PDF viewer: a single tap while reading exits the document to a full-screen single-page view

[IoSonoPiero]

⚠️ Before posting ⚠️

• This is a bug, not a question or an enhancement.
• I've searched for similar issues and didn't find a duplicate.
• I've written a clear and descriptive title for this issue.
• I agree to follow Nextcloud's Code of Conduct.

Steps to reproduce

1. Open a multi-page PDF from the Files list (native in-app viewer, not "open with" / browser).
2. Scroll down a few pages.
3. While reading, tap once anywhere on the page (no drag).
4. The app opens a separate full-screen view showing only that single page.
5. Press back → you return to the document but the reading/scroll position is lost (back near the top).

Expected behaviour

A single tap on the page while reading should not leave the scrollable document, and the reading position must be preserved. Accidental taps are very frequent when reading a long PDF one-handed.

Actual behaviour

PreviewPdfAdapter registers an OnClickListener on the whole page view. Any click on a page calls PreviewPdfViewModel.onClickPage(), which writes the page bitmap to a temp file and launches PreviewBitmapActivity — a separate full-screen activity showing only the tapped page, outside the scrollable RecyclerView. Coming back from it drops the reading position.

Source (current master)

• app/src/main/java/com/owncloud/android/ui/preview/pdf/PreviewPdfAdapter.kt L33-35 — binding.root.setOnClickListener { onClickListener(bitmap) }: whole-page click target, no gesture discrimination.
• app/src/main/java/com/owncloud/android/ui/preview/pdf/PreviewPdfFragment.kt L79-92 — click → viewModel.onClickPage(page) → observer on previewImagePath starts PreviewBitmapActivity.
• app/src/main/java/com/owncloud/android/ui/preview/pdf/PreviewPdfViewModel.kt L55-61 — onClickPage() saves the bitmap to cache and sets _previewImagePath.

Android version

16

Device brand and model

Xiaomi Poco X7 Pro 5G

Stock or custom OS?

Stock (Xiaomi HyperOS)

Nextcloud android app version

34.1.1

Nextcloud server version

34.0.3

Using a reverse proxy?

Yes (Traefik) — not relevant, PDF rendering is fully client-side.

Additional information

The full-screen single-page view appears intended as a "tap to zoom" feature, but bound to a plain click on the entire page it fires on every accidental tap during reading. Possible directions: require a double-tap for the zoom view, shrink the tap target, or at least preserve/restore the RecyclerView scroll position when returning from PreviewBitmapActivity.