Fix horizontal source scrolling

ios/Sources/DetailScreens.swift

@@ -343,6 +343,7 @@ final class RepositoryFileViewController: UIViewController, QLPreviewControllerD
     private let spinner = UIActivityIndicatorView(style: .medium)
     private var loadingTask: Task<Void, Never>?
     private var previewURL: URL?
+    private weak var sourceTextView: UITextView?
 
     init(context: AppContext, owner: String, repository: String, path: String) {
         self.context = context
@@ -379,6 +380,11 @@ final class RepositoryFileViewController: UIViewController, QLPreviewControllerD
         }
     }
 
+    override func viewDidLayoutSubviews() {
+        super.viewDidLayoutSubviews()
+        updateSourceContentSize()
+    }
+
     private func isMediaFile(_ path: String) -> Bool {
         guard let type = UTType(filenameExtension: (path as NSString).pathExtension) else {
             return false
@@ -403,33 +409,59 @@ final class RepositoryFileViewController: UIViewController, QLPreviewControllerD
     }
 
     private func showSource(_ source: String) {
+        let highlighter = Highlighter()
+        highlighter?.setTheme(
+            traitCollection.userInterfaceStyle == .dark ? "atom-one-dark" : "atom-one-light"
+        )
+        highlighter?.theme.setCodeFont(.monospacedSystemFont(ofSize: 13, weight: .regular))
+        let highlighted = highlighter?.highlight(source, as: sourceLanguage(path))
+            ?? NSAttributedString(string: source, attributes: [
+                .font: UIFont.monospacedSystemFont(ofSize: 13, weight: .regular),
+                .foregroundColor: UIColor.label,
+            ])
+        let text = NSMutableAttributedString(attributedString: highlighted)
+        let paragraph = NSMutableParagraphStyle()
+        paragraph.lineBreakMode = .byClipping
+        text.addAttribute(.paragraphStyle, value: paragraph, range: NSRange(location: 0, length: text.length))
+
         let textView = UITextView(frame: view.bounds)
+        textView.textContainer.size = CGSize(
+            width: CGFloat.greatestFiniteMagnitude,
+            height: CGFloat.greatestFiniteMagnitude
+        )
+        textView.textContainer.lineBreakMode = .byClipping
+        textView.textContainer.widthTracksTextView = false
+        textView.textStorage.setAttributedString(text)
         textView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
         textView.isEditable = false
         textView.isSelectable = true
         textView.alwaysBounceHorizontal = true
         textView.isDirectionalLockEnabled = true
         textView.showsHorizontalScrollIndicator = true
+        sourceTextView = textView
+        view.addSubview(textView)
+        updateSourceContentSize()
+    }
+
+    private func updateSourceContentSize() {
+        guard let textView = sourceTextView else { return }
         textView.textContainer.widthTracksTextView = false
         textView.textContainer.size = CGSize(
             width: CGFloat.greatestFiniteMagnitude,
             height: CGFloat.greatestFiniteMagnitude
         )
-        let highlighter = Highlighter()
-        highlighter?.setTheme(
-            traitCollection.userInterfaceStyle == .dark ? "atom-one-dark" : "atom-one-light"
-        )
-        highlighter?.theme.setCodeFont(.monospacedSystemFont(ofSize: 13, weight: .regular))
-        textView.attributedText = highlighter?.highlight(source, as: sourceLanguage(path))
-            ?? NSAttributedString(string: source, attributes: [
-                .font: UIFont.monospacedSystemFont(ofSize: 13, weight: .regular),
-                .foregroundColor: UIColor.label,
-            ])
         textView.layoutManager.ensureLayout(for: textView.textContainer)
-        textView.contentSize.width = textView.layoutManager.usedRect(for: textView.textContainer).width
+        let textSize = textView.layoutManager.usedRect(for: textView.textContainer).size
-            + textView.textContainerInset.left
+        textView.contentSize = CGSize(
-            + textView.textContainerInset.right
+            width: max(
-        view.addSubview(textView)
+                textView.bounds.width,
+                ceil(textSize.width + textView.textContainerInset.left + textView.textContainerInset.right)
+            ),
+            height: max(
+                textView.bounds.height,
+                ceil(textSize.height + textView.textContainerInset.top + textView.textContainerInset.bottom)
+            )
+        )
     }
 
     private func showQuickLook(_ data: Data) throws {