feat(album): add pull-to-refresh to album entry

suixinkan/Features/TravelAlbum/ViewModels/TravelAlbumEntryViewModel.swift

@@ -52,7 +52,10 @@ final class TravelAlbumEntryViewModel {
     }
 
     /// 重新拉取相册列表。
-    func loadAlbums(api: any TravelAlbumServing) async {
+    func loadAlbums(
+        api: any TravelAlbumServing,
+        preservingContentOnFailure: Bool = false
+    ) async {
         isLoading = true
         notifyStateChange()
         defer {
@@ -67,12 +70,20 @@ final class TravelAlbumEntryViewModel {
         } catch is CancellationError {
             return
         } catch {
-            albums = []
-            albumTotal = 0
+            if !preservingContentOnFailure {
+                albums = []
+                albumTotal = 0
+            }
             onShowMessage?(error.localizedDescription)
         }
     }
 
+    /// 用户下拉刷新相册列表；失败时保留当前内容，避免页面瞬间清空。
+    func refreshAlbums(api: any TravelAlbumServing) async {
+        guard !isLoading else { return }
+        await loadAlbums(api: api, preservingContentOnFailure: true)
+    }
+
     /// 打开创建相册弹窗。
     func openCreateSheet(api: any TravelAlbumServing) async {
         guard !isCreating else { return }

suixinkan/UI/TravelAlbum/TravelAlbumEntryViewController.swift

@@ -36,6 +36,7 @@ final class TravelAlbumEntryViewController: BaseViewController {
     private let heroCard = TravelAlbumHeroCard()
     private let titleLabel = UILabel()
     private let tableView = UITableView(frame: .zero, style: .plain)
+    private let refreshControl = UIRefreshControl()
     private let emptyView = TravelAlbumEmptyView()
     private var dataSource: UITableViewDiffableDataSource<Int, TravelAlbum>!
     private var refreshState = TravelAlbumReturnRefreshState()
@@ -65,6 +66,8 @@ final class TravelAlbumEntryViewController: BaseViewController {
         tableView.separatorStyle = .none
         tableView.rowHeight = UITableView.automaticDimension
         tableView.estimatedRowHeight = 148
+        tableView.alwaysBounceVertical = true
+        tableView.refreshControl = refreshControl
         tableView.delegate = self
         tableView.register(TravelAlbumTaskCell.self, forCellReuseIdentifier: TravelAlbumTaskCell.reuseIdentifier)
 
@@ -84,6 +87,7 @@ final class TravelAlbumEntryViewController: BaseViewController {
         view.addSubview(titleLabel)
         view.addSubview(tableView)
         view.addSubview(emptyView)
+        emptyView.isUserInteractionEnabled = false
     }
 
     override func setupConstraints() {
@@ -108,6 +112,7 @@ final class TravelAlbumEntryViewController: BaseViewController {
 
     override func bindActions() {
         heroCard.addTarget(self, action: #selector(createTapped), for: .touchUpInside)
+        refreshControl.addTarget(self, action: #selector(refreshPulled), for: .valueChanged)
         viewModel.onStateChange = { [weak self] in
             Task { @MainActor in self?.applyViewModel() }
         }
@@ -138,8 +143,8 @@ final class TravelAlbumEntryViewController: BaseViewController {
         heroCard.isLoading = viewModel.isCreating
         titleLabel.text = "我的任务（\(viewModel.albumTotal)）"
         titleLabel.isHidden = viewModel.albums.isEmpty
-        tableView.isHidden = viewModel.albums.isEmpty
-        emptyView.isHidden = !viewModel.albums.isEmpty || viewModel.isLoading
+        emptyView.isHidden = !viewModel.albums.isEmpty
+            || (viewModel.isLoading && !refreshControl.isRefreshing)
         var snapshot = NSDiffableDataSourceSnapshot<Int, TravelAlbum>()
         snapshot.appendSections([0])
         snapshot.appendItems(viewModel.albums)
@@ -147,13 +152,23 @@ final class TravelAlbumEntryViewController: BaseViewController {
             snapshot,
             animatingDifferences: !refreshState.suppressesSnapshotAnimations
         )
-        if viewModel.isLoading && viewModel.albums.isEmpty {
+        if viewModel.isLoading && viewModel.albums.isEmpty && !refreshControl.isRefreshing {
             showLoading()
         } else {
             hideLoading()
         }
     }
 
+    @objc private func refreshPulled() {
+        Task {
+            await viewModel.refreshAlbums(api: api)
+            await MainActor.run {
+                self.refreshControl.endRefreshing()
+                self.applyViewModel()
+            }
+        }
+    }
+
     @objc private func createTapped() {
         Task {
             await viewModel.openCreateSheet(api: api)