#32 feat: add PDF export option

BifcodePackage/Sources/BifcodeFeature/ContentView.swift

@@ -91,6 +91,7 @@ public struct ContentView: View {
     @AppStorage("fontSize") private var fontSize: Double = 14
     @AppStorage("selectedTheme") private var selectedThemeRaw: String = EditorThemeOption.atomOneDark.rawValue
     @AppStorage("themeMode") private var themeModeRaw: String = ThemeMode.dark.rawValue
+    @AppStorage("exportFormat") private var exportFormatRaw: String = ExportFormat.png.rawValue
 
     private var layout: WindowLayout {
         WindowLayout(rawValue: windowLayoutRaw) ?? .horizontal
@@ -112,6 +113,10 @@ public struct ContentView: View {
         ThemeMode(rawValue: themeModeRaw) ?? .dark
     }
 
+    private var exportFormat: ExportFormat {
+        ExportFormat(rawValue: exportFormatRaw) ?? .png
+    }
+
     public init() {}
 
     /// Check if both code panels are empty (export should be disabled)
@@ -251,7 +256,7 @@ public struct ContentView: View {
         }
 
         do {
-            let savedURL = try await viewModel.saveImage(nsImage)
+            let savedURL = try await viewModel.saveImage(nsImage, format: exportFormat)
             withAnimation(reduceMotion ? nil : .easeInOut(duration: 0.25)) {
                 exportResult = .success(savedURL)
             }

BifcodePackage/Sources/BifcodeFeature/Models/SettingsTypes.swift

@@ -246,6 +246,59 @@ public enum WindowLayout: String, CaseIterable, Sendable {
     }
 }
 
+// MARK: - Export Format
+
+/// The file format for exported images.
+///
+/// Controls whether exports are saved as PNG images or PDF documents.
+///
+/// ## Usage
+///
+/// ```swift
+/// @AppStorage("exportFormat") private var exportFormat = ExportFormat.png.rawValue
+/// ```
+///
+/// ## Topics
+///
+/// ### Formats
+///
+/// - ``png``
+/// - ``pdf``
+public enum ExportFormat: String, CaseIterable, Sendable {
+    /// PNG image format.
+    ///
+    /// Raster format with full color support and transparency.
+    /// Ideal for sharing on social media and web.
+    case png
+
+    /// PDF document format.
+    ///
+    /// Vector format that maintains quality at any zoom level.
+    /// Ideal for printing and documentation.
+    case pdf
+
+    /// A human-readable label for display in pickers.
+    public var label: String {
+        switch self {
+        case .png: "PNG"
+        case .pdf: "PDF"
+        }
+    }
+
+    /// The file extension for this format.
+    public var fileExtension: String {
+        rawValue
+    }
+
+    /// The UTType identifier for this format.
+    public var utType: String {
+        switch self {
+        case .png: "public.png"
+        case .pdf: "com.adobe.pdf"
+        }
+    }
+}
+
 // MARK: - Theme Mode
 
 /// The color mode for the code editor themes.

BifcodePackage/Sources/BifcodeFeature/ViewModels/AppViewModel.swift

@@ -7,6 +7,7 @@
 
 import CodeEditLanguages
 import Foundation
+import PDFKit
 import SwiftUI
 
 /// The main view model managing application state and export functionality.
@@ -148,11 +149,13 @@ public final class AppViewModel {
     /// Save an image to the configured save location.
     ///
     /// Handles security-scoped resource access for bookmarked locations.
-    /// - Parameter image: The NSImage to save as PNG
-    /// - Returns: The URL where the image was saved
+    /// - Parameters:
+    ///   - image: The NSImage to save
+    ///   - format: The export format (PNG or PDF)
+    /// - Returns: The URL where the file was saved
     /// - Throws: `ExportError` if conversion or saving fails
     @discardableResult
-    public func saveImage(_ image: NSImage) async throws -> URL {
+    public func saveImage(_ image: NSImage, format: ExportFormat = .png) async throws -> URL {
         let location = saveLocation
         let needsSecurityScope = hasCustomSaveLocation
 
@@ -169,9 +172,21 @@ public final class AppViewModel {
             }
         }
 
-        let filename = "bifcode-\(Date().timeIntervalSince1970).png"
+        let filename = "bifcode-\(Date().timeIntervalSince1970).\(format.fileExtension)"
         let url = location.appendingPathComponent(filename)
 
