Allow toggling with a swipe gesture, fixes #49

[lolmaus]

Implemented toggling with a swipe gesture. Fixes #49.

Notes:

1. I used ember-gestures for finger gestures support.
2. I used simple panning instead of actual handle dragging because the logic behind dragging would be way more complicated. You can have an idea from this prototype. The gotcha is that with panning toggling happens immediately and not after mouse/finger release.
3. ember-gestures needs an update of ember-hammertime to support Ember 2.15+. PR pending. This PR currently uses a feature branch of ember-gestures. You can try it out locally, but don't merge this yet.
4. Animation direction of the skewed styles inverted for consistency with all other styles. This makes a difference because swiping is directional.
5. Fixed a bug with skewed active state: on Chrome Desktop with mouse clicking it didn't work, on Chrome Android with finger tapping/swiping the toggle stayed active (and misaligned) indefinitely, until user tapped elsewhere.

[lolmaus]

Something weird in Travis. Can you please try clearing all caches and restarting the build?

[knownasilya]

Cleared and restarted

[knownasilya]

Looks like we need to update the version of node for travis, probably to 6.x. See if changing that fixes this issue.

[eriktrom]

fyi - blocked by html-next/ember-gestures#102 fyi

[lolmaus]

@vvainio has brought my attention to the fact that my initial implementation does not support mouse gestures, only touch. This was probably due to the fact that ember-gestures has a minimum stroke length for the swipe gesture which is rarely achieved with a mouse.

I've changed swipe to pan, so now both mouse and finger gestures behave consistently.

This revealed a gotcha: when you pan with a mouse and release the mouse button over the toggle, a click even is produced on the <label> element, which immediately undoes toggling. I came up with a witty workaround which resolves the problem without interfering with a11y.

@knownasilya I've bumped Node and it didn't help. Lets wait for html-next/ember-gestures#102 to finalize, it may resolve the issue.

[webark]

@lolmaus I'm currently using this in a project without jquery. Is there anyway we could handle this without having to use it?

[lolmaus]

@webark Granted.

[webark]

🙏

[eriktrom]

ember-gestures fixed upstream, released as 0.4.7, fyi

[lolmaus]

@eriktrom Thank you. 🙇 PR updated.

[knownasilya]

Just some small changes, then we should be able to merge 👍

[knownasilya]

Could you make this a multi line if with { .. }.

[knownasilya]

Missing semicolon

[lolmaus]

@knownasilya I've addressed your comments and squashed.

[knownasilya]

Published as 5.1.0

[lolmaus]

@knownasilya Thank you, comrade.