Add Sparkle auto-update flow and titlebar update UI

Sources/WindowToolbarController.swift

@@ -0,0 +1,135 @@
+import AppKit
+import SwiftUI
+
+final class WindowToolbarController: NSObject, NSToolbarDelegate {
+    private let commandItemIdentifier = NSToolbarItem.Identifier("cmux.focusedCommand")
+    private let updateItemIdentifier = NSToolbarItem.Identifier("cmux.updatePill")
+
+    private weak var tabManager: TabManager?
+    private weak var updateViewModel: UpdateViewModel?
+
+    private var commandLabels: [ObjectIdentifier: NSTextField] = [:]
+    private var observers: [NSObjectProtocol] = []
+
+    init(updateViewModel: UpdateViewModel) {
+        self.updateViewModel = updateViewModel
+        super.init()
+    }
+
+    deinit {
+        for observer in observers {
+            NotificationCenter.default.removeObserver(observer)
+        }
+    }
+
+    func start(tabManager: TabManager) {
+        self.tabManager = tabManager
+        attachToExistingWindows()
+        installObservers()
+        updateFocusedCommandText()
+    }
+
+    private func installObservers() {
+        let center = NotificationCenter.default
+        observers.append(center.addObserver(
+            forName: .ghosttyDidSetTitle,
+            object: nil,
+            queue: .main
+        ) { [weak self] _ in
+            self?.updateFocusedCommandText()
+        })
+
+        observers.append(center.addObserver(
+            forName: .ghosttyDidFocusTab,
+            object: nil,
+            queue: .main
+        ) { [weak self] _ in
+            self?.updateFocusedCommandText()
+        })
+
+        observers.append(center.addObserver(
+            forName: NSWindow.didBecomeMainNotification,
+            object: nil,
+            queue: .main
+        ) { [weak self] notification in
+            guard let window = notification.object as? NSWindow else { return }
+            self?.attach(to: window)
+        })
+    }
+
+    private func attachToExistingWindows() {
+        for window in NSApp.windows {
+            attach(to: window)
+        }
+    }
+
+    private func attach(to window: NSWindow) {
+        guard window.toolbar == nil else { return }
+        let toolbar = NSToolbar(identifier: NSToolbar.Identifier("cmux.toolbar"))
+        toolbar.delegate = self
+        toolbar.displayMode = .iconOnly
+        toolbar.allowsUserCustomization = false
+        toolbar.autosavesConfiguration = false
+        toolbar.showsBaselineSeparator = false
+        window.toolbar = toolbar
+        window.toolbarStyle = .unified
+        window.titleVisibility = .visible
+    }
+
+    private func updateFocusedCommandText() {
+        guard let tabManager else { return }
+        let text: String
+        if let selectedId = tabManager.selectedTabId,
+           let tab = tabManager.tabs.first(where: { $0.id == selectedId }) {
+            let title = tab.title.trimmingCharacters(in: .whitespacesAndNewlines)
+            text = title.isEmpty ? "Cmd: —" : "Cmd: \(title)"
+        } else {
+            text = "Cmd: —"
+        }
+
+        for label in commandLabels.values {
+            label.stringValue = text
+        }
+    }
+
+    // MARK: - NSToolbarDelegate
+
+    func toolbarAllowedItemIdentifiers(_ toolbar: NSToolbar) -> [NSToolbarItem.Identifier] {
+        [commandItemIdentifier, .flexibleSpace, updateItemIdentifier]
+    }
+
+    func toolbarDefaultItemIdentifiers(_ toolbar: NSToolbar) -> [NSToolbarItem.Identifier] {
+        [commandItemIdentifier, .flexibleSpace, updateItemIdentifier]
+    }
+
+    func toolbar(_ toolbar: NSToolbar, itemForItemIdentifier itemIdentifier: NSToolbarItem.Identifier, willBeInsertedIntoToolbar flag: Bool) -> NSToolbarItem? {
+        if itemIdentifier == commandItemIdentifier {
+            let item = NSToolbarItem(itemIdentifier: itemIdentifier)
+            let label = NSTextField(labelWithString: "Cmd: —")
+            label.font = NSFont.systemFont(ofSize: 12, weight: .medium)
+            label.textColor = .secondaryLabelColor
+            label.lineBreakMode = .byTruncatingMiddle
+            label.setContentHuggingPriority(.defaultHigh, for: .horizontal)
+            item.view = label
+            commandLabels[ObjectIdentifier(toolbar)] = label
+            updateFocusedCommandText()
+            return item
+        }
+
+        if itemIdentifier == updateItemIdentifier, let updateViewModel {
+            let item = NSToolbarItem(itemIdentifier: itemIdentifier)
+            let view = NonDraggableHostingView(rootView: UpdatePill(
+                model: updateViewModel,
+                showWhenIdle: true,
+                onIdleTap: {
+                    guard let delegate = NSApp.delegate as? AppDelegate else { return }
+                    delegate.checkForUpdates(nil)
+                }
+            ))
+            item.view = view
+            return item
+        }
+
+        return nil
+    }
+}