feat: add bottom loader

Mastodon.xcodeproj/project.pbxproj

@@ -46,6 +46,7 @@
 		2D206B9225F60EA700143C56 /* UIControl.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2D206B9125F60EA700143C56 /* UIControl.swift */; };
 		2D24E11D2626D8B100A59D4F /* NotificationStatusTableViewCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2D24E11C2626D8B100A59D4F /* NotificationStatusTableViewCell.swift */; };
 		2D24E1232626ED9D00A59D4F /* UIView+Gesture.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2D24E1222626ED9D00A59D4F /* UIView+Gesture.swift */; };
+		2D24E12D2626FD2E00A59D4F /* NotificationViewModel+LoadOldestState.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2D24E12C2626FD2E00A59D4F /* NotificationViewModel+LoadOldestState.swift */; };
 		2D32EAAC25CB96DC00C9ED86 /* TimelineMiddleLoaderTableViewCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2D32EAAB25CB96DC00C9ED86 /* TimelineMiddleLoaderTableViewCell.swift */; };
 		2D32EABA25CB9B0500C9ED86 /* UIView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2D32EAB925CB9B0500C9ED86 /* UIView.swift */; };
 		2D32EADA25CBCC3300C9ED86 /* PublicTimelineViewModel+LoadMiddleState.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2D32EAD925CBCC3300C9ED86 /* PublicTimelineViewModel+LoadMiddleState.swift */; };
@@ -435,6 +436,7 @@
 		2D206B9125F60EA700143C56 /* UIControl.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UIControl.swift; sourceTree = "<group>"; };
 		2D24E11C2626D8B100A59D4F /* NotificationStatusTableViewCell.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NotificationStatusTableViewCell.swift; sourceTree = "<group>"; };
 		2D24E1222626ED9D00A59D4F /* UIView+Gesture.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UIView+Gesture.swift"; sourceTree = "<group>"; };
+		2D24E12C2626FD2E00A59D4F /* NotificationViewModel+LoadOldestState.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "NotificationViewModel+LoadOldestState.swift"; sourceTree = "<group>"; };
 		2D32EAAB25CB96DC00C9ED86 /* TimelineMiddleLoaderTableViewCell.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TimelineMiddleLoaderTableViewCell.swift; sourceTree = "<group>"; };
 		2D32EAB925CB9B0500C9ED86 /* UIView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UIView.swift; sourceTree = "<group>"; };
 		2D32EAD925CBCC3300C9ED86 /* PublicTimelineViewModel+LoadMiddleState.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "PublicTimelineViewModel+LoadMiddleState.swift"; sourceTree = "<group>"; };
@@ -1679,6 +1681,7 @@
 				2D607AD726242FC500B70763 /* NotificationViewModel.swift */,
 				2D084B8C26258EA3003AA3AF /* NotificationViewModel+diffable.swift */,
 				2D084B9226259545003AA3AF /* NotificationViewModel+LoadLatestState.swift */,
+				2D24E12C2626FD2E00A59D4F /* NotificationViewModel+LoadOldestState.swift */,
 				2D35237F26256F470031AF25 /* TableViewCell */,
 			);
 			path = Notification;
@@ -2401,6 +2404,7 @@
 				2D76319F25C1521200929FB9 /* StatusSection.swift in Sources */,
 				DB35FC252612FD7A006193C9 /* ProfileFieldView.swift in Sources */,
 				2D650FAB25ECDC9300851B58 /* Mastodon+Entity+Error+Detail.swift in Sources */,
+				2D24E12D2626FD2E00A59D4F /* NotificationViewModel+LoadOldestState.swift in Sources */,
 				DB118A8C25E4BFB500FAB162 /* HighlightDimmableButton.swift in Sources */,
 				DBAE3FA92617106E004B8251 /* MastodonMetricFormatter.swift in Sources */,
 				2D35237A26256D920031AF25 /* NotificationSection.swift in Sources */,

Mastodon/Scene/Notification/NotificationViewController.swift

@@ -11,6 +11,7 @@ import OSLog
 import CoreData
 import CoreDataStack
 import MastodonSDK
+import GameplayKit
 
 final class NotificationViewController: UIViewController, NeedsDependency {
     
@@ -123,6 +124,7 @@ extension NotificationViewController {
         } else {
             viewModel.notificationPredicate.value = MastodonNotification.predicate(domain: domain, type: Mastodon.Entity.Notification.NotificationType.mention.rawValue)
         }
+        viewModel.selectedIndex.value = sender.selectedSegmentIndex
     }
     
