Same hack as in https://github.com/twbs/bootstrap/pull/22426 (modulo the selector, which is wrong in that PR and will be updated in a separate PR) to get tooltips to work correctly on iOS. Dynamically adds/removes empty (`noop`) `touchstart` event handlers to all children of `<body>` in order to coax iOS into proper event delegation/bubbling
* Add carousel mouse listeners even if touch events enabled
- touch events are enabled not just on "mobile", just also on
touch-enabled desktop/laptop devices; additionally, it's possible to
pair a mouse with traditionally touch-only devices (e.g. Android
phones/tablets); currently, in these situations the carousel WON'T pause
even when using a mouse
* Restart cycle after touchend
as `mouseenter` is fired as part of the touch compatibility events, the
previous change results in carousels which cycle until the user
tapped/interacted with them. after that they stop cycling (as
`mouseleave` is not sent to the carousel after user scrolled/tapped
away).
this fix resets the cycling after `touchend` - essentially returning
to the previous behavior, where on touch the carousel essentially never
pauses, but now with the previous fix it at least pauses correctly for
mouse users on touch-enabled devices.
includes documentation for this new behavior.
* Replace backdrop with simple noop mouse listener
As discussed in https://github.com/twbs/bootstrap/pull/22422 the current
approach of injecting a backdrop (to work around iOS' broken event
delegation for the `click` event) has annoying consequences on
touch-enabled laptop/desktop devices.
Instead of a backdrop `<div>`, here we simply add extra empty/noop
mouse listeners to the immediate children of `<body>` (and remove
them when the dropdown is closed) in order to force iOS to properly
bubble a `click` resulting from a tap (essentially, method 2 from
https://www.quirksmode.org/blog/archives/2014/02/mouse_event_bub.html)
This is sufficient (except in rare cases where the user does manage to tap
on the body itself, rather than any child elements of body - which is not
very likely in an iOS phone/tablet scenario for most layouts) to get iOS to
get a grip and do the correct event bubbling/delegation, meaning the regular
"click" event will bubble back to the `<body>` when tapping outside of the dropdown,
and the dropdown will close properly (just like it already does, even without
this fix, in non-iOS touchscreen devices/browsers, like Chrome/Android and
Windows on a touch laptop).
This approach, though a bit hacky, has no impact on the DOM structure, and
has no unforeseen side effects on touch-enabled laptops/desktops. And crucially,
it works just fine in iOS.
* Remove dropdown backdrop styles
* Update doc for dropdowns and touch-enabled devices
...as touch is not exclusive to "mobile" anymore nowadays. also explicitly clarifies this is a fix for iOS, and that it impacts touch laptops etc as well. lastly, renames the variable from "dropdown" to "backdrop" for clarity/consistency
* Remove aria-expanded from collapse.js target element
aria-expanded="true"/aria-expanded="false" only applies to the trigger,
not the element that is being expanded/collapsed.
* Tweak collapse.js accessibility section
...to make it clearer that the aria-expanded attribute always just goes
on the control.
* Fix collapse.js unit tests
- reword some of the text to make it clear we're checking behavior of
trigger/control
- move incorrect aria-expanded out of the <div>s and to the actual
trigger/control <a>s
- fix incorrect test assertion text output false -> true
* Only change aria-pressed if it's not an input-based radio or checkbox group
aria-pressed="true"/aria-pressed="false" is really only useful for
making on/off toggles out of, say, `<button>` elements. the attribute is
useless (and potentially confusing/conflicting) on, say, `<label>`
elements for an existing `<input type="radio">` or similar.
* Add unit test for buttons.js and radio/checkbox inputs in button groups
- Create backdrop only if the menu is actually open (do not create it if the show event is prevented)
- Drop the backdrop only when the corresponding menu is closed (do not remove if there is no menu to close or if the hide event is prevented)
* Remove IE compatibility mode meta tag from docs, examples, and JS tests as we no longer support IE9 and IE8
* update and remove some IE bits from our supported browser page
* update introduction.md to match
* reword starter template intro
