Add configurable cmux.json workspace and tab bar actions

Sources/AppDelegate.swift

@@ -2223,19 +2223,22 @@ final class AppDelegate: NSObject, NSApplicationDelegate, UNUserNotificationCent
         let tabManager: TabManager
         let sidebarState: SidebarState
         let sidebarSelectionState: SidebarSelectionState
+        var cmuxConfigStore: CmuxConfigStore?
         weak var window: NSWindow?
 
         init(
             windowId: UUID,
             tabManager: TabManager,
             sidebarState: SidebarState,
             sidebarSelectionState: SidebarSelectionState,
+            cmuxConfigStore: CmuxConfigStore?,
             window: NSWindow?
         ) {
             self.windowId = windowId
             self.tabManager = tabManager
             self.sidebarState = sidebarState
             self.sidebarSelectionState = sidebarSelectionState
+            self.cmuxConfigStore = cmuxConfigStore
             self.window = window
         }
     }
@@ -4825,7 +4828,8 @@ final class AppDelegate: NSObject, NSApplicationDelegate, UNUserNotificationCent
         windowId: UUID,
         tabManager: TabManager,
         sidebarState: SidebarState,
-        sidebarSelectionState: SidebarSelectionState
+        sidebarSelectionState: SidebarSelectionState,
+        cmuxConfigStore: CmuxConfigStore? = nil
     ) {
         tabManager.window = window
 
@@ -4835,15 +4839,18 @@ final class AppDelegate: NSObject, NSApplicationDelegate, UNUserNotificationCent
         #endif
         if let existing = mainWindowContexts[key] {
             existing.window = window
+            existing.cmuxConfigStore = cmuxConfigStore
         } else if let existing = mainWindowContexts.values.first(where: { $0.windowId == windowId }) {
             existing.window = window
+            existing.cmuxConfigStore = cmuxConfigStore
             reindexMainWindowContextIfNeeded(existing, for: window)
         } else {
             mainWindowContexts[key] = MainWindowContext(
                 windowId: windowId,
                 tabManager: tabManager,
                 sidebarState: sidebarState,
                 sidebarSelectionState: sidebarSelectionState,
+                cmuxConfigStore: cmuxConfigStore,
                 window: window
             )
             NotificationCenter.default.addObserver(
@@ -6583,6 +6590,86 @@ final class AppDelegate: NSObject, NSApplicationDelegate, UNUserNotificationCent
         _ = createMainWindow()
     }
 
