Disable swipe gesture on TabBar

[alexstanbury]

I'd like to be able to disable the swipe gesture on the TabBar on Android. My use case is that I have a list of swipeable components in the tab and can't swipe them because the TabBar is receiving the gesture. Can it be done?

[grahammendick]

The TabBar on Android maps to the ViewPager. This widget does support horizontally scrolling content. I know this because I investigated it when I added right-to-left (RTL) language support. Android, instead of adding RTL support to the ViewPager, decided to write a whole new widget called ViewPager2. I was going to move over to ViewPager2 but found out that it doesn’t support horizontally scrolling content. I didn’t want to lose this functionality, so the TabBar maps to the ViewPager for LTR and ViewPager2 for RTL languages.

So you should be able to add a horizontal ScrollView to a tab in the TabBar, for example.

[alexstanbury]

You're right, ScrollView does indeed work ok and intercepts the gesture ahead of the tab bar. I'm actually using PanGestureHandler from react-native-gesture-handler for my swiper and that doesn't seem to be able to override the pager yet.

Looks like it's possible to disable scrolling at the native level, see https://stackoverflow.com/questions/7814017/is-it-possible-to-disable-scrolling-on-a-viewpager

Would you accept a PR that implements it?

[grahammendick]

What happens if you put the PanGestureHandler inside a horizontal ScrollView? Who gets the swipe?

[alexstanbury]

Tried that in various permutations, I can stop the ViewPager from scrolling and get the onStart for the swiper but not the onActive or onEnd events. Going to dig into it and see if there's something else I'm missing. I tested with putting a slider in the tab and that works fine (doesn't trigger the ViewPager to move) so there must be something going on...

[grahammendick]

I meant for you to try it without a TabBar. Just a PanGestureHandler inside a plain old ScrollView. Was wondering who won the swipe war in that case

[alexstanbury]

Fixed it! Dug into my code and found that I had activeOffsetX set to [-50, 50] (this swiper is a in a vertically scrolling long list of items). Setting it to [-10, 10] still allows vertical scroll but most importantly I can now swipe left and right and the ViewPager doesn't get the gesture. So it looks like ViewPager must have a tolerance of somewhere between 10 and 50 before it takes over the pan event.