feat: add debug tools

alt-tab-macos.xcodeproj/project.pbxproj

@@ -227,6 +227,7 @@
 		D04BA2A6FF9DDDC5A1A68E36 /* Applications.swift in Sources */ = {isa = PBXBuildFile; fileRef = D04BA282BB16C1554595A968 /* Applications.swift */; };
 		D04BA2D8099594E1593EC8EF /* InfoPlist.strings in Resources */ = {isa = PBXBuildFile; fileRef = D04BA88EDDDD6CB3FBE71FC5 /* InfoPlist.strings */; };
 		D04BA2E64C59D96F6EB27D9D /* FeedbackWindow.swift in Sources */ = {isa = PBXBuildFile; fileRef = D04BA26C75F76C277653C932 /* FeedbackWindow.swift */; };
+		D04BA2F0A1B2C3D4E5F60003 /* DebugWindow.swift in Sources */ = {isa = PBXBuildFile; fileRef = D04BA2F0A1B2C3D4E5F60004 /* DebugWindow.swift */; };
 		D04BA328F7C85DD1A6C1C7ED /* Localizable.strings in Resources */ = {isa = PBXBuildFile; fileRef = D04BAB163FDEE79F096A410A /* Localizable.strings */; };
 		D04BA34AC850A273AB288B1E /* Localizable.strings in Resources */ = {isa = PBXBuildFile; fileRef = D04BA3B51D05213404938366 /* Localizable.strings */; };
 		D04BA3744F48116DF4252B19 /* Localizable.strings in Resources */ = {isa = PBXBuildFile; fileRef = D04BA02355EB28D639F854DF /* Localizable.strings */; };
@@ -604,6 +605,7 @@
 		D04BA2D022B64A876CCA6BB7 /* apple-touch-icon.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = "apple-touch-icon.png"; sourceTree = "<group>"; };
 		D04BA2E723062A1DAC58618F /* setup_ci_pr.sh */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.script.sh; path = setup_ci_pr.sh; sourceTree = "<group>"; };
 		D04BA2E8D5D5CC23456BC8F7 /* tr */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.plist.strings; name = tr; path = Localizable.strings; sourceTree = "<group>"; };
+		D04BA2F0A1B2C3D4E5F60004 /* DebugWindow.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = DebugWindow.swift; sourceTree = "<group>"; };
 		D04BA32F25860B686DFE818A /* 3 windows - 1 line.jpg */ = {isa = PBXFileReference; lastKnownFileType = image.jpeg; path = "3 windows - 1 line.jpg"; sourceTree = "<group>"; };
 		D04BA3632A2EB5C64A3FEE59 /* hu */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.plist.strings; name = hu; path = InfoPlist.strings; sourceTree = "<group>"; };
 		D04BA369B4D9FD6A13936F53 /* changelog-bare.html */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.html; path = "changelog-bare.html"; sourceTree = "<group>"; };
@@ -1471,6 +1473,7 @@
 				D04BABCD12CA72B06290C248 /* settings-window */,
 				D04BAD905546AA93E5117B0A /* Menubar.swift */,
 				D04BA26C75F76C277653C932 /* FeedbackWindow.swift */,
+				D04BA2F0A1B2C3D4E5F60004 /* DebugWindow.swift */,
 				D04BA2CBF267F267225CA671 /* generic-components */,
 				D04BA1C271F0DA573345B860 /* permission-window */,
 				D04BAAF79737A0673502FEB5 /* AppCenterApplication.h */,
@@ -2511,6 +2514,7 @@
 				D04BA8092885B40CE3527370 /* PoliciesTab.swift in Sources */,
 				D04BAD451966B43720120D2E /* Menubar.swift in Sources */,
 				D04BA2E64C59D96F6EB27D9D /* FeedbackWindow.swift in Sources */,
+				D04BA2F0A1B2C3D4E5F60003 /* DebugWindow.swift in Sources */,
 				D04BA76A74267B1346D23687 /* GridView.swift in Sources */,
 				D04BAB4EB890853B5B9B2C61 /* BoldLabel.swift in Sources */,
 				D04BAABE804F3769CE22BEB6 /* HyperlinkLabel.swift in Sources */,

resources/l10n/Localizable.strings

@@ -172,6 +172,9 @@
 /* No comment provided by engineer. */
 "Dark" = "Dark";
 
