Hi @justinmc, I assigned you as a reviewer as you took part in the issue discussion.

Could you please take a look at this PR when you have time?

I know why the Google testing is failing - I can fix it. I had to make a similar change in #176063 in the JNI (will need to rebase it if that one lands first).

I know why the Google testing is failing - I can fix it. I had to make a similar change in #176063 in the JNI (will need to rebase it if that one lands first).

Thanks a lot for taking a look at the Google Testing failure!
I will do a rebase after your PR is merged.

@mboetger, could you please take a look at why Google Testing failed?

@mboetger, could you please take a look at why Google Testing failed?

Working on it.

Hi @justinmc, thanks a lot for your review!

Is there any reason to think that we couldn't reuse the same mechanism to pass this value from iOS as well some day? Seems like it should work to me but want to make sure.

As was discussed in #97349, the iOS API for getting display corner radii is private. The only safe way to get the radii values is to generate a lookup table ahead and use its values at runtime. I would be happy to work on the iOS implementation in a separate PR after this lands.

A major edge case: What about a foldable phone that the user unfolds? Does that change the radius values?

I don't have a physical foldable device, but I tried to run a demo on the Pixel 9 Pro Fold emulator, and the display corner radius values are updated according to the fold status.

import 'package:flutter/material.dart';

void main() {
  runApp(const App());
}

class App extends StatelessWidget {
  const App({super.key});

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Screen(),
    );
  }
}

class Screen extends StatefulWidget {
  const Screen({super.key});

  @override
  State<Screen> createState() => _ScreenState();
}

class _ScreenState extends State<Screen> with SingleTickerProviderStateMixin {
  @override
  Widget build(BuildContext context) {
    print('dpr: ${MediaQuery.devicePixelRatioOf(context)}');

    return Scaffold(
      body: Padding(
        padding: const EdgeInsets.all(20),
        child: Center(
          child: DisplayCornerRadiiReactor(),
        ),
      ),
    );
  }
}

class DisplayCornerRadiiReactor extends StatefulWidget {
  const DisplayCornerRadiiReactor({super.key});

  @override
  State<DisplayCornerRadiiReactor> createState() =>
      _DisplayCornerRadiiReactorState();
}

class _DisplayCornerRadiiReactorState extends State<DisplayCornerRadiiReactor> {
  @override
  Widget build(BuildContext context) {
    return Column(
      mainAxisSize: MainAxisSize.min,
      spacing: 20,
      children: [
        Text(
          'displayCornerRadii: ${View.of(context).displayCornerRadii}',
          textAlign: TextAlign.center,
          style: TextStyle(fontSize: 20),
        ),
        Text(
          'displayCornerRadii: ${MediaQuery.displayCornerRadiiOf(context)}',
          textAlign: TextAlign.center,
          style: TextStyle(fontSize: 20),
        ),
      ],
    );
  }
}

@justinmc thanks for your review!
We already have a LGTM from @mdebbar #179219 (review)
Or you would like to get another look from the web team?

Ah I missed that, sorry 😅 .

I reran one test that appeared to be a flake, otherwise this is ready to land.

Thanks a lot, everyone, for your reviews and feedback!