iOS Accessibility Value Out of Sync
Description
On iOS it seems that after an accessibility action is triggered the value of accessibility value is read an arbitrary amount of time later. This can lead to VoiceOver reading the previous value again rather than the new value.
This means that sometimes the value will be read correctly, depending on how quickly react native renders the updated accessibility action.
However in my moderately complex RN project I was unable to reliably get everything rendering quickly enough. Even when Flipper said the component in question was rendering in a few ms the bug would still sometimes occur (about 1 in 20 actions).
Note: On Android, TalkBack waits any length of time before reading the updated value. Even an artificial of delay of 500ms will still be read correctly.
Version
0.68.5
Output of npx react-native info
System: OS: macOS 12.6 CPU: (16) x64 Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz Memory: 37.62 MB / 32.00 GB Shell: 5.8.1 - /bin/zsh Binaries: Node: 18.12.1 - ~/.nvm/versions/node/v18.12.1/bin/node Yarn: 1.22.10 - /usr/local/bin/yarn npm: 8.19.2 - ~/.nvm/versions/node/v18.12.1/bin/npm Watchman: 2022.06.06.00 - /usr/local/bin/watchman Managers: CocoaPods: 1.11.3 - /usr/local/bin/pod SDKs: iOS SDK: Platforms: DriverKit 22.2, iOS 16.2, macOS 13.1, tvOS 16.1, watchOS 9.1 Android SDK: API Levels: 30, 31 Build Tools: 30.0.2, 31.0.0, 33.0.1 System Images: android-24 | Google APIs Intel x86 Atom, android-30 | Google APIs Intel x86 Atom, android-30 | Google Play Intel x86 Atom, android-31 | Google APIs Intel x86 Atom_64, android-31 | Google Play Intel x86 Atom_64 Android NDK: Not Found IDEs: Android Studio: 2021.3 AI-213.7172.25.2113.9123335 Xcode: 14.2/14C18 - /usr/bin/xcodebuild Languages: Java: 18.0.1 - /usr/bin/javac npmPackages: @react-native-community/cli: Not Found react: 17.0.2 => 17.0.2 react-native: 0.68.5 => 0.68.5 react-native-macos: Not Found npmGlobalPackages: react-native: Not Found
Steps to reproduce
Accessible components with the following properties:
-
accessibleRole="adjustable" -
accessibilityActionsfor increment and decrement -
accessibilityValuewith text property set
In an app where the component is not guaranteed to render quickly enough.
Running with VoiceOver on iOS (Reading speed didn't seem to change the issue)
Snack, code example, screenshot, or link to a repository
https://snack.expo.dev/@scarlin/ios-accessibility-value-bug-demo
This issue is still happening on iOS with React Native version 0.71.7
Also noticed it occurring on a switch component, where the announced checked state after toggling a component is incorrect.
This issue is still happening with v0.72.6
This issue is still happening with v0.73.2.
A change in a checked value using accessibilityState does not help and previous value is being read. On an older android device it works perfectly so could be a race-condition error or iOS error.
I'm seeing similar behavior in accessibilityRole="adjustable" components. When updating the accessibilityValue's now property from eg. 1 to 2, iOS VoiceOver incorrectly announces the new state as "one".
Similarly, when modifying the checked property in components' accessibilityState, iOS VoiceOver incorrectly announces the previous value (eg. when checked is changed from false to true, VoiceOver announces "unchecked").
I'm seeing this behavior with both custom checkbox components as well as with React Native's Switch component.
I'm currently running RN v0.73.6 (Expo SDK 50)