Twenty Fourteen: swipe touch events on slider have a slight delay

[sonjanyc]

Slight delay on swipe touch events, like on an iPad or iPhone.

To repeat

1. Swipe with your finger between slides
2. Note how the swipe event starts with delay and sometimes overlays a half or less, then stops for a second and then completes to show full next slide.

See example video: ​http://wpthemetestdata.files.wordpress.com/2013/12/2014-slider-mobile-behavior.mov

[lancewillett]

@Frank Klein is looking at this one.

[lancewillett]

Severity is low on this, nice to fix but not a blocker for 3.8 release.

[bassgang]

For the 1. case (swiping) I am not sure,
but probably "FastClick" ​https://github.com/ftlabs/fastclick could help to solve case 2. and 3. (seems like a normal "click").

[lancewillett]

I think cases 2 and 3 are fine -- it's 1 we need to patch.

[kwight]

This has been an issue I've noticed with FlexSlider since (I believe) the original pre-WooThemes FlexSlider (v1).

[lancewillett]

@kwight Interesting ... good to know. I'll ping the authors to see if they have an opinion. Did you see any open issues in GitHub related to it?

[kwight]

No I didn't see anything related, but FlexSlider gets very little love on GitHub (470+ open issues).

[iandstewart]

I can't reproduce 2 and 3 on an iPhone 5s using iOS 7.0.4 but do notice a slight delay with swiping in number 1.

[iandstewart]

I can reproduce issue 1 on an iPad where the same delay seen on the iPhone becomes more noticeable.

[rachelbaker]

I looked into the mobile swiping issue on iOS with the Featured Content Slider but wasn't able to completely remove the delay. I did notice that the delay time reduces as you continue swiping through the individual slides.

Also found a related issue, with swiping backward on iOS:

1. Swipe from the first slide to the last slide.
2. You will see a flash of all the slides before settling on the last slide.
3. Now swipe backward again.
4. You will notice the same flash of all the slides before settling on the second to last slide.
5. Swipe backward again.
6. You will experience the expected behavior of just viewing the previous slide, without the flash of all images.

[lancewillett]

Replying to rachelbaker:

I looked into the mobile swiping issue on iOS with the Featured Content Slider but wasn't able to completely remove the delay. I did notice that the delay time reduces as you continue swiping through the individual slides.

After more testing and debugging, I think is isn't something we can "fix" because the swipe event is so dependent on the actual movement of the finger. So you start to move it, and it'll jerk over because you're dragging it. :)

I think we'll need to wontfix it.

Also found a related issue, with swiping backward on iOS:

Thanks for finding that. I'll look.

[lancewillett]

In 26665:

Twenty Fourteen: fix two usability issues with touch events on mobile devices with the Featured Content slider:

• Try to avoid the slight delay when swiping from one slide to the next.
• Fix bug where second to last slide was animating like it was the last.

Fixes #26191.

[lancewillett]

In 26666:

Twenty Fourteen: remove unused variable in slider.js, see #26191.