Fix file-editor arrow-key navigation and add a word-wrap setting (#5227)

Packages/CmuxSettings/Sources/CmuxSettings/Keys/FileEditorCatalogSection.swift

@@ -0,0 +1,24 @@
+import Foundation
+
+/// Settings under the dotted-id prefix `fileEditor.*`.
+///
+/// Controls the built-in plain-text file editor (the text preview that the
+/// file explorer and `cmux` file routing open for editable text files). This
+/// is distinct from the rendered markdown viewer, whose settings live in
+/// ``MarkdownCatalogSection``.
+public struct FileEditorCatalogSection: SettingCatalogSection {
+    /// Whether long lines soft-wrap at the editor's right edge.
+    ///
+    /// `false` (the default) preserves the established behavior: lines extend
+    /// past the viewport and a horizontal scroller appears. `true` wraps each
+    /// line to the visible width and hides the horizontal scroller, the way a
+    /// prose editor does. Changing this applies live to open editors.
+    public let wordWrap = DefaultsKey<Bool>(
+        id: "fileEditor.wordWrap",
+        defaultValue: false,
+        userDefaultsKey: "fileEditor.wordWrap"
+    )
+
+    /// Creates the file editor settings section with its default keys.
+    public init() {}
+}

Packages/CmuxSettings/Sources/CmuxSettings/Keys/SettingCatalog.swift

@@ -32,6 +32,8 @@ public struct SettingCatalog: SettingCatalogSection {
     public let browser = BrowserCatalogSection()
     /// Settings for the built-in markdown viewer (the `markdown.*` keys).
     public let markdown = MarkdownCatalogSection()
+    /// Settings for the built-in plain-text file editor (the `fileEditor.*` keys).
+    public let fileEditor = FileEditorCatalogSection()
     public let betaFeatures = BetaFeaturesCatalogSection()
     public let shortcuts = KeyboardShortcutsCatalogSection()
     public let integrations = IntegrationsCatalogSection()

Packages/CmuxSettingsUI/Sources/CmuxSettingsUI/Navigation/CuratedSettingEntry+Default.swift

@@ -41,6 +41,7 @@ extension Array where Element == CuratedSettingEntry {
             .init(section: .app, id: "preferred-editor", title: "Open Files With", synonyms: "app.preferredEditor editor open file code vscode visual studio zed sublime subl cursor"),
             .init(section: .app, id: "supported-file-previews", title: "Open Supported Files in cmux", synonyms: "app.openSupportedFilesInCmux cmd click file preview pdf image video audio quicklook quick look editor external"),
             .init(section: .app, id: "markdown-viewer", title: "Open Markdown in cmux Viewer", synonyms: "app.openMarkdownInCmuxViewer md markdown mdx viewer preview readme"),
+            .init(section: .app, id: "file-editor-word-wrap", title: "File Editor Word Wrap", synonyms: "fileEditor.wordWrap file editor word wrap soft wrap reflow lines text horizontal scroll preview"),
             .init(section: .app, id: "terminal-config", title: "Terminal Config", synonyms: "ghostty config merged generated preview terminal configuration window open config"),
             .init(section: .app, id: "imessage-mode", title: "iMessage Mode", synonyms: "app.iMessageMode imessage message messages chat prompt prompts submitted texting reorder move workspace top agent send"),
             .init(section: .app, id: "reorder-notification", title: "Reorder on Notification", synonyms: "app.reorderOnNotification notification reorder move workspace top unread sort"),

Packages/CmuxSettingsUI/Sources/CmuxSettingsUI/Sections/AppSection.swift

@@ -38,6 +38,7 @@ public struct AppSection: View {
     @State private var markdownFontSize: DefaultsValueModel<Int>
     @State private var markdownFontFamily: DefaultsValueModel<String>
     @State private var markdownMaxWidth: DefaultsValueModel<Int>
+    @State private var fileEditorWordWrap: DefaultsValueModel<Bool>
     @State private var iMessage: DefaultsValueModel<Bool>
     @State private var reorder: DefaultsValueModel<Bool>
     @State private var dockBadge: DefaultsValueModel<Bool>
@@ -81,6 +82,7 @@ public struct AppSection: View {
         _markdownFontSize = State(initialValue: DefaultsValueModel(store: defaultsStore, key: catalog.markdown.fontSize))
         _markdownFontFamily = State(initialValue: DefaultsValueModel(store: defaultsStore, key: catalog.markdown.fontFamily))
         _markdownMaxWidth = State(initialValue: DefaultsValueModel(store: defaultsStore, key: catalog.markdown.maxWidth))
+        _fileEditorWordWrap = State(initialValue: DefaultsValueModel(store: defaultsStore, key: catalog.fileEditor.wordWrap))
         _iMessage = State(initialValue: DefaultsValueModel(store: defaultsStore, key: catalog.app.iMessageMode))
         _reorder = State(initialValue: DefaultsValueModel(store: defaultsStore, key: catalog.app.reorderOnNotification))
         _dockBadge = State(initialValue: DefaultsValueModel(store: defaultsStore, key: catalog.notifications.dockBadge))
@@ -380,6 +382,19 @@ public struct AppSection: View {
             }
             SettingsCardDivider()
 
