feat: migrate to standard os-backed preferences (closes #161)

alt-tab-macos/logic/DebugProfile.swift

@@ -42,9 +42,9 @@ class DebugProfile {
     }
 
     private static func appPreferences() -> String {
-        return nestedSeparator + Preferences.rawValues
+        return nestedSeparator + Preferences.all
                 .sorted { $0.0 < $1.0 }
-                .map { $0 + intraSeparator + $1 }
+                .map { $0.key + intraSeparator + Preferences.getAsString($0.key)! }
                 .joined(separator: nestedSeparator)
     }
 

alt-tab-macos/logic/Preferences.swift

@@ -1,193 +1,113 @@
 import Cocoa
 import Carbon.HIToolbox.Events
 
+let defaults = UserDefaults.standard
+
 class Preferences {
-    // the following constant are not exposed as preferences but may be in the future, probably through macro preferences
-    static let windowMaterial = NSVisualEffectView.Material.dark
-    static let fontColor = NSColor.white
-    static let windowPadding = CGFloat(23)
-    static let interCellPadding = CGFloat(5)
-    static let intraCellPadding = CGFloat(5)
-    static let fontIconSize = CGFloat(20)
-
-    static let themeMacro = MacroPreferenceHelper<(CGFloat, CGFloat, CGFloat, NSColor, NSColor)>([
-        MacroPreference(" macOS", (0, 5, 20, .clear, NSColor(red: 0, green: 0, blue: 0, alpha: 0.4))),
-        MacroPreference("❖ Windows 10", (2, 0, 0, .white, .clear))
-    ])
-    static let metaKeyMacro = MacroPreferenceHelper<([Int], NSEvent.ModifierFlags)>([
-        MacroPreference("⌥ option", ([kVK_Option, kVK_RightOption], .option)),
-        MacroPreference("⌃ control", ([kVK_Control, kVK_RightControl], .control)),
-        MacroPreference("⌘ command", ([kVK_Command, kVK_RightCommand], .command))
-    ])
-    static let showOnScreenMacro = MacroPreferenceHelper<ShowOnScreenPreference>([
-        MacroPreference("Main screen", ShowOnScreenPreference.main),
-        MacroPreference("Screen including mouse", ShowOnScreenPreference.mouse),
-    ])
-
-    static var defaults: [String: String] = [
-        "maxScreenUsage": "80",
-        "minCellsPerRow": "5",
-        "maxCellsPerRow": "10",
-        "minRows": "3",
-        "iconSize": "32",
-        "fontHeight": "15",
-        "tabKeyCode": String(kVK_Tab),
-        "metaKey": metaKeyMacro.macros[0].label,
-        "windowDisplayDelay": "0",
-        "theme": themeMacro.macros[0].label,
-        "showOnScreen": showOnScreenMacro.macros[0].label,
-        "hideSpaceNumberLabels": String(false),
+    // default values
+    static var defaultValues: [String : Any] = [
+        "maxScreenUsage": Float(80),
+        "minCellsPerRow": Float(5),
+        "maxCellsPerRow": Float(10),
+        "minRows": Float(3),
+        "iconSize": Float(32),
+        "fontHeight": Float(15),
+        "tabKeyCode": kVK_Tab,
+        "windowDisplayDelay": 0,
+        "metaKey": MacroPreferences.metaKeyList.keys.first!,
+        "theme": MacroPreferences.themeList.keys.first!,
+        "showOnScreen": MacroPreferences.showOnScreenList.keys.first!,
+        "hideSpaceNumberLabels": false,
     ]
-    static var rawValues = [String: String]()
 
