check surface device chrome 70 touch supports

[zhishaofei3]

check surface device chrome 70 touch supports

#5335
https://codepen.io/katwhocodes/post/using-javascript-to-detect-touch-events

[asturur]

#4302 <--- what about this?
We switched from one to the other 1 year ago.

[asturur]

also
maaaaark/bcSwipe#4

[asturur]

https://hacks.mozilla.org/2013/04/detecting-touch-its-the-why-not-the-how/

[tatsuyafw]

@zhishaofei3

Any updates for this PR?
I've also faced the same problem when using a touch monitor.
（Ref: 898045 - Free drawing using a touch monitor shows nothing with fabric.js. - chromium - Monorail）

[JSteunou]

I @asturur been a while :) We are also facing the same problem. Any chance to see this fix published?

[JSteunou]

I think previous fix #4302 was to aggressive. Chrome 70 comes with better touch support, so we need more fine grain now. This PR should be rewrite against source file, but the idea is good.

[asturur]

is just unclear to me if this is fixing because:

"ontouchstart" in fabric.document.documentElement

OR because the new condition is:

navigator.maxTouchPoints > 0

The original authour never answered.

[JSteunou]

I will search about this monday. Ping me if I forget 😉

[asturur]

i ll undust my surface to see if i can also figure out

[JSteunou]

👍

If someday this bug appears again, this can be a good resource https://patrickhlauke.github.io/touch/touchscreen-detection/