#26 feat: add multiple font family selection

BifcodePackage/Sources/BifcodeFeature/ContentView.swift

@@ -2,7 +2,7 @@
 //  ContentView.swift
 //
 //  Created on 17.12.2025.
-//  Copyright © 2025 IGR Soft. All rights reserved.
+//  Copyright © 2026 IGR Soft. All rights reserved.
 //
 
 import AppKit
@@ -89,6 +89,7 @@ public struct ContentView: View {
     @AppStorage("indicatorSize") private var indicatorSize: Double = 48
     @AppStorage("showTitle") private var showTitle: Bool = true
     @AppStorage("fontSize") private var fontSize: Double = 14
+    @AppStorage("fontFamily") private var fontFamilyRaw: String = FontFamily.system.rawValue
     @AppStorage("selectedTheme") private var selectedThemeRaw: String = EditorThemeOption.atomOneDark.rawValue
     @AppStorage("themeMode") private var themeModeRaw: String = ThemeMode.dark.rawValue
 
@@ -104,6 +105,10 @@ public struct ContentView: View {
         IndicatorStyle(rawValue: indicatorStyleRaw) ?? .iconAndText
     }
 
+    private var fontFamily: FontFamily {
+        FontFamily(rawValue: fontFamilyRaw) ?? .system
+    }
+
     private var selectedTheme: EditorThemeOption {
         EditorThemeOption(rawValue: selectedThemeRaw) ?? .atomOneDark
     }
@@ -292,7 +297,7 @@ public struct ContentView: View {
     @MainActor
     private func renderExportViewToImage() async -> NSImage? {
         // Calculate size based on layout and content
-        let font = NSFont.monospacedSystemFont(ofSize: fontSize, weight: .regular)
+        let font = fontFamily.font(size: fontSize)
 
         // Find the longest line in both panels
         let doLines = viewModel.doPanel.code.components(separatedBy: "\n")

BifcodePackage/Sources/BifcodeFeature/Models/SettingsTypes.swift

@@ -2,13 +2,92 @@
 //  SettingsTypes.swift
 //
 //  Created on 17.12.2025.
-//  Copyright © 2025 IGR Soft. All rights reserved.
+//  Copyright © 2026 IGR Soft. All rights reserved.
 //
 
 import AppKit
 import CodeEditSourceEditor
 import Foundation
 
+// MARK: - Font Family
+
+/// The font family for code display in the editor.
+///
+/// Provides a selection of popular monospace fonts suitable for code editing.
+/// The default is the system monospace font (SF Mono on macOS).
+///
+/// ## Usage
+///
+/// ```swift
+/// @AppStorage("fontFamily") private var fontFamily = FontFamily.system.rawValue
+/// ```
+///
+/// ## Available Fonts
+///
+/// - **System** - SF Mono (default system monospace)
+/// - **Menlo** - Classic macOS monospace font
+/// - **Monaco** - Legacy macOS programming font
+/// - **Courier** - Traditional monospace font
+///
+/// ## Topics
+///
+/// ### Fonts
+///
+/// - ``system``
+/// - ``menlo``
+/// - ``monaco``
+/// - ``courier``
+public enum FontFamily: String, CaseIterable, Sendable {
+    /// System monospace font (SF Mono on macOS).
+    ///
+    /// The default font, matching Apple's design guidelines
+    /// for code display. Available in all weights.
+    case system
+
+    /// Menlo font family.
+    ///
+    /// A classic macOS monospace font derived from Bitstream Vera Sans Mono.
+    /// Has been the default Terminal font for many years.
+    case menlo = "Menlo"
+
+    /// Monaco font family.
+    ///
+    /// The original macOS programming font, used in classic Mac OS
+    /// and early versions of Xcode. Has a distinctive, compact style.
+    case monaco = "Monaco"
+
+    /// Courier New font family.
+    ///
+    /// A traditional typewriter-style monospace font. Has a more
+    /// classic, formal appearance than other options.
+    case courier = "Courier New"
+
+    /// A human-readable label for display in pickers.
+    public var label: String {
+        switch self {
+        case .system: "SF Mono"
+        case .menlo: "Menlo"
+        case .monaco: "Monaco"
+        case .courier: "Courier New"
+        }
+    }
+
+    /// Creates an NSFont with this font family at the specified size.
+    ///
+    /// - Parameter size: The font size in points.
+    /// - Returns: An NSFont configured with this font family, or the
+    ///   system monospace font if the specified font is unavailable.
+    public func font(size: CGFloat) -> NSFont {
+        switch self {
+        case .system:
+            NSFont.monospacedSystemFont(ofSize: size, weight: .regular)
+        case .menlo, .monaco, .courier:
+            NSFont(name: rawValue, size: size)
+                ?? NSFont.monospacedSystemFont(ofSize: size, weight: .regular)
+        }
+    }
+}
+
 // MARK: - Indicator Position
 
 /// The position of the indicator badge within a code panel.