Implemented example app with sample hooks

Closes #15

Author: lukaskubanek

Example/InterposeKitExample.xcodeproj/project.pbxproj

@@ -10,6 +10,9 @@
 		8078DF9F2DA016EE009A0B1A /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 8078DF962DA016EE009A0B1A /* Assets.xcassets */; };
 		8078DFA02DA016EE009A0B1A /* MainMenu.xib in Resources */ = {isa = PBXBuildFile; fileRef = 8078DF982DA016EE009A0B1A /* MainMenu.xib */; };
 		8078DFA12DA016EE009A0B1A /* AppDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8078DF9A2DA016EE009A0B1A /* AppDelegate.swift */; };
+		8078DFA52DA01B90009A0B1A /* InterposeKit in Frameworks */ = {isa = PBXBuildFile; productRef = 8078DFA42DA01B90009A0B1A /* InterposeKit */; };
+		8078DFAA2DA04DAA009A0B1A /* HookExample.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8078DFA92DA04DAA009A0B1A /* HookExample.swift */; };
+		8078DFAC2DA04DC6009A0B1A /* ContentView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8078DFAB2DA04DC6009A0B1A /* ContentView.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXFileReference section */
@@ -18,13 +21,16 @@
 		8078DF972DA016EE009A0B1A /* Base */ = {isa = PBXFileReference; lastKnownFileType = file.xib; name = Base; path = Base.lproj/MainMenu.xib; sourceTree = "<group>"; };
 		8078DF9A2DA016EE009A0B1A /* AppDelegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppDelegate.swift; sourceTree = "<group>"; };
 		8078DF9C2DA016EE009A0B1A /* InterposeKitExample.entitlements */ = {isa = PBXFileReference; lastKnownFileType = text.plist.entitlements; path = InterposeKitExample.entitlements; sourceTree = "<group>"; };
+		8078DFA92DA04DAA009A0B1A /* HookExample.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = HookExample.swift; sourceTree = "<group>"; };
+		8078DFAB2DA04DC6009A0B1A /* ContentView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ContentView.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
 		8078DF802DA016B6009A0B1A /* Frameworks */ = {
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				8078DFA52DA01B90009A0B1A /* InterposeKit in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -60,6 +66,8 @@
 			isa = PBXGroup;
 			children = (
 				8078DF9A2DA016EE009A0B1A /* AppDelegate.swift */,
+				8078DFA92DA04DAA009A0B1A /* HookExample.swift */,
+				8078DFAB2DA04DC6009A0B1A /* ContentView.swift */,
 			);
 			path = Sources;
 			sourceTree = "<group>";
@@ -99,6 +107,7 @@
 			);
 			name = InterposeKitExample;
 			packageProductDependencies = (
+				8078DFA42DA01B90009A0B1A /* InterposeKit */,
 			);
 			productName = InterposeKitExample;
 			productReference = 8078DF832DA016B6009A0B1A /* InterposeKitExample.app */;
@@ -128,6 +137,8 @@
 			);
 			mainGroup = 8078DF7A2DA016B6009A0B1A;
 			minimizedProjectReferenceProxies = 1;
+			packageReferences = (
+			);
 			preferredProjectObjectVersion = 77;
 			productRefGroup = 8078DF842DA016B6009A0B1A /* Products */;
 			projectDirPath = "";
@@ -155,7 +166,9 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				8078DFAA2DA04DAA009A0B1A /* HookExample.swift in Sources */,
 				8078DFA12DA016EE009A0B1A /* AppDelegate.swift in Sources */,
+				8078DFAC2DA04DC6009A0B1A /* ContentView.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -308,6 +321,7 @@
 					"$(inherited)",
 					"@executable_path/../Frameworks",
 				);
+				MACOSX_DEPLOYMENT_TARGET = 13.5;
 				MARKETING_VERSION = 1.0;
 				PRODUCT_BUNDLE_IDENTIFIER = eu.structuredpath.InterposeKitExample;
 				PRODUCT_NAME = "$(TARGET_NAME)";
@@ -334,6 +348,7 @@
 					"$(inherited)",
 					"@executable_path/../Frameworks",
 				);
+				MACOSX_DEPLOYMENT_TARGET = 13.5;
 				MARKETING_VERSION = 1.0;
 				PRODUCT_BUNDLE_IDENTIFIER = eu.structuredpath.InterposeKitExample;
 				PRODUCT_NAME = "$(TARGET_NAME)";
@@ -365,6 +380,13 @@
 			defaultConfigurationName = Release;
 		};
 /* End XCConfigurationList section */
+
+/* Begin XCSwiftPackageProductDependency section */
+		8078DFA42DA01B90009A0B1A /* InterposeKit */ = {
+			isa = XCSwiftPackageProductDependency;
+			productName = InterposeKit;
+		};
+/* End XCSwiftPackageProductDependency section */
 	};
 	rootObject = 8078DF7B2DA016B6009A0B1A /* Project object */;
 }