-    static var cellBorderWidth: CGFloat!
-    static var cellCornerRadius: CGFloat!
-    static var tabKeyCode: UInt16!
-    static var highlightBorderColor: NSColor!
-    static var highlightBackgroundColor: NSColor!
-    static var metaKeyCodes: [UInt16]!
-    static var metaModifierFlag: NSEvent.ModifierFlags!
-    static var windowDisplayDelay: DispatchTimeInterval!
-    static var windowCornerRadius: CGFloat!
-    static var showOnScreen: ShowOnScreenPreference!
-    static var hideSpaceNumberLabels: Bool!
-    static var maxScreenUsage: CGFloat!
-    static var iconSize: CGFloat!
-    static var fontHeight: CGFloat!
-    static var font: NSFont!
-    static var minCellsPerRow: CGFloat!
-    static var maxCellsPerRow: CGFloat!
-    static var minRows: CGFloat!
+    // constant values
+    // not exposed as preferences now but may be in the future, probably through macro preferences
+    static var windowMaterial: NSVisualEffectView.Material { .dark }
+    static var fontColor: NSColor { .white }
+    static var windowPadding: CGFloat { 23 }
+    static var interCellPadding: CGFloat { 5 }
+    static var intraCellPadding: CGFloat { 5 }
+    static var fontIconSize: CGFloat { 20 }
 
-    private static let defaultsFile = fileFromPreferencesFolder("alt-tab-macos-defaults.json")
-    private static let userFile = fileFromPreferencesFolder("alt-tab-macos.json")
+    // persisted values
+    static var maxScreenUsage: CGFloat { CGFloat(defaults.float(forKey: "maxScreenUsage") / 100) }
+    static var minCellsPerRow: CGFloat { CGFloat(defaults.float(forKey: "minCellsPerRow")) }
+    static var maxCellsPerRow: CGFloat { CGFloat(defaults.float(forKey: "maxCellsPerRow")) }
+    static var minRows: CGFloat { CGFloat(defaults.float(forKey: "minRows")) }
+    static var iconSize: CGFloat { CGFloat(defaults.float(forKey: "iconSize")) }
+    static var fontHeight: CGFloat { CGFloat(defaults.float(forKey: "fontHeight")) }
+    static var tabKeyCode: UInt16 { UInt16(defaults.integer(forKey: "tabKeyCode")) }
+    static var windowDisplayDelay: DispatchTimeInterval { DispatchTimeInterval.milliseconds(defaults.integer(forKey: "windowDisplayDelay")) }
+    static var hideSpaceNumberLabels: Bool { defaults.bool(forKey: "hideSpaceNumberLabels") }
 
-    static func loadFromDiskAndUpdateValues() {
-        do {
-            try saveDefaultsToDisk()
-            let preferencesExist = FileManager.default.fileExists(atPath: userFile.path)
-            if !preferencesExist {
-                try FileManager.default.copyItem(at: defaultsFile, to: userFile)
-            }
-            rawValues = try loadFromDisk(userFile)
-            if preferencesExist {
-                let compatiblePreferences = rawValues.filter { defaults[$0.key] != nil }
-                rawValues = defaults.merging(compatiblePreferences) { (_, new) in new }
-            }
-            try rawValues.forEach { try updateAndValidateFromString($0.key, $0.value) }
-            if preferencesExist {
-                try saveRawToDisk()
-            }
-        } catch {
-            debugPrint("Error loading preferences", error)
-            if (FileManager.default.fileExists(atPath: userFile.path)) {
-                try! FileManager.default.removeItem(at: userFile)
-            }
-            loadFromDiskAndUpdateValues()
-        }
+    // macro values
+    static var theme: Theme { MacroPreferences.themeList[defaults.string(forKey: "theme")!]! }
+    static var metaKey: MetaKey { MacroPreferences.metaKeyList[defaults.string(forKey: "metaKey")!]! }
+    static var showOnScreen: ShowOnScreenPreference { MacroPreferences.showOnScreenList[defaults.string(forKey: "showOnScreen")!]! }
+
+    // derived values
+    static var cellBorderWidth: CGFloat { theme.cellBorderWidth }
+    static var cellCornerRadius: CGFloat { theme.cellCornerRadius }
+    static var windowCornerRadius: CGFloat { theme.windowCornerRadius }
+    static var highlightBorderColor: NSColor { theme.highlightBorderColor }
+    static var highlightBackgroundColor: NSColor { theme.highlightBackgroundColor }
+    static var metaKeyCodes: [UInt16] { metaKey.keyCodes.map { UInt16($0) } }
+    static var metaModifierFlag: NSEvent.ModifierFlags { metaKey.modifierFlag }
+    static var font: NSFont { NSFont.systemFont(ofSize: fontHeight) }
+
+    static func registerDefaults() {
+        defaults.register(defaults: defaultValues)
     }
 
