SavedStateHandle support

KMMViewModel.xcodeproj/project.pbxproj

@@ -20,6 +20,9 @@
 		1D43F3EC2ABAFCA600EB3DFE /* ObservableViewModelPublisher.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1D43F3EB2ABAFCA600EB3DFE /* ObservableViewModelPublisher.swift */; };
 		1D43F3EE2ABAFD7D00EB3DFE /* ObservableViewModelPublishers.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1D43F3ED2ABAFD7D00EB3DFE /* ObservableViewModelPublishers.swift */; };
 		1D6641DD2A5175C3000180D7 /* ChildViewModels.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1D6641DC2A5175C3000180D7 /* ChildViewModels.swift */; };
+		1D9474232B5084690064A727 /* SavedStateHandle.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1D9474222B5084690064A727 /* SavedStateHandle.swift */; };
+		1D9474272B5084BC0064A727 /* SavedStateObserver.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1D9474262B5084BC0064A727 /* SavedStateObserver.swift */; };
+		1D9E9A8A2B51DB7C009F4D43 /* SavedStateManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1D9E9A892B51DB7C009F4D43 /* SavedStateManager.swift */; };
 		1DDAF21E293545DD0049C114 /* KMMViewModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1DDAF21D293545DD0049C114 /* KMMViewModel.swift */; };
 /* End PBXBuildFile section */
 
@@ -55,6 +58,10 @@
 		1D43F3EB2ABAFCA600EB3DFE /* ObservableViewModelPublisher.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ObservableViewModelPublisher.swift; sourceTree = "<group>"; };
 		1D43F3ED2ABAFD7D00EB3DFE /* ObservableViewModelPublishers.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ObservableViewModelPublishers.swift; sourceTree = "<group>"; };
 		1D6641DC2A5175C3000180D7 /* ChildViewModels.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ChildViewModels.swift; sourceTree = "<group>"; };
+		1D9474202B5083310064A727 /* KMMViewModelSavedState.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = KMMViewModelSavedState.framework; sourceTree = BUILT_PRODUCTS_DIR; };
+		1D9474222B5084690064A727 /* SavedStateHandle.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SavedStateHandle.swift; sourceTree = "<group>"; };
+		1D9474262B5084BC0064A727 /* SavedStateObserver.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SavedStateObserver.swift; sourceTree = "<group>"; };
+		1D9E9A892B51DB7C009F4D43 /* SavedStateManager.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SavedStateManager.swift; sourceTree = "<group>"; };
 		1DDAF21D293545DD0049C114 /* KMMViewModel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = KMMViewModel.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
@@ -82,6 +89,13 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
+		1D94741A2B5083310064A727 /* Frameworks */ = {
+			isa = PBXFrameworksBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
 /* End PBXFrameworksBuildPhase section */
 
 /* Begin PBXGroup section */
@@ -91,6 +105,7 @@
 				1D0DA7F9293369A80057DDAD /* KMMViewModelCore */,
 				1D198B282933BFD900EF778D /* KMMViewModelCoreObjC */,
 				1D0DA809293370E60057DDAD /* KMMViewModelSwiftUI */,
+				1D9474212B5083D10064A727 /* KMMViewModelSavedState */,
 				1D0DA7DE293367DE0057DDAD /* Products */,
 				1D0DA8112933715A0057DDAD /* Frameworks */,
 			);
@@ -102,6 +117,7 @@
 				1D0DA7F8293369A80057DDAD /* KMMViewModelCore.framework */,
 				1D0DA808293370E60057DDAD /* KMMViewModelSwiftUI.framework */,
 				1D198B272933BFD900EF778D /* KMMViewModelCoreObjC.framework */,
+				1D9474202B5083310064A727 /* KMMViewModelSavedState.framework */,
 			);
 			name = Products;
 			sourceTree = "<group>";
@@ -146,6 +162,16 @@
 			path = KMMViewModelCoreObjC;
 			sourceTree = "<group>";
 		};
+		1D9474212B5083D10064A727 /* KMMViewModelSavedState */ = {
+			isa = PBXGroup;
+			children = (
+				1D9474222B5084690064A727 /* SavedStateHandle.swift */,
+				1D9474262B5084BC0064A727 /* SavedStateObserver.swift */,
+				1D9E9A892B51DB7C009F4D43 /* SavedStateManager.swift */,
+			);
+			path = KMMViewModelSavedState;
+			sourceTree = "<group>";
+		};
 /* End PBXGroup section */
 
