@@ -49,6 +49,10 @@ protected override UICollectionViewLayout SelectLayout()
4949
5050 var layout = new UICollectionViewCompositionalLayout ( ( sectionIndex , environment ) =>
5151 {
52+ if ( VirtualView is null )
53+ {
54+ return null ;
55+ }
5256 double sectionMargin = 0.0 ;
5357 if ( ! IsHorizontal )
5458 {
@@ -77,57 +81,67 @@ protected override UICollectionViewLayout SelectLayout()
7781 var group = IsHorizontal ? NSCollectionLayoutGroup . GetHorizontalGroup ( groupSize , item , 1 ) :
7882 NSCollectionLayoutGroup . GetVerticalGroup ( groupSize , item , 1 ) ;
7983
80- int currentPosition = 0 ;
81-
8284 // Create our section layout
8385 var section = NSCollectionLayoutSection . Create ( group : group ) ;
8486 section . InterGroupSpacing = itemSpacing ;
8587 section . OrthogonalScrollingBehavior = UICollectionLayoutSectionOrthogonalScrollingBehavior . GroupPagingCentered ;
8688 section . VisibleItemsInvalidationHandler = ( items , offset , env ) =>
8789 {
90+ //This will allow us to SetPosition when we are scrolling the items
91+ //based on the current page
8892 var page = ( offset . X + sectionMargin ) / env . Container . ContentSize . Width ;
8993
90- // Check if we are at the beginning or end of the page
91- if ( Math . Abs ( page % 1 ) <= ( double . Epsilon * 100 ) && Controller . ItemsSource . ItemCount > 0 )
94+ // Check if we not are at the beginning or end of the page and if we have items
95+ if ( Math . Abs ( page % 1 ) > ( double . Epsilon * 100 ) || Controller . ItemsSource . ItemCount <= 0 )
9296 {
93- var pageIndex = ( int ) page ;
97+ return ;
98+ }
99+
100+ var pageIndex = ( int ) page ;
101+ var carouselPosition = pageIndex ;
102+
103+ var cv2Controller = ( CarouselViewController2 ) Controller ;
94104
95- if ( ItemsView . Loop )
105+ //If we are looping, we need to get the correct position
106+ if ( ItemsView . Loop )
107+ {
108+ var maxIndex = ( Controller . ItemsSource as ILoopItemsViewSource ) . LoopCount - 1 ;
109+
110+ //To mimic looping, we needed to modify the ItemSource and inserted a new item at the beginning and at the end
111+ if ( pageIndex == maxIndex )
96112 {
97- var maxIndex = ( Controller . ItemsSource as Items . ILoopItemsViewSource ) . LoopCount - 1 ;
113+ //When at last item, we need to change to 2nd item, so we can scroll right or left
114+ pageIndex = 1 ;
115+ }
116+ else if ( pageIndex == 0 )
117+ {
118+ //When at first item, need to change to one before last, so we can scroll right or left
119+ pageIndex = maxIndex - 1 ;
120+ }
98121
99- //To mimic looping, we needed to modify the ItemSource and inserted a new item at the beginning and at the end
100- if ( pageIndex == maxIndex )
101- {
102- //When at last item, we need to change to 2nd item, so we can scroll right or left
103- pageIndex = 1 ;
104- }
105- else if ( pageIndex == 0 )
122+ //since we added one item at the beginning of our ItemSource, we need to subtract one
123+ carouselPosition = pageIndex - 1 ;
124+
125+ if ( ItemsView . Position != carouselPosition )
126+ {
127+ //If we are updating the ItemsSource, we don't want to scroll the CollectionView
128+ if ( cv2Controller . IsUpdating ( ) )
106129 {
107- //When at first item, need to change to one before last, so we can scroll right or left
108- pageIndex = maxIndex - 1 ;
130+ return ;
109131 }
110132
111- //since we added one item at the beginning, we need to subtract one
112- var realPage = pageIndex - 1 ;
133+ var goToIndexPath = cv2Controller . GetScrollToIndexPath ( carouselPosition ) ;
113134
114- if ( currentPosition != realPage )
115- {
116- currentPosition = realPage ;
117- var pageNumberIndex = NSIndexPath . FromRowSection ( pageIndex , 0 ) ;
118- Controller . CollectionView . ScrollToItem ( pageNumberIndex , UICollectionViewScrollPosition . Left , false ) ;
135+ //This will move the carousel to fake the loop
136+ Controller . CollectionView . ScrollToItem ( NSIndexPath . FromItemSection ( pageIndex , 0 ) , UICollectionViewScrollPosition . Left , false ) ;
119137
120- //Update the CarouselView position
121- ( Controller as CarouselViewController2 ) ? . SetPosition ( realPage ) ;
122- }
123- }
124- else
125- {
126- ( Controller as CarouselViewController2 ) ? . SetPosition ( ( int ) page ) ;
127138 }
128139 }
129- } ;
140+
141+ //Update the CarouselView position
142+ cv2Controller ? . SetPosition ( carouselPosition ) ;
130143
144+ } ;
131145 return section ;
132146 } ) ;
133147
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