Add USB mouse/trackpad auto-detection, cleanup

ScrollSwitcher.xcodeproj/project.pbxproj

@@ -11,6 +11,8 @@
 		D62D7D8326DE7A9F001DCC5F /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = D62D7D8226DE7A9F001DCC5F /* Assets.xcassets */; };
 		D62D7D9226DF237A001DCC5F /* PreferencePanesSupport.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = D62D7D9126DF237A001DCC5F /* PreferencePanesSupport.framework */; };
 		D6955CDC26DF287800EB0723 /* main.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6955CDB26DF287800EB0723 /* main.swift */; };
+		D6AB3C8A26EE52020019A4F7 /* Preferences.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6AB3C8926EE52010019A4F7 /* Preferences.swift */; };
+		D6AB3C8C26EE56540019A4F7 /* Direction.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6AB3C8B26EE56540019A4F7 /* Direction.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXFileReference section */
@@ -21,6 +23,8 @@
 		D62D7D8F26DF228D001DCC5F /* ScrollSwitcher-Bridging-Header.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "ScrollSwitcher-Bridging-Header.h"; sourceTree = "<group>"; };
 		D62D7D9126DF237A001DCC5F /* PreferencePanesSupport.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = PreferencePanesSupport.framework; path = ../../../../System/Library/PrivateFrameworks/PreferencePanesSupport.framework; sourceTree = "<group>"; };
 		D6955CDB26DF287800EB0723 /* main.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = main.swift; sourceTree = "<group>"; };
+		D6AB3C8926EE52010019A4F7 /* Preferences.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Preferences.swift; sourceTree = "<group>"; };
+		D6AB3C8B26EE56540019A4F7 /* Direction.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Direction.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -58,6 +62,8 @@
 				D62D7D8C26DE7B36001DCC5F /* Info.plist */,
 				D6955CDB26DF287800EB0723 /* main.swift */,
 				D62D7D7E26DE7A9D001DCC5F /* AppDelegate.swift */,
+				D6AB3C8B26EE56540019A4F7 /* Direction.swift */,
+				D6AB3C8926EE52010019A4F7 /* Preferences.swift */,
 				D62D7D8F26DF228D001DCC5F /* ScrollSwitcher-Bridging-Header.h */,
 				D62D7D8226DE7A9F001DCC5F /* Assets.xcassets */,
 			);
@@ -143,6 +149,8 @@
 			files = (
 				D6955CDC26DF287800EB0723 /* main.swift in Sources */,
 				D62D7D7F26DE7A9D001DCC5F /* AppDelegate.swift in Sources */,
+				D6AB3C8A26EE52020019A4F7 /* Preferences.swift in Sources */,
+				D6AB3C8C26EE56540019A4F7 /* Direction.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -283,6 +291,7 @@
 					"$(inherited)",
 					"@executable_path/../Frameworks",
 				);
+				MACOSX_DEPLOYMENT_TARGET = 11.3;
 				MARKETING_VERSION = 1.0;
 				PRODUCT_BUNDLE_IDENTIFIER = net.shadowfacts.ScrollSwitcher;
 				PRODUCT_NAME = "$(TARGET_NAME)";
@@ -315,6 +324,7 @@
 					"$(inherited)",
 					"@executable_path/../Frameworks",
 				);
+				MACOSX_DEPLOYMENT_TARGET = 11.3;
 				MARKETING_VERSION = 1.0;
 				PRODUCT_BUNDLE_IDENTIFIER = net.shadowfacts.ScrollSwitcher;
 				PRODUCT_NAME = "$(TARGET_NAME)";

ScrollSwitcher/AppDelegate.swift

@@ -6,14 +6,24 @@
 //
 
 import Cocoa
+import IOKit
+import Combine
+import OSLog
 
-let defaultsKey = "com.apple.swipescrolldirection"
+let logger = Logger(subsystem: Bundle.main.bundleIdentifier!, category: "main")
 
 class AppDelegate: NSObject, NSApplicationDelegate {
     
     // things that need to be retained to keep them from disappearing
     private var prefPanesSupport: Bundle!
     private var item: NSStatusItem!
+    private var manager: IOHIDManager!
+    private var cancellables = Set<AnyCancellable>()
+    
+    // internal not private because they need to be accessible from global IOHIDManager callbacks
+    var hidDevicesChangedSubject = PassthroughSubject<Void, Never>()
+    var trackpadCount = 0
+    var mouseCount = 0
     