-    static func updateAndValidateFromString(_ valueName: String, _ value: String) throws {
-        switch valueName {
-            case "maxScreenUsage":
-                maxScreenUsage = try CGFloat(CGFloat(value).orThrow() / 100)
-            case "minCellsPerRow":
-                minCellsPerRow = try CGFloat(value).orThrow()
-            case "maxCellsPerRow":
-                maxCellsPerRow = try CGFloat(value).orThrow()
-            case "minRows":
-                minRows = try CGFloat(value).orThrow()
-            case "iconSize":
-                iconSize = try CGFloat(value).orThrow()
-            case "fontHeight":
-                fontHeight = try CGFloat(value).orThrow()
-                font = NSFont.systemFont(ofSize: fontHeight)
-            case "tabKeyCode":
-                tabKeyCode = try UInt16(value).orThrow()
-            case "metaKey":
-                let p = try metaKeyMacro.labelToMacro[value].orThrow()
-                metaKeyCodes = p.preferences.0.map { UInt16($0) }
-                metaModifierFlag = p.preferences.1
-            case "theme":
-                let p = try themeMacro.labelToMacro[value].orThrow()
-                cellBorderWidth = p.preferences.0
-                cellCornerRadius = p.preferences.1
-                windowCornerRadius = p.preferences.2
-                highlightBorderColor = p.preferences.3
-                highlightBackgroundColor = p.preferences.4
-            case "windowDisplayDelay":
-                windowDisplayDelay = DispatchTimeInterval.milliseconds(try Int(value).orThrow())
-            case "showOnScreen":
-                let p = try showOnScreenMacro.labelToMacro[value].orThrow()
-                showOnScreen = p.preferences
-            case "hideSpaceNumberLabels":
-                hideSpaceNumberLabels = try Bool(value).orThrow()
-            default:
-                throw NSError.make(domain: "Preferences", message: "Tried to update an unknown preference: '\(valueName)' = '\(value)'")
-        }
-        rawValues[valueName] = value
+    static func get(_ key: String) -> Any? {
+        defaults.object(forKey: key)
     }
 
-    static func saveRawToDisk() throws {
-        ProcessInfo.processInfo.disableSuddenTermination()
-        try saveToDisk(rawValues, userFile)
-        ProcessInfo.processInfo.enableSuddenTermination()
+    static func getAsString(_ key: String) -> String? {
+        defaults.string(forKey: key)
     }
 
-    private static func preferencesVersion(_ url: URL) throws -> Int {
-        return try Int(loadFromDisk(url)["version"] ?? "0").orThrow()
+    static func set(_ key: String, _ value: Any?) {
+        defaults.set(value, forKey: key)
     }
 
-    private static func loadFromDisk(_ url: URL) throws -> [String: String] {
-        return try JSONDecoder().decode([String: String].self, from: Data(contentsOf: url))
-    }
-
-    private static func saveDefaultsToDisk() throws {
-        try saveToDisk(defaults, defaultsFile)
-    }
-
-    private static func saveToDisk(_ values: [String: String], _ path: URL) throws {
-        let encoder = JSONEncoder()
-        encoder.outputFormatting = .prettyPrinted
-        try encoder
-                .encode(values)
-                .write(to: path)
-    }
-
-    private static func fileFromPreferencesFolder(_ fileName: String) -> URL {
-        return FileManager.default
-                .urls(for: .libraryDirectory, in: .userDomainMask)
-                .first!
-                .appendingPathComponent("Preferences", isDirectory: true)
-                .appendingPathComponent(fileName)
-    }
+    static var all: [String: Any] { defaults.dictionaryRepresentation() }
 }
 
