Android: Scroll View Stretch Effect Inconsistency

Description

Tested on Android Pixel 9.

I am trying to understand an issue. I found some threads. #35424 and #47021. When I use a ScrollView with overScrollMode="always" and the content is smaller than the ScrollView the stretch effect does not show when I drag on a child view.. It works fine when I use a horizontal scroll.

I looked into Androids ScrollView code. It has a return in onInterceptTouchEvent:

// Don't try to intercept touch if we can't scroll anyway.
if (getScrollY() == 0 && !canScrollVertically(1)) {
    return false;
}

Is this a correct fix?

@Override
boolean canScrollVertically(int direction) {
    return super.canScrollVertically(direction)
    || (direction > 0. MScrollEnabled && getOverScrollMode() == OVER_SCROLL_ALWAYS);
}

If I set ALWAYS the view can give feedback. So reporting it as scrollable will fix the issue... Accessibility and nested-scroll parents will also see the view, as scrollable in that mode.

Steps to reproduce

Create a ScrollView with some text children:

<ScrollView style={{ height: 150 }} overScrollMode="always">
    <Text style={{ padding: 8 }}>Row one</Text>
    <Text style={{ padding: 8 }}>Row two</Text>
</ScrollView>

The difference:

• If I set the scroll to horizontal there is a visible Stretch effect no matter where I drag from.
• If I set it to vertical it does not work when I tap and drag from the Text.

React Native Version

React-native 0.85.3

Affected Platforms

Runtime - Android

Output of npx @react-native-community/cli info

System:
  OS: macOS 26.5.1
  CPU: (12) arm64 Apple M2 Pro
  Memory: 316.38 MB / 32.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 24.1.0
    path: /Users/davidmalesevic/.nvm/versions/node/v24.1.0/bin/node
  Yarn: Not Found
  npm:
    version: 11.7.0
    path: /Users/davidmalesevic/.nvm/versions/node/v24.1.0/bin/npm
  Watchman: Not Found
Managers:
  CocoaPods:
    version: 1.16.2
    path: /opt/homebrew/bin/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 25.5
      - iOS 26.5
      - macOS 26.5
      - tvOS 26.5
      - visionOS 26.5
      - watchOS 26.5
  Android SDK: Not Found
IDEs:
  Android Studio: 2025.2 AI-252.28238.7.2523.14688667
  Xcode:
    version: 26.6/17F113
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 17.0.18
    path: /opt/homebrew/opt/openjdk@17/bin/javac
  Ruby:
    version: 2.6.10
    path: /usr/bin/ruby
npmPackages:
  "@react-native-community/cli": Not Found
  react:
    installed: 19.2.3
    wanted: 19.2.3
  react-native:
    installed: 0.85.3
    wanted: 0.85.3
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: Not found
  newArchEnabled: Not found
iOS:
  hermesEnabled: Not found
  newArchEnabled: Not found

Stacktrace or Logs

N/A

MANDATORY Reproducer

https://github.com/Alforofous/rn-vertical-stretch-repro

Screenshots and Videos

Bắt đầu bằng cách chạy reproducer bắt buộc và so sánh hành vi của ScrollView dọc và ngang với overScrollMode="always". Đọc logic của onInterceptTouchEvent và canScrollVertically trong Android ScrollView, sau đó lần theo phần tích hợp React Native ScrollView. Được xem là hoàn tất khi thao tác kéo từ một child tạo ra hiệu ứng kéo giãn theo chiều dọc mà không có thay đổi ngoài ý muốn đối với khả năng truy cập hoặc thao tác cuộn lồng nhau.