Support Nullable Primitives or Lint Warning in Typesafe Navigation [351994237]

Fixed

Feature Request

Status Update

No update yet.

Description

ag...@wayfair.com

created issue #1

Jul 9, 2024 01:51PM

Component used: Navigation Version used: 2.8.0-beta03 Devices/Android versions reproduced on:

Simply make a class with a nullable primitive like an Int?

@Serializable data class ExampleRoute(val accountMethod: Int?)

and runtime crash:

java.lang.IllegalArgumentException: integer does not allow nullable values
at androidx.navigation.NavArgument.<init>(NavArgument.kt:210)
at androidx.navigation.NavArgument$Builder.build(NavArgument.kt:199)
at androidx.navigation.NavArgumentBuilder.build(NavDestinationBuilder.kt:394)
at androidx.navigation.NamedNavArgumentKt.navArgument(NamedNavArgument.kt:21)
at androidx.navigation.serialization.RouteSerializerKt.generateNavArguments(RouteSerializer.kt:109)
at androidx.navigation.NavDestinationBuilder.<init>(NavDestinationBuilder.kt:94)
at androidx.navigation.compose.ComposeNavigatorDestinationBuilder.<init>(ComposeNavigatorDestinationBuilder.kt:95)

In the IDE, there is no indication this is wrong, and is perfectly valid in Kotlinx serialization. I understand complex types requiring a barrier, but a nullable primitive seems logical in kotlin. A lint warning or error would be also highly helpful to prevent this from potentially crashing at runtime.

Comments

jb...@google.com <jb...@google.com> Jul 9, 2024 01:51PM

Assigned to cl...@google.com.

ap...@google.com <ap...@google.com> #2Jul 23, 2024 11:28PM

Nested scrolling works partially (as per

http://b/122818889). Let's discuss if we need full support and if so make sure it works.

cl...@google.com <cl...@google.com> Jul 24, 2024 01:06AM

Accepted by cl...@google.com.

ap...@google.com <ap...@google.com> #3Jul 24, 2024 06:47PM

Hi!

What is 'partially' exactly?
How do I see it?
Thanks!

ap...@google.com <ap...@google.com> #4Jul 24, 2024 06:50PM

As of now:
- Nesting scroll views with a scroll direction perpendicular to the ViewPager2's orientation inside ViewPager2 works
- Nesting scroll views with a scroll direction parallel to the ViewPager2's orientation inside ViewPager2 does not work

ap...@google.com <ap...@google.com> #5Jul 24, 2024 06:52PM

Horizontal ViewPager2 not correctly working into a vertical RecyclerView
Set a setNestedScrollingEnabled to the RecyclerView into the ViewPager2 (across reflection) resolves the problem

cl...@google.com <cl...@google.com> #6Jul 24, 2024 07:06PM

Marked as fixed.

ageevvalentin@gmail.com, could you provide a sample app? I'd like to learn more about the circumstances that cause the problem; putting a clean ViewPager2 inside a clean RecyclerView seems to work fine, so there must be other factors involved.

ap...@google.com <ap...@google.com> #7Jul 25, 2024 11:56PM

Added a patch for androidx-master-dev that demos a horizontal ViewPager2 inside a vertical RecyclerView.

Verified that it works correctly on a:
- Nexus 4 emulator with API 17
- Nexus 5X emulator with API 28
- Pixel 2 device with API 29

To reproduce:
- Check out the Android Jetpack source (at commit 256899f482ff85cddfb050f37550be7b5ec927ef) (see steps in [1])
- Apply the patch (`git apply 0001-Add-sample-where-a-horizontal-ViewPager2-is-nested-i.patch`)
- Build and install viewpager2's integration-tests app: `./gradlew viewpager2:integration-tests:testapp:installDebug`
- Run it

Closing the issue for now, but please reopen if you have a minimal reproduction app

[1]

https://android.googlesource.com/platform/frameworks/support/+/256899f482ff85cddfb050f37550be7b5ec927ef

pr...@google.com <pr...@google.com> #8Aug 13, 2024 06:59PM

Re-opening as requested by a few users. Narrowed down the focus to nested scrolling elements with the same scroll direction.