This is missing OnOffSwitchLabelsIndex now.

Oh, I was working on the Flutter 2.10 engine codebase and I didn't notice the addition. I'll fix it.

something that iterates over the values in flutter::AccessibliityFeatureFlag

Unfortunately I couldn't find any non-hacky way to iterate over an enum or enum class in C++. Do you have any idea?

Hmm. I guess there are weird ways using template metaprogramming but that's ok.

Maybe we could just add something like kFlutterAccessibilityFeatureLast, and have a static_assert(flutter::AccessibilityFeatureFlag::kLast == kFlutterAccessibilityFeatureLast)?

(with some kind of comment to keep that value last of course)

add something like kFlutterAccessibilityFeatureLast

This doesn't seem to be possible because

and if we set explicit values to kFlutterAccessibilityFeatureLast and AccessibilityFeatureFlag::kLast, then the comparison of the values will be pointless.

By the way I just noticed that there are other enum types (SemanticsAction and SemanticsFlags) which have a similar characteristic to AccessibilityFeature. Should I update them as well or am I still missing something? (If you think broader changes should be made that are not covered by this PR, please don't mind to close this PR and open new one with your changes.)

You are of course right.

Updating the other enum types is fine.

@chinmaygarde or @cbracken may have some good idea for some way we could analyze this statically. But I'm starting to suspect it'll be beyond the scope of this PR.

I've got a work-in-progress patch that adds a test for this.

If you'd like to add one more, turns out we're also missing the IsMultiline semantics flag. This would go just after kFlutterSemanticsFlagHasImplicitScrolling and just before kFlutterSemanticsFlagIsReadOnly, around line 212 of embedder.h.

  /// Whether the value of the semantics node is coming from a multi-line text  
  /// field.                                                                        
  ///                                                                               
  /// This is used for text fields to distinguish single-line text fields from  
  /// multi-line ones.                                                              
  kFlutterSemanticsFlagIsMultiline = 1 << 19, 

@cbracken I also noticed it but thought it had been excluded intentionally because the comments said:

But I'll add it anyway. Thanks for the catch!

Looks like that field was addded for Flutter web. While it's apparently not used for non-web platforms, I'm surprised it's commented out in the internal enum + the Android enum.

Looks like it was added in #9850. Perhaps @mdebbar and @yjbanov can provide some context. If we know it'll be unused on non-web platforms, perhaps we should avoid exposing it here and I can adapt the test with an exceptions list.

The specific question is whether this is an enum value that we should explicitly avoid exposing in our enums. There are several other enum values that are used on some platforms but not others, but that we add to all enums for consistency. If there's no reason for treating IsMultiline differently, we should probably make it available everywhere.

Adding kIsMultiline to the native embedder SGTM. It's already part of the dart:ui public API, so it has to be stable.

LGTM. #32408 will add a test for this.