Added Reformatting Guide

Example/CodeEditSourceEditorExample/CodeEditSourceEditorExample/Views/ContentView.swift

@@ -28,6 +28,8 @@ struct ContentView: View {
     @State private var treeSitterClient = TreeSitterClient()
     @AppStorage("showMinimap") private var showMinimap: Bool = true
     @State private var indentOption: IndentOption = .spaces(count: 4)
+    @AppStorage("reformatAtColumn") private var reformatAtColumn: Int = 80
+    @AppStorage("showReformattingGuide") private var showReformattingGuide: Bool = false
 
     init(document: Binding<CodeEditSourceEditorExampleDocument>, fileURL: URL?) {
         self._document = document
@@ -52,7 +54,9 @@ struct ContentView: View {
                 contentInsets: NSEdgeInsets(top: proxy.safeAreaInsets.top, left: 0, bottom: 28.0, right: 0),
                 additionalTextInsets: NSEdgeInsets(top: 1, left: 0, bottom: 1, right: 0),
                 useSystemCursor: useSystemCursor,
-                showMinimap: showMinimap
+                showMinimap: showMinimap,
+                reformatAtColumn: reformatAtColumn,
+                showReformattingGuide: showReformattingGuide
             )
             .overlay(alignment: .bottom) {
                 StatusBar(
@@ -65,7 +69,9 @@ struct ContentView: View {
                     language: $language,
                     theme: $theme,
                     showMinimap: $showMinimap,
-                    indentOption: $indentOption
+                    indentOption: $indentOption,
+                    reformatAtColumn: $reformatAtColumn,
+                    showReformattingGuide: $showReformattingGuide
                 )
             }
             .ignoresSafeArea()

Example/CodeEditSourceEditorExample/CodeEditSourceEditorExample/Views/StatusBar.swift

@@ -24,12 +24,25 @@ struct StatusBar: View {
     @Binding var theme: EditorTheme
     @Binding var showMinimap: Bool
     @Binding var indentOption: IndentOption
+    @Binding var reformatAtColumn: Int
+    @Binding var showReformattingGuide: Bool
 
     var body: some View {
         HStack {
             Menu {
+                IndentPicker(indentOption: $indentOption, enabled: document.text.isEmpty)
+                    .buttonStyle(.borderless)
                 Toggle("Wrap Lines", isOn: $wrapLines)
                 Toggle("Show Minimap", isOn: $showMinimap)
+                Toggle("Show Reformatting Guide", isOn: $showReformattingGuide)
+                Picker("Reformat column at column", selection: $reformatAtColumn) {
+                    ForEach([40, 60, 80, 100, 120, 140, 160, 180, 200], id: \.self) { column in
+                        Text("\(column)").tag(column)
+                    }
+                }
+                .onChange(of: reformatAtColumn) { _, newValue in
+                    reformatAtColumn = max(1, min(200, newValue))
+                }
                 if #available(macOS 14, *) {
                     Toggle("Use System Cursor", isOn: $useSystemCursor)
                 } else {
@@ -65,8 +78,6 @@ struct StatusBar: View {
                 .frame(height: 12)
             LanguagePicker(language: $language)
                 .buttonStyle(.borderless)
-            IndentPicker(indentOption: $indentOption, enabled: document.text.isEmpty)
-                .buttonStyle(.borderless)
         }
         .font(.subheadline)
         .fontWeight(.medium)