     func applicationDidFinishLaunching(_ aNotification: Notification) {
         item = NSStatusBar.system.statusItem(withLength: NSStatusItem.squareLength)
@@ -23,6 +33,28 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         
         // update the icon when system prefs changes
         DistributedNotificationCenter.default().addObserver(self, selector: #selector(updateIcon), name: .swipeScrollDirectionDidChangeNotification, object: nil)
+        
+        // register for HID device addition/removal notifications
+        manager = IOHIDManagerCreate(kCFAllocatorDefault, 0 /* kIOHIDManagerOptionNone */)
+        
+        var dict = IOServiceMatching(kIOHIDDeviceKey)! as! [String: Any]
+        dict[kIOHIDDeviceUsagePageKey] = kHIDPage_GenericDesktop
+        dict[kIOHIDDeviceUsageKey] = kHIDUsage_GD_Mouse
+        IOHIDManagerSetDeviceMatching(manager, dict as CFDictionary)
+        
+        IOHIDManagerRegisterDeviceMatchingCallback(manager, hidDeviceAdded(context:result:sender:device:), nil)
+        IOHIDManagerRegisterDeviceRemovalCallback(manager, hidDeviceRemoved(context:result:sender:device:), nil)
+        
+        IOHIDManagerScheduleWithRunLoop(manager, CFRunLoopGetCurrent(), CFRunLoopMode.commonModes.rawValue)
+        
+        // handle HID device changes debounced, because IOKit sends a whole at initialization (and seemingly duplicates when devices are removed/connected)
+        hidDevicesChangedSubject
+            .debounce(for: .seconds(0.1), scheduler: RunLoop.main)
+            .sink { [unowned self] (_) in
+                logger.info("HID devices changed, trackpads: \(self.trackpadCount, privacy: .public), mice: \(self.mouseCount, privacy: .public)")
+                self.updateDirectionForAutoMode()
+            }
+            .store(in: &cancellables)
     }
     
     @objc private func updateIcon() {
@@ -43,11 +75,31 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         menu.delegate = self
         let state = Direction.current == .natural ? "On" : "Off"
         let status = NSMenuItem(title: "Natural Scrolling: \(state)", action: nil, keyEquivalent: "")
+        status.isEnabled = true
+        status.attributedTitle = NSAttributedString(string: "Natural Scrolling: \(state)", attributes: [
+            .foregroundColor: NSColor.white,
+        ])
         menu.addItem(status)
         let verb = Direction.current == .natural ? "Disable" : "Enable"
         let toggleItem = NSMenuItem(title: "\(verb) Natural Scrolling", action: #selector(toggleScrollDirection), keyEquivalent: "")
         menu.addItem(toggleItem)
+        
         menu.addItem(NSMenuItem.separator())
+        
+        let autoItem = NSMenuItem(title: "Auto Switching Mode", action: nil, keyEquivalent: "")
+        let autoMenu = NSMenu()
+        for mode in Preferences.AutoMode.allCases {
+            let modeItem = NSMenuItem(title: mode.displayName, action: #selector(modeChanged(_:)), keyEquivalent: "")
+            modeItem.tag = mode.rawValue
+            modeItem.toolTip = mode.displayDescription
+            modeItem.state = Preferences.autoMode == mode ? .on : .off
+            autoMenu.addItem(modeItem)
+        }
+        autoItem.submenu = autoMenu
+        menu.addItem(autoItem)
+        
+        menu.addItem(NSMenuItem.separator())
+        
         menu.addItem(withTitle: "Quit", action: #selector(NSApplication.terminate(_:)), keyEquivalent: "q")
         return menu
     }
@@ -56,31 +108,29 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         setDirection(.current == Direction.natural ? .normal : .natural)
     }
     