Example/InterposeKitExample/Sources/AppDelegate.swift

@@ -1,9 +1,14 @@
 import AppKit
+import InterposeKit
 import SwiftUI
 
 @main
 class AppDelegate: NSObject, NSApplicationDelegate {
 
+    // ============================================================================ //
+    // MARK: Window & Content View
+    // ============================================================================ //
+    
     private lazy var window: NSWindow = {
         let window = NSWindow(
             contentRect: .zero,
@@ -12,17 +17,109 @@ class AppDelegate: NSObject, NSApplicationDelegate {
             defer: false
         )
 
-        window.title = "InterposeKit Example"
-        window.contentViewController = self.hostingController
-        
+        let hostingController = NSHostingController(rootView: self.contentView)
+        window.contentViewController = hostingController
         return window
     }()
 
-    private lazy var hostingController: NSViewController = {
-        return NSHostingController(rootView: ContentView())
+    private lazy var contentView: ContentView = {
+        ContentView(
+            onHookToggled: { [weak self] example, isEnabled in
+                guard let self else { return }
+                
+                let hook = self.hook(for: example)
+                
+                do {
+                    if isEnabled {
+                        try hook.apply()
+                    } else {
+                        try hook.revert()
+                    }
+                } catch {
+                    fatalError("\(error)")
+                }
+            },
+            onWindowTitleChanged: { [weak self] title in
+                self?.window.title = title
+            }
+        )
     }()
 
+    // ============================================================================ //
+    // MARK: Hooks
+    // ============================================================================ //
+    
+    private func hook(
+        for example: HookExample
+    ) -> Hook {
+        if let hook = self._hooks[example] { return hook }
+        
+        let hook = self._makeHook(for: example)
+        self._hooks[example] = hook
+        return hook
+    }
+    
+    private func _makeHook(
+        for example: HookExample
+    ) -> Hook {
+        do {
+            switch example {
+            case .NSApplication_sendEvent:
+                return try Interpose.prepareHook(
+                    on: NSApplication.shared,
+                    for: #selector(NSApplication.sendEvent(_:)),
+                    methodSignature: (@convention(c) (NSApplication, Selector, NSEvent) -> Void).self,
+                    hookSignature: (@convention(block) (NSApplication, NSEvent) -> Void).self
+                ) { hook in
+                    return { `self`, event in
+                        print("NSApplication.sendEvent(_:) \(event)")
+                        hook.original(self, hook.selector, event)
+                    }
+                }
+            case .NSWindow_setTitle:
+                return try Interpose.prepareHook(
+                    on: self.window,
+                    for: #selector(setter: NSWindow.title),
+                    methodSignature: (@convention(c) (NSWindow, Selector, String) -> Void).self,
+                    hookSignature: (@convention(block) (NSWindow, String) -> Void).self
+                ) { hook in
+                    return { `self`, title in
+                        hook.original(self, hook.selector, "## \(title.uppercased()) ##")
+                    }
+                }
+            case .NSMenuItem_title:
+                return try Interpose.prepareHook(
+                    on: NSMenuItem.self,
+                    for: #selector(getter: NSMenuItem.title),
+                    methodSignature: (@convention(c) (NSMenuItem, Selector) -> String).self,
+                    hookSignature: (@convention(block) (NSMenuItem) -> String).self
+                ) { hook in
+                    return { `self` in
+                        let title = hook.original(`self`, hook.selector)
+                        return "## \(title) ##"
+                    }
+                }
+            case .NSColor_controlAccentColor:
+                fatalError("Not implemented")
+            }
+        } catch {
+            fatalError("\(error)")
+        }
+    }
+    
+    private var _hooks = [HookExample: Hook]()
+    
+    // ============================================================================ //
+    // MARK: NSApplicationDelegate
+    // ============================================================================ //
+    
+    func applicationWillFinishLaunching(_ notification: Notification) {
+        Interpose.isLoggingEnabled = true
+    }
+    
     func applicationDidFinishLaunching(_ notification: Notification) {
+        self.window.contentView?.layoutSubtreeIfNeeded()
+        
         Task { @MainActor in
             self.window.center()
             self.window.makeKeyAndOrderFront(nil)
@@ -36,12 +133,3 @@ class AppDelegate: NSObject, NSApplicationDelegate {
     }
 
