private void OnHeadersPanelHostDirectManipulationStarted(object sender, object e)
{
if (_isAnimating)
{
return;
}
_isScrolling = true;
var header = TypedHeaders.Single(h => h.IsChecked == true);
if (GetHeaderIndex(header) != SelectedIndex)
{
return;
}
var headerContainer = GetHeaderContainer(header);
// _headersPanel goes over the its parent ScrollViewer's viewport, so we need to use it.
var offsetX = headerContainer.RelativePosition(_headersPanel).X.ToFloat();
var offsetAnimation = _compositor.CreateExpressionAnimation($"CurrentOffsetX + {ScrollerTranslationX} + LeftMargin");
offsetAnimation.SetReferenceParameter(Scroller, _headersScrollingProperties);
offsetAnimation.SetScalarParameter("LeftMargin", 12.0f);
offsetAnimation.SetScalarParameter("CurrentOffsetX", offsetX);
_selectedHeaderIndicatorVisual.StartAnimation("Offset.X", offsetAnimation);
}
private void SyncUnderlineVisual()
{
var header = TypedHeaders.Single((h) => h.IsChecked == true);
if (GetHeaderIndex(header) == SelectedIndex)
{
var textBlock = GetHeaderTextBlock(header);
var offsetX = textBlock.OffsetX(_headersPanelHost);
var scaleX = textBlock.ActualWidth.ToFloat(); // The ActualWidth of the HeaderUnderline Rectangle is 1 so I ignored the /1 here
_underline.StartOffsetAnimation(AnimationAxis.X, null, offsetX, 400, easing: _compositor.EaseInOutCubic());
_underline.StartScaleAnimation(AnimationAxis.X, null, scaleX, 400, easing: _compositor.EaseInOutCubic());
}
}
private void SyncSelectedHeaderIndicatorVisual()
{
var header = TypedHeaders.Single(h => h.IsChecked == true);
if (GetHeaderIndex(header) != SelectedIndex)
{
return;
}
var container = GetHeaderContainer(header);
var offsetX = container.RelativePosition(HeadersPanelHost).X.ToFloat() + 11.0f;
// The ActualWidth of the selected header indication Rectangle is 1 so I ignored the /1 here.
var scaleX = container.ActualWidth.ToFloat() - 24.0f;
_selectedHeaderIndicatorVisual.StartOffsetAnimation(AnimationAxis.X, null, offsetX, 400, easing: _compositor.EaseInOutCubic());
_selectedHeaderIndicatorVisual.StartScaleAnimation(AnimationAxis.X, null, scaleX, 400, easing: _compositor.EaseInOutCubic());
}
private void SyncCheckedTabHeaderItem(int index)
{
var header = TypedHeaders.Single((h) => GetHeaderIndex(h) == index);
header.IsChecked = true;
}
