fix index view

dimensionhub/Views/Index/IndexMainView.swift

@@ -28,9 +28,8 @@ struct IndexMainView: View {
     @State private var footerRefreshing: Bool = false
     @State private var noMore: Bool = false
     
-    // 控制显示区域的可见性
-    @State private var footerPublisher = PassthroughSubject<Int, Never>()
-    @State var cancel: AnyCancellable?
+    // 保存底部元素在global坐标系里面的minY值
+    @State private var footerOffset: Int = 0
     
     var body: some View {
         VStack(alignment: .center) {
@@ -76,18 +75,33 @@ struct IndexMainView: View {
                     }
                 }
                 
-                Rectangle()
-                    .frame(height: 0)
-                    .background(GeometryReader { geometry in
-                        Color.clear.onChange(of: geometry.frame(in: .global).minY) { _, newValue in
-                            footerPublisher.send(Int(newValue))
-                        }
-                    })
-                
                 ProgressView()
+                    .background(GeometryReader { geometry in
+                        let minY = geometry.frame(in: .global).minY
+                        Color.clear.preference(key: FooterOffsetPreferenceKey.self, value: Int(minY))
+                    })
             }
             .frame(width: 370)
             .coordinateSpace(name: "indexScrollView")
+            .onScrollPhaseChange { oldPhase, newPhase in
+                print("scroll old: \(oldPhase), new: \(newPhase), footer-offset: \(footerOffset)")
+                guard !footerRefreshing && !showDateNavPopover else {
+                    return
+                }
+                
+                // 滑动停止的时候，检测是否到达了底部
+                let height = Int(UIScreen.main.bounds.height)
+                if newPhase == .idle && self.footerOffset < height + 500 {
+                    self.footerRefreshing = true
+                    Task {
+                        await self.indexModel.loadMoreUpdateDramas(userId: self.userId, mode: .next)
+                        await MainActor.run {
+                            self.footerRefreshing = false
+                        }
+                    }
+                }
+                
+            }
             .refreshable {
                 guard !self.showDateNavPopover && !self.headerRefreshing else {
                     return
@@ -143,29 +157,13 @@ struct IndexMainView: View {
                 indexModel.setFixedDrameGroup(groupId: minFrame.key)
             }
         }
-        .onAppear {
-            cancel = footerPublisher
-                .debounce(for: 0.1, scheduler: RunLoop.main)
-                .sink { offset in
-                    guard !footerRefreshing && !showDateNavPopover else {
-                        return
+        .onPreferenceChange(FooterOffsetPreferenceKey.self) { offset in
+            // 延迟到当前帧结束更新state的值，避免导致循环更新的警告
+            DispatchQueue.main.async {
+                self.footerOffset = offset
+            }
         }
         
-                    let height = Int(UIScreen.main.bounds.height)
-                    if offset < height + 500 && !footerRefreshing {
-                        self.footerRefreshing = true
-                        Task {
-                            await self.indexModel.loadMoreUpdateDramas(userId: self.userId, mode: .next)
-                            await MainActor.run {
-                                self.footerRefreshing = false
-                            }
-                        }
-                    }
-                }
-        }
-        .onDisappear {
-            self.cancel?.cancel()
-        }
     }
     
 }
@@ -249,6 +247,12 @@ extension IndexMainView {
         }
     }
     
+    
+}
+
+// MARK: PreferenceKey
+extension IndexMainView {
+    
     // 元素的坐标的距离变化, [groupId : minY]
     struct DramaGroupElementPreferenceKey: PreferenceKey {
         static var defaultValue: [String: CGFloat] = [:]
@@ -258,7 +262,20 @@ extension IndexMainView {
         }
     }
     
+    // 底部的元素的坐标信息变化
+    struct FooterOffsetPreferenceKey: PreferenceKey {
+        static var defaultValue: Int = 0
+        
+        static func reduce(value: inout Int, nextValue: () -> Int) {
+            let newValue = nextValue()
+            if newValue > 0 && abs(newValue - value) >= 50 {
+                value = newValue
             }
+        }
+    }
+    
+}
+
 
 #Preview {
     IndexMainView()

dimensionhub/dimensionhubApp.swift

@@ -43,8 +43,8 @@ struct dimensionhubApp: App {
     var body: some Scene {
         WindowGroup {
             NavigationStack(path: $appNav.path) {
-                //IndexView()
-                TestView()
+                IndexView()
+                //TestView()
                     .navigationDestination(for: AppNavigation.Destination.self) { dest in
                         switch dest {
                         case .detail(id: let id):