onTap property
Called when the user taps the content and Readium handled nothing internally — no hyperlink, no footnote, no interactive element.
That filter is WebView-only. PDF and CBZ have no equivalent, so a tap on a PDF link annotation both follows the link and fires this callback.
Does not fire where the native edge-tap overlay claims the touch: the
left and right edge strips, edgeTapAreaPoints wide. Both platforms
claim them only while enableEdgeTapNavigation is on and the reader is
paginated. docs/api-reference/reader-widget.md has the whole rule.
The position is in logical pixels, relative to the top-left of the platform view.
Implementation
final void Function(Offset position)? onTap;