[iOS] PDF pages with transparent backgrounds render with a black background

[salvadortumoni]

On iOS, PDF pages that have a transparent background are incorrectly rendered with a solid black background. This appears to be caused by the native PdfView creating an opaque graphics context, whose default black color shows through the PDF's transparent areas.

This issue only occurs on iOS and only for specific PDF documents that utilize transparency. The same document renders correctly on Android.

To Reproduce

1. Use the <PdfView /> component in a React Native application on an iOS device or simulator.
2. Display a PDF document that contains a page with a transparent background.

[alpha0010]

Could you attach a sample PDF I can test with?

[salvadortumoni]

@alpha0010 Sure, here it is.

Here's how it looks on iOS:

And this is how it looks on Android, same pdf:

[alpha0010]

Sorry it took so long to respond. I am uncertain what is going on here, since that should already be handled https://github.com/alpha0010/react-native-pdf-viewer/blob/master/ios/PdfView.swift#L177-L179 . If you are still experiencing this issue, could you post a more complete code snippet, in case something else is causing this interaction?

This is how it looks for me on iOS: