iOS uses AccessibilityManager
fro that (which is not available for Android)
https://github.com/facebook/react-native/blob/1151c096dab17e5d9a6ac05b61aacecd4305f3db/IntegrationTests/AccessibilityManagerTest.js
Android uses a native solution, https://stackoverflow.com/questions/21546805/how-to-prevent-system-font-size-changing-effects-to-android-application/32832216#32832216
Important info:
React Native 0.59
will come with maxFontSizeMultiplier
prop for Text
and TextInput
. https://facebook.github.io/react-native/docs/next/text#maxfontsizemultiplier
With it, the app will be able to have a cross-platform solution to set font scale capping from JS only
Probably the app will be able to set it globally with this:
Text.defaultProps.maxFontSizeMultiplier = 1.3;
TextInput.defaultProps.maxFontSizeMultiplier = 1.3;