onAdditionalLoading modifier for scrollview

Development/Development.xcodeproj/project.pbxproj

@@ -7,6 +7,8 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		4B08E0AB2CF5805500B05999 /* BookScrollView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4B08E0AA2CF5805200B05999 /* BookScrollView.swift */; };
+		4B08E0AD2CF5947100B05999 /* ScrollTracking in Frameworks */ = {isa = PBXBuildFile; productRef = 4B08E0AC2CF5947100B05999 /* ScrollTracking */; };
 		4B26A67B2A33239500B75FB4 /* DevelopmentApp.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4B26A67A2A33239500B75FB4 /* DevelopmentApp.swift */; };
 		4B26A67D2A33239500B75FB4 /* ContentView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4B26A67C2A33239500B75FB4 /* ContentView.swift */; };
 		4B26A67F2A33239600B75FB4 /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 4B26A67E2A33239600B75FB4 /* Assets.xcassets */; };
@@ -39,6 +41,7 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		4B08E0AA2CF5805200B05999 /* BookScrollView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = BookScrollView.swift; sourceTree = "<group>"; };
 		4B26A6772A33239500B75FB4 /* Development.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = Development.app; sourceTree = BUILT_PRODUCTS_DIR; };
 		4B26A67A2A33239500B75FB4 /* DevelopmentApp.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DevelopmentApp.swift; sourceTree = "<group>"; };
 		4B26A67C2A33239500B75FB4 /* ContentView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ContentView.swift; sourceTree = "<group>"; };
@@ -59,6 +62,7 @@
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				4B08E0AD2CF5947100B05999 /* ScrollTracking in Frameworks */,
 				4BC34FAF2CDB1B9200D22811 /* CollectionView in Frameworks */,
 				4BEAFA4E2A3CE48800478C59 /* AsyncMultiplexImage-Nuke in Frameworks */,
 				4BEAFA4C2A3CE48800478C59 /* AsyncMultiplexImage in Frameworks */,
@@ -91,6 +95,7 @@
 		4B26A6792A33239500B75FB4 /* Development */ = {
 			isa = PBXGroup;
 			children = (
+				4B08E0AA2CF5805200B05999 /* BookScrollView.swift */,
 				4BC34FB02CDB1C0500D22811 /* BookCollectionView.swift */,
 				4B26A67A2A33239500B75FB4 /* DevelopmentApp.swift */,
 				4B26A67C2A33239500B75FB4 /* ContentView.swift */,
@@ -144,6 +149,7 @@
 				4BEAFA4B2A3CE48800478C59 /* AsyncMultiplexImage */,
 				4BEAFA4D2A3CE48800478C59 /* AsyncMultiplexImage-Nuke */,
 				4BC34FAE2CDB1B9200D22811 /* CollectionView */,
+				4B08E0AC2CF5947100B05999 /* ScrollTracking */,
 			);
 			productName = Development;
 			productReference = 4B26A6772A33239500B75FB4 /* Development.app */;
@@ -209,6 +215,7 @@
 				4B3722682A33C701005FF24A /* BookUIKitBasedCompositional.swift in Sources */,
 				4BD04C172B2C13BB00FE41D9 /* Logger.swift in Sources */,
 				4BD04C192B2C15E100FE41D9 /* Color.swift in Sources */,
+				4B08E0AB2CF5805500B05999 /* BookScrollView.swift in Sources */,
 				4BC34FB12CDB1C0C00D22811 /* BookCollectionView.swift in Sources */,
 				4BD04C152B2C05C600FE41D9 /* BookPlainCollectionView.swift in Sources */,
 				4B910EBC2A77A2F50079D26D /* BookUIKitBasedFlow.swift in Sources */,
@@ -348,7 +355,7 @@
 				INFOPLIST_KEY_UILaunchScreen_Generation = YES;
 				INFOPLIST_KEY_UISupportedInterfaceOrientations_iPad = "UIInterfaceOrientationPortrait UIInterfaceOrientationPortraitUpsideDown UIInterfaceOrientationLandscapeLeft UIInterfaceOrientationLandscapeRight";
 				INFOPLIST_KEY_UISupportedInterfaceOrientations_iPhone = "UIInterfaceOrientationPortrait UIInterfaceOrientationLandscapeLeft UIInterfaceOrientationLandscapeRight";
-				IPHONEOS_DEPLOYMENT_TARGET = 16.6;
+				IPHONEOS_DEPLOYMENT_TARGET = 16;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
@@ -378,7 +385,7 @@
 				INFOPLIST_KEY_UILaunchScreen_Generation = YES;
 				INFOPLIST_KEY_UISupportedInterfaceOrientations_iPad = "UIInterfaceOrientationPortrait UIInterfaceOrientationPortraitUpsideDown UIInterfaceOrientationLandscapeLeft UIInterfaceOrientationLandscapeRight";
 				INFOPLIST_KEY_UISupportedInterfaceOrientations_iPhone = "UIInterfaceOrientationPortrait UIInterfaceOrientationLandscapeLeft UIInterfaceOrientationLandscapeRight";
-				IPHONEOS_DEPLOYMENT_TARGET = 16.6;
+				IPHONEOS_DEPLOYMENT_TARGET = 16;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
@@ -435,6 +442,10 @@
 /* End XCRemoteSwiftPackageReference section */
 