Sources/CodeEditSourceEditor/CodeEditSourceEditor/CodeEditSourceEditor.swift

@@ -50,6 +50,9 @@ public struct CodeEditSourceEditor: NSViewControllerRepresentable {
     ///   - useSystemCursor: If true, uses the system cursor on `>=macOS 14`.
     ///   - undoManager: The undo manager for the text view. Defaults to `nil`, which will create a new CEUndoManager
     ///   - coordinators: Any text coordinators for the view to use. See ``TextViewCoordinator`` for more information.
+    ///   - showMinimap: Whether to show the minimap
+    ///   - reformatAtColumn: The column to reformat at
+    ///   - showReformattingGuide: Whether to show the reformatting guide
     public init(
         _ text: Binding<String>,
         language: CodeLanguage,
@@ -72,7 +75,9 @@ public struct CodeEditSourceEditor: NSViewControllerRepresentable {
         useSystemCursor: Bool = true,
         undoManager: CEUndoManager? = nil,
         coordinators: [any TextViewCoordinator] = [],
-        showMinimap: Bool
+        showMinimap: Bool,
+        reformatAtColumn: Int,
+        showReformattingGuide: Bool
     ) {
         self.text = .binding(text)
         self.language = language
@@ -100,6 +105,8 @@ public struct CodeEditSourceEditor: NSViewControllerRepresentable {
         self.undoManager = undoManager
         self.coordinators = coordinators
         self.showMinimap = showMinimap
+        self.reformatAtColumn = reformatAtColumn
+        self.showReformattingGuide = showReformattingGuide
     }
 
     /// Initializes a Text Editor
@@ -129,6 +136,9 @@ public struct CodeEditSourceEditor: NSViewControllerRepresentable {
     ///                           See `BracketPairEmphasis` for more information. Defaults to `nil`
     ///   - undoManager: The undo manager for the text view. Defaults to `nil`, which will create a new CEUndoManager
     ///   - coordinators: Any text coordinators for the view to use. See ``TextViewCoordinator`` for more information.
+    ///   - showMinimap: Whether to show the minimap
+    ///   - reformatAtColumn: The column to reformat at
+    ///   - showReformattingGuide: Whether to show the reformatting guide
     public init(
         _ text: NSTextStorage,
         language: CodeLanguage,
@@ -151,7 +161,9 @@ public struct CodeEditSourceEditor: NSViewControllerRepresentable {
         useSystemCursor: Bool = true,
         undoManager: CEUndoManager? = nil,
         coordinators: [any TextViewCoordinator] = [],
-        showMinimap: Bool
+        showMinimap: Bool,
+        reformatAtColumn: Int,
+        showReformattingGuide: Bool
     ) {
         self.text = .storage(text)
         self.language = language
@@ -179,6 +191,8 @@ public struct CodeEditSourceEditor: NSViewControllerRepresentable {
         self.undoManager = undoManager
         self.coordinators = coordinators
         self.showMinimap = showMinimap
+        self.reformatAtColumn = reformatAtColumn
+        self.showReformattingGuide = showReformattingGuide
     }
 
     package var text: TextAPI
@@ -203,6 +217,8 @@ public struct CodeEditSourceEditor: NSViewControllerRepresentable {
     private var undoManager: CEUndoManager?
     package var coordinators: [any TextViewCoordinator]
     package var showMinimap: Bool
+    private var reformatAtColumn: Int
+    private var showReformattingGuide: Bool
 
     public typealias NSViewControllerType = TextViewController
 
@@ -229,7 +245,9 @@ public struct CodeEditSourceEditor: NSViewControllerRepresentable {
             bracketPairEmphasis: bracketPairEmphasis,
             undoManager: undoManager,
             coordinators: coordinators,
-            showMinimap: showMinimap
+            showMinimap: showMinimap,
+            reformatAtColumn: reformatAtColumn,
+            showReformattingGuide: showReformattingGuide
         )
         switch text {
         case .binding(let binding):
@@ -286,6 +304,14 @@ public struct CodeEditSourceEditor: NSViewControllerRepresentable {
         updateEditorProperties(controller)
         updateThemeAndLanguage(controller)
         updateHighlighting(controller, coordinator: coordinator)
+
+        if controller.reformatAtColumn != reformatAtColumn {
+            controller.reformatAtColumn = reformatAtColumn
+        }
+
+        if controller.showReformattingGuide != showReformattingGuide {
+            controller.showReformattingGuide = showReformattingGuide
+        }
     }
 
     private func updateTextProperties(_ controller: TextViewController) {
@@ -369,6 +395,8 @@ public struct CodeEditSourceEditor: NSViewControllerRepresentable {
         controller.bracketPairEmphasis == bracketPairEmphasis &&
         controller.useSystemCursor == useSystemCursor &&
         controller.showMinimap == showMinimap &&
+        controller.reformatAtColumn == reformatAtColumn &&
+        controller.showReformattingGuide == showReformattingGuide &&
         areHighlightProvidersEqual(controller: controller, coordinator: coordinator)
     }
 

