public CGSize CollectionView(UICollectionView collectionView, UICollectionViewLayout collectionViewLayout,
NSIndexPath indexPath)
{
if (!(collectionViewLayout is UICollectionViewFlowLayout layout))
{
throw new ImagePickerException("currently only UICollectionViewFlowLayout is supported");
}
var layoutModel = new LayoutModel(Configuration, 0);
switch (indexPath.Section)
{
case 0:
//this will make sure that action item is either square if there are 2 items,
//or a recatangle if there is only 1 item
//let width = sizeForItem(numberOfItemsInRow: 2, preferredWidthOrHeight: nil, collectionView: collectionView, scrollDirection: layout.scrollDirection).width
nfloat ratio = 0.25f;
nfloat width = collectionView.Frame.Width * ratio;
return(SizeForItem(layoutModel.NumberOfItems(Configuration.SectionIndexForActions),
width, collectionView, layout.ScrollDirection));
case 1:
//lets keep this ratio so camera item is a nice rectangle
var traitCollection = collectionView.TraitCollection;
ratio = 160f / 212f;
switch (traitCollection.UserInterfaceIdiom)
{
case var _
when traitCollection.HorizontalSizeClass == UIUserInterfaceSizeClass.Unspecified &&
traitCollection.VerticalSizeClass == UIUserInterfaceSizeClass.Compact:
case var _ when traitCollection.HorizontalSizeClass == UIUserInterfaceSizeClass.Regular &&
traitCollection.VerticalSizeClass == UIUserInterfaceSizeClass.Compact:
case var _ when traitCollection.HorizontalSizeClass == UIUserInterfaceSizeClass.Compact &&
traitCollection.VerticalSizeClass == UIUserInterfaceSizeClass.Compact:
ratio = 1 / ratio;
break;
}
var widthOrHeight = collectionView.Frame.Height * ratio;
return(SizeForItem(layoutModel.NumberOfItems(Configuration.SectionIndexForCamera),
widthOrHeight, collectionView, layout.ScrollDirection));
case 2:
//make sure there is at least 1 item, othewise invalid layout
if (Configuration.NumberOfAssetItemsInRow < 0)
{
throw new ImagePickerException(
"invalid layout - numberOfAssetItemsInRow must be > 0, check your layout configuration ");
}
return(SizeForItem(Configuration.NumberOfAssetItemsInRow, null, collectionView,
layout.ScrollDirection));
default:
throw new ImagePickerException("unexpected sections count");
}
}
public override nint GetItemsCount(UICollectionView collectionView, nint section)
{
return(_layoutModel.NumberOfItems((int)section));
}