     @objc private func refreshControlValueChanged(_ sender: UIRefreshControl) {
@@ -179,16 +181,16 @@ extension NotificationViewController: NotificationTableViewCellDelegate {
     
 }
 
-//// MARK: - UIScrollViewDelegate
+// MARK: - UIScrollViewDelegate
-//extension NotificationViewController {
+extension NotificationViewController {
-//    func scrollViewDidScroll(_ scrollView: UIScrollView) {
+    func scrollViewDidScroll(_ scrollView: UIScrollView) {
-//        handleScrollViewDidScroll(scrollView)
+        handleScrollViewDidScroll(scrollView)
-//    }
+    }
-//}
+}
-//
+
-//extension NotificationViewController: LoadMoreConfigurableTableViewContainer {
+extension NotificationViewController: LoadMoreConfigurableTableViewContainer {
-//    typealias BottomLoaderTableViewCell = SearchBottomLoader
+    typealias BottomLoaderTableViewCell = CommonBottomLoader
-//    typealias LoadingState = NotificationViewController.LoadOldestState.Loading
+    typealias LoadingState = NotificationViewModel.LoadOldestState.Loading
-//    var loadMoreConfigurableTableView: UITableView { return tableView }
+    var loadMoreConfigurableTableView: UITableView { return tableView }
-//    var loadMoreConfigurableStateMachine: GKStateMachine { return viewModel.loadoldestStateMachine }
+    var loadMoreConfigurableStateMachine: GKStateMachine { return viewModel.loadoldestStateMachine }
-//}
+}