+/* Menubar option */
+"Debug tools" = "Debug tools";
+
 /* No comment provided by engineer. */
 "Disabled" = "Disabled";
 

resources/l10n/hu.lproj/Localizable.strings

@@ -1,5 +1,5 @@
 "About" = "Az App-ról";
-"About %@" = "Körülbelül %@";
+"About %@" = "Az %@ról";
 "Accessibility" = "Kisegítő lehetőségek";
 "Acknowledgments" = "Köszönetnyílvánítás";
 "Active app" = "Aktív alkalmazás";
@@ -126,7 +126,7 @@
 "Preview selected window:" = "Választott ablak előnézete:";
 "Preview the selected window." = "A kiválasztott ablak előnézete";
 "Quit" = "Kilépés";
-"Quit %@" = "Kilépés %@";
+"Quit %@" = "Kilépés az %@ból";
 "Quit app" = "Kilépés az alkalmazásból";
 "Recently Created" = "Nemrég Elindított";
 "Recently Created First" = "Mostanában megnyitott";

src/api-wrappers/Logger.swift

@@ -10,16 +10,31 @@ class Logger {
     static func initialize() {
         let console = ConsoleDestination()
         console.useTerminalColors = true
-        console.levelString.verbose = "VERB"
-        console.levelString.debug = "DEBG"
-        console.levelString.info = "INFO"
-        console.levelString.warning = "WARN"
-        console.levelString.error = "ERRO"
-        console.format = "$C$D\(longDateTimeFormat)$d $L$c $N.swift:$l $F $M"
+        configureDestination(console)
+        console.format = "$C$D\(shortDateTimeFormat)$d $L$c $N.swift:$l $F $M"
         console.minLevel = decideLevel()
         logger.addDestination(console)
     }
 
+    static func configureDestination(_ dest: BaseDestination) {
+        dest.levelString.verbose = "VERB"
+        dest.levelString.debug = "DEBG"
+        dest.levelString.info = "INFO"
+        dest.levelString.warning = "WARN"
+        dest.levelString.error = "ERRO"
+        dest.format = "$D\(shortDateTimeFormat)$d $L $N.swift:$l $F $M"
+    }
+
+    @discardableResult
+    static func addDestination(_ dest: BaseDestination) -> Bool {
+        logger.addDestination(dest)
+    }
+
+    @discardableResult
+    static func removeDestination(_ dest: BaseDestination) -> Bool {
+        logger.removeDestination(dest)
+    }
+
     static func decideLevel() -> SwiftyBeaver.Level {
         if let level = (CommandLine.arguments.first { $0.starts(with: flag) })?.dropFirst(flag.count) {
             switch level {
@@ -66,3 +81,26 @@ class Logger {
         }
     }
 }
+
+/// custom destination to display logs in the debug window
+class DebugWindowDestination: BaseDestination {
+    var onNewEntry: ((SwiftyBeaver.Level, String) -> Void)?
+
+    override var defaultHashValue: Int { return 2 }
+
+    override init() {
+        super.init()
+        Logger.configureDestination(self)
+        minLevel = .debug
+    }
+
+    override func send(_ level: SwiftyBeaver.Level, msg: String, thread: String,
+                       file: String, function: String, line: Int, context: Any? = nil) -> String? {
+        let formattedString = super.send(level, msg: msg, thread: thread,
+                                         file: file, function: function, line: line, context: context)
+        guard let formatted = formattedString else { return nil }
+        let callback = onNewEntry
+        DispatchQueue.main.async { callback?(level, formatted) }
+        return formattedString
+    }
+}