Sources/CodeEditSourceEditor/Controller/TextViewController+LoadView.swift

@@ -25,6 +25,15 @@ extension TextViewController {
         gutterView.updateWidthIfNeeded()
         scrollView.addFloatingSubview(gutterView, for: .horizontal)
 
+        guideView = ReformattingGuideView(
+            column: self.reformatAtColumn,
+            isVisible: self.showReformattingGuide,
+            theme: theme
+        )
+        guideView.wantsLayer = true
+        scrollView.addFloatingSubview(guideView, for: .vertical)
+        guideView.updatePosition(in: textView)
+
         minimapView = MinimapView(textView: textView, theme: theme)
         scrollView.addFloatingSubview(minimapView, for: .vertical)
 
@@ -43,6 +52,7 @@ extension TextViewController {
         styleScrollView()
         styleGutterView()
         styleMinimapView()
+
         setUpHighlighter()
         setUpTextFormation()
 
@@ -51,7 +61,7 @@ extension TextViewController {
         }
 
         setUpConstraints()
-        setUpListeners()
+        setUpOberservers()
 
         textView.updateFrameIfNeeded()
 
@@ -90,20 +100,21 @@ extension TextViewController {
         ])
     }
 
-    func setUpListeners() {
-        // Layout on scroll change
+    func setUpOnScrollChangeObserver() {
         NotificationCenter.default.addObserver(
             forName: NSView.boundsDidChangeNotification,
             object: scrollView.contentView,
             queue: .main
         ) { [weak self] notification in
-            guard let clipView = notification.object as? NSClipView else { return }
-            self?.textView.updatedViewport(self?.scrollView.documentVisibleRect ?? .zero)
+            guard let clipView = notification.object as? NSClipView,
+                  let textView = self?.textView else { return }
+            textView.updatedViewport(self?.scrollView.documentVisibleRect ?? .zero)
             self?.gutterView.needsDisplay = true
             self?.minimapXConstraint?.constant = clipView.bounds.origin.x
         }
+    }
 
-        // Layout on frame change
+    func setUpOnScrollViewFrameChangeObserver() {
         NotificationCenter.default.addObserver(
             forName: NSView.frameDidChangeNotification,
             object: scrollView.contentView,
@@ -114,20 +125,26 @@ extension TextViewController {
             self?.emphasisManager?.removeEmphases(for: EmphasisGroup.brackets)
             self?.updateTextInsets()
         }
+    }
 
+    func setUpTextViewFrameChangeObserver() {
         NotificationCenter.default.addObserver(
             forName: NSView.frameDidChangeNotification,
             object: textView,
             queue: .main
         ) { [weak self] _ in
+            guard let textView = self?.textView else { return }
             self?.gutterView.frame.size.height = (self?.textView.frame.height ?? 0) + 10
             self?.gutterView.frame.origin.y = (self?.textView.frame.origin.y ?? 0.0)
             - (self?.scrollView.contentInsets.top ?? 0)
 
             self?.gutterView.needsDisplay = true
+            self?.guideView?.updatePosition(in: textView)
             self?.scrollView.needsLayout = true
         }
+    }
 
+    func setUpSelectionChangedObserver() {
         NotificationCenter.default.addObserver(
             forName: TextSelectionManager.selectionChangedNotification,
             object: textView.selectionManager,
@@ -136,7 +153,9 @@ extension TextViewController {
             self?.updateCursorPosition()
             self?.emphasizeSelectionPairs()
         }
+    }
 
+    func setUpAppearanceChangedObserver() {
         NSApp.publisher(for: \.effectiveAppearance)
             .receive(on: RunLoop.main)
             .sink { [weak self] newValue in
@@ -153,6 +172,14 @@ extension TextViewController {
             .store(in: &cancellables)
     }
 
