Unable to resize editor on mobile

[Marek Lewandowski]

Resize handler does not work on mobile browsers. Tested both on Android and iOS.

[Marek Lewandowski]

Related issue in Drupal tracker: ​#2716747.

[Tade0]

Added touch support for resizing.

Also did some major refactoring since the resize plugin in its current form does not pass style checks.

Changes pushed to ​branch:t/14619.

[Tomasz Jakut]

Although the resizing is now working, it's almost impossible to touch exactly on the drag handler. Only after maximal zooming in I was able to put my finger on it and resize the editor. It's like 1/30 tries were successful.

I'm also not sure if we shouldn't add ​`touch-action` to handler's CSS. Without this property starting a touch on handler when the page is zoomed in could cause a page scroll.

The browser is also complaining about actual performance of our current solution. I got ~12 errors like that:

Handling of 'touchmove' input event was delayed for 110 ms due to main thread being busy. Consider marking event handler as 'passive' to make the page more responive.

Probably it could be nice if we can address these issues in some way (throttling resize on our side?).

I'm not sure what to do with the current solution. It's working, but the problem now is how it's working. For me it's unusable in terms of UX. To be honest, for the first 15 minutes of dealing with it I was pretty sure that it still didn't work – the handler is so hard to tap. I think we should think how to improve the UX before saying that resizing is possible on mobile devices.

From other news: I've fixed tags for manual test and rebased branch to major.

[Marek Lewandowski]

I agree that there's no point in adding a fix if it's not usable in real cases.

How much work would it require to implement it correctly?

[Tade0]

It depends on the solution.

I think a vertical pinch-out would be great here(shouldn't be hard to implement), but its major disadvantage is that it's not obvious, since there's already an action connected with a similar gesture.

[Tade0]

Enlarging the resizer didn't help much, so I'll have to find another way to solve this problem.

[Marek Lewandowski]

Droping from the milestone, we'll reconsider this issue if it's truly required by the community.