src/logic/WindowDiscriminator.swift

@@ -5,7 +5,7 @@ class WindowDiscriminator {
         // Minimized windows or windows of a hidden app have subrole "AXDialog"
         // Activity Monitor main window subrole is "AXDialog" for a brief moment at launch; it then becomes "AXStandardWindow"
         // Some non-windows have cgWindowId == 0 (e.g. windows of apps starting at login with the checkbox "Hidden" checked)
-        // Logger.error { (app.bundleIdentifier, level, title, subrole, role, size) }
+        Logger.debug { (app.debugId, wid, level, title, subrole, role, size) }
         return wid != 0
             // Finder's file copy dialogs are wide but < 100 height (see https://github.com/lwouis/alt-tab-macos/issues/1466)
             // Sonoma introduced a bug: a caps-lock & language indicators shows as a small window.

src/ui/App.swift

@@ -21,13 +21,14 @@ class App: AppCenterApplication {
     var isTerminating = false
     var thumbnailsPanel: TilesPanel!
     var previewPanel: PreviewPanel!
-    var settingsWindow: SettingsWindow!
-    var aboutWindow: AboutWindow!
-    var permissionsWindow: PermissionsWindow?
     var appIsBeingUsed = false
     var shortcutIndex = 0
     var forceDoNothingOnRelease = false
+    var settingsWindow: SettingsWindow!
+    var aboutWindow: AboutWindow!
+    var permissionsWindow: PermissionsWindow?
     private var feedbackWindow: FeedbackWindow!
+    private var debugWindow: DebugWindow!
     private var isFirstSummon = true
     private var isVeryFirstSummon = true
     // periphery:ignore
@@ -95,8 +96,9 @@ class App: AppCenterApplication {
     private func allSecondaryWindowsCanBecomeKey(_ canBecomeKey_: Bool) {
         settingsWindow?.canBecomeKey_ = canBecomeKey_
         aboutWindow?.canBecomeKey_ = canBecomeKey_
-        feedbackWindow?.canBecomeKey_ = canBecomeKey_
         permissionsWindow?.canBecomeKey_ = canBecomeKey_
+        feedbackWindow?.canBecomeKey_ = canBecomeKey_
+        debugWindow?.canBecomeKey_ = canBecomeKey_
     }
 
     func closeSelectedWindow() {
@@ -161,6 +163,10 @@ class App: AppCenterApplication {
         showSecondaryWindow(getOrCreateFeedbackWindow())
     }
 
+    @objc func showDebugWindow() {
+        showSecondaryWindow(getOrCreateDebugWindow())
+    }
+
     @objc func showSettingsWindow() {
         showSecondaryWindow(getOrCreateSettingsWindow())
         if settingsWindow?.isVisible != true {
@@ -206,6 +212,13 @@ class App: AppCenterApplication {
         return feedbackWindow
     }
 
+    private func getOrCreateDebugWindow() -> DebugWindow {
+        if debugWindow == nil {
+            debugWindow = DebugWindow()
+        }
+        return debugWindow
+    }
+
     private func getOrCreatePermissionsWindow() -> PermissionsWindow {
         if permissionsWindow == nil {
             permissionsWindow = PermissionsWindow()