-struct MacroPreference<T> {
+struct Theme {
     let label: String
-    let preferences: T
-
-    init(_ label: String, _ preferences: T) {
-        self.label = label
-        self.preferences = preferences
-    }
+    let cellBorderWidth: CGFloat
+    let cellCornerRadius: CGFloat
+    let windowCornerRadius: CGFloat
+    let highlightBorderColor: NSColor
+    let highlightBackgroundColor: NSColor
 }
 
-class MacroPreferenceHelper<T> {
-    let macros: [MacroPreference<T>]
-    var labels = [String]()
-    var labelToMacro = [String: MacroPreference<T>]()
-
-    init(_ array: [MacroPreference<T>]) {
-        self.macros = array
-        array.forEach {
-            labelToMacro[$0.label] = $0
-            labels.append($0.label)
-        }
-    }
+struct MetaKey {
+    let label: String
+    let keyCodes: [Int]
+    let modifierFlag: NSEvent.ModifierFlags
 }
 
 enum ShowOnScreenPreference {
     case main
     case mouse
 }
+
+// macros are collection of values derived from a single key
+// we don't want to store every value in UserDefaults as the user could change them and contradict the macro
+class MacroPreferences {
+    static let themeList = [
+        " macOS": Theme(label: " macOS", cellBorderWidth: 0, cellCornerRadius: 5, windowCornerRadius: 20, highlightBorderColor: .clear, highlightBackgroundColor: NSColor(red: 0, green: 0, blue: 0, alpha: 0.4)),
+        "❖ Windows 10": Theme(label: "❖ Windows 10", cellBorderWidth: 2, cellCornerRadius: 0, windowCornerRadius: 0, highlightBorderColor: .white, highlightBackgroundColor: .clear),
+    ]
+    static let metaKeyList = [
+        "⌥ option": MetaKey(label: "⌥ option", keyCodes: [kVK_Option, kVK_RightOption], modifierFlag: .option),
+        "⌃ control": MetaKey(label: "⌃ control", keyCodes: [kVK_Control, kVK_RightControl], modifierFlag: .control),
+        "⌘ command": MetaKey(label: "⌘ command", keyCodes: [kVK_Command, kVK_RightCommand], modifierFlag: .command)
+    ]
+    static let showOnScreenList = [
+        "Main screen": ShowOnScreenPreference.main,
+        "Screen including mouse": ShowOnScreenPreference.mouse,
+    ]
+}

alt-tab-macos/logic/Screen.swift

@@ -2,7 +2,7 @@ import Cocoa
 
 class Screen {
     static func preferred() -> NSScreen {
-        switch Preferences.showOnScreen! {
+        switch Preferences.showOnScreen {
             case .mouse: return withMouse() ?? NSScreen.main!; // .main as fall-back
             case .main: return NSScreen.main!;
         }

alt-tab-macos/ui/App.swift

@@ -32,7 +32,7 @@ class App: NSApplication, NSApplicationDelegate, NSWindowDelegate {
         #endif
         SystemPermissions.ensureAccessibilityCheckboxIsChecked()
         SystemPermissions.ensureScreenRecordingCheckboxIsChecked()
-        Preferences.loadFromDiskAndUpdateValues()
+        Preferences.registerDefaults()
         statusItem = Menubar.make(self)
         loadMainMenuXib()
         initPreferencesDependentComponents()

alt-tab-macos/ui/preferences-window/LabelAndControl.swift

@@ -4,7 +4,7 @@ class LabelAndControl: NSObject {
     static var callbackTarget: PreferencesWindow!
 
