Replace listbatch-model for Following-list with UIScrollViewDelegate-implementation

No more recursion due to no timer and better state handling

Mastodon/Scene/Profile/Following/FollowingListViewController.swift

@@ -68,11 +68,11 @@ final class FollowingListViewController: UIViewController, NeedsDependency {
         )
 
         // setup batch fetch
-        viewModel.listBatchFetchViewModel.setup(scrollView: tableView)
+        viewModel.shouldFetch
-        viewModel.listBatchFetchViewModel.shouldFetch
             .receive(on: DispatchQueue.main)
             .sink { [weak self] _ in
                 guard let self = self else { return }
+                
                 self.viewModel.stateMachine.enter(FollowingListViewModel.State.Loading.self)
             }
             .store(in: &disposeBag)
@@ -154,3 +154,26 @@ extension FollowingListViewController: DataSourceProvider {
         return tableView.indexPath(for: cell)
     }
 }
+
+//MARK: - UIScrollViewDelegate
+
+extension FollowingListViewController: UIScrollViewDelegate {
+    func scrollViewDidScroll(_ scrollView: UIScrollView) {
+
+        if scrollView.isDragging || scrollView.isTracking { return }
+
+        let frame = scrollView.frame
+        let contentOffset = scrollView.contentOffset
+        let contentSize = scrollView.contentSize
+
+        let visibleBottomY = contentOffset.y + frame.height
+        let offset = 2 * frame.height
+        let fetchThrottleOffsetY = contentSize.height - offset
+
+        if visibleBottomY > fetchThrottleOffsetY {
+            viewModel.shouldFetch.send()
+        }
+
+    }
+}
+

Mastodon/Scene/Profile/Following/FollowingListViewModel+State.swift

@@ -139,6 +139,14 @@ extension FollowingListViewModel.State {
                         authenticationBox: viewModel.authContext.mastodonAuthenticationBox
                     )
 
+                    if accountResponse.value.isEmpty {
+                        await enter(state: NoMore.self)
+
+                        viewModel.accounts = []
+                        viewModel.relationships = []
+                        return
+                    }
+
                     var hasNewAppend = false
 
                     let newRelationships = try await viewModel.context.apiService.relationship(forAccounts: accountResponse.value, authenticationBox: viewModel.authContext.mastodonAuthenticationBox)

Mastodon/Scene/Profile/Following/FollowingListViewModel.swift

@@ -21,11 +21,11 @@ final class FollowingListViewModel {
     @Published var accounts: [Mastodon.Entity.Account]
     @Published var relationships: [Mastodon.Entity.Relationship]
 
-    let listBatchFetchViewModel: ListBatchFetchViewModel
-
     @Published var domain: String?
     @Published var userID: String?
 
+    let shouldFetch = PassthroughSubject<Void, Never>()
+
     var tableView: UITableView?
 
     // output
@@ -55,6 +55,5 @@ final class FollowingListViewModel {
         self.userID = userID
         self.accounts = []
         self.relationships = []
-        self.listBatchFetchViewModel = ListBatchFetchViewModel()
     }
 }