+        switch format {
+        case .png:
+            try savePNG(image: image, to: url)
+        case .pdf:
+            try savePDF(image: image, to: url)
+        }
+
+        return url
+    }
+
+    /// Saves an image as PNG to the specified URL.
+    private func savePNG(image: NSImage, to url: URL) throws {
         guard let tiffData = image.tiffRepresentation,
               let bitmap = NSBitmapImageRep(data: tiffData),
               let pngData = bitmap.representation(using: .png, properties: [:])
@@ -180,7 +195,35 @@ public final class AppViewModel {
         }
 
         try pngData.write(to: url)
-        return url
+    }
+
+    /// Saves an image as PDF to the specified URL.
+    private func savePDF(image: NSImage, to url: URL) throws {
+        let imageSize = image.size
+
+        // Create PDF data with the image rendered as a PDF page
+        let pdfData = NSMutableData()
+        var mediaBox = CGRect(origin: .zero, size: imageSize)
+
+        guard let consumer = CGDataConsumer(data: pdfData as CFMutableData),
+              let pdfContext = CGContext(consumer: consumer, mediaBox: &mediaBox, nil)
+        else {
+            throw ExportError.conversionFailed
+        }
+
+        pdfContext.beginPDFPage(nil)
+
+        // Draw the image in the PDF context
+        if let cgImage = image.cgImage(forProposedRect: nil, context: nil, hints: nil) {
+            pdfContext.draw(cgImage, in: mediaBox)
+        } else {
+            throw ExportError.conversionFailed
+        }
+
+        pdfContext.endPDFPage()
+        pdfContext.closePDF()
+
+        try pdfData.write(to: url)
     }
 }
 
@@ -219,8 +262,8 @@ public enum ExportError: LocalizedError {
 
     public var errorDescription: String? {
         switch self {
-        case .conversionFailed: "Failed to convert image to PNG"
-        case .saveFailed: "Failed to save image"
+        case .conversionFailed: "Failed to convert image"
+        case .saveFailed: "Failed to save file"
         case .accessDenied: "Cannot access save location. Please choose a new folder."
         }
     }

BifcodePackage/Sources/BifcodeFeature/Views/ToolBarView.swift

@@ -60,6 +60,7 @@ public struct ToolBarView: View {
     @AppStorage("fontSize") private var fontSize: Double = 14
     @AppStorage("selectedTheme") private var selectedThemeRaw: String = EditorThemeOption.atomOneDark.rawValue
     @AppStorage("themeMode") private var themeModeRaw: String = ThemeMode.dark.rawValue
+    @AppStorage("exportFormat") private var exportFormatRaw: String = ExportFormat.png.rawValue
 
     @AppStorage("selectedLanguage") private var selectedLanguageRaw: String = "swift"
 
@@ -90,6 +91,11 @@ public struct ToolBarView: View {
         EditorThemeOption.allCases
     }
 
+    /// Current export format derived from stored raw value
+    private var currentExportFormat: ExportFormat {
+        ExportFormat(rawValue: exportFormatRaw) ?? .png
+    }
+
     @Binding private var doTitleSetting: String
     @Binding private var dontTitleSetting: String
 
@@ -510,6 +516,20 @@ public struct ToolBarView: View {
             .accessibilityHint("Title shown above negative code example")
     }
 
+    // MARK: - Export Format
+
+    private var exportFormatPicker: some View {
+        Picker("", selection: $exportFormatRaw) {
+            ForEach(ExportFormat.allCases, id: \.rawValue) { format in
+                Text(format.label).tag(format.rawValue)
+            }
+        }
+        .pickerStyle(.segmented)
+        .fixedSize()
+        .accessibilityLabel("Export Format")
+        .accessibilityHint("Choose PNG or PDF format")
+    }
+
     // MARK: - Export Button
 
     @State private var isExportButtonHovered = false
@@ -538,14 +558,16 @@ public struct ToolBarView: View {
                 isExportButtonHovered = hovering
             }
             .disabled(isExportDisabled)
-            .help("Export as PNG")
-            .accessibilityLabel("Export as PNG")
+            .help("Export as \(currentExportFormat.label)")
+            .accessibilityLabel("Export as \(currentExportFormat.label)")
             .accessibilityHint(isExportDisabled
                 ? "Disabled: Add code to enable export"
-                : "Save comparison image to selected folder")
+                : "Save comparison as \(currentExportFormat.label) to selected folder")
 
             // Secondary Actions
             VStack(spacing: 8) {
+                exportFormatPicker
+
                 Button {
                     chooseSaveLocation()
                 } label: {
@@ -555,7 +577,7 @@ public struct ToolBarView: View {
                 .buttonStyle(.borderless)
                 .help("Choose save location")
                 .accessibilityLabel("Choose Save Location")
-                .accessibilityHint("Select folder for exported images")
+                .accessibilityHint("Select folder for exported files")
 
                 storeButton
                     .padding(.top, 32)