     static func makeLabelWithInput(_ labelText: String, _ rawName: String, _ width: CGFloat, _ suffixText: String? = nil, _ suffixUrl: String? = nil, _ validator: ((String) -> Bool)? = nil) -> [NSView] {
-        let input = TextField(Preferences.rawValues[rawName]!)
+        let input = TextField(Preferences.getAsString(rawName)!)
         input.validationHandler = validator
         input.delegate = input
         input.visualizeValidationState()
@@ -15,19 +15,19 @@ class LabelAndControl: NSObject {
 
     static func makeLabelWithCheckbox(_ labelText: String, _ rawName: String) -> [NSView] {
         let checkbox = NSButton(checkboxWithTitle: "", target: nil, action: nil)
-        setControlValue(checkbox, Preferences.rawValues[rawName]!)
+        setControlValue(checkbox, Preferences.getAsString(rawName)!)
         return makeLabelWithProvidedControl(labelText, rawName, checkbox)
     }
 
     static func makeLabelWithDropdown(_ labelText: String, _ rawName: String, _ values: [String], _ suffixText: String? = nil) -> [NSView] {
         let popUp = NSPopUpButton()
         popUp.addItems(withTitles: values)
-        popUp.selectItem(withTitle: Preferences.rawValues[rawName]!)
+        popUp.selectItem(withTitle: Preferences.getAsString(rawName)!)
         return makeLabelWithProvidedControl(labelText, rawName, popUp, suffixText)
     }
 
     static func makeLabelWithSlider(_ labelText: String, _ rawName: String, _ minValue: Double, _ maxValue: Double, _ numberOfTickMarks: Int, _ allowsTickMarkValuesOnly: Bool, _ unitText: String = "") -> [NSView] {
-        let value = Preferences.rawValues[rawName]!
+        let value = Preferences.getAsString(rawName)!
         let suffixText = value + " " + unitText
         let slider = NSSlider()
         slider.minValue = minValue
@@ -74,8 +74,6 @@ class LabelAndControl: NSObject {
         return suffix
     }
 
-
-
     static func getControlValue(_ control: NSControl) -> String {
         if control is NSPopUpButton {
             return (control as! NSPopUpButton).titleOfSelectedItem!
@@ -107,13 +105,10 @@ class LabelAndControl: NSObject {
         }
     }
 
-
-
     private static func updateSuffixWithValue(_ control: NSControl, _ value: String) {
         let suffixIdentifierPredicate = { (view: NSView) -> Bool in
             view.identifier?.rawValue == control.identifier!.rawValue + ControlIdentifierDiscriminator.SUFFIX.rawValue
         }
-
         if let suffixView: NSTextField = control.superview?.subviews.first(where: suffixIdentifierPredicate) as? NSTextField {
             let regex = try! NSRegularExpression(pattern: "^[0-9]+") // first decimal
             let range = NSMakeRange(0, suffixView.stringValue.count)

alt-tab-macos/ui/preferences-window/PreferencesWindow.swift

@@ -1,7 +1,6 @@
 import Cocoa
 
 class PreferencesWindow: NSWindow {
-    var windowCloseRequested = false
     let tabViewController = TabViewController()
 
     override init(contentRect: NSRect, styleMask style: StyleMask, backing backingStoreType: BackingStoreType, defer flag: Bool) {
@@ -17,29 +16,10 @@ class PreferencesWindow: NSWindow {
     }
 