src/ui/DebugWindow.swift

@@ -0,0 +1,389 @@
+import Cocoa
+import SwiftyBeaver
+
+class DebugWindow: NSPanel {
+    var canBecomeKey_ = true
+    override var canBecomeKey: Bool { canBecomeKey_ }
+    private var scrollView: NSScrollView!
+    private var textView: NSTextView!
+    private var filterControl: NSSegmentedControl!
+    private var selectedMinLevel: SwiftyBeaver.Level = .debug
+    private var isAutoScrolling = true
+    private var isPerformingAutoScroll = false
+    private var entries = [(SwiftyBeaver.Level, String)]()
+    private var destination: DebugWindowDestination?
+    private var inspectButton: NSButton!
+    private var inspectColumns: NSStackView!
+    private var inspectAppField: NSTextField!
+    private var inspectCgField: NSTextField!
+    private var inspectAxField: NSTextField!
+    private var inspectTimer: Timer?
+    private var inspectClickMonitor: Any?
+    private var isInspecting = false
+    private static let logFont = NSFont.userFixedPitchFont(ofSize: 11)!
+    private static let levels: [SwiftyBeaver.Level] = [.debug, .info, .warning, .error]
+    private static let defaultAttrs: [NSAttributedString.Key: Any] = [.font: logFont, .foregroundColor: NSColor.textColor]
+    private static let levelWords: [SwiftyBeaver.Level: String] = [.debug: "DEBG", .info: "INFO", .warning: "WARN", .error: "ERRO"]
+
+    convenience init() {
+        self.init(contentRect: NSRect(x: 0, y: 0, width: 1100, height: 750),
+                  styleMask: [.titled, .utilityWindow, .closable, .miniaturizable, .resizable],
+                  backing: .buffered, defer: false)
+        setupWindow()
+        setupView()
+    }
+
+    private func setupWindow() {
+        title = NSLocalizedString("Debug tools", comment: "")
+        hidesOnDeactivate = false
+        isReleasedWhenClosed = false
+        minSize = NSSize(width: 400, height: 300)
+    }
+
+    private static func colorForLevel(_ level: SwiftyBeaver.Level) -> NSColor {
+        switch level {
+            case .debug: return NSColor(calibratedRed: 0.0, green: 0.7, blue: 0.0, alpha: 1.0)
+            case .info: return NSColor(calibratedRed: 0.0, green: 0.5, blue: 0.85, alpha: 1.0)
+            case .warning: return NSColor(calibratedRed: 0.82, green: 0.62, blue: 0.0, alpha: 1.0)
+            case .error: return NSColor(calibratedRed: 0.85, green: 0.15, blue: 0.3, alpha: 1.0)
+            default: return .textColor
+        }
+    }
+
+    private static func colorDot(_ color: NSColor) -> NSImage {
+        let size = NSSize(width: 8, height: 8)
+        let image = NSImage(size: size)
+        image.lockFocus()
+        color.setFill()
+        NSBezierPath(ovalIn: NSRect(origin: .zero, size: size)).fill()
+        image.unlockFocus()
+        return image
+    }
+
+    private func setupView() {
+        // Inspect section
+        inspectButton = NSButton(title: "Inspect window", target: nil, action: nil)
+        inspectButton.translatesAutoresizingMaskIntoConstraints = false
+        inspectButton.bezelStyle = .rounded
+        inspectButton.onAction = { [weak self] _ in self?.toggleInspect() }
+        inspectAppField = Self.makeInspectColumn("App", ["Name", "BundleID", "PID"])
+        inspectCgField = Self.makeInspectColumn("Window (CG API)", ["Title", "WID", "Level (kCGWindowLayer)", "Level (CGSGetWindowLevel)", "Size", "Position", "Alpha", "IsOnScreen"])
+        inspectAxField = Self.makeInspectColumn("Window (AX API)", ["Title", "Role", "Subrole", "Minimized", "Fullscreen", "Size", "Position"])
+        inspectColumns = NSStackView(views: [inspectAppField, inspectCgField, inspectAxField])
+        inspectColumns.translatesAutoresizingMaskIntoConstraints = false
+        inspectColumns.orientation = .horizontal
+        inspectColumns.alignment = .top
+        inspectColumns.spacing = 16
+        inspectColumns.distribution = .fillEqually
+        // Log header and filter
+        let filterLabel = NSTextField(labelWithString: "Log Level:")
+        filterLabel.translatesAutoresizingMaskIntoConstraints = false
