Fix a bug where the preview controller breaks when swiping quickly.

element-hq · Feb 6, 2025 · d7e39f1 · d7e39f1
1 parent 7560f2c
commit d7e39f1
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/ElementX/Sources/Screens/FilePreviewScreen/View/TimelineMediaPreviewController.swift b/ElementX/Sources/Screens/FilePreviewScreen/View/TimelineMediaPreviewController.swift
@@ -25,6 +25,7 @@ class TimelineMediaPreviewController: QLPreviewController {
 
     private var navigationBar: UINavigationBar? { view.subviews.first?.subviews.first { $0 is UINavigationBar } as? UINavigationBar }
     private var toolbar: UIToolbar? { view.subviews.first?.subviews.last { $0 is UIToolbar } as? UIToolbar }
+    private var pageScrollView: UIScrollView? { view.subviews.first?.subviews.first?.subviews.first?.subviews.first?.subviews.first?.subviews.first as? UIScrollView }
     private var captionView: UIView { captionHostingController.view }
 
     override var overrideUserInterfaceStyle: UIUserInterfaceStyle {
@@ -184,6 +185,13 @@ class TimelineMediaPreviewController: QLPreviewController {
 
     private func handleFileLoaded(itemID: TimelineItemIdentifier.EventOrTransactionID) {
         guard (currentPreviewItem as? TimelineMediaPreviewItem.Media)?.id == itemID else { return }
+
+        // There's a bug where refreshCurrentPreviewItem completely breaks the QLPreviewController
+        // if it's called whilst swiping between items. So don't let that happen.
+        if let scrollView = pageScrollView, scrollView.isDragging || scrollView.isDecelerating {
+            return
+        }
+
         refreshCurrentPreviewItem()
     }