Add editable untitled Markdown previews

.gitignore

@@ -73,3 +73,7 @@ fastlane/test_output
 
 # Editor bundle build (scripts/editor-bundle)
 node_modules/
+
+# Local design tooling
+.superpowers/
+.worktrees/

Info.plist

@@ -10,7 +10,7 @@
 			<key>CFBundleTypeName</key>
 			<string>Markdown Document</string>
 			<key>CFBundleTypeRole</key>
-			<string>Viewer</string>
+			<string>Editor</string>
 			<key>LSHandlerRank</key>
 			<string>Owner</string>
 			<key>LSItemContentTypes</key>

md-preview/AppDelegate.swift

@@ -111,14 +111,12 @@ final class AppDelegate: NSObject, NSApplicationDelegate {
     private weak var darkAppearanceMenuItem: NSMenuItem?
     private weak var normalContentWidthMenuItem: NSMenuItem?
     private weak var fullContentWidthMenuItem: NSMenuItem?
-    private var isOpeningDocumentFromPrompt = false
     private var isPromptingForDocument = false
-    private var isDocumentPromptScheduled = false
-    private var documentPromptScheduleGeneration = 0
+    private var isUntitledDocumentScheduled = false
+    private var untitledDocumentScheduleGeneration = 0
     private var didReceiveOpenURLsDuringLaunch = false
     private var hasFinishedLaunching = false
     private var pendingOpenURLCount = 0
-    private weak var activeOpenPanel: NSOpenPanel?
     private var isTerminationSaveInProgress = false
     private var pendingTerminationSaveCount = 0
     private var terminationSaveFailed = false
@@ -140,7 +138,7 @@ final class AppDelegate: NSObject, NSApplicationDelegate {
         installZoomMenuItemIcons()
         hasFinishedLaunching = true
         if !didReceiveOpenURLsDuringLaunch {
-            scheduleDocumentPrompt(requiresNoDocuments: true)
+            scheduleUntitledDocument(requiresNoDocuments: true)
         }
     }
 
@@ -149,13 +147,13 @@ final class AppDelegate: NSObject, NSApplicationDelegate {
     }
 
     func applicationOpenUntitledFile(_ sender: NSApplication) -> Bool {
-        scheduleDocumentPrompt(requiresNoDocuments: true)
+        scheduleUntitledDocument(requiresNoDocuments: true)
         return true
     }
 
     func applicationShouldHandleReopen(_ sender: NSApplication, hasVisibleWindows flag: Bool) -> Bool {
         if !flag {
-            scheduleDocumentPrompt(requiresNoDocuments: true)
+            scheduleUntitledDocument(requiresNoDocuments: true)
             return false
         }
         return true
@@ -165,7 +163,7 @@ final class AppDelegate: NSObject, NSApplicationDelegate {
         if !hasFinishedLaunching {
             didReceiveOpenURLsDuringLaunch = true
         }
-        cancelScheduledDocumentPrompt()
+        cancelScheduledUntitledDocument()
 
         for url in urls {
             if url.isExistingDirectory {
@@ -182,7 +180,7 @@ final class AppDelegate: NSObject, NSApplicationDelegate {
                 guard let self else { return }
                 self.pendingOpenURLCount -= 1
                 if error != nil, self.pendingOpenURLCount == 0 {
-                    self.scheduleDocumentPrompt(requiresNoDocuments: true)
+                    self.scheduleUntitledDocument(requiresNoDocuments: true)
                 }
             }
         }
@@ -340,47 +338,40 @@ final class AppDelegate: NSObject, NSApplicationDelegate {
         defer { isPromptingForDocument = false }
 
         let panel = makeOpenPanel()
-        activeOpenPanel = panel
-        defer { activeOpenPanel = nil }
         guard panel.runModal() == .OK, let url = panel.url else { return }
         if url.isExistingDirectory {
             openFolder(url)
             return
         }
 
-        isOpeningDocumentFromPrompt = true
         NSDocumentController.shared.openDocument(withContentsOf: url,
-                                                 display: true) { [weak self] _, _, error in
-            self?.isOpeningDocumentFromPrompt = false
+                                                 display: true) { _, _, error in
             guard let error else { return }
             NSAlert(error: error).runModal()
         }
     }
 
-    private func scheduleDocumentPrompt(requiresNoDocuments: Bool = false) {
-        guard !isPromptingForDocument,
-              !isDocumentPromptScheduled else { return }
-
-        isDocumentPromptScheduled = true
-        documentPromptScheduleGeneration += 1
-        let scheduleGeneration = documentPromptScheduleGeneration
+    private func scheduleUntitledDocument(requiresNoDocuments: Bool = false) {
+        guard !isUntitledDocumentScheduled else { return }
+        isUntitledDocumentScheduled = true
+        untitledDocumentScheduleGeneration += 1
+        let generation = untitledDocumentScheduleGeneration
         DispatchQueue.main.async { [weak self] in
-            guard let self else { return }
-            guard self.documentPromptScheduleGeneration == scheduleGeneration else { return }
-            self.isDocumentPromptScheduled = false
+            guard let self,
+                  self.untitledDocumentScheduleGeneration == generation else { return }
+            self.isUntitledDocumentScheduled = false
             guard !requiresNoDocuments || NSDocumentController.shared.documents.isEmpty else { return }
+            guard !self.isPromptingForDocument else { return }
+            guard self.pendingOpenURLCount == 0 else { return }
             NSApp.activate(ignoringOtherApps: true)
-            self.promptForDocument()
+            NSDocumentController.shared.newDocument(nil)
         }
     }
 
-    private func cancelScheduledDocumentPrompt() {
-        // Dismiss a prompt that already made it past the generation check and
-        // is sitting in runModal() when the open event arrives.
-        activeOpenPanel?.cancel(nil)
-        guard isDocumentPromptScheduled else { return }
-        documentPromptScheduleGeneration += 1
-        isDocumentPromptScheduled = false
+    private func cancelScheduledUntitledDocument() {
+        guard isUntitledDocumentScheduled else { return }
+        untitledDocumentScheduleGeneration += 1
+        isUntitledDocumentScheduled = false
     }
 
     private func openFolder(_ url: URL) {