iOS: Add file picker (#747)

* iOS: Add file picker

* Fix lock placement

include/ios_driver.h

@@ -3,4 +3,5 @@
 #include <QuartzCore/QuartzCore.h>
 
 void iosCreateEmulator();
+void iosLoadROM(NSString* pathNS);
 void iosRunFrame(CAMetalLayer* layer);

src/ios_driver.mm

@@ -23,10 +23,6 @@ IOS_EXPORT void iosCreateEmulator() {
 	emulator = std::make_unique<Emulator>();
 	hidService = &emulator->getServiceManager().getHID();
 	emulator->initGraphicsContext(nullptr);
-
-	// TODO: Add game selection on iOS frontend
-	auto path = emulator->getAppDataRoot() / "toon_shading.elf";
-	emulator->loadROM(path);
 }
 
 IOS_EXPORT void iosRunFrame(CAMetalLayer* layer) {
@@ -35,3 +31,8 @@ IOS_EXPORT void iosRunFrame(CAMetalLayer* layer) {
 	emulator->getRenderer()->setMTKLayer(layerBridged);
 	emulator->runFrame();
 }
+
+IOS_EXPORT void iosLoadROM(NSString* pathNS) {
+    auto path = std::filesystem::path([pathNS UTF8String]);
+    emulator->loadROM(path);
+}

src/pandios/Alber/Headers/ios_driver.h

@@ -3,4 +3,5 @@
 #include <QuartzCore/QuartzCore.h>
 
 void iosCreateEmulator();
+void iosLoadROM(NSString* pathNS);
 void iosRunFrame(CAMetalLayer* layer);

src/pandios/Pandios.xcodeproj/project.pbxproj

@@ -51,11 +51,7 @@
 /* End PBXFileReference section */
 
 /* Begin PBXFileSystemSynchronizedRootGroup section */
-		4F6E8FC42D77C0120025DD0D /* Pandios */ = {
+		4F6E8FC42D77C0120025DD0D /* Pandios */ = {isa = PBXFileSystemSynchronizedRootGroup; explicitFileTypes = {}; explicitFolders = (); path = Pandios; sourceTree = "<group>"; };
-			isa = PBXFileSystemSynchronizedRootGroup;
-			path = Pandios;
-			sourceTree = "<group>";
-		};
 /* End PBXFileSystemSynchronizedRootGroup section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -202,6 +198,7 @@
 				};
 			};
 			buildConfigurationList = 4F6E8FBD2D77C0120025DD0D /* Build configuration list for PBXProject "Pandios" */;
+			compatibilityVersion = "Xcode 16.0.Superseded.1";
 			developmentRegion = en;
 			hasScannedForEncodings = 0;
 			knownRegions = (
@@ -210,7 +207,6 @@
 			);
 			mainGroup = 4F6E8FB92D77C0120025DD0D;
 			minimizedProjectReferenceProxies = 1;
-			preferredProjectObjectVersion = 70;
 			productRefGroup = 4F6E8FC32D77C0120025DD0D /* Products */;
 			projectDirPath = "";
 			projectRoot = "";

src/pandios/Pandios/ContentView.swift

@@ -3,6 +3,47 @@ import SwiftUI
 import MetalKit
 import Darwin
 
+var emulatorLock = NSLock()
+
+class DocumentViewController: UIViewController, DocumentDelegate {
+    var documentPicker: DocumentPicker!
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+
+        /// set up the document picker
+        documentPicker = DocumentPicker(presentationController: self, delegate: self)
+        /// When the view loads (ie user opens the app) show the file picker
+        show()
+    }
+    
+    /// callback from the document picker
+    func didPickDocument(document: Document?) {
+        if let pickedDoc = document {
+            let fileURL = pickedDoc.fileURL
+            
+            print("Loading ROM", fileURL)
+            emulatorLock.lock()
+            iosLoadROM(fileURL.path(percentEncoded: false))
+            emulatorLock.unlock()
+        }
+    }
+    
+    func show() {
+        documentPicker.displayPicker()
+    }
+}
+
+struct DocumentView: UIViewControllerRepresentable {
+    func makeUIViewController(context: Context) -> DocumentViewController {
+        return DocumentViewController()
+    }
+    
+    func updateUIViewController(_ uiViewController: DocumentViewController, context: Context) {
+        // No update needed
+    }
+}
+
 struct ContentView: UIViewRepresentable {
     @State var showFileImporter = true
 
@@ -32,7 +73,9 @@ struct ContentView: UIViewRepresentable {
             iosCreateEmulator()
             
             while (true) {
+                emulatorLock.lock()
                 iosRunFrame(metalLayer);
+                emulatorLock.unlock()
             }
         }
 
@@ -46,6 +89,7 @@ struct ContentView: UIViewRepresentable {
 
 struct ContentView_Previews: PreviewProvider {
     static var previews: some View {
-        ContentView()
+        DocumentView();
+        ContentView();
     }
 }

src/pandios/Pandios/DocumentPicker.swift

@@ -0,0 +1,75 @@
+//  From https://gist.github.com/aheze/dbc7f9b452e4f86f2d8fe278b3c5001f
+//  DocumentPicker.swift
+
+import UIKit
+import MobileCoreServices
+import UniformTypeIdentifiers
+
+protocol DocumentDelegate: AnyObject {
+    func didPickDocument(document: Document?)
+}
+
+class Document: UIDocument {
+    var data: Data?
+    override func contents(forType typeName: String) throws -> Any {
+        guard let data = data else { return Data() }
+        return try NSKeyedArchiver.archivedData(withRootObject:data,
+                                                requiringSecureCoding: true)
+    }
+    override func load(fromContents contents: Any, ofType typeName:
+        String?) throws {
+        guard let data = contents as? Data else { return }
+        self.data = data
+    }
+}
+
+open class DocumentPicker: NSObject {
+    private var pickerController: UIDocumentPickerViewController?
+    private weak var presentationController: UIViewController?
+    private weak var delegate: DocumentDelegate?
+
+    private var pickedDocument: Document?
+
+    init(presentationController: UIViewController, delegate: DocumentDelegate) {
+        super.init()
+        self.presentationController = presentationController
+        self.delegate = delegate
+    }
+
+    public func displayPicker() {
+        self.pickerController = UIDocumentPickerViewController(forOpeningContentTypes: [UTType.data])
+        self.pickerController!.delegate = self
+        self.presentationController?.present(self.pickerController!, animated: true)
+    }
+}
+
+extension DocumentPicker: UIDocumentPickerDelegate {
+    /// delegate method, when the user selects a file
+    public func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
+        guard let url = urls.first else {
+            return
+        }
+        documentFromURL(pickedURL: url)
+        delegate?.didPickDocument(document: pickedDocument)
+    }
+
+    /// delegate method, when the user cancels
+    public func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
+        delegate?.didPickDocument(document: nil)
+    }
+
+    private func documentFromURL(pickedURL: URL) {
+        /// start accessing the resource
+        let shouldStopAccessing = pickedURL.startAccessingSecurityScopedResource()
+
+        defer {
+            if shouldStopAccessing {
+                pickedURL.stopAccessingSecurityScopedResource()
+            }
+        }
+        NSFileCoordinator().coordinate(readingItemAt: pickedURL, error: NSErrorPointer.none) { (readURL) in
+            let document = Document(fileURL: readURL)
+            pickedDocument = document
+        }
+    }
+}

src/pandios/Pandios/PandiosApp.swift

@@ -5,6 +5,7 @@ struct PandiosApp: App {
     var body: some Scene {
         WindowGroup {
             ContentView()
+            DocumentView()
         }
     }
 }