private async Task ToggleListItemAnimationAsync(bool show)
{
_listItemVisual.Opacity = 0f;
var targetImageSize = GetTargetImageSize();
var targetImagePosition = GetTargetPosition();
this.Visibility = Visibility.Visible;
if (show && !_detailContentGirdSizeSpecified)
{
UpdateDetailContentGridSize();
await DetailContentGrid.WaitForSizeChangedAsync();
}
var listItemSize = new Vector2((float)_listItem.ActualWidth, (float)_listItem.ActualHeight);
var listItemCenterPosition = _listItem.TransformToVisual(Window.Current.Content)
.TransformPoint(new Point(_listItem.ActualWidth / 2, _listItem.ActualHeight / 2));
var targetSize = GetTargetImageSize();
var offsetXAbs = (float)listItemCenterPosition.X - (targetImagePosition.X + targetImageSize.X / 2);
var offsetYAbs = (float)listItemCenterPosition.Y - (targetImagePosition.Y + targetImageSize.Y / 2);
var startX = show ? offsetXAbs : _detailContentGridVisual.GetTranslation().X;
var startY = show ? offsetYAbs : _detailContentGridVisual.GetTranslation().Y;
var endX = show ? 0f : offsetXAbs;
var endY = show ? 0f : offsetYAbs;
var startScale = show ? listItemSize.X / targetImageSize.X : 1f;
var endScale = show ? 1f : listItemSize.X / targetImageSize.X;
_detailGridVisual.Opacity = 1f;
_detailContentGridVisual.CenterPoint = new Vector3(targetImageSize.X / 2f, targetImageSize.Y / 2f, 1f);
var scaleAnim = _compositor.CreateVector3KeyFrameAnimation();
scaleAnim.Duration = TimeSpan.FromMilliseconds(400);
scaleAnim.InsertKeyFrame(0f, new Vector3(startScale, startScale, 1f));
scaleAnim.InsertKeyFrame(1f, new Vector3(endScale, endScale, 1f));
_detailContentGridVisual.StartAnimation("Scale", scaleAnim);
var offsetAnim = _compositor.CreateVector3KeyFrameAnimation();
offsetAnim.Duration = TimeSpan.FromMilliseconds(400);
offsetAnim.InsertKeyFrame(0f, new Vector3(startX, startY, 0f));
offsetAnim.InsertKeyFrame(1f, new Vector3(endX, endY, 0f));
_detailContentGridVisual.StartAnimation("Translation", offsetAnim);
}
private async Task UpdateDetailContentGridSizeAsync(bool awaitForSizeChanged)
{
var size = GetTargetSize();
DetailContentGrid.Width = size.X;
DetailContentGrid.Height = size.Y;
DetailContentGrid.Clip = new RectangleGeometry()
{
Rect = new Rect(0, 0, size.X, size.Y)
};
_detailContentGirdSizeSpecified = true;
if (awaitForSizeChanged)
{
await DetailContentGrid.WaitForSizeChangedAsync();
}
}