Open multiple documents per markdown file

MarkdownViewer/ContentView.swift

@@ -1,77 +1,34 @@
 import SwiftUI
-import UniformTypeIdentifiers
-import AppKit
 
 struct ContentView: View {
-    @State private var selectedFileURL: URL?
-    @State private var markdownContent: String = ""
-    
     var body: some View {
-        NavigationSplitView {
-            VStack {
-                Button("Open Markdown File") {
-                    openFile()
-                }
-                .padding()
-                
-                if let url = selectedFileURL {
-                    Text("File: \(url.lastPathComponent)")
-                        .foregroundColor(.secondary)
-                        .font(.caption)
-                        .truncationMode(.middle)
-                        .padding(.horizontal)
-                }
-                
-                Spacer()
-            }
-            .frame(minWidth: 200)
-            .navigationSplitViewColumnWidth(min: 200, ideal: 250)
-        } detail: {
-            if !markdownContent.isEmpty {
-                MarkdownRenderer(content: markdownContent)
-                    .onAppear {
-                        print("MarkdownRenderer appeared with content length: \(markdownContent.count)")
-                    }
-            } else {
         VStack {
             Image(systemName: "doc.text")
-                        .font(.system(size: 60))
+                .font(.system(size: 80))
                 .foregroundColor(.secondary)
-                    Text("Select a markdown file to preview")
+            Text("Markdown Viewer")
+                .font(.largeTitle)
+                .fontWeight(.medium)
+            Text("Open markdown files from the File menu")
                 .foregroundColor(.secondary)
-                        .padding()
+                .padding(.top, 8)
+            Text("⌘O")
+                .foregroundColor(.secondary)
+                .font(.caption)
+                .padding(.top, 4)
         }
         .frame(maxWidth: .infinity, maxHeight: .infinity)
     }
-        }
-        .navigationTitle("Markdown Viewer")
-    }
+}
 
-    private func openFile() {
-        let panel = NSOpenPanel()
-        panel.allowsMultipleSelection = false
-        panel.canChooseDirectories = false
-        panel.canChooseFiles = true
-        panel.allowedContentTypes = [UTType.plainText, UTType(filenameExtension: "md")!]
+struct MarkdownDocumentView: View {
+    let content: String
+    let fileName: String
     
-        if panel.runModal() == .OK {
-            if let url = panel.url {
-                selectedFileURL = url
-                loadMarkdownFile(from: url)
-            }
-        }
-    }
-    
-    private func loadMarkdownFile(from url: URL) {
-        do {
-            let content = try String(contentsOf: url, encoding: .utf8)
-            print("File loaded successfully, content length: \(content.count)")
-            print("First 100 characters: \(String(content.prefix(100)))")
-            markdownContent = content
-        } catch {
-            print("Error reading file: \(error)")
-            markdownContent = "Error loading file: \(error.localizedDescription)"
-        }
+    var body: some View {
+        MarkdownRenderer(content: content)
+            .navigationTitle(fileName)
+            .frame(maxWidth: .infinity, maxHeight: .infinity)
     }
 }
 

MarkdownViewer/MarkdownViewerApp.swift

@@ -1,10 +1,84 @@
 import SwiftUI
+import UniformTypeIdentifiers
+import AppKit
 
 @main
 struct MarkdownViewerApp: App {
     var body: some Scene {
-        WindowGroup {
-            ContentView()
+        Settings {
+            EmptyView()
+        }
+        .commands {
+            CommandGroup(replacing: .newItem) {
+                Button("Open Markdown File...") {
+                    openMarkdownFile()
+                }
+                .keyboardShortcut("o", modifiers: .command)
+            }
+        }
+    }
+    
+    private func openMarkdownFile() {
+        let panel = NSOpenPanel()
+        panel.allowsMultipleSelection = true
+        panel.canChooseDirectories = false
+        panel.canChooseFiles = true
+        panel.allowedContentTypes = [UTType.plainText, UTType(filenameExtension: "md")!]
+        
+        if panel.runModal() == .OK {
+            for url in panel.urls {
+                openNewWindow(for: url)
+            }
+        }
+    }
+    
+    private func openNewWindow(for url: URL) {
+        do {
+            let content = try String(contentsOf: url, encoding: .utf8)
+            let newWindow = NSWindow(
+                contentRect: NSRect(x: 0, y: 0, width: 800, height: 600),
+                styleMask: [.titled, .closable, .resizable, .miniaturizable],
+                backing: .buffered,
+                defer: false
+            )
+            
+            newWindow.title = url.lastPathComponent
+            newWindow.contentView = NSHostingView(
+                rootView: MarkdownDocumentView(
+                    content: content,
+                    fileName: url.lastPathComponent
+                )
+            )
+            newWindow.center()
+            newWindow.makeKeyAndOrderFront(nil)
+            
+        } catch {
+            print("Error reading file: \(error)")
+            // Show error in a new window
+            let newWindow = NSWindow(
+                contentRect: NSRect(x: 0, y: 0, width: 400, height: 200),
+                styleMask: [.titled, .closable],
+                backing: .buffered,
+                defer: false
+            )
+            
+            newWindow.title = "Error"
+            newWindow.contentView = NSHostingView(
+                rootView: VStack {
+                    Image(systemName: "exclamationmark.triangle")
+                        .font(.system(size: 40))
+                        .foregroundColor(.red)
+                    Text("Error loading file")
+                        .font(.headline)
+                    Text(error.localizedDescription)
+                        .font(.caption)
+                        .foregroundColor(.secondary)
+                        .multilineTextAlignment(.center)
+                }
+                .padding()
+            )
+            newWindow.center()
+            newWindow.makeKeyAndOrderFront(nil)
         }
     }
 }