 /* Begin XCSwiftPackageProductDependency section */
+		4B08E0AC2CF5947100B05999 /* ScrollTracking */ = {
+			isa = XCSwiftPackageProductDependency;
+			productName = ScrollTracking;
+		};
 		4B9981D72A34F9B500840751 /* CompositionKit */ = {
 			isa = XCSwiftPackageProductDependency;
 			package = 4B9981D62A34F9B500840751 /* XCRemoteSwiftPackageReference "CompositionKit" */;

Development/Development/BookScrollView.swift

@@ -0,0 +1,42 @@
+//
+//  BookScrollView.swift
+//  Development
+//
+//  Created by Muukii on 2024/11/26.
+//
+
+import SwiftUI
+import ScrollTracking
+
+
+struct OnAdditionalLoading_Previews: View, PreviewProvider {
+
+  @State var items: [Int] = (0..<100).map { $0 }
+  @State var isLoading: Bool = false
+
+  var body: some View {
+    ScrollView {
+      LazyVGrid(columns: [GridItem(.adaptive(minimum: 100))]) {
+        ForEach(items, id: \.self) { index in            
+          Text("Item \(index)")
+            .font(.title)
+        }
+      }
+      if isLoading {
+        Text(isLoading ? "Loading..." : "End")
+      }
+    }
+    .onAdditionalLoading(isLoading: $isLoading) {
+      print("👨🏻 load")
+      try? await Task.sleep(for: .seconds(1))
+      items.append(contentsOf: (items.count..<(items.count + 100)).map { $0 })
+      print("appended")
+    }
+  }
+
+  static var previews: some View {
+    Self()
+  }
+}
+
+

Development/Development/ContentView.swift

@@ -32,6 +32,10 @@ struct ContentView: View {
         NavigationLink("CollectionView") {
           BookCollectionViewSingleSection()
         }
+
+        NavigationLink("ScrollView") {
+          OnAdditionalLoading_Previews()
+        }
       }
     }
   }

Package.swift

@@ -15,10 +15,16 @@ let package = Package(
     .library(
       name: "CollectionView",
       targets: ["CollectionView"]
-    )
+    ),
+    .library(
+      name: "ScrollTracking",
+      targets: ["ScrollTracking"]
+    ),
   ],
   dependencies: [
     .package(url: "https://github.com/FluidGroup/swift-indexed-collection", from: "0.2.1"),
+    .package(url: "https://github.com/siteline/swiftui-introspect", from: "1.3.0"),
+    .package(url: "https://github.com/FluidGroup/swift-with-prerender", from: "1.0.0")
   ],
   targets: [
     // Targets are the basic building blocks of a package, defining a module or a test suite.
@@ -34,9 +40,17 @@ let package = Package(
         .product(name: "IndexedCollection", package: "swift-indexed-collection"),
       ]
     ),
+    .target(
+      name: "ScrollTracking",
+      dependencies: [
+        .product(name: "SwiftUIIntrospect", package: "swiftui-introspect"),
+        .product(name: "WithPrerender", package: "swift-with-prerender"),
+      ]
+    ),
     .testTarget(
       name: "DynamicListTests",
       dependencies: ["DynamicList"]
     ),
-  ]
+  ],
+  swiftLanguageModes: [.v6]
 )