+    @discardableResult
+    func performNewWorkspaceAction(
+        tabManager preferredTabManager: TabManager? = nil,
+        event: NSEvent? = nil,
+        debugSource: String = "newWorkspace"
+    ) -> Bool {
+        let preferredContext = preferredTabManager.flatMap { mainWindowContext(for: $0) }
+        if mainWindowContexts.isEmpty && preferredContext == nil {
+#if DEBUG
+            logWorkspaceCreationRouting(
+                phase: "fallback_new_window",
+                source: debugSource,
+                reason: "no_main_windows",
+                event: event,
+                chosenContext: nil
+            )
+#endif
+            openNewMainWindow(nil)
+            return true
+        }
+
+        let context = preferredContext
+            ?? preferredMainWindowContextForWorkspaceCreation(event: event, debugSource: debugSource)
+
+        if let context,
+           executeConfiguredNewWorkspaceCommandIfAvailable(in: context, debugSource: debugSource) {
+            return true
+        }
+
+        if let preferredTabManager, preferredContext != nil {
+            preferredTabManager.addWorkspace()
+            return true
+        }
+
+        if addWorkspaceInPreferredMainWindow(event: event, debugSource: debugSource) == nil {
+#if DEBUG
+            logWorkspaceCreationRouting(
+                phase: "fallback_new_window",
+                source: debugSource,
+                reason: "workspace_creation_returned_nil",
+                event: event,
+                chosenContext: nil
+            )
+#endif
+            openNewMainWindow(nil)
+        }
+        return true
+    }
+
+    private func mainWindowContext(for tabManager: TabManager) -> MainWindowContext? {
+        mainWindowContexts.values.first(where: { $0.tabManager === tabManager })
+    }
+
+    private func executeConfiguredNewWorkspaceCommandIfAvailable(
+        in context: MainWindowContext,
+        debugSource: String
+    ) -> Bool {
+        guard let cmuxConfigStore = context.cmuxConfigStore,
+              let configured = cmuxConfigStore.resolvedNewWorkspaceCommand() else {
+            return false
+        }
+        let rawCwd = context.tabManager.selectedWorkspace?.currentDirectory
+        let baseCwd = (rawCwd?.isEmpty == false) ? rawCwd!
+            : FileManager.default.homeDirectoryForCurrentUser.path
+#if DEBUG
+        dlog(
+            "newWorkspace.configCommand source=\(debugSource) " +
+            "command=\(configured.command.name) windowId=\(String(context.windowId.uuidString.prefix(8)))"
+        )
+#endif
+        CmuxConfigExecutor.execute(
+            command: configured.command,
+            tabManager: context.tabManager,
+            baseCwd: baseCwd,
+            configSourcePath: configured.sourcePath,
+            globalConfigPath: cmuxConfigStore.globalConfigPath
+        )
+        return true
+    }
+
     /// Shows the "Open Folder" panel and creates a workspace for the selected directory.
     /// Called from both the SwiftUI menu and `handleCustomShortcut`.
     func showOpenFolderPanel() {
@@ -7225,7 +7312,8 @@ final class AppDelegate: NSObject, NSApplicationDelegate, UNUserNotificationCent
             windowId: windowId,
             tabManager: tabManager,
             sidebarState: sidebarState,
-            sidebarSelectionState: sidebarSelectionState
+            sidebarSelectionState: sidebarSelectionState,
+            cmuxConfigStore: cmuxConfigStore
         )
         installFileDropOverlay(on: window, tabManager: tabManager)
         if TerminalController.shouldSuppressSocketCommandActivation() {
@@ -11071,32 +11159,7 @@ final class AppDelegate: NSObject, NSApplicationDelegate, UNUserNotificationCent
 #if DEBUG
             dlog("shortcut.action name=newWorkspace \(debugShortcutRouteSnapshot(event: event))")
 #endif
-            // Cmd+N semantics:
-            // - If there are no main windows, create a new window.
-            // - Otherwise, create a new workspace in the active window.
-            if mainWindowContexts.isEmpty {
-                #if DEBUG
-                logWorkspaceCreationRouting(
-                    phase: "fallback_new_window",
-                    source: "shortcut.cmdN",
-                    reason: "no_main_windows",
-                    event: event,
-                    chosenContext: nil
-                )
-                #endif
-                openNewMainWindow(nil)
-            } else if addWorkspaceInPreferredMainWindow(event: event, debugSource: "shortcut.cmdN") == nil {
-                #if DEBUG
-                logWorkspaceCreationRouting(
-                    phase: "fallback_new_window",
-                    source: "shortcut.cmdN",
-                    reason: "workspace_creation_returned_nil",
-                    event: event,
-                    chosenContext: nil
-                )
-                #endif
-                openNewMainWindow(nil)
-            }
+            performNewWorkspaceAction(event: event, debugSource: "shortcut.cmdN")
             return true
         }
 

