Collapse should use touchstart event on touch devices

[romancieslik]

When collapsing the navbar-collapse, it takes around 1 second for the menu to respond to the event. Changing the event from

click.bs.collapse.data-api

to

touchstart.bs.collapse.data-api

solved this for us. The menu reacts almost instantly then.

Do you plan to make this event configurable?

[cvrebert]

When collapsing the navbar-collapse, it takes around 1 second for the menu to respond to the event.

On what browser & OS?

If this is on a touch device, have you checked whether :hover styles might be the culprit for the delay?

[romancieslik]

It is on Chrome (iOS and Android) and Mobile Safari.
The :hover styles do not have any effect on this.

[cvrebert]

Hmm, and it isn't the supposedly-fixed-in-Android-Chrome-32 300ms click delay related to double-tap-to-zoom support?

[romancieslik]

Nope, as it is the same issue in Safari and Chrome on iOS

[cvrebert]

@romancieslik AFAIK, that doesn't have any bearing on my previous question.
(Also, you're aware that Chrome on iOS is basically the same as Safari as far as the rendering & JS engines go, right?)

[romancieslik]

Oops, to answer your question: The issue persist on Android’s latest Chrome.
(Yep, I'm aware there’s no real Chrome on iOS.)

[zlatanvasovic]

touchstart.bs.collapse.data-api will slow down the response on the desktop.

We have to test the touch support first, then change it.

[romancieslik]

Great. Looking forward to your investigation results.

[zlatanvasovic]

There isn't the right way for the touch support detection. We can implement the current one that Modernizr have.

We have to do:

// some way to check touch support
// ...

if (touchsupport) {
  event = touchstart.bs.collapse.data-api
}
else {
  event = click.bs.collapse.data-api
}

I don't have any other ideas.

[romancieslik]

Sounds like a workaround, but good enough for our purposes.

[hnrch02]

I can't reproduce on getbootstrap.com using iOS 7.1.2's Safari. Tried it using this JS Bin which uses the touchstart event instead of the click event and it is indeed faster.

@mdo @fat Should we do something about this? Maybe punt to v4?

[fat]

Yeah touch start is definitely faster.

I'd like to rethink a lot of our components for mobile in v4. This would be a good candidate for that imho

[mdo]

Punting to v4.