Pixel shows 15 regressions, these are expected changes that are
fixing issues on specific viewports that fixes the following:
[At exactly the tablet breakpoint]
* the more menu dropdown was being
shown at the same time as the other menu items, resulting in duplicates
(see https://phabricator.wikimedia.org/F35285379)
[At exactly the desktop breakpoint]
* The table of contents AND the
table of contents toggle button to the left of the title were showing
(see https://phabricator.wikimedia.org/F35285392)
* The sticky header was not showing
* The fly out table of contents was showing instead of the sidebar
table of contents on scroll
* The top of the sidebar is brought into alignment with the tabs
(see https://phabricator.wikimedia.org/F35285408)
Bug: T310536
Change-Id: I6e870a032c8ba4ec003d00ff3f91732aaa2f38b0
Previously, we relied on setting pointer-events:none on all child
elements of ToC links.
This propagated the click event up to the link itself in Javascript
and allowed us check if an element with the class `.sidebar-toc-link`
was clicked.
Unfortunately as of Chromium 101 this approach causes the entire link
in the sidebar to be unclickable.
Instead, this patch checks if the ToC link or any of it's children
have been clicked (using the less efficient `Element.closest()` ).
Bug: T307271
Change-Id: I2264b7862f6e1ef50c5c722daee81acc39eea54e
- If TOC A/B test is enabled, page is in treatment group, and
viewport is below tablet, force legacy TOC to render.
- If TOC A/B test is disabled and new TOC feature is enabled,
and viewport is below tablet, neither TOC should render.
Bug: T300975
Change-Id: Ib30c3473eb47d6ac60924f40ccd0e42d29625407
Can only be merged after I8c0924f6de28b15602969de873a843b4cd69548b
has been in production for 3 days
Bug: T300875
Change-Id: I924a69b37214a34f989f49f0425c701650928e17
This uses the sticky header's `.mw-sticky-header-element` utility class
to conditionally offset the table of contents to the height of the
sticky header only when the sticky header is enabled.
Bug: T300077
Change-Id: Ibad97a11e708ba19acf27ca82320f7c3e5f80447
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
This commits sets up the Table of Contents to bold the active section
when the section is scrolled.
Unfortunately, because our content does not have actual sections but
instead has a flat list of headings and paragraphs, we can't use
IntersectionObserver in the conventional way as it is optimized to find
intersections of elements that are *within* the viewport and the
callback will not reliably fire during certain scenarios (e.g. with fast
scrolling or when the headings are not currently within the viewport).
Furthermore, iterating through a list of elements and calling
`getBoundingClientRect()` can be expensive and can also cause
significant forced synchronous layouts that block the main thread.
The best compromise in terms of performance and function that I've found
is to use a combination of a throttled scroll event listener and
IntersectionObserver's ability to asyncronously find the
boundingClientRect of all elements off the main thread when `.observe`
is called which is the approach this patch takes. Although this is an
unorthodox way to use IntersectionObserver, performance profiles
recorded while holding the "down" arrow and scrolling for 10 seconds
with a 6x CPU throttle are comparable between master and this patch:
master: https://phabricator.wikimedia.org/F34930737
this patch: https://phabricator.wikimedia.org/F34930738
Bug: T297614
Change-Id: I4077d86a1786cc1f4a7d85b20b7cf402960940e7
