feat: allowFontScaling prop

[hejsztynx]

Summary

Thanks for the feature suggestion in this issue!

Implemented a allowFontScaling prop

• when set to true, the font size will be scaled to satisfy the system's accessibility font size settings (default behaviour)
• when set to false, it works independently of the current settings

Videos

EnrichedTextInput

Screen.Recording.2026-05-27.at.16.18.28.mov

EnrichedText

Screen.Recording.2026-05-27.at.16.20.20.mov

Compatibility

OS	Implemented
iOS	✅
Android	✅

Checklist

• E2E tests are passing
• Required E2E tests have been added (if applicable)

[exploIF]

Works good

[kacperzolkiewski]

Looks and works correct! 🚀

[szydlovsky]

I wouldn't put it here. Only internal flags used in config are instantiated here (see flags that track font recreation above). Since _allowFontScaling is essentially mirroring a prop and only set via updateProps, I think we can entirely drop this statement.

[szydlovsky]

I did some research and we actually shouldn't need the adjustsFontForContentSizeCategory prop. It is used for automatic resizing only if the font was instantiated either via
UIFont.preferredFont(forTextStyle: ..)
or
UIFontMetrics(forTextStyle: ..).scaledFont(for: ..)

We don't use either - instead we are subscribed to traitCollectionDidChange, which in turn calls [config invalidateFonts].

Instead of these calls however, we definitely want to run [config invalidateFonts] here if the allowFontScaling prop was changed - maybe we didn't touch the accessibility scaling but just the prop change alone should cause fonts recalculation.

[szydlovsky]

Instead of reading props we can just access the allowFontScaling from the config.

[szydlovsky]

Same as in input, we probably want to exchange this call with a [config invalidateFonts].

[szydlovsky]

Also, I believe we don't need isFirstMount check here - oldViewProps on first mount will usually be not defined so any first value will always be different than the compared "old" one. Please also check it for the input.

[szydlovsky]

Same as in input, we can just access the allowFontScaling from the config.

[szydlovsky]

One more improvement, we can make the previousTraitCollection an early return too:
(might be formatted wrongly)

Suggested change

	if (!config.allowFontScaling) {
	return;
	}
	if (previousTraitCollection.preferredContentSizeCategory !=
	self.traitCollection.preferredContentSizeCategory) {
	if (!config.allowFontScaling) {
	return;
	}
	if (previousTraitCollection.preferredContentSizeCategory == self.traitCollection.preferredContentSizeCategory) {
	return;
	}