eloo.haop.hr - The page slightly scrolls while zooming over the map area

[webcompat-bot]

URL: https://eloo.haop.hr/public/otpad/pregled

Browser / Version: Firefox Mobile 77.0
Operating System: Android
Tested Another Browser: Yes Chrome

Problem type: Something else
Description: Can't zoom in. Two-finger zoom zooms in the whole page and not just the map. Works perfectly fine in Chrome. In Chrome, pinching with two fingers zooms in only the map, and not the whole page.
Steps to Reproduce:
Go the the mentioned url, and try zooming in with two fingers. In Firefox Preview it zooms in the whole page instead of only the map. In Chrome it only zooms in the map, as it should be.

Browser Configuration

• None

From webcompat.com with ❤️

[cipriansv]

Thanks for the report.

I was indeed able to reproduce the issue. The page slightly scrolls while zooming over the map area.

Tested with:
Browser / Version: Firefox Preview Nightly 200503 (🦎 77.0a1-20200430082621), Chrome Mobile 81.0.4044.117
Operating System: OnePlus6 (Android 10) - 1080 x 2280 pixels (~402 ppi pixel density)

Moving the issue to needsdiagnosis.

[karlcow]

So this is working and not working. it's not a all fail all the time. I wonder if it's a performance issue. this is using pointer events

[denschub]

I was expecting this to be another Leaflet issue, but they somehow wrote their own map library as far as I can tell. We've had similar issues ("scrolling instead of zooming/panning") with Leaflet, and while I was not able to closely follow all the issues to know the cause, I know that all of them have been fixed.

Looking at this site, everything appears to be fine on my Moto g7 (and it's usually really smooth, but the screen recording tanked the performance):

screen-20210527-193756.mp4.mp4

I gave the site a good shakedown, disabled pointer events, force-simulated a mouse, and looked at the CSS for potentially problematic layout pieces and I could not find anything that looked concerning. Given we have not seen another report about this, it's not a high-priority site, and it appears to be working just fine in my tests, let's assume this was related to one of the things we've seen with Leaflet - and close this as worksforme.

[karlcow]

@denschub about scrolling vs zooming, there is #73148 if you have a clue.