Add Markdown file previews

ios/Gotcha.xcodeproj/project.pbxproj

@@ -14,6 +14,7 @@
 		950C584D58E80106DF350A22 /* AppDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9C0921C76676A14A024BA417 /* AppDelegate.swift */; };
 		96C4AFC206A1DBAE3D3E00CE /* SettingsViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8F145F13B8ED83A5AB0009A4 /* SettingsViewController.swift */; };
 		D59D3ED36ABCC1D8690A9088 /* gotcha_core.swift in Sources */ = {isa = PBXBuildFile; fileRef = FE12480725C13293FAFDDA52 /* gotcha_core.swift */; };
+		D78A121E9ADA0B72E2CF94DC /* MarkdownUI in Frameworks */ = {isa = PBXBuildFile; productRef = 8AD463F3AC817A44306C2297 /* MarkdownUI */; };
 		E7AC0B140F5CFC5EF226D174 /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = DDAABE6B13ADC6D08D9438AF /* Assets.xcassets */; };
 		EC7F8B4703DDE37A0B10CD9B /* AppContext.swift in Sources */ = {isa = PBXBuildFile; fileRef = F61515849F6AACD721FE915C /* AppContext.swift */; };
 		F55A89489B2758D694F3B27D /* Support.swift in Sources */ = {isa = PBXBuildFile; fileRef = F75B3E4FFB9C9992517C4D69 /* Support.swift */; };
@@ -38,6 +39,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				7DD332583B169B3CA1CA46E0 /* Highlighter in Frameworks */,
+				D78A121E9ADA0B72E2CF94DC /* MarkdownUI in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -103,6 +105,7 @@
 			name = Gotcha;
 			packageProductDependencies = (
 				EC5F999F50905E3801E8A71A /* Highlighter */,
+				8AD463F3AC817A44306C2297 /* MarkdownUI */,
 			);
 			productName = Gotcha;
 			productReference = 5FB3250A93766966A60A685E /* Gotcha.app */;
@@ -134,6 +137,7 @@
 			minimizedProjectReferenceProxies = 1;
 			packageReferences = (
 				85EFB86C5B2FDE8DEAD98A24 /* XCRemoteSwiftPackageReference "HighlighterSwift" */,
+				0B96240AE4FB1E82EE0D6B17 /* XCRemoteSwiftPackageReference "swift-markdown-ui" */,
 			);
 			preferredProjectObjectVersion = 77;
 			productRefGroup = F059299C038F3CAFCE470831 /* Products */;
@@ -389,6 +393,14 @@
 /* End XCConfigurationList section */
 
 /* Begin XCRemoteSwiftPackageReference section */
+		0B96240AE4FB1E82EE0D6B17 /* XCRemoteSwiftPackageReference "swift-markdown-ui" */ = {
+			isa = XCRemoteSwiftPackageReference;
+			repositoryURL = "https://github.com/gonzalezreal/swift-markdown-ui";
+			requirement = {
+				kind = upToNextMajorVersion;
+				minimumVersion = 2.1.0;
+			};
+		};
 		85EFB86C5B2FDE8DEAD98A24 /* XCRemoteSwiftPackageReference "HighlighterSwift" */ = {
 			isa = XCRemoteSwiftPackageReference;
 			repositoryURL = "https://github.com/smittytone/HighlighterSwift";
@@ -400,6 +412,11 @@
 /* End XCRemoteSwiftPackageReference section */
 
 /* Begin XCSwiftPackageProductDependency section */
+		8AD463F3AC817A44306C2297 /* MarkdownUI */ = {
+			isa = XCSwiftPackageProductDependency;
+			package = 0B96240AE4FB1E82EE0D6B17 /* XCRemoteSwiftPackageReference "swift-markdown-ui" */;
+			productName = MarkdownUI;
+		};
 		EC5F999F50905E3801E8A71A /* Highlighter */ = {
 			isa = XCSwiftPackageProductDependency;
 			package = 85EFB86C5B2FDE8DEAD98A24 /* XCRemoteSwiftPackageReference "HighlighterSwift" */;

ios/Gotcha.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved

@@ -1,5 +1,5 @@
 {
-  "originHash" : "00a1c96095892a05bfd089593813422ede18735e452666e3e7a642ebd9048a45",
+  "originHash" : "7a8d1ff34841e518cc21434c2148b0c9b3d7c0d8b436c01ab8711755963dcc94",
   "pins" : [
     {
       "identity" : "highlighterswift",
@@ -9,6 +9,33 @@
         "revision" : "fe7aae9c9b31d3b296fd3d2dd575e1a207bb29e0",
         "version" : "3.1.0"
       }
+    },
+    {
+      "identity" : "networkimage",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/gonzalezreal/NetworkImage",
+      "state" : {
+        "revision" : "2849f5323265386e200484b0d0f896e73c3411b9",
+        "version" : "6.0.1"
+      }
+    },
+    {
+      "identity" : "swift-cmark",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/swiftlang/swift-cmark",
+      "state" : {
+        "revision" : "924936d0427cb25a61169739a7660230bffa6ea6",
+        "version" : "0.8.0"
+      }
+    },
+    {
+      "identity" : "swift-markdown-ui",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/gonzalezreal/swift-markdown-ui",
+      "state" : {
+        "revision" : "5f613358148239d0292c0cef674a3c2314737f9e",
+        "version" : "2.4.1"
+      }
     }
   ],
   "version" : 3

ios/Sources/DetailScreens.swift

@@ -1,5 +1,7 @@
 import Highlighter
+import MarkdownUI
 import QuickLook
+import SwiftUI
 import UIKit
 import UniformTypeIdentifiers
 