+    @objc private func modeChanged(_ sender: NSMenuItem) {
+        Preferences.autoMode = Preferences.AutoMode(rawValue: sender.tag) ?? .disabled
+        updateDirectionForAutoMode()
+    }
+    
     private func setDirection(_ new: Direction) {
-        // can't construct a UserDefaults with NSGlobalDomain, so set it via the command line
+        logger.debug("Changing scroll direction to \(new == .normal ? "Normal" : "Natural", privacy: .public)")
-        let proc = Process()
-//        let out = Pipe()
-//        let err = Pipe()
-        proc.launchPath = "/usr/bin/env"
-        let newVal = new == .normal ? "NO" : "YES"
-        proc.arguments = ["defaults", "write", "-g", "com.apple.swipescrolldirection", "-bool", newVal]
-//        proc.standardOutput = out
-//        proc.standardError = err
-        proc.launch()
-        proc.waitUntilExit()
-
-//        let outData = out.fileHandleForReading.readDataToEndOfFile()
-//        let errData = err.fileHandleForReading.readDataToEndOfFile()
-        if proc.terminationStatus != 0 {
-            fatalError("uh oh, exit code: \(proc.terminationStatus)")
-        }
-        
-        // makes system preferences update
-        DistributedNotificationCenter.default().postNotificationName(.swipeScrollDirectionDidChangeNotification, object: nil, userInfo: nil, deliverImmediately: false)
-        // make the actual input behavior update
         setSwipeScrollDirection(new == .natural)
     }
     
+    private func updateDirectionForAutoMode() {
+        switch Preferences.autoMode {
+        case .disabled:
+            return
+            
+        case .normalWhenMousePresent:
+            setDirection(mouseCount > 0 ? .normal : .natural)
+            
+        case .naturalWhenTrackpadPresent:
+            setDirection(trackpadCount > 0 ? .natural : .normal)
+        }
+    }
+
 }
 
 extension AppDelegate: NSMenuDelegate {
@@ -90,28 +140,81 @@ extension AppDelegate: NSMenuDelegate {
     }
 }
 
-enum Direction: Equatable {
-    case normal, natural
-    
-    static var current: Direction {
-        let value = UserDefaults.standard.bool(forKey: defaultsKey)
-        if value {
-            return .natural
-        } else {
-            return .normal
-        }
-    }
-    
-    var image: NSImage {
-        switch self {
-        case .normal:
-            return NSImage(systemSymbolName: "scroll", accessibilityDescription: nil)!
-        case .natural:
-            return NSImage(systemSymbolName: "scroll.fill", accessibilityDescription: nil)!
-        }
-    }
-}
-
 extension Notification.Name {
     static let swipeScrollDirectionDidChangeNotification = Notification.Name(rawValue: "SwipeScrollDirectionDidChangeNotification")
 }
+
+func hidDeviceAdded(context: UnsafeMutableRawPointer?, result: IOReturn, sender: UnsafeMutableRawPointer?, device: IOHIDDevice) {
+    // it is not clear to me why you can interpolate device here but not in the log message
+    let deviceDesc = "\(device)"
+    
+    let name = IOHIDDeviceGetProperty(device, kIOHIDProductKey as CFString) as? String
+    guard let name = name else {
+        logger.warning("Could not get product name for \(deviceDesc, privacy: .public)")
+        return
+    }
+    
+    let usage = IOHIDDeviceGetProperty(device, kIOHIDPrimaryUsageKey as CFString) as? UInt32
+    // we get this callback for non kHIDUsage_GD_Mouse devices even though we specify that in the matching dict
+    // (specifically, something with kHIDUsage_GD_SystemControl), so filter ourselves
+    guard let usage = usage else {
+        logger.warning("Could not get usage for \(deviceDesc, privacy: .public)")
+        return
+    }
+    guard usage == kHIDUsage_GD_Mouse else {
+        logger.info("Unexpected usage 0x\(usage, format: .hex, privacy: .public) for device '\(name, privacy: .public)'")
+        return
+    }
+    
+    logger.debug("HID device '\(name, privacy: .public)' added")
+    
+    let delegate = NSApp.delegate as! AppDelegate
+
+    if deviceNameIsProbablyTrackpad(name) {
+        delegate.trackpadCount += 1
+    } else {
+        delegate.mouseCount += 1
+    }
+
+    delegate.hidDevicesChangedSubject.send()
+}
+
+func hidDeviceRemoved(context: UnsafeMutableRawPointer?, result: IOReturn, sender: UnsafeMutableRawPointer?, device: IOHIDDevice) {
+    let deviceDesc = "\(device)"
+    
+    let name = IOHIDDeviceGetProperty(device, kIOHIDProductKey as CFString) as? String
+    guard let name = name else {
+        logger.warning("Could not get product name for \(deviceDesc, privacy: .public)")
+        return
+    }
+    
+    let usage = IOHIDDeviceGetProperty(device, kIOHIDPrimaryUsageKey as CFString) as? UInt32
+    guard let usage = usage else {
+        logger.warning("Could not get usage for \(deviceDesc, privacy: .public)")
+        return
+    }
+    guard usage == kHIDUsage_GD_Mouse else {
+        logger.info("Unexpected usage 0x\(usage, format: .hex, privacy: .public) for device '\(name, privacy: .public)'")
+        return
+    }
+    
+    logger.debug("HID device '\(name, privacy: .public)' removed")
+    
+    let delegate = NSApp.delegate as! AppDelegate
+
+    if deviceNameIsProbablyTrackpad(name) {
+        delegate.trackpadCount -= 1
+    } else {
+        delegate.mouseCount -= 1
+    }
+
+    delegate.hidDevicesChangedSubject.send()
+}
+
+// dumb heuristics because USB HID doesn't differentiate between mice/trackpads
+func deviceNameIsProbablyTrackpad(_ name: String) -> Bool {
+    if name.lowercased().contains("trackpad") {
+        return true
+    }
+    return false
+}