+            // File Editor Word Wrap
+            SettingsCardRow(
+                configurationReview: .json("fileEditor.wordWrap"),
+                String(localized: "settings.app.fileEditorWordWrap", defaultValue: "File Editor Word Wrap"),
+                subtitle: String(localized: "settings.app.fileEditorWordWrap.subtitle", defaultValue: "Wrap long lines at the editor's right edge instead of scrolling horizontally. Applies to the plain-text file editor.")
+            ) {
+                Toggle("", isOn: Binding(get: { fileEditorWordWrap.current }, set: { fileEditorWordWrap.set($0) }))
+                    .labelsHidden()
+                    .controlSize(.small)
+                    .accessibilityIdentifier("SettingsFileEditorWordWrapToggle")
+            }
+            SettingsCardDivider()
+
             // iMessage Mode
             SettingsCardRow(
                 configurationReview: .json("app.iMessageMode"),

Packages/CmuxSettingsUI/Tests/CmuxSettingsUITests/SettingsRowAnchorResolutionTests.swift

@@ -74,6 +74,7 @@ struct SettingsRowAnchorResolutionTests {
         "browser.showSearchSuggestions",
         "browser.theme",
         "browser.urlsToAlwaysOpenExternally",
+        "fileEditor.wordWrap",
         "notifications.command",
         "notifications.dockBadge",
         "notifications.paneFlash",

Resources/Localizable.xcstrings

@@ -569,6 +569,40 @@
         }
       }
     },
+    "settings.app.fileEditorWordWrap": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "File Editor Word Wrap"
+          }
+        },
+        "ja": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "ファイルエディタの行折り返し"
+          }
+        }
+      }
+    },
+    "settings.app.fileEditorWordWrap.subtitle": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "Wrap long lines at the editor's right edge instead of scrolling horizontally. Applies to the plain-text file editor."
+          }
+        },
+        "ja": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "長い行を横スクロールせずにエディタの右端で折り返します。プレーンテキストのファイルエディタに適用されます。"
+          }
+        }
+      }
+    },
     "settings.search.alias.setting.app.markdown-font-size": {
       "extractionState": "manual",
       "localizations": {
@@ -620,6 +654,23 @@
         }
       }
     },
+    "settings.search.alias.setting.app.file-editor-word-wrap": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "fileEditor.wordWrap file editor word wrap soft wrap reflow lines text horizontal scroll preview"
+          }
+        },
+        "ja": {
+          "stringUnit": {
+            "state": "translated",
+            "value": "fileEditor.wordWrap ファイル エディタ 行折り返し ワードラップ 折り返し 改行 テキスト 横スクロール プレビュー"
+          }
+        }
+      }
+    },
     "cli.hooks.kiro.postInstallNote": {
       "localizations": {
         "en": {

Sources/App/ShortcutRoutingSupport.swift

@@ -170,13 +170,21 @@ func shouldDispatchCommandPaletteHorizontalArrowViaFirstResponderKeyDown(
     }
 }
 
-func shouldDispatchTextBoxInputArrowViaFirstResponderKeyDown(
+/// Whether an arrow keyDown belongs to a focused standalone editable text
+/// responder (text-box input, file-preview editor, …) so it should be
+/// forwarded to `firstResponder.keyDown` rather than swallowed by the original
+/// `NSWindow.performKeyEquivalent`.
+///
+/// Owns the four arrows (keyCodes 123–126) for the modifier combos a text
+/// editor handles itself: plain (move), Shift (extend selection), Option
+/// (word/paragraph), and Command (line/document boundary) plus their Shift
+/// combos. Cmd+Option+Arrow is excluded so it still reaches cmux's pane-focus
+/// shortcuts. Marked text (IME composition) is left to the input method.
+private func standaloneTextResponderOwnsArrowKeyDown(
     keyCode: UInt16,
-    firstResponderIsTextBoxInput: Bool,
-    firstResponderHasMarkedText: Bool = false,
+    firstResponderHasMarkedText: Bool,
     flags: NSEvent.ModifierFlags
 ) -> Bool {
-    guard firstResponderIsTextBoxInput else { return false }
     guard !firstResponderHasMarkedText else { return false }
     guard (123...126).contains(keyCode) else { return false }
 