+        filterControl = NSSegmentedControl(labels: ["Debug", "Info", "Warning", "Error"],
+                                           trackingMode: .selectOne, target: nil, action: nil)
+        filterControl.translatesAutoresizingMaskIntoConstraints = false
+        filterControl.selectedSegment = 0
+        filterControl.onAction = { [weak self] _ in self?.filterChanged() }
+        for i in 0..<Self.levels.count {
+            filterControl.setImage(Self.colorDot(Self.colorForLevel(Self.levels[i])), forSegment: i)
+            filterControl.setImageScaling(.scaleProportionallyDown, forSegment: i)
+        }
+        let filterRow = NSStackView(views: [filterLabel, filterControl])
+        filterRow.translatesAutoresizingMaskIntoConstraints = false
+        filterRow.orientation = .horizontal
+        filterRow.spacing = 8
+        // Log scroll view
+        scrollView = NSScrollView()
+        scrollView.translatesAutoresizingMaskIntoConstraints = false
+        scrollView.hasVerticalScroller = true
+        scrollView.hasHorizontalScroller = true
+        scrollView.autohidesScrollers = true
+        scrollView.drawsBackground = true
+        textView = NSTextView()
+        textView.isEditable = false
+        textView.isSelectable = true
+        textView.isRichText = true
+        textView.font = Self.logFont
+        textView.isHorizontallyResizable = true
+        textView.maxSize = NSSize(width: CGFloat.greatestFiniteMagnitude, height: CGFloat.greatestFiniteMagnitude)
+        textView.textContainer?.widthTracksTextView = false
+        textView.textContainer?.containerSize = NSSize(width: CGFloat.greatestFiniteMagnitude, height: CGFloat.greatestFiniteMagnitude)
+        textView.drawsBackground = true
+        textView.backgroundColor = NSColor(calibratedWhite: 0.95, alpha: 1.0)
+        scrollView.documentView = textView
+        scrollView.contentView.postsBoundsChangedNotifications = true
+        NotificationCenter.default.addObserver(self, selector: #selector(scrollViewDidScroll),
+                                               name: NSView.boundsDidChangeNotification,
+                                               object: scrollView.contentView)
+        // Inspect group box
+        let inspectBox = NSBox()
+        inspectBox.translatesAutoresizingMaskIntoConstraints = false
+        inspectBox.title = "Inspect"
+        inspectBox.contentView = NSView()
+        inspectBox.contentView!.addSubview(inspectButton)
+        inspectBox.contentView!.addSubview(inspectColumns)
+        NSLayoutConstraint.activate([
+            inspectButton.topAnchor.constraint(equalTo: inspectBox.contentView!.topAnchor, constant: 4),
+            inspectButton.leadingAnchor.constraint(equalTo: inspectBox.contentView!.leadingAnchor, constant: 4),
+            inspectColumns.topAnchor.constraint(equalTo: inspectButton.bottomAnchor, constant: 8),
+            inspectColumns.leadingAnchor.constraint(equalTo: inspectBox.contentView!.leadingAnchor, constant: 4),
+            inspectColumns.trailingAnchor.constraint(equalTo: inspectBox.contentView!.trailingAnchor, constant: -4),
+            inspectColumns.bottomAnchor.constraint(equalTo: inspectBox.contentView!.bottomAnchor, constant: -4),
+        ])
+        // Log group box
+        let logBox = NSBox()
+        logBox.translatesAutoresizingMaskIntoConstraints = false
+        logBox.title = "Logs"
+        logBox.contentView = NSView()
+        logBox.contentView!.addSubview(filterRow)
+        logBox.contentView!.addSubview(scrollView)
+        NSLayoutConstraint.activate([
+            filterRow.topAnchor.constraint(equalTo: filterRow.superview!.topAnchor, constant: 8),
+            filterRow.leadingAnchor.constraint(equalTo: logBox.contentView!.leadingAnchor, constant: 4),
+            scrollView.topAnchor.constraint(equalTo: filterRow.bottomAnchor, constant: 8),
+            scrollView.leadingAnchor.constraint(equalTo: logBox.contentView!.leadingAnchor, constant: 4),
