Server render the table of contents in a collapsed state when the total
number of headings is equal or greater than the value of
`$wgVectorTableOfContentsCollapseAtCount`. Otherwise, the table of
contents will be server rendered in its "expanded" state.
In addition:
* Revise table of contents tests to call one `assertion` per element so
that it is easier to see the exact element that may fail an assertion.
* Revise table of contents tests to call a mount function that can merge
props to allow for a more flexible set of tests.
* Revise table of contents tests by wrapping a `describe` around tests
that expect the same prop state.
* Adds typedef for table of sections props
Bug: T300973
Depends-On: Ifaee451e1903f2accd0ada2f2ed6dfa3f83037b6
Change-Id: I382200bc603b6abf757a91f14a8a55a6581969bd
Collapses sub-sections in the new table of contents by default
(except for non-js and reduced-motion users) and expands the
sections when the top-level section link has been clicked.
Refactors the `activateSection` TableOfContents methods into separate
`activateSection` and `deactivateSection` functions.
Adds `expandSection` and `collapseSection` methods.
Adds triangle icon as a visual expand/collapsed indicator
next to all ToC section headings and are hidden via CSS based on
whether or not the section contains subsections.
Adds test for tableOfContents.
Bug: T299361
Change-Id: I36b3ae7f9f633877683bc17a9444c970d7fa7293
We want the link that the user has clicked inside the TOC to be "active"
(e.g. bolded) regardless of whether the browser's scroll position
corresponds to that section. Therefore, we need to temporarily ignore
section observer until the browser has finished scrolling to the section
(if needed).
However, because the scroll event happens asyncronously after the user
clicks on a link and may not even happen at all (e.g. the user has
scrolled all the way to the bottom and clicks a section that is already
in the viewport), determining when we should resume section observer is
a bit tricky.
Because a scroll event may not even be triggered after clicking the
link, we instead allow the browser to perform a maximum number of
repaints before resuming sectionObserver. Per T297614#7687656, Firefox
wasn't consistently activating the table of contents section that the
user clicked even after waiting 2 frames. After further investigation,
it sometimes waits up to 3 frames before painting the new scroll
position so we have that as the limit.
Bug: T297614
Change-Id: If3632529f58c15348a7200258f4f5999ea0dadc4