@@ -191,6 +199,47 @@ func shouldDispatchTextBoxInputArrowViaFirstResponderKeyDown(
     }
 }
 
+func shouldDispatchTextBoxInputArrowViaFirstResponderKeyDown(
+    keyCode: UInt16,
+    firstResponderIsTextBoxInput: Bool,
+    firstResponderHasMarkedText: Bool = false,
+    flags: NSEvent.ModifierFlags
+) -> Bool {
+    guard firstResponderIsTextBoxInput else { return false }
+    return standaloneTextResponderOwnsArrowKeyDown(
+        keyCode: keyCode,
+        firstResponderHasMarkedText: firstResponderHasMarkedText,
+        flags: flags
+    )
+}
+
+/// Whether an arrow keyDown should be forwarded straight to the focused
+/// standalone editable text view instead of falling through to the original
+/// `NSWindow.performKeyEquivalent`, which swallows plain arrows before the
+/// view's `keyDown` runs.
+///
+/// This generalizes the per-surface arrow-forwarding seam (browser, omnibar,
+/// command palette, text-box input) to cover the whole class of standalone
+/// editable `NSTextView`s cmux hosts — the file-preview editor today, any
+/// future one tomorrow. Field editors (the omnibar / command-palette / find
+/// field editors) are excluded by the caller because they have their own
+/// dedicated routing or work through the normal field-editor path. Shares the
+/// keyCode/modifier policy with ``shouldDispatchTextBoxInputArrowViaFirstResponderKeyDown``
+/// via ``standaloneTextResponderOwnsArrowKeyDown(keyCode:firstResponderHasMarkedText:flags:)``.
+func shouldDispatchEditableTextViewArrowViaFirstResponderKeyDown(
+    keyCode: UInt16,
+    firstResponderIsEditableTextView: Bool,
+    firstResponderHasMarkedText: Bool = false,
+    flags: NSEvent.ModifierFlags
+) -> Bool {
+    guard firstResponderIsEditableTextView else { return false }
+    return standaloneTextResponderOwnsArrowKeyDown(
+        keyCode: keyCode,
+        firstResponderHasMarkedText: firstResponderHasMarkedText,
+        flags: flags
+    )
+}
+
 func shouldToggleMainWindowFullScreenForCommandControlFShortcut(
     flags: NSEvent.ModifierFlags,
     chars: String,

Sources/AppDelegate.swift

@@ -16186,6 +16186,7 @@ private var cmuxBrowserArrowForwardingDepth = 0
 private var cmuxBrowserOmnibarMarkedTextForwardingDepth = 0
 private var cmuxCommandPaletteArrowForwardingDepth = 0
 private var cmuxTextBoxInputArrowForwardingDepth = 0
+private var cmuxEditableTextViewArrowForwardingDepth = 0
 private var cmuxWindowFirstResponderBypassDepth = 0
 private var cmuxFieldEditorOwningWebViewAssociationKey: UInt8 = 0
 
@@ -16860,6 +16861,14 @@ private extension NSWindow {
         )
         let firstResponderOmnibarPanelId = browserOmnibarPanelId(for: self.firstResponder)
         let firstResponderIsTextBoxInput = self.firstResponder is TextBoxInputTextView
+        // A standalone editable document text view (e.g. the file-preview
+        // editor's SavingTextView) owns arrow navigation through its own
+        // keyDown. Field editors (omnibar / command palette / find) are
+        // excluded — they route through their dedicated paths above.
+        let firstResponderIsStandaloneEditableTextView: Bool = {
+            guard let textView = self.firstResponder as? NSTextView else { return false }
+            return textView.isEditable && !textView.isFieldEditor
+        }()
         if ShortcutRecorderEventRouter.dispatchActiveRecordingEvent(event, preferredWindow: self) {
             return true
         }
@@ -17010,6 +17019,25 @@ private extension NSWindow {
             return true
         }
 
+        // The file-preview editor and any other standalone editable NSTextView
+        // would otherwise lose plain/selection/word/line arrows to the original
+        // NSWindow.performKeyEquivalent. Route them to the text view's keyDown so
+        // arrow navigation works as in any text editor (manaflow-ai/cmux#5227).
+        if shouldDispatchEditableTextViewArrowViaFirstResponderKeyDown(
+            keyCode: event.keyCode,
+            firstResponderIsEditableTextView: firstResponderIsStandaloneEditableTextView,
+            firstResponderHasMarkedText: firstResponderHasMarkedText,
+            flags: event.modifierFlags
+        ) {
+            if cmuxEditableTextViewArrowForwardingDepth > 0 {
+                return false
+            }
+            cmuxEditableTextViewArrowForwardingDepth += 1
+            defer { cmuxEditableTextViewArrowForwardingDepth = max(0, cmuxEditableTextViewArrowForwardingDepth - 1) }
+            self.firstResponder?.keyDown(with: event)
+            return true
+        }
+
         // Web forms rely on Return/Enter flowing through keyDown. If the original
         // NSWindow.performKeyEquivalent consumes Enter first, submission never reaches
         // WebKit. Route Return/Enter directly to the current first responder and

