tipsy was "deprecated" years ago, with no suitable substitute.
current doc recommends using "oojs", but i could not locate any oojs functionality pertaining to tooltips, IOW, no oojs class/object/api which can replace tipsy.
at the very least, i suggest removing this null recommendation from the doc.
if i missed something, and there _si_ some oojs things which can replace tipsy, please provide more precise link in the doc (and in any answer to this post).
thanks, peace -
sorry, but popup is not adequate, or even inadequate, replacement for tipsy.
the main functionality of tipsy is handling the "hover" feature, i.e., responding to "mouseenter/mouseleave" events (with some timers intermingled), handling the display/hide of the tooltip based on mouse pointer location.
popup does not provide any support there, and in order to implement tooltip functionality, the programmer has to reimplement 80% of tipsy code herself, capturing the events and controlling the visibility of the popup.
IOW, popup can't be considered replacement for tipsy.
if i missed some key functionality of popup, and it can actually do some of what tipsy does, i will be very grateful to learn.
peace.
I wouldn't say that implementing said logic is hard, but on the other hand I don't know what your specific requirements are. Here you can find a desktop-oriented gadget that registers hover events for an OOjs-ui tooltip.
Anything relying on hover is fundamentally incompatible with mobile users, who are the majority of readers and a growing portion of editors (albeit still the smaller part). I don't expect there will be a hover-based functionality shipped. Please stop using them.
unfortunately, mobile does not support hover.
that said, wikimedia projects do support "desktop only" features, some of which depend on "hover", e.g. "page preview" and "cite preview" features.
there are other desktop only features, including most project-specific gadgets, and having better tooltip tool is important.
i don't love tipsy, and would like to have a good ooui tool to replace it, so i don't have to re-implement it in each script or gadget that uses tipsy today.
peace
We use Tipsy to provide mobile users with tooltips that are otherwise hidden to them. Instead of displaying a tooltip on hover, the tooltip is displayed when the user touches or taps the text that should display the tooltip.
For example, we have some tooltips created with this code:
<span class="explain" title="This is a tooltip">Text</span>
Desktop already displays a tooltip on hover. On mobile, users can tap the text to display the tooltip thanks to Tipsy. Text marked with class="explain" gets a dotted underline to give users a hint that there's some tooltip there.
The deprecation means it may be removed from MediaWiki core in the future. But I don't mind, because we've gadgetized the tipsy code as to not depend on this core feature. Of course, on a non-WMF wiki :)