Sources/CmuxConfig.swift

@@ -3,7 +3,37 @@ import Combine
 import Foundation
 
 struct CmuxConfigFile: Codable, Sendable {
+    var newWorkspaceCommand: String?
     var commands: [CmuxCommandDefinition]
+
+    private enum CodingKeys: String, CodingKey {
+        case newWorkspaceCommand
+        case commands
+    }
+
+    init(newWorkspaceCommand: String? = nil, commands: [CmuxCommandDefinition]) {
+        self.newWorkspaceCommand = newWorkspaceCommand
+        self.commands = commands
+    }
+
+    init(from decoder: Decoder) throws {
+        let container = try decoder.container(keyedBy: CodingKeys.self)
+        if let rawNewWorkspaceCommand = try container.decodeIfPresent(String.self, forKey: .newWorkspaceCommand) {
+            let trimmed = rawNewWorkspaceCommand.trimmingCharacters(in: .whitespacesAndNewlines)
+            if trimmed.isEmpty {
+                throw DecodingError.dataCorrupted(
+                    DecodingError.Context(
+                        codingPath: decoder.codingPath + [CodingKeys.newWorkspaceCommand],
+                        debugDescription: "newWorkspaceCommand must not be blank"
+                    )
+                )
+            }
+            newWorkspaceCommand = trimmed
+        } else {
+            newWorkspaceCommand = nil
+        }
+        commands = try container.decode([CmuxCommandDefinition].self, forKey: .commands)
+    }
 }
 
 struct CmuxCommandDefinition: Codable, Sendable, Identifiable {
@@ -256,9 +286,15 @@ enum CmuxSurfaceType: String, Codable, Sendable {
     case browser
 }
 
+struct CmuxResolvedCommand: Sendable {
+    let command: CmuxCommandDefinition
+    let sourcePath: String?
+}
+
 @MainActor
 final class CmuxConfigStore: ObservableObject {
     @Published private(set) var loadedCommands: [CmuxCommandDefinition] = []
+    @Published private(set) var newWorkspaceCommandName: String?
     @Published private(set) var configRevision: UInt64 = 0
 
     /// Which config file each command came from, keyed by command id.
@@ -353,10 +389,14 @@ final class CmuxConfigStore: ObservableObject {
         var commands: [CmuxCommandDefinition] = []
         var seenNames = Set<String>()
         var sourcePaths: [String: String] = [:]
+        var configuredNewWorkspaceCommandName: String?
 
         // Local config takes precedence
         if let localPath = localConfigPath {
             if let localConfig = parseConfig(at: localPath) {
+                if let newWorkspaceCommand = localConfig.newWorkspaceCommand {
+                    configuredNewWorkspaceCommandName = newWorkspaceCommand
+                }
                 for command in localConfig.commands {
                     if !seenNames.contains(command.name) {
                         commands.append(command)
@@ -369,6 +409,10 @@ final class CmuxConfigStore: ObservableObject {
 
         // Global config fills in the rest
         if let globalConfig = parseConfig(at: globalConfigPath) {
+            if configuredNewWorkspaceCommandName == nil,
+               let newWorkspaceCommand = globalConfig.newWorkspaceCommand {
+                configuredNewWorkspaceCommandName = newWorkspaceCommand
+            }
             for command in globalConfig.commands {
                 if !seenNames.contains(command.name) {
                     commands.append(command)
@@ -380,9 +424,23 @@ final class CmuxConfigStore: ObservableObject {
 
         loadedCommands = commands
         commandSourcePaths = sourcePaths
+        newWorkspaceCommandName = configuredNewWorkspaceCommandName
         configRevision &+= 1
     }
 
+    func resolvedNewWorkspaceCommand() -> CmuxResolvedCommand? {
+        guard let commandName = newWorkspaceCommandName else { return nil }
+        guard let command = loadedCommands.first(where: { $0.name == commandName }) else {
+            NSLog("[CmuxConfig] newWorkspaceCommand '%@' does not match any loaded command", commandName)
+            return nil
+        }
+        guard command.workspace != nil else {
+            NSLog("[CmuxConfig] newWorkspaceCommand '%@' must reference a workspace command", commandName)
+            return nil
+        }
+        return CmuxResolvedCommand(command: command, sourcePath: commandSourcePaths[command.id])
+    }
+
     // MARK: - Parsing
 