     func controlWasChanged(_ senderControl: NSControl) {
-        let key: String = senderControl.identifier!.rawValue
-        let previousValue: String = Preferences.rawValues[key]!
-        let newValue: String = LabelAndControl.getControlValue(senderControl)
-        let invalidTextField = senderControl is TextField && !(senderControl as! TextField).isValid()
-
-        if (invalidTextField && !windowCloseRequested) || (newValue == previousValue && !invalidTextField) {
-            return
-        }
-
+        let newValue = LabelAndControl.getControlValue(senderControl)
         LabelAndControl.updateControlExtras(senderControl, newValue)
-
-        do {
-            // TODO: remove conditional as soon a Preference does validation on its own
-            if invalidTextField && windowCloseRequested {
-                throw NSError.make(domain: "Preferences", message: "Please enter a valid value for '" + key + "'")
-            }
-            try Preferences.updateAndValidateFromString(key, newValue)
-            try Preferences.saveRawToDisk()
-            (App.shared as! App).initPreferencesDependentComponents()
-        } catch let error {
-            debugPrint("PreferencesWindow: save: error", key, newValue, error)
-            showSaveErrorSheetModal(error as NSError, senderControl, key, previousValue) // allows recursive call by user choice
-        }
+        Preferences.set(senderControl.identifier!.rawValue, newValue)
+        (App.shared as! App).initPreferencesDependentComponents()
     }
 
     private func setupWindow() {
@@ -56,47 +36,4 @@ class PreferencesWindow: NSWindow {
         tabViewController.addTabViewItem(UpdatesTab.make())
         tabViewController.addTabViewItem(AboutTab.make())
     }
-
-    private func challengeNextInvalidEditableTextField() {
-        let invalidFields = (contentView?
-                .findNestedViews(subclassOf: TextField.self)
-                .filter({ !$0.isValid() })
-        )
-        let focusedField = invalidFields?.filter({ $0.currentEditor() != nil }).first
-        let fieldToNotify = focusedField ?? invalidFields?.first
-        fieldToNotify?.delegate?.controlTextDidChange?(Notification(name: NSControl.textDidChangeNotification, object: fieldToNotify))
-
-        if fieldToNotify != focusedField {
-            makeFirstResponder(fieldToNotify)
-        }
-    }
-
-    private func showSaveErrorSheetModal(_ nsError: NSError, _ control: NSControl, _ key: String, _ previousValue: String) {
-        let alert = NSAlert()
-        alert.messageText = NSLocalizedString("Could not save Preference", comment: "")
-        alert.informativeText = nsError.localizedDescription + "\n"
-        alert.addButton(withTitle: NSLocalizedString("Edit", comment: ""))
-        alert.addButton(withTitle: NSLocalizedString("Cancel", comment: ""))
-        alert.addButton(withTitle: NSLocalizedString("Check again", comment: ""))
-
-        alert.beginSheetModal(for: self, completionHandler: { (modalResponse: NSApplication.ModalResponse) -> Void in
-            if modalResponse == NSApplication.ModalResponse.alertFirstButtonReturn {
-                debugPrint("PreferencesWindow: save: error: user choice: edit")
-                self.windowCloseRequested = false
-            }
-            if modalResponse == NSApplication.ModalResponse.alertSecondButtonReturn {
-                debugPrint("PreferencesWindow: save: error: user choice: cancel -> revert value and eventually close window")
-                try! Preferences.updateAndValidateFromString(key, previousValue)
-                LabelAndControl.setControlValue(control, previousValue)
-                LabelAndControl.updateControlExtras(control, previousValue)
-                if self.windowCloseRequested {
-                    self.close()
-                }
-            }
-            if modalResponse == NSApplication.ModalResponse.alertThirdButtonReturn {
-                debugPrint("PreferencesWindow: save: error: user choice: check again")
-                self.controlWasChanged(control)
-            }
-        })
-    }
 }

