In scrolled mode the header chapter title was wrong while transitioning
between sections, while paginated mode was correct (#4436). foliate-js
#getVisibleRange returned the first overlapping view (topmost in scroll
order), so when the tail of one section was a thin sliver at the top of
the viewport and the next section occupied the centre and most of the
screen, the relocate event reported the sliver's section — and its title
lagged behind what the reader was reading.
Bump foliate-js to prefer the view covering the viewport centre
(readest/foliate-js#37) and add a browser-lane regression test that
scrolls a sliver of section K to the top with K+1 across the centre and
asserts the relocate index is K+1.
Fixes#4436
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The two #4112 scrolled-mode preload browser tests asserted that the
previous-previous section (F-1) was not loaded after navigating to a section,
checking it after `waitForFillComplete()`.
The eager backward buffer (minPages) is suppressed while `#display` is
stabilizing, but pulls F-1 (and beyond) in on the first scroll events once the
fill settles. So the post-fill assertion raced the buffer: it passed locally but
failed intermittently on CI (loaded set [1,2,3,4,5]).
Assert the precondition the instant `#display` stabilizes — where the buffer is
provably suppressed and only the immediate-previous section is loaded — before
the fill settles. The eager buffer loading F-1 later is exactly what the second
test wants once it navigates back. Test-only; production behaviour is unchanged.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Bump foliate-js: compensate the scroll position when a previous section is prepended above the viewport, so the browser's scroll-anchoring suppression at scrollTop 0 no longer drifts the view into chapter n-1; preload the previous section on backward navigation and eagerly while scrolling toward the top; and stop the blank-screen flash on adjacent navigation in continuous scrolled mode.
Split paginator-multiview.browser.test.ts into paginator-scrolled and paginator-paginated, adding regression tests for the drift, previous-section preloading, the eager backward buffer, and the flash-free transition.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Huang Xin