Sources/CmuxSettingsJSONPathSupport.swift

@@ -165,6 +165,7 @@ extension CmuxSettingsFileStore {
         "markdown.fontSize",
         "markdown.fontFamily",
         "markdown.maxWidth",
+        "fileEditor.wordWrap",
         "shortcuts.bindings",
     ]
 }

Sources/CommandPalette/CommandPaletteSettingsToggle.swift

@@ -217,6 +217,17 @@ enum CommandPaletteSettingsToggleCommands {
                     CmdClickMarkdownRouteSettings.notifyDidChange(notificationCenter: notificationCenter)
                 }
             ),
+            CommandPaletteSettingToggleDescriptor(
+                commandId: commandIdPrefix + "fileEditorWordWrap",
+                settingsKey: "fileEditor.wordWrap",
+                title: {
+                    String(localized: "settings.app.fileEditorWordWrap", defaultValue: "File Editor Word Wrap")
+                },
+                sectionTitle: app,
+                keywords: ["fileEditor.wordWrap", "file", "editor", "word", "wrap", "soft", "reflow", "lines", "preview"],
+                defaultValue: FilePreviewWordWrapSettings.defaultEnabled,
+                defaultsKey: FilePreviewWordWrapSettings.key
+            ),
             CommandPaletteSettingToggleDescriptor(
                 commandId: commandIdPrefix + "iMessageMode",
                 settingsKey: "app.iMessageMode",

Sources/KeyboardShortcutSettingsFileStore+Template.swift

@@ -197,6 +197,11 @@ extension CmuxSettingsFileStore {
                     "maxWidth": Int(MarkdownMaxWidthSettings.defaultCSSPixels),
                 ],
             ],
+            [
+                "fileEditor": [
+                    "wordWrap": FilePreviewWordWrapSettings.defaultEnabled,
+                ],
+            ],
             [
                 "shortcuts": [
                     "bindings": shortcutsBindings,

Sources/KeyboardShortcutSettingsFileStore.swift

@@ -366,6 +366,9 @@ final class CmuxSettingsFileStore {
         if let markdownSection = root["markdown"] as? [String: Any] {
             parseMarkdownSection(markdownSection, sourcePath: sourcePath, snapshot: &snapshot)
         }
+        if let fileEditorSection = root["fileEditor"] as? [String: Any] {
+            parseFileEditorSection(fileEditorSection, sourcePath: sourcePath, snapshot: &snapshot)
+        }
         if let workspaceGroupsSection = root["workspaceGroups"] as? [String: Any] {
             parseWorkspaceGroupsSection(workspaceGroupsSection, sourcePath: sourcePath, snapshot: &snapshot)
         }
@@ -629,6 +632,18 @@ final class CmuxSettingsFileStore {
         }
     }
 
+    private func parseFileEditorSection(
+        _ section: [String: Any],
+        sourcePath: String,
+        snapshot: inout ResolvedSettingsSnapshot
+    ) {
+        if let value = jsonBool(section["wordWrap"]) {
+            snapshot.managedUserDefaults[FilePreviewWordWrapSettings.key] = .bool(value)
+        } else if section.keys.contains("wordWrap") {
+            logInvalid("fileEditor.wordWrap", sourcePath: sourcePath)
+        }
+    }
+
     private func parseSidebarSection(
         _ section: [String: Any],
         sourcePath: String,

Sources/Panels/FilePreviewPanel.swift

@@ -1284,6 +1284,7 @@ struct FilePreviewPanelView: View {
 
     @State private var focusFlashOpacity = 0.0
     @State private var focusFlashAnimationGeneration = 0
+    @AppStorage(FilePreviewWordWrapSettings.key) private var fileEditorWordWrap = FilePreviewWordWrapSettings.defaultEnabled
 
     private var themeForegroundColor: NSColor {
         appearance.foregroundColor
@@ -1354,7 +1355,8 @@ struct FilePreviewPanelView: View {
                     isVisibleInUI: isVisibleInUI,
                     themeBackgroundColor: contentBackgroundColor,
                     themeForegroundColor: themeForegroundColor,
-                    drawsBackground: appearance.drawsContentBackground
+                    drawsBackground: appearance.drawsContentBackground,
+                    wordWrap: fileEditorWordWrap
                 )
             case .pdf:
                 FilePreviewPDFView(