         self.updateFooterView()
         
         if self.dataSource.hasIncrementalDataForLeft() {
-            self.leftIncrementalIndicator = DKPhotoIncrementalIndicator.indicator(with: .left) {
-                self.dataSource.incrementalItemsForLeft { [weak self] (count) in
+            self.leftIncrementalIndicator = DKPhotoIncrementalIndicator.indicator(with: .left) { [weak self] in
+                guard let strongSelf = self else { return }
+                
+                strongSelf.dataSource.incrementalItemsForLeft { [weak self] (count) in
                     guard let strongSelf = self, let leftIncrementalIndicator = strongSelf.leftIncrementalIndicator else { return }
                     
                     let scrollView = strongSelf.mainView


}

internal protocol DKPhotoGalleryContentDelegate {
    
    func contentVCCanScrollToPreviousOrNext(_ contentVC: DKPhotoGalleryContentVC) -> Bool
    

@objc
open class DKPhotoGalleryContentVC: UIViewController, UIScrollViewDelegate {
    
    internal weak var dataSource: DKPhotoGalleryContentDataSource!
    internal weak var delegate: DKPhotoGalleryContentDelegate?
    
    public var pageChangeBlock: ((_ index: Int) -> Void)?
    public var prepareToShow: ((_ previewVC: DKPhotoBasePreviewVC) -> Void)?