 /* Begin PBXHeadersBuildPhase section */
@@ -172,6 +198,13 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
+		1D9474142B5083310064A727 /* Headers */ = {
+			isa = PBXHeadersBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
 /* End PBXHeadersBuildPhase section */
 
 /* Begin PBXNativeTarget section */
@@ -231,6 +264,24 @@
 			productReference = 1D198B272933BFD900EF778D /* KMMViewModelCoreObjC.framework */;
 			productType = "com.apple.product-type.framework";
 		};
+		1D9474112B5083310064A727 /* KMMViewModelSavedState */ = {
+			isa = PBXNativeTarget;
+			buildConfigurationList = 1D94741D2B5083310064A727 /* Build configuration list for PBXNativeTarget "KMMViewModelSavedState" */;
+			buildPhases = (
+				1D9474142B5083310064A727 /* Headers */,
+				1D9474152B5083310064A727 /* Sources */,
+				1D94741A2B5083310064A727 /* Frameworks */,
+				1D94741C2B5083310064A727 /* Resources */,
+			);
+			buildRules = (
+			);
+			dependencies = (
+			);
+			name = KMMViewModelSavedState;
+			productName = KMMViewModelSwiftUI;
+			productReference = 1D9474202B5083310064A727 /* KMMViewModelSavedState.framework */;
+			productType = "com.apple.product-type.framework";
+		};
 /* End PBXNativeTarget section */
 
 /* Begin PBXProject section */
@@ -251,6 +302,9 @@
 					1D198B262933BFD900EF778D = {
 						CreatedOnToolsVersion = 14.0.1;
 					};
+					1D9474112B5083310064A727 = {
+						LastSwiftMigration = 1500;
+					};
 				};
 			};
 			buildConfigurationList = 1D0DA7D7293367DE0057DDAD /* Build configuration list for PBXProject "KMMViewModel" */;
@@ -269,6 +323,7 @@
 				1D0DA7F7293369A80057DDAD /* KMMViewModelCore */,
 				1D198B262933BFD900EF778D /* KMMViewModelCoreObjC */,
 				1D0DA807293370E60057DDAD /* KMMViewModelSwiftUI */,
+				1D9474112B5083310064A727 /* KMMViewModelSavedState */,
 			);
 		};
 /* End PBXProject section */
@@ -295,6 +350,13 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
+		1D94741C2B5083310064A727 /* Resources */ = {
+			isa = PBXResourcesBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
 /* End PBXResourcesBuildPhase section */
 
 /* Begin PBXSourcesBuildPhase section */
@@ -329,6 +391,16 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
+		1D9474152B5083310064A727 /* Sources */ = {
+			isa = PBXSourcesBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+				1D9474272B5084BC0064A727 /* SavedStateObserver.swift in Sources */,
+				1D9E9A8A2B51DB7C009F4D43 /* SavedStateManager.swift in Sources */,
+				1D9474232B5084690064A727 /* SavedStateHandle.swift in Sources */,
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
 /* End PBXSourcesBuildPhase section */
 
