Add prepareViewForSkeleton to SkeletonCollectionViewDataSource (#505)

README.md

@@ -250,6 +250,7 @@ public protocol SkeletonCollectionViewDataSource: UICollectionViewDataSource {
     func collectionSkeletonView(_ skeletonView: UICollectionView, supplementaryViewIdentifierOfKind: String, at indexPath: IndexPath) -> ReusableCellIdentifier? // default: nil
     func collectionSkeletonView(_ skeletonView: UICollectionView, skeletonCellForItemAt indexPath: IndexPath) -> UICollectionViewCell?  // default: nil
     func collectionSkeletonView(_ skeletonView: UICollectionView, prepareCellForSkeleton cell: UICollectionViewCell, at indexPath: IndexPath)
+    func collectionSkeletonView(_ skeletonView: UICollectionView, prepareViewForSkeleton view: UICollectionReusableView, at indexPath: IndexPath)
 }
 ```
 

SkeletonViewCore/Sources/API/Collections/CollectionViews/SkeletonCollectionViewProtocols.swift

@@ -15,6 +15,7 @@ public protocol SkeletonCollectionViewDataSource: UICollectionViewDataSource {
     func collectionSkeletonView(_ skeletonView: UICollectionView, supplementaryViewIdentifierOfKind: String, at indexPath: IndexPath) -> ReusableCellIdentifier?
     func collectionSkeletonView(_ skeletonView: UICollectionView, skeletonCellForItemAt indexPath: IndexPath) -> UICollectionViewCell?
     func collectionSkeletonView(_ skeletonView: UICollectionView, prepareCellForSkeleton cell: UICollectionViewCell, at indexPath: IndexPath)
+    func collectionSkeletonView(_ skeletonView: UICollectionView, prepareViewForSkeleton view: UICollectionReusableView, at indexPath: IndexPath)
 }
 
 public extension SkeletonCollectionViewDataSource {
@@ -35,6 +36,8 @@ public extension SkeletonCollectionViewDataSource {
     }
 
     func collectionSkeletonView(_ skeletonView: UICollectionView, prepareCellForSkeleton cell: UICollectionViewCell, at indexPath: IndexPath) { }
+
+    func collectionSkeletonView(_ skeletonView: UICollectionView, prepareViewForSkeleton view: UICollectionReusableView, at indexPath: IndexPath) { }
 }
 
 public protocol SkeletonCollectionViewDelegate: UICollectionViewDelegate { }

SkeletonViewCore/Sources/Internal/Collections/SkeletonCollectionDataSource.swift

@@ -103,6 +103,8 @@ extension SkeletonCollectionDataSource: UICollectionViewDataSource {
                         at indexPath: IndexPath) -> UICollectionReusableView {
         if let viewIdentifier = originalCollectionViewDataSource?.collectionSkeletonView(collectionView, supplementaryViewIdentifierOfKind: kind, at: indexPath) {
             let view = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: viewIdentifier, for: indexPath)
+
+            originalCollectionViewDataSource?.collectionSkeletonView(collectionView, prepareViewForSkeleton: view, at: indexPath)
             skeletonizeViewIfContainerSkeletonIsActive(container: collectionView, view: view)
             return view
         }