/// <summary>
/// TabView is panned. Update horizontal line location during pan.
/// </summary>
private void OnPanChanged(object sender, PanChangedArgs args)
{
_previousPanChangedArgs = args;
View leftChild = null;
View rightChild = null;
int leftIndex = (int)Math.Floor(args.Location);
leftIndex = leftIndex < 0 ? _children.Count - 1 : leftIndex;
int rightIndex = (int)Math.Ceiling(args.Location);
rightIndex = rightIndex > _children.Count - 1 || leftIndex == _children.Count - 1 ? 0 : rightIndex;
leftChild = _children[leftIndex].Child;
rightChild = _children[rightIndex].Child;
double panWidth = leftChild.Width + ((rightChild.Width - leftChild.Width) * (args.Location - leftIndex));
double panXDelta = ((rightChild.X + rightChild.TranslationX) - (leftChild.X + leftChild.TranslationX)) * (args.Location - leftIndex);
double panX = leftChild.X + leftChild.TranslationX + panXDelta;
ChildInfo lastChild = _children.Last();
ChildInfo firstChild = _children.First();
if ((panX + (panWidth / 2) > Width / 2 && lastChild.Size.Request.Width + lastChild.Child.TranslationX > Width) ||
(panX + (panWidth / 2) <= Width / 2 && firstChild.Child.TranslationX < 0))
{
double newPanX = (Width - panWidth) / 2;
double childrenPanDelta = panX - newPanX;
View firstIndexChild = _children.First(c => c.Index == 0).Child;
if (firstIndexChild.TranslationX - childrenPanDelta > 0)
{
childrenPanDelta += (firstIndexChild.TranslationX - childrenPanDelta);
}
View lastIndexChild = _children.First(c => c.Index == _children.Count - 1).Child;
if (lastIndexChild.TranslationX + lastIndexChild.Bounds.Width - childrenPanDelta < Width)
{
childrenPanDelta = -(Width - (lastIndexChild.TranslationX + lastIndexChild.Bounds.Width));
}
foreach (ChildInfo child in _children)
{
child.Child.TranslationX -= childrenPanDelta;
}
panX = newPanX;
}
LayoutChildIntoBoundingRegion(_focusLine, new Rectangle(panX, Height - FocusLineHeightRequest, panWidth, FocusLineHeightRequest));
}
private void OnTabViewPanChanged(object sender, PanChangedArgs args)
{
if (sender is CarouselView carouselView && carouselView.ItemsLayout is CarouselLayout carouselLayout)
{
if (_relatedViews == null)
{
_relatedViews = new RelatedViews(this);
}
foreach (View child in carouselLayout.Children)
{
ScrollView scrollView = VisualTreeHelper.FindVisualChildren <ScrollView>(child).FirstOrDefault();
if (scrollView != null && scrollView.ScrollY != _scrollY)
{
ScrollSource.UpdateScrollViewStart(this, _relatedViews.ContentPage, _relatedViews.NavigationPage, scrollView, _scrollY);
}
}
}
}
/// <summary>
/// Event when CarouselLayout pan changed
/// </summary>
protected void OnPanChanged(object sender, PanChangedArgs args)
{
// Continue event raise
PanChanged?.Invoke(this, args);
}