+            scrollView.trailingAnchor.constraint(equalTo: logBox.contentView!.trailingAnchor, constant: -4),
+            scrollView.bottomAnchor.constraint(equalTo: logBox.contentView!.bottomAnchor, constant: -4),
+        ])
+        // Main container
+        let container = NSView()
+        container.translatesAutoresizingMaskIntoConstraints = false
+        container.addSubview(inspectBox)
+        container.addSubview(logBox)
+        contentView = container
+        let padding: CGFloat = 12
+        NSLayoutConstraint.activate([
+            inspectBox.topAnchor.constraint(equalTo: container.topAnchor, constant: padding),
+            inspectBox.leadingAnchor.constraint(equalTo: container.leadingAnchor, constant: padding),
+            inspectBox.trailingAnchor.constraint(equalTo: container.trailingAnchor, constant: -padding),
+            logBox.topAnchor.constraint(equalTo: inspectBox.bottomAnchor, constant: padding),
+            logBox.leadingAnchor.constraint(equalTo: container.leadingAnchor, constant: padding),
+            logBox.trailingAnchor.constraint(equalTo: container.trailingAnchor, constant: -padding),
+            logBox.bottomAnchor.constraint(equalTo: container.bottomAnchor, constant: -padding),
+        ])
+    }
+
+    private func startListening() {
+        guard destination == nil else { return }
+        let dest = DebugWindowDestination()
+        dest.onNewEntry = { [weak self] level, message in
+            self?.appendEntry(level, message)
+        }
+        Logger.addDestination(dest)
+        destination = dest
+    }
+
+    private func stopListening() {
+        guard let dest = destination else { return }
+        Logger.removeDestination(dest)
+        destination = nil
+    }
+
+    private func filterChanged() {
+        selectedMinLevel = Self.levels[filterControl.selectedSegment]
+        rebuildText()
+    }
+
+    private func attributedLine(_ text: String, _ level: SwiftyBeaver.Level) -> NSAttributedString {
+        let result = NSMutableAttributedString(string: text, attributes: Self.defaultAttrs)
+        guard let word = Self.levelWords[level],
+              let range = text.range(of: word) else { return result }
+        result.addAttribute(.foregroundColor, value: Self.colorForLevel(level),
+                            range: NSRange(range, in: text))
+        return result
+    }
+
+    private func rebuildText() {
+        let filtered = entries.filter { $0.0.rawValue >= selectedMinLevel.rawValue }
+        let result = NSMutableAttributedString()
+        for (i, entry) in filtered.enumerated() {
+            if i > 0 { result.append(NSAttributedString(string: "\n", attributes: Self.defaultAttrs)) }
+            result.append(attributedLine(entry.1, entry.0))
+        }
+        textView.textStorage?.setAttributedString(result)
+        textView.needsDisplay = true
+        if isAutoScrolling {
+            scrollToBottom()
+        }
+    }
+
+    private func appendEntry(_ level: SwiftyBeaver.Level, _ message: String) {
+        entries.append((level, message))
+        guard level.rawValue >= selectedMinLevel.rawValue else { return }
+        let prefix = textView.string.isEmpty ? "" : "\n"
+        textView.textStorage?.append(attributedLine(prefix + message, level))
+        if isAutoScrolling {
+            scrollToBottom()
+        }
+    }
+
+    private func scrollToBottom() {
+        textView.layoutManager?.ensureLayout(for: textView.textContainer!)
+        guard let documentView = scrollView.documentView else { return }
+        let clipView = scrollView.contentView
+        let maxY = documentView.frame.height - clipView.bounds.height
+        guard maxY > 0 else { return }
+        isPerformingAutoScroll = true
+        clipView.setBoundsOrigin(NSPoint(x: clipView.bounds.origin.x, y: maxY))
+        isPerformingAutoScroll = false
+    }
+
+    @objc private func scrollViewDidScroll(_ notification: Notification) {
+        guard !isPerformingAutoScroll,
+              let documentView = scrollView.documentView else { return }
+        let clipView = scrollView.contentView