 }
-
-fileprivate struct ContentView: View {
-    fileprivate var body: some View {
-        Text("Hello from InterposeKit!")
-            .font(.title)
-            .fixedSize()
-            .padding(200)
-    }
-}

Example/InterposeKitExample/Sources/ContentView.swift

@@ -0,0 +1,83 @@
+import SwiftUI
+
+struct ContentView: View {
+    
+    // ============================================================================ //
+    // MARK: Configuration
+    // ============================================================================ //
+    
+    let onHookToggled: (HookExample, Bool) -> Void
+    let onWindowTitleChanged: (String) -> Void
+
+    // ============================================================================ //
+    // MARK: State
+    // ============================================================================ //
+    
+    @State
+    private var hookStates = Dictionary(
+        uniqueKeysWithValues: HookExample.allCases.map { ($0, false) }
+    )
+    
+    @State
+    private var windowTitle = "InterposeKit Example"
+    
+    // ============================================================================ //
+    // MARK: View Body
+    // ============================================================================ //
+    
+    var body: some View {
+        VStack {
+            Form {
+                Section("Hooks") {
+                    ForEach(HookExample.allCases, id: \.self) { example in
+                        let isOn = Binding(
+                            get: { self.hookStates[example] ?? false },
+                            set: { newValue in
+                                self.hookStates[example] = newValue
+                                self.onHookToggled(example, newValue)
+                            }
+                        )
+                        
+                        LabeledContent {
+                            Toggle("", isOn: isOn)
+                                .toggleStyle(.switch)
+                                .labelsHidden()
+                                .padding(.leading, 20)
+                        } label: {
+                            Group {
+                                Text(example.selector)
+                                    .monospaced()
+                                
+                                Text(example.description)
+                                    .font(.subheadline)
+                            }
+                            .opacity(example == .NSColor_controlAccentColor ? 0.5 : 1)
+                        }
+                        .disabled(example == .NSColor_controlAccentColor)
+                    }
+                }
+            }
+            .formStyle(.grouped)
+            
+            LabeledContent("Window Title:") {
+                TextField("", text: self.$windowTitle)
+                    .onSubmit {
+                        self.onWindowTitleChanged(self.windowTitle)
+                    }
+                
+                Button {
+                    self.onWindowTitleChanged(self.windowTitle)
+                } label: {
+                    Text("Set").padding(.horizontal, 4)
+                }
+            }
+            .padding(.horizontal, 20)
+            .padding(.bottom, 28)
+        }
+        .fixedSize()
+        .onAppear {
+            self.onWindowTitleChanged(self.windowTitle)
+        }
+    }
+    
+}

Example/InterposeKitExample/Sources/HookExample.swift

@@ -0,0 +1,46 @@
+enum HookExample: CaseIterable {
+    case NSApplication_sendEvent
+    case NSWindow_setTitle
+    case NSMenuItem_title
+    case NSColor_controlAccentColor
+}
+
+extension HookExample {
+    var selector: String {
+        switch self {
+        case .NSApplication_sendEvent:
+            return "-[NSApplication sendEvent:]"
+        case .NSWindow_setTitle:
+            return "-[NSWindow setTitle:]"
+        case .NSMenuItem_title:
+            return "-[NSMenuItem title]"
+        case .NSColor_controlAccentColor:
+            return "+[NSColor controlAccentColor]"
+        }
+    }
+    
+    var description: String {
+        switch self {
+        case .NSApplication_sendEvent:
+            return """
+            An object hook on the shared NSApplication instance that logs all events passed \ 
+            through sendEvent(_:).
+            """
+        case .NSWindow_setTitle:
+            return """
+            An object hook on the main NSWindow that uppercases the title and wraps it with \
+            decorative markers whenever it’s set. This can be tested using the text field below.
+            """
+        case .NSMenuItem_title:
+            return """
+            A class hook on NSMenuItem that wraps all menu item titles with decorative markers, \ 
+            visible in the main menu and the text field’s context menu.
+            """
+        case .NSColor_controlAccentColor:
+            return """
+            A class hook that overrides the system accent color by hooking the corresponding \
+            class method on NSColor. (Not implemented.)
+            """
+        }
+    }
+}