Vertical-rl books paged along the vertical scroll axis: page turns slid
up/down and only vertical swipes turned pages. Vertical books read with
right-to-left page progression, so page turns now work horizontally,
matching printed vertical books:
- Swipes track the finger: the page follows a horizontal drag and the
release commits the turn (past half a page width or a flick in the
drag direction) or settles the page back.
- Arrow keys, tap zones, and the wheel follow the same rtl mapping that
horizontal-rtl books use.
- Animated turns run a two-phase horizontal slide that continues from
the dragged offset: the outgoing page exits along the page
progression, the scroll jumps while off-screen, and the incoming page
follows in from the opposite edge. A single-phase push is impossible
because CSS multicol stacks vertical-rl pages along the vertical
scroll axis inside one iframe, so the outgoing and incoming page can
never be on screen side by side.
- With animation disabled (or e-ink), turns swap instantly as before.
The paginator changes live in the foliate-js submodule; this bumps the
pointer and adds browser tests with a vertical-rl EPUB fixture covering
direction detection, drag tracking, drag revert, horizontal swipe
mapping in both directions, the legacy vertical swipe, the horizontal
slide animation, the instant non-animated swap, and the unchanged
horizontal-ltr swipe behavior.
Fixes#624
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
Huang Xin