ScrollSwitcher/Direction.swift

@@ -0,0 +1,33 @@
+//
+//  Direction.swift
+//  ScrollSwitcher
+//
+//  Created by Shadowfacts on 9/12/21.
+//
+
+import AppKit
+
+let defaultsKey = "com.apple.swipescrolldirection"
+
+enum Direction: Equatable {
+    case normal, natural
+    
+    static var current: Direction {
+        let value = UserDefaults.standard.bool(forKey: defaultsKey)
+        if value {
+            return .natural
+        } else {
+            return .normal
+        }
+    }
+    
+    var image: NSImage {
+        switch self {
+        case .normal:
+            return NSImage(systemSymbolName: "scroll", accessibilityDescription: nil)!
+        case .natural:
+            return NSImage(systemSymbolName: "scroll.fill", accessibilityDescription: nil)!
+        }
+    }
+}
+

ScrollSwitcher/Preferences.swift

@@ -0,0 +1,52 @@
+//
+//  Preferences.swift
+//  ScrollSwitcher
+//
+//  Created by Shadowfacts on 9/12/21.
+//
+
+import Foundation
+
+struct Preferences {
+    
+    private static let autoModeKey = "autoMode"
+    static var autoMode: AutoMode {
+        get {
+            AutoMode(rawValue: UserDefaults.standard.integer(forKey: autoModeKey)) ?? .disabled
+        }
+        set {
+            UserDefaults.standard.set(newValue.rawValue, forKey: autoModeKey)
+        }
+    }
+    
+}
+
+extension Preferences {
+    enum AutoMode: Int, Codable, CaseIterable, Equatable {
+        case disabled = 0
+        case normalWhenMousePresent = 1
+        case naturalWhenTrackpadPresent = 2
+        
+        var displayName: String {
+            switch self {
+            case .disabled:
+                return "Disabled"
+            case .normalWhenMousePresent:
+                return "Normal when mouse present"
+            case .naturalWhenTrackpadPresent:
+                return "Natural when trackpad present"
+            }
+        }
+        
+        var displayDescription: String {
+            switch self {
+            case .disabled:
+                return "Scroll direction is never changed automatically"
+            case .normalWhenMousePresent:
+                return "Scroll direction is changed to normal when at least 1 mouse is connected. Optimal for computers with built-in trackpads."
+            case .naturalWhenTrackpadPresent:
+                return "Scroll direction is changed to natural when at least 1 trackpad is connected. Optimal for computers with rarely-connected trackpads."
+            }
+        }
+    }
+}

ScrollSwitcher/ScrollSwitcher-Bridging-Header.h

@@ -8,8 +8,8 @@
 #ifndef ScrollSwitcher_Bridging_Header_h
 #define ScrollSwitcher_Bridging_Header_h
 
-#import <CoreFoundation/CoreFoundation.h>
+#import <stdbool.h>
 
-void setSwipeScrollDirection(BOOL natural);
+extern void setSwipeScrollDirection(bool natural);
 
 #endif /* ScrollSwitcher_Bridging_Header_h */