     private func parseConfig(at path: String) -> CmuxConfigFile? {

Sources/ContentView.swift

@@ -3073,7 +3073,12 @@ struct ContentView: View {
                     anchorView: fullscreenControlsViewModel.notificationsAnchorView
                 )
             },
-            onNewTab: { tabManager.addTab() },
+            onNewTab: {
+                AppDelegate.shared?.performNewWorkspaceAction(
+                    tabManager: tabManager,
+                    debugSource: "titlebar.fullscreenNewWorkspace"
+                )
+            },
             visibilityMode: .alwaysVisible
         )
     }
@@ -3978,7 +3983,8 @@ struct ContentView: View {
                 windowId: windowId,
                 tabManager: tabManager,
                 sidebarState: sidebarState,
-                sidebarSelectionState: sidebarSelectionState
+                sidebarSelectionState: sidebarSelectionState,
+                cmuxConfigStore: cmuxConfigStore
             )
             installFileDropOverlayWhenReady(on: window, tabManager: tabManager)
         }))
@@ -7569,7 +7575,10 @@ struct ContentView: View {
 
     private func registerCommandPaletteHandlers(_ registry: inout CommandPaletteHandlerRegistry) {
         registry.register(commandId: "palette.newWorkspace") {
-            tabManager.addWorkspace()
+            AppDelegate.shared?.performNewWorkspaceAction(
+                tabManager: tabManager,
+                debugSource: "palette.newWorkspace"
+            )
         }
         registry.register(commandId: "palette.openFolder") {
             // Defer so the command palette dismisses before the modal sheet appears.

Sources/Update/UpdateTitlebarAccessory.swift

@@ -558,7 +558,9 @@ struct HiddenTitlebarSidebarControlsView: View {
                     anchorView: viewModel.notificationsAnchorView
                 )
             },
-            onNewTab: { _ = AppDelegate.shared?.tabManager?.addTab() },
+            onNewTab: {
+                AppDelegate.shared?.performNewWorkspaceAction(debugSource: "titlebar.hiddenNewWorkspace")
+            },
             visibilityMode: .onHover
         )
         .frame(width: hostWidth, height: hostHeight, alignment: .leading)
@@ -791,7 +793,7 @@ final class TitlebarControlsAccessoryViewController: NSTitlebarAccessoryViewCont
         self.notificationStore = notificationStore
         let toggleSidebar = { _ = AppDelegate.shared?.sidebarState?.toggle() }
         let toggleNotifications: () -> Void = { _ = AppDelegate.shared?.toggleNotificationsPopover(animated: true) }
-        let newTab = { _ = AppDelegate.shared?.tabManager?.addTab() }
+        let newTab = { _ = AppDelegate.shared?.performNewWorkspaceAction(debugSource: "titlebar.accessoryNewWorkspace") }
         hostingView = NonDraggableHostingView(
             rootView: TitlebarControlsView(
                 notificationStore: notificationStore,

Sources/cmuxApp.swift

@@ -584,16 +584,12 @@ struct cmuxApp: App {
 
                 splitCommandButton(title: String(localized: "menu.file.newWorkspace", defaultValue: "New Workspace"), shortcut: menuShortcut(for: .newTab)) {
                     if let appDelegate = AppDelegate.shared {
-                        if appDelegate.addWorkspaceInPreferredMainWindow(debugSource: "menu.newWorkspace") == nil {
-#if DEBUG
-                            FocusLogStore.shared.append(
-                                "cmdn.route phase=fallback_new_window src=menu.newWorkspace reason=workspace_creation_returned_nil"
-                            )
-#endif
-                            appDelegate.openNewMainWindow(nil)
-                        }
+                        appDelegate.performNewWorkspaceAction(
+                            tabManager: activeTabManager,
+                            debugSource: "menu.newWorkspace"
+                        )
                     } else {
-                        activeTabManager.addTab()
+                        activeTabManager.addWorkspace()
                     }
                 }