+        let contentHeight = documentView.frame.height
+        let scrollOffset = clipView.bounds.origin.y + clipView.bounds.height
+        isAutoScrolling = scrollOffset >= contentHeight - 1
+    }
+
+    override func makeKeyAndOrderFront(_ sender: Any?) {
+        startListening()
+        super.makeKeyAndOrderFront(sender)
+    }
+
+    override func close() {
+        stopInspecting()
+        stopListening()
+        clearInspectData()
+        entries.removeAll()
+        textView.textStorage?.setAttributedString(NSAttributedString())
+        selectedMinLevel = .debug
+        filterControl.selectedSegment = 0
+        isAutoScrolling = true
+        hideAppIfLastWindowIsClosed()
+        super.close()
+    }
+
+    private func toggleInspect() {
+        if isInspecting { stopInspecting() } else { startInspecting() }
+    }
+
+    private func startInspecting() {
+        isInspecting = true
+        inspectButton.title = "Stop inspecting"
+        inspectTimer = Timer.scheduledTimer(withTimeInterval: 0.1, repeats: true) { [weak self] _ in
+            self?.updateInspectData()
+        }
+        inspectClickMonitor = NSEvent.addGlobalMonitorForEvents(matching: .leftMouseDown) { [weak self] _ in
+            self?.stopInspecting()
+        }
+    }
+
+    private func stopInspecting() {
+        guard isInspecting else { return }
+        isInspecting = false
+        inspectButton.title = "Inspect window"
+        inspectTimer?.invalidate()
+        inspectTimer = nil
+        if let monitor = inspectClickMonitor {
+            NSEvent.removeMonitor(monitor)
+            inspectClickMonitor = nil
+        }
+    }
+
+    private func updateInspectData() {
+        let mouseLocation = NSEvent.mouseLocation
+        guard let mainScreen = NSScreen.screens.first else { return }
+        let cgMousePoint = CGPoint(x: mouseLocation.x, y: mainScreen.frame.height - mouseLocation.y)
+        let myWid = CGWindowID(windowNumber)
+        guard let found = CGWindow.windows(.optionOnScreenOnly).first(where: { win in
+            guard let wid = win.id(), wid != myWid,
+                  let bounds = win.bounds() else { return false }
+            return CGRect(x: bounds.origin.x, y: bounds.origin.y, width: bounds.width, height: bounds.height)
+                .contains(cgMousePoint)
+        }) else {
+            clearInspectData()
+            return
+        }
+        let wid = (found[kCGWindowNumber] as? Int).map { CGWindowID($0) }
+        let pid = found.ownerPID()
+        // App column
+        var appName = "-"
+        var appBundleId = "-"
+        let pidStr = pid.map { String($0) } ?? "-"
+        if let pid {
+            let app = NSRunningApplication(processIdentifier: pid)
+            appName = app?.localizedName ?? "-"
+            appBundleId = app?.bundleIdentifier ?? "-"
+        }
+        inspectAppField.stringValue = Self.formatColumn("App", [
+            ("Name", appName), ("BundleID", appBundleId), ("PID", pidStr),
+        ])
+        // CG column
+        let cgTitle = found.title() ?? "-"
+        let widStr = wid.map { "\($0)" } ?? "-"
+        let cgLayer = found.layer().map { "\($0)" } ?? "-"
+        let cgsLevel = wid.map { "\($0.level())" } ?? "-"
+        let bounds = found.bounds()
+        let cgSize = bounds.map { "\(Int($0.width))x\(Int($0.height))" } ?? "-"
+        let cgPos = bounds.map { "\(Int($0.origin.x)),\(Int($0.origin.y))" } ?? "-"
+        let alpha = (found[kCGWindowAlpha] as? Double).map { "\($0)" } ?? "-"
+        let isOnScreen = (found[kCGWindowIsOnscreen] as? Bool).map { "\($0)" } ?? "-"
+        inspectCgField.stringValue = Self.formatColumn("Window (CG API)", [
+            ("Title", cgTitle), ("WID", widStr),
+            ("Level (kCGWindowLayer)", cgLayer), ("Level (CGSGetWindowLevel)", cgsLevel),
+            ("Size", cgSize), ("Position", cgPos), ("Alpha", alpha), ("IsOnScreen", isOnScreen),
+        ])
+        // AX column
+        var axTitle = "-"
+        var axRole = "-"
+        var axSubrole = "-"