 /* Begin PBXTargetDependency section */
@@ -658,6 +730,69 @@
 			};
 			name = Release;
 		};
+		1D94741E2B5083310064A727 /* Debug */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				CLANG_ENABLE_MODULES = YES;
+				CODE_SIGN_STYLE = Automatic;
+				CURRENT_PROJECT_VERSION = 1;
+				DEFINES_MODULE = YES;
+				DYLIB_COMPATIBILITY_VERSION = 1;
+				DYLIB_CURRENT_VERSION = 1;
+				DYLIB_INSTALL_NAME_BASE = "@rpath";
+				GENERATE_INFOPLIST_FILE = YES;
+				INFOPLIST_KEY_NSHumanReadableCopyright = "";
+				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
+				LD_RUNPATH_SEARCH_PATHS = (
+					"@executable_path/Frameworks",
+					"@loader_path/Frameworks",
+				);
+				"LD_RUNPATH_SEARCH_PATHS[sdk=macosx*]" = (
+					"@executable_path/../Frameworks",
+					"@loader_path/Frameworks",
+				);
+				MARKETING_VERSION = 1.0;
+				PRODUCT_BUNDLE_IDENTIFIER = com.rickclephas.kmm.KMMViewModelSavedState;
+				PRODUCT_NAME = "$(TARGET_NAME)";
+				SKIP_INSTALL = YES;
+				SWIFT_EMIT_LOC_STRINGS = YES;
+				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
+				SWIFT_VERSION = 5.0;
+				TARGETED_DEVICE_FAMILY = "1,2";
+			};
+			name = Debug;
+		};
+		1D94741F2B5083310064A727 /* Release */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				CLANG_ENABLE_MODULES = YES;
+				CODE_SIGN_STYLE = Automatic;
+				CURRENT_PROJECT_VERSION = 1;
+				DEFINES_MODULE = YES;
+				DYLIB_COMPATIBILITY_VERSION = 1;
+				DYLIB_CURRENT_VERSION = 1;
+				DYLIB_INSTALL_NAME_BASE = "@rpath";
+				GENERATE_INFOPLIST_FILE = YES;
+				INFOPLIST_KEY_NSHumanReadableCopyright = "";
+				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
+				LD_RUNPATH_SEARCH_PATHS = (
+					"@executable_path/Frameworks",
+					"@loader_path/Frameworks",
+				);
+				"LD_RUNPATH_SEARCH_PATHS[sdk=macosx*]" = (
+					"@executable_path/../Frameworks",
+					"@loader_path/Frameworks",
+				);
+				MARKETING_VERSION = 1.0;
+				PRODUCT_BUNDLE_IDENTIFIER = com.rickclephas.kmm.KMMViewModelSavedState;
+				PRODUCT_NAME = "$(TARGET_NAME)";
+				SKIP_INSTALL = YES;
+				SWIFT_EMIT_LOC_STRINGS = YES;
+				SWIFT_VERSION = 5.0;
+				TARGETED_DEVICE_FAMILY = "1,2";
+			};
+			name = Release;
+		};
 /* End XCBuildConfiguration section */
 
 /* Begin XCConfigurationList section */
@@ -697,6 +832,15 @@
 			defaultConfigurationIsVisible = 0;
 			defaultConfigurationName = Release;
 		};
+		1D94741D2B5083310064A727 /* Build configuration list for PBXNativeTarget "KMMViewModelSavedState" */ = {
+			isa = XCConfigurationList;
+			buildConfigurations = (
+				1D94741E2B5083310064A727 /* Debug */,
+				1D94741F2B5083310064A727 /* Release */,
+			);
+			defaultConfigurationIsVisible = 0;
+			defaultConfigurationName = Release;
+		};
 /* End XCConfigurationList section */
 	};
 	rootObject = 1D0DA7D4293367DE0057DDAD /* Project object */;

KMMViewModelSavedState/SavedStateHandle.swift

@@ -0,0 +1,13 @@
+//
+//  SavedStateHandle.swift
+//  KMMViewModelSavedState
+//
+//  Created by Rick Clephas on 11/01/2024.
+//
+
+import Foundation
+
+public protocol SavedStateHandle: AnyObject {
+    var data: Data? { get set }
+    func setStateChangedListener(listener: @escaping (Data?) -> Void)
+}

