVisual(ProfileImage);
// Create and start an ExpressionAnimation to scale the profile image with scroll position
ExpressionNode scaleAnimation = EF.Lerp(1, scaleFactorNode, progressNode);
profileVisual.StartAnimation("Scale.X", scaleAnimation);
profileVisual.StartAnimation("Scale.Y", scaleAnimation);
// Get backing visuals for the text blocks so that their properties can be animated
Visual blurbVisual = ElementCompositionPreview.GetElementVisual(Blurb);
Visual subtitleVisual = ElementCompositionPreview.GetElementVisual(SubtitleBlock);
Visual moreVisual = ElementCompositionPreview.GetElementVisual(MoreText);
// Create an ExpressionAnimation that moves between 1 and 0 with scroll progress, to be used for text block opacity
ExpressionNode textOpacityAnimation = EF.Clamp(1 - (progressNode * 2), 0, 1);
// Start opacity and scale animations on the text block visuals
blurbVisual.StartAnimation("Opacity", textOpacityAnimation);
blurbVisual.StartAnimation("Scale.X", scaleAnimation);
blurbVisual.StartAnimation("Scale.Y", scaleAnimation);
subtitleVisual.StartAnimation("Opacity", textOpacityAnimation);
subtitleVisual.StartAnimation("Scale.X", scaleAnimation);
subtitleVisual.StartAnimation("Scale.Y", scaleAnimation);
moreVisual.StartAnimation("Opacity", textOpacityAnimation);
moreVisual.StartAnimation("Scale.X", scaleAnimation);
moreVisual.StartAnimation("Scale.Y", scaleAnimation);
// Get the backing visuals for the text and button containers so that their properites can be animated
Visual textVisual = ElementCompositionPreview.GetElementVisual(TextContainer);
Visual buttonVisual = ElementCompositionPreview.GetElementVisual(ButtonPanel);
// When the header stops scrolling it is 150 pixels offscreen. We want the text header to end up with 50 pixels of its content
// offscreen which means it needs to go from offset 0 to 100 as we traverse through the scrollable region
ExpressionNode contentOffsetAnimation = progressNode * 100;
textVisual.StartAnimation("Offset.Y", contentOffsetAnimation);
ExpressionNode buttonOffsetAnimation = progressNode * -100;
buttonVisual.StartAnimation("Offset.Y", buttonOffsetAnimation);
}