Mastodon/Scene/Notification/NotificationViewModel+LoadOldestState.swift

@@ -0,0 +1,128 @@
+//
+//  NotificationViewModel+LoadOldestState.swift
+//  Mastodon
+//
+//  Created by sxiaojian on 2021/4/14.
+//
+
+import os.log
+import Foundation
+import GameplayKit
+import MastodonSDK
+
+extension NotificationViewModel {
+    class LoadOldestState: GKState {
+        weak var viewModel: NotificationViewModel?
+        
+        init(viewModel: NotificationViewModel) {
+            self.viewModel = viewModel
+        }
+        
+        override func didEnter(from previousState: GKState?) {
+            os_log("%{public}s[%{public}ld], %{public}s: enter %s, previous: %s", ((#file as NSString).lastPathComponent), #line, #function, self.debugDescription, previousState.debugDescription)
+            viewModel?.loadOldestStateMachinePublisher.send(self)
+        }
+    }
+}
+
+extension NotificationViewModel.LoadOldestState {
+    class Initial: NotificationViewModel.LoadOldestState {
+        override func isValidNextState(_ stateClass: AnyClass) -> Bool {
+            guard let viewModel = viewModel else { return false }
+            guard !(viewModel.fetchedResultsController.fetchedObjects ?? []).isEmpty else { return false }
+            return stateClass == Loading.self
+        }
+    }
+    
+    class Loading: NotificationViewModel.LoadOldestState {
+        override func isValidNextState(_ stateClass: AnyClass) -> Bool {
+            return stateClass == Fail.self || stateClass == Idle.self || stateClass == NoMore.self
+        }
+        
+        override func didEnter(from previousState: GKState?) {
+            super.didEnter(from: previousState)
+            guard let viewModel = viewModel, let stateMachine = stateMachine else { return }
+            guard let activeMastodonAuthenticationBox = viewModel.context.authenticationService.activeMastodonAuthenticationBox.value else {
+                assertionFailure()
+                stateMachine.enter(Fail.self)
+                return
+            }
+
+            guard let last = viewModel.fetchedResultsController.fetchedObjects?.last else {
+                stateMachine.enter(Idle.self)
+                return
+            }
+            
+            let maxID = last.id
+            let query = Mastodon.API.Notifications.Query(
+                maxID: maxID,
+                sinceID: nil,
+                minID: nil,
+                limit: nil,
+                excludeTypes: Mastodon.API.Notifications.allExcludeTypes(),
+                accountID: nil)
+            viewModel.context.apiService.allNotifications(
+                domain: activeMastodonAuthenticationBox.domain,
+                query: query,
+                mastodonAuthenticationBox: activeMastodonAuthenticationBox)
+                .sink { completion in
+                    switch completion {
+                    case .failure(let error):
+                        os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s: fetch notification failed. %s", ((#file as NSString).lastPathComponent), #line, #function, error.localizedDescription)
+                    case .finished:
+                        // handle isFetchingLatestTimeline in fetch controller delegate
+                        break
+                    }
+                    
+                    stateMachine.enter(Idle.self)
+                } receiveValue: { [weak viewModel] response in
+                    guard let viewModel = viewModel else { return }
+                    if viewModel.selectedIndex.value == 1 {
+                        let list = response.value.filter { $0.type == Mastodon.Entity.Notification.NotificationType.mention }
+                        if list.isEmpty {
+                            stateMachine.enter(NoMore.self)
+                        } else {
+                            stateMachine.enter(Idle.self)
+                        }
+                    } else {
+                        if response.value.isEmpty {
+                            stateMachine.enter(NoMore.self)
+                        } else {
+                            stateMachine.enter(Idle.self)
+                        }
+                    }
+                }
+                .store(in: &viewModel.disposeBag)
+        }
+    }
+    
+    class Fail: NotificationViewModel.LoadOldestState {
+        override func isValidNextState(_ stateClass: AnyClass) -> Bool {
+            return stateClass == Loading.self || stateClass == Idle.self
+        }
+    }
+    
+    class Idle: NotificationViewModel.LoadOldestState {
+        override func isValidNextState(_ stateClass: AnyClass) -> Bool {
+            return stateClass == Loading.self
+        }
+    }
+
+    class NoMore: NotificationViewModel.LoadOldestState {
+        override func isValidNextState(_ stateClass: AnyClass) -> Bool {
+            // reset state if needs
+            return stateClass == Idle.self
+        }
+        
+        override func didEnter(from previousState: GKState?) {
+            guard let viewModel = viewModel else { return }
+            guard let diffableDataSource = viewModel.diffableDataSource else {
+                assertionFailure()
+                return
+            }
+            var snapshot = diffableDataSource.snapshot()
+            snapshot.deleteItems([.bottomLoader])
+            diffableDataSource.apply(snapshot)
+        }
+    }
+}

Mastodon/Scene/Notification/NotificationViewModel.swift

@@ -23,6 +23,7 @@ final class NotificationViewModel: NSObject  {
     weak var contentOffsetAdjustableTimelineViewControllerDelegate: ContentOffsetAdjustableTimelineViewControllerDelegate?
     
     let viewDidLoad = PassthroughSubject<Void, Never>()
+    let selectedIndex = CurrentValueSubject<Int,Never>(0)
     
     let activeMastodonAuthenticationBox: CurrentValueSubject<AuthenticationService.MastodonAuthenticationBox?, Never>
     let fetchedResultsController: NSFetchedResultsController<MastodonNotification>!
@@ -48,6 +49,21 @@ final class NotificationViewModel: NSObject  {
     
     lazy var loadLatestStateMachinePublisher = CurrentValueSubject<LoadLatestState?, Never>(nil)
     
+    // bottom loader
+    private(set) lazy var loadoldestStateMachine: GKStateMachine = {
+        // exclude timeline middle fetcher state
+        let stateMachine = GKStateMachine(states: [
+            LoadOldestState.Initial(viewModel: self),
+            LoadOldestState.Loading(viewModel: self),
+            LoadOldestState.Fail(viewModel: self),
+            LoadOldestState.Idle(viewModel: self),
+            LoadOldestState.NoMore(viewModel: self),
+        ])
+        stateMachine.enter(LoadOldestState.Initial.self)
+        return stateMachine
+    }()
+    lazy var loadOldestStateMachinePublisher = CurrentValueSubject<LoadOldestState?, Never>(nil)
+    
     init(context: AppContext) {
         self.context = context
         self.activeMastodonAuthenticationBox = CurrentValueSubject(context.authenticationService.activeMastodonAuthenticationBox.value)