+    func setUpOberservers() {
+        setUpOnScrollChangeObserver()
+        setUpOnScrollViewFrameChangeObserver()
+        setUpTextViewFrameChangeObserver()
+        setUpSelectionChangedObserver()
+        setUpAppearanceChangedObserver()
+    }
+
     func setUpKeyBindings(eventMonitor: inout Any?) {
         eventMonitor = NSEvent.addLocalMonitorForEvents(matching: .keyDown) { [weak self] event -> NSEvent? in
             guard let self = self else { return event }

Sources/CodeEditSourceEditor/Controller/TextViewController+ReloadUI.swift

@@ -19,5 +19,10 @@ extension TextViewController {
         highlighter?.invalidate()
         minimapView.updateContentViewHeight()
         minimapView.updateDocumentVisibleViewPosition()
+
+        // Update reformatting guide position
+        if let guideView = textView.subviews.first(where: { $0 is ReformattingGuideView }) as? ReformattingGuideView {
+            guideView.updatePosition(in: textView)
+        }
     }
 }

Sources/CodeEditSourceEditor/Controller/TextViewController.swift

@@ -16,7 +16,7 @@ import TextFormation
 ///
 /// A view controller class for managing a source editor. Uses ``CodeEditTextView/TextView`` for input and rendering,
 /// tree-sitter for syntax highlighting, and TextFormation for live editing completions.
-public class TextViewController: NSViewController {
+public class TextViewController: NSViewController { // swiftlint:disable:this type_body_length
     // swiftlint:disable:next line_length
     public static let cursorPositionUpdatedNotification: Notification.Name = .init("TextViewController.cursorPositionNotification")
 
@@ -69,6 +69,7 @@ public class TextViewController: NSViewController {
             gutterView.textColor = theme.text.color.withAlphaComponent(0.35)
             gutterView.selectedLineTextColor = theme.text.color
             minimapView.setTheme(theme)
+            guideView?.setTheme(theme)
         }
     }
 
@@ -233,6 +234,37 @@ public class TextViewController: NSViewController {
         )
     }
 
+    /// The column at which to show the reformatting guide
+    public var reformatAtColumn: Int = 80 {
+        didSet {
+            if let guideView = self.guideView {
+                guideView.setColumn(reformatAtColumn)
+                guideView.updatePosition(in: textView)
+                guideView.needsDisplay = true
+            }
+        }
+    }
+
+    /// Whether to show the reformatting guide
+    public var showReformattingGuide: Bool = false {
+        didSet {
+            if let guideView = self.guideView {
+                guideView.setVisible(showReformattingGuide)
+                guideView.updatePosition(in: textView)
+                guideView.needsDisplay = true
+            }
+        }
+    }
+
+    /// The reformatting guide view
+    var guideView: ReformattingGuideView! {
+        didSet {
+            if let oldValue = oldValue {
+                oldValue.removeFromSuperview()
+            }
+        }
+    }
+
     // MARK: Init
 
     init(
@@ -257,7 +289,9 @@ public class TextViewController: NSViewController {
         bracketPairEmphasis: BracketPairEmphasis?,
         undoManager: CEUndoManager? = nil,
         coordinators: [TextViewCoordinator] = [],
-        showMinimap: Bool
+        showMinimap: Bool,
+        reformatAtColumn: Int = 80,
+        showReformattingGuide: Bool = false
     ) {
         self.language = language
         self.font = font
@@ -278,6 +312,8 @@ public class TextViewController: NSViewController {
         self.bracketPairEmphasis = bracketPairEmphasis
         self._undoManager = undoManager
         self.showMinimap = showMinimap
+        self.reformatAtColumn = reformatAtColumn
+        self.showReformattingGuide = showReformattingGuide
 
         super.init(nibName: nil, bundle: nil)
 
@@ -306,6 +342,9 @@ public class TextViewController: NSViewController {
             delegate: self
         )
 
+        // Initialize guide view
+        self.guideView = ReformattingGuideView(column: reformatAtColumn, isVisible: showReformattingGuide, theme: theme)
+
         coordinators.forEach {
             $0.prepareCoordinator(controller: self)
         }