KMMViewModelSavedState/SavedStateManager.swift

@@ -0,0 +1,63 @@
+//
+//  SavedStateManager.swift
+//  KMMViewModelSavedState
+//
+//  Created by Rick Clephas on 12/01/2024.
+//
+
+import Combine
+import SwiftUI
+
+public extension View {
+
+    @available(iOS 14.0, macOS 11.0, tvOS 14.0, watchOS 7.0, *)
+    func savedStateManager() -> some View {
+        modifier(SavedStateManagerViewModifier())
+    }
+}
+
+@available(iOS 14.0, macOS 11.0, tvOS 14.0, watchOS 7.0, *)
+private struct SavedStateManagerViewModifier: ViewModifier {
+
+    @SceneStorage("KMMViewModelSavedState") private var state: Data?
+    @StateObject private var manager = SavedStateManager()
+
+    func body(content: Content) -> some View {
+        content.environmentObject(manager).onReceive(manager.stateChanged) {
+            state = manager.getState()
+        }.onAppear {
+            manager.setState(state)
+        }
+    }
+}
+
+@available(iOS 14.0, macOS 11.0, tvOS 14.0, watchOS 7.0, *)
+internal class SavedStateManager: ObservableObject {
+
+    let stateChanged = ObservableObjectPublisher()
+
+    private var states: [String:Data] = [:]
+    private var state: Data? = nil
+
+    func getState(for key: String) -> Data? { states[key] }
+
+    func setState(_ state: Data?, for key: String) {
+        if let state {
+            states[key] = state
+        } else {
+            states.removeValue(forKey: key)
+        }
+        self.state = try! NSKeyedArchiver.archivedData(withRootObject: states, requiringSecureCoding: true)
+        stateChanged.send()
+    }
+
+    func getState() -> Data? { state }
+
+    func setState(_ state: Data?) {
+        guard let state, self.state == nil else { return }
+        self.state = state
+        states = try! NSKeyedUnarchiver.unarchivedDictionary(
+            ofKeyClass: NSString.self, objectClass: NSData.self, from: state
+        ) as [String : Data]? ?? [:]
+    }
+}

KMMViewModelSavedState/SavedStateObserver.swift

@@ -0,0 +1,63 @@
+//
+//  SavedStateObserver.swift
+//  KMMViewModelSavedState
+//
+//  Created by Rick Clephas on 11/01/2024.
+//
+
+import Combine
+import SwiftUI
+
+public extension View {
+
+    @available(iOS 14.0, macOS 11.0, tvOS 14.0, watchOS 7.0, *)
+    func savedState(_ key: String, _ savedStateHandle: SavedStateHandle) -> some View {
+        modifier(SavedStateObserverViewModifier(key, savedStateHandle))
+    }
+}
+
+@available(iOS 14.0, macOS 11.0, tvOS 14.0, watchOS 7.0, *)
+internal struct SavedStateObserverViewModifier: ViewModifier {
+
+    @EnvironmentObject private var manager: SavedStateManager
+    @StateObject private var observer: SavedStateObserver
+
+    init(_ key: String, _ savedStateHandle: SavedStateHandle) {
+        self._observer = StateObject(wrappedValue: {
+            SavedStateObserver(key, savedStateHandle)
+        }())
+    }
+
+    func body(content: Content) -> some View {
+        content.onAppear {
+            observer.setManager(manager)
+        }
+    }
+}
+
+@available(iOS 14.0, macOS 11.0, tvOS 14.0, watchOS 7.0, *)
+private class SavedStateObserver: ObservableObject {
+
+    private let key: String
+    private let savedStateHandle: SavedStateHandle
+    private var manager: SavedStateManager? = nil
+
+    init(_ key: String, _ savedStateHandle: SavedStateHandle) {
+        self.key = key
+        self.savedStateHandle = savedStateHandle
+        savedStateHandle.setStateChangedListener { [weak self] data in
+            guard let self else { return }
+            self.manager?.setState(data, for: key)
+        }
+    }
+
+    func setManager(_ manager: SavedStateManager) {
+        guard self.manager == nil else { return }
+        self.manager = manager
+        savedStateHandle.data = manager.getState(for: key)
+    }
+
+    deinit {
+        manager?.setState(nil, for: key)
+    }
+}