+        var axMinimized = "-"
+        var axFullscreen = "-"
+        var axSize = "-"
+        var axPosition = "-"
+        if let pid, let wid {
+            let axApp = AXUIElementCreateApplication(pid)
+            if let axWindows = try? axApp.attributes([kAXWindowsAttribute]).windows {
+                for axWin in axWindows {
+                    if let axWid = try? axWin.cgWindowId(), axWid == wid {
+                        let attrs = try? axWin.attributes([kAXTitleAttribute, kAXRoleAttribute, kAXSubroleAttribute,
+                                                           kAXMinimizedAttribute, kAXFullscreenAttribute,
+                                                           kAXSizeAttribute, kAXPositionAttribute])
+                        axTitle = attrs?.title ?? "-"
+                        axRole = attrs?.role ?? "-"
+                        axSubrole = attrs?.subrole ?? "-"
+                        axMinimized = attrs?.isMinimized.map { "\($0)" } ?? "-"
+                        axFullscreen = attrs?.isFullscreen.map { "\($0)" } ?? "-"
+                        if let s = attrs?.size { axSize = "\(Int(s.width))x\(Int(s.height))" }
+                        if let p = attrs?.position { axPosition = "\(Int(p.x)),\(Int(p.y))" }
+                        break
+                    }
+                }
+            }
+        }
+        inspectAxField.stringValue = Self.formatColumn("Window (AX API)", [
+            ("Title", axTitle), ("Role", axRole), ("Subrole", axSubrole),
+            ("Minimized", axMinimized), ("Fullscreen", axFullscreen),
+            ("Size", axSize), ("Position", axPosition),
+        ])
+    }
+
+    private func clearInspectData() {
+        inspectAppField.stringValue = Self.formatColumn("App", [("Name", "-"), ("BundleID", "-"), ("PID", "-")])
+        inspectCgField.stringValue = Self.formatColumn("Window (CG API)", [
+            ("Title", "-"), ("WID", "-"), ("Level (kCGWindowLayer)", "-"), ("Level (CGSGetWindowLevel)", "-"),
+            ("Size", "-"), ("Position", "-"), ("Alpha", "-"), ("IsOnScreen", "-"),
+        ])
+        inspectAxField.stringValue = Self.formatColumn("Window (AX API)", [
+            ("Title", "-"), ("Role", "-"), ("Subrole", "-"), ("Minimized", "-"), ("Fullscreen", "-"), ("Size", "-"), ("Position", "-"),
+        ])
+    }
+
+    private static func makeInspectColumn(_ title: String, _ labels: [String]) -> NSTextField {
+        let field = NSTextField(labelWithString: formatColumn(title, labels.map { ($0, "-") }))
+        field.translatesAutoresizingMaskIntoConstraints = false
+        field.font = logFont
+        field.isSelectable = true
+        field.maximumNumberOfLines = 0
+        field.cell?.lineBreakMode = .byTruncatingTail
+        field.cell?.truncatesLastVisibleLine = true
+        field.setContentHuggingPriority(.defaultLow, for: .horizontal)
+        field.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
+        return field
+    }
+
+    private static func formatColumn(_ title: String, _ rows: [(String, String)]) -> String {
+        return "\(title)\n" + rows.map { "• \($0.0): \($0.1)" }.joined(separator: "\n")
+    }
+}

src/ui/Menubar.swift

@@ -29,6 +29,7 @@ class Menubar {
         addMenuItem(NSLocalizedString("Check permissions…", comment: "Menubar option"), #selector(App.app.checkPermissions), "", "hand.raised")
         menu.addItem(NSMenuItem.separator())
         addMenuItem(String(format: NSLocalizedString("About %@", comment: "Menubar option. %@ is AltTab"), App.name), #selector(App.app.showAboutWindow), "", "info.circle")
+        addMenuItem(NSLocalizedString("Debug tools", comment: "Menubar option"), #selector(App.app.showDebugWindow), "", "scope")
         addMenuItem(NSLocalizedString("Send feedback…", comment: "Menubar option"), #selector(App.app.showFeedbackPanel), "", "text.bubble")
         addMenuItem(NSLocalizedString("Support this project", comment: "Menubar option"), App.supportProjectAction, "", "heart.fill", .red)
         menu.addItem(NSMenuItem.separator())