alt-tab-macos/ui/preferences-window/tabs/AppearanceTab.swift

@@ -9,14 +9,14 @@ class AppearanceTab {
 
     private static func makeView() -> NSGridView {
         let view = GridView.make([
-            LabelAndControl.makeLabelWithDropdown(NSLocalizedString("Theme", comment: ""), "theme", Preferences.themeMacro.labels),
+            LabelAndControl.makeLabelWithDropdown(NSLocalizedString("Theme", comment: ""), "theme", MacroPreferences.themeList.values.map { $0.label }),
             LabelAndControl.makeLabelWithSlider(NSLocalizedString("Max size on screen", comment: ""), "maxScreenUsage", 10, 100, 10, true, "%"),
             LabelAndControl.makeLabelWithSlider(NSLocalizedString("Min windows per row", comment: ""), "minCellsPerRow", 1, 20, 20, true),
             LabelAndControl.makeLabelWithSlider(NSLocalizedString("Max windows per row", comment: ""), "maxCellsPerRow", 1, 40, 20, true),
             LabelAndControl.makeLabelWithSlider(NSLocalizedString("Min rows of windows", comment: ""), "minRows", 1, 20, 20, true),
             LabelAndControl.makeLabelWithSlider(NSLocalizedString("Window app icon size", comment: ""), "iconSize", 0, 64, 11, false, "px"),
             LabelAndControl.makeLabelWithSlider(NSLocalizedString("Window title font size", comment: ""), "fontHeight", 0, 64, 11, false, "px"),
-            LabelAndControl.makeLabelWithDropdown(NSLocalizedString("Show on", comment: ""), "showOnScreen", Preferences.showOnScreenMacro.labels),
+            LabelAndControl.makeLabelWithDropdown(NSLocalizedString("Show on", comment: ""), "showOnScreen", Array(MacroPreferences.showOnScreenList.keys)),
             LabelAndControl.makeLabelWithSlider(NSLocalizedString("Apparition delay", comment: ""), "windowDisplayDelay", 0, 2000, 11, false, "ms"),
             LabelAndControl.makeLabelWithCheckbox(NSLocalizedString("Hide space number labels", comment: ""), "hideSpaceNumberLabels"),
         ])

alt-tab-macos/ui/preferences-window/tabs/ShortcutsTab.swift

@@ -22,7 +22,7 @@ class ShortcutsTab {
         }
 
         let view = GridView.make([
-            LabelAndControl.makeLabelWithDropdown(NSLocalizedString("Alt key", comment: ""), "metaKey", Preferences.metaKeyMacro.labels),
+            LabelAndControl.makeLabelWithDropdown(NSLocalizedString("Alt key", comment: ""), "metaKey", MacroPreferences.metaKeyList.values.map { $0.label }),
             LabelAndControl.makeLabelWithInput(NSLocalizedString("Tab key", comment: ""), "tabKeyCode", 33, NSLocalizedString("KeyCodes Reference", comment: ""), "https://eastmanreference.com/complete-list-of-applescript-key-codes", tabKeyCodeValidator),
         ])
         view.column(at: 0).xPlacement = .trailing

alt-tab-macos/ui/preferences-window/tabs/UpdatesTab.swift

@@ -6,6 +6,8 @@ class UpdatesTab: NSObject {
     static var periodicallyCheck: NSButton!
     static var periodicallyInstall: NSButton!
     static var policyObserver = PolicyObserver()
+    // this helps prevent double-dipping (i.e. user updates the UI > changes the preference > updates the UI)
+    static var policyLock = false
 
     static func make() -> NSTabViewItem {
         return TabViewItem.make(NSLocalizedString("Updates", comment: ""), NSImage.refreshTemplateName, makeView())
@@ -49,13 +51,16 @@ class UpdatesTab: NSObject {
 
     @objc
     static func updatePolicyCallback() {
+        policyLock = true
         SUUpdater.shared().automaticallyDownloadsUpdates = periodicallyInstall.state == .on
         SUUpdater.shared().automaticallyChecksForUpdates = periodicallyInstall.state == .on || periodicallyCheck.state == .on
+        policyLock = false
     }
 }
 
 class PolicyObserver: NSObject {
     override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey: Any]?, context: UnsafeMutableRawPointer?) {
+        guard !UpdatesTab.policyLock else { return }
         if SUUpdater.shared().automaticallyDownloadsUpdates {
             UpdatesTab.periodicallyInstall.state = .on
             // Sparkle UI "Automatically download and install updates in the future" doesn't activate periodical checks; we do it manually