1. Touch event won't trigger after the first touch, because the drag event is triggered.
Please share your code / test case
2. Is there a demo or example for mobile devices?
All the examples work in touch devices also.
virtualX & virtualY are kept false for swipe support in touch devices, otherwise the virtual scrollbars can be used for scrolling.
Ex:
https://paramquery.com/pro/demos/grid_json3. For touch libraries, there are touch-punch.dev.js and jquery.ui.touch-punch.js. Which js should I use for touch events?
Please use touch-punch.(dev/min).js
4. Can I change the scroll style in mobile device? I want to show it like normal mobile scroll like in other webs. (ex. scroll is very thin and disappears when I don't scroll and appears when I scroll again.)
That is native scrolling. pqgrid uses virtual scrolling with ( virtual scrollbars or swipe support ) and native scrolling is not available.
If you feel strongly about any missed feature in pqgrid, please add in the feature request board.