@@ -336,6 +338,8 @@ final class RepositoryDirectoryViewController: RefreshingTableViewController {
 
 @MainActor
 final class RepositoryFileViewController: UIViewController, QLPreviewControllerDataSource {
+    private enum MarkdownMode: Int { case preview, source }
+
     private let context: AppContext
     private let owner: String
     private let repository: String
@@ -343,6 +347,9 @@ final class RepositoryFileViewController: UIViewController, QLPreviewControllerD
     private let spinner = UIActivityIndicatorView(style: .medium)
     private var loadingTask: Task<Void, Never>?
     private var previewURL: URL?
+    private var markdownSource: String?
+    private var displayedController: UIViewController?
+    private var displayedView: UIView?
     private weak var sourceScrollView: UIScrollView?
     private weak var sourceTextView: UITextView?
 
@@ -370,7 +377,11 @@ final class RepositoryFileViewController: UIViewController, QLPreviewControllerD
                     path: path
                 )
                 if !isMediaFile(path), let source = String(data: data, encoding: .utf8) {
-                    showSource(source)
+                    if isMarkdownFile {
+                        showMarkdown(source)
+                    } else {
+                        showSource(source)
+                    }
                 } else {
                     try showQuickLook(data)
                 }
@@ -396,6 +407,10 @@ final class RepositoryFileViewController: UIViewController, QLPreviewControllerD
             || type.conforms(to: .pdf)
     }
 
+    private var isMarkdownFile: Bool {
+        ["md", "markdown", "mdown", "mkd"].contains((path as NSString).pathExtension.lowercased())
+    }
+
     deinit {
         loadingTask?.cancel()
         if let previewURL { try? FileManager.default.removeItem(at: previewURL) }
@@ -409,7 +424,40 @@ final class RepositoryFileViewController: UIViewController, QLPreviewControllerD
         previewURL! as NSURL
     }
 
+    private func showMarkdown(_ source: String) {
+        markdownSource = source
+        navigationItem.prompt = title
+        let modeControl = UISegmentedControl(items: ["Preview", "Source"])
+        modeControl.selectedSegmentIndex = MarkdownMode.preview.rawValue
+        modeControl.addTarget(self, action: #selector(markdownModeChanged(_:)), for: .valueChanged)
+        modeControl.accessibilityLabel = "Markdown view"
+        navigationItem.titleView = modeControl
+        showMarkdownPreview(source)
+    }
+
+    @objc private func markdownModeChanged(_ sender: UISegmentedControl) {
+        guard let mode = MarkdownMode(rawValue: sender.selectedSegmentIndex),
+              let source = markdownSource else { return }
+        switch mode {
+        case .preview: showMarkdownPreview(source)
+        case .source: showSource(source)
+        }
+    }
+
+    private func showMarkdownPreview(_ source: String) {
+        removeDisplayedView()
+        let preview = UIHostingController(rootView: RepositoryMarkdownPreview(source: source))
+        addChild(preview)
+        preview.view.frame = view.bounds
+        preview.view.autoresizingMask = [.flexibleWidth, .flexibleHeight]
+        displayedController = preview
+        displayedView = preview.view
+        view.addSubview(preview.view)
+        preview.didMove(toParent: self)
+    }
+
     private func showSource(_ source: String) {
+        removeDisplayedView()
         let highlighter = Highlighter()
         highlighter?.setTheme(
             traitCollection.userInterfaceStyle == .dark ? "atom-one-dark" : "atom-one-light"
@@ -445,10 +493,21 @@ final class RepositoryFileViewController: UIViewController, QLPreviewControllerD
         sourceScrollView = scrollView
         sourceTextView = textView
         scrollView.addSubview(textView)
+        displayedView = scrollView
         view.addSubview(scrollView)
         updateSourceLayout()
     }
 
+    private func removeDisplayedView() {
+        displayedController?.willMove(toParent: nil)
+        displayedView?.removeFromSuperview()
+        displayedController?.removeFromParent()
+        displayedController = nil
+        displayedView = nil
+        sourceScrollView = nil
+        sourceTextView = nil
+    }
+
     private func updateSourceLayout() {
         guard let scrollView = sourceScrollView, let textView = sourceTextView else { return }
         textView.textContainer.widthTracksTextView = false
@@ -488,6 +547,20 @@ final class RepositoryFileViewController: UIViewController, QLPreviewControllerD
     }
 }
 
+private struct RepositoryMarkdownPreview: View {
+    let source: String
+
+    var body: some View {
+        ScrollView {
+            Markdown(source)
+                .markdownTheme(.gitHub)
+                .frame(maxWidth: .infinity, alignment: .leading)
+                .padding()
+        }
+        .background(Color(uiColor: .systemBackground))
+    }
+}
+
 enum DiffSource {
     case commit(owner: String, repository: String, sha: String, path: String)
     case pull(owner: String, repository: String, number: Int64, path: String)

ios/project.yml

@@ -7,6 +7,9 @@ packages:
   Highlighter:
     url: https://github.com/smittytone/HighlighterSwift
     from: 3.1.0
+  MarkdownUI:
+    url: https://github.com/gonzalezreal/swift-markdown-ui
+    from: 2.1.0
 targets:
   Gotcha:
     type: application
@@ -35,6 +38,7 @@ targets:
       - Generated/gotcha_core.swift
     dependencies:
       - package: Highlighter
+      - package: MarkdownUI
     preBuildScripts:
       - name: Build Rust core
         basedOnDependencyAnalysis: false