iOS: Key the platform view factory registries by NSString by cbracken · Pull Request #191855 · flutter/flutter

cbracken · 2026-08-27T04:01:23Z

FlutterPlatformViewsController was holding its view factories and their gesture blocking policies in std::unordered_maps keyed by std::string, so both the registration path and the create path converted an NSString to a std::string first. But all the mapped values are Obj-C types so we can migrate to na NSMutableDictionary. This matches how we do it in the macOS embedder.

This removes the last of the UTF8String conversions in this file. As noted in #191853 and #191854 std::string's const char* constructor determines the length using strlen, so it truncates at an embedded NUL and dereferences null if UTF8String ever returns NULL, which it does for a nil receiver.

Spotted while working on: #191616

No new tests since this just changes the implementation without changing any semantics.

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`FlutterPlatformViewsController` was holding its view factories and their gesture blocking policies in `std::unordered_map`s keyed by `std::string`, so both the registration path and the create path converted an `NSString` to a `std::string` first. But all the mapped values are Obj-C types so we can migrate to na `NSMutableDictionary`. This matches how we do it in the macOS embedder. This removes the last of the `UTF8String` conversions in this file. As noted in flutter#191853 and flutter#191854 `std::string`'s `const char*` constructor determines the length using `strlen`, so it truncates at an embedded NUL and dereferences null if `UTF8String` ever returns NULL, which it does for a nil receiver. Spotted while working on: flutter#191616 No new tests since this just changes the implementation without changing any semantics.

flutter-dashboard · 2026-08-27T04:01:30Z

It looks like this pull request may not have tests. Please make sure to add tests or get an explicit test exemption before merging.

If you are not sure if you need tests, consider this rule of thumb: the purpose of a test is to make sure someone doesn't accidentally revert the fix. Ask yourself, is there anything in your PR that you feel it is important we not accidentally revert back to how it was before your fix?

Reviewers: Read the Tree Hygiene page and make sure this patch meets those guidelines before LGTMing. If you believe this PR qualifies for a test exemption, contact "@test-exemption-reviewer" in the #hackers channel in Discord (don't just cc them here, they won't see it!). The test exemption team is a small volunteer group, so all reviewers should feel empowered to ask for tests, without delegating that responsibility entirely to the test exemption group.

gemini-code-assist

Code Review

This pull request refactors FlutterPlatformViewsController by replacing C++ std::unordered_map with Objective-C NSMutableDictionary for managing platform view factories and gesture blocking policies. Feedback recommends adding defensive FML_CHECK assertions to verify that both factoryId and factory are not nil before inserting them into the dictionary, which prevents potential runtime exceptions.

stuartmorgan-g · 2026-08-27T14:21:49Z

test-exempt: code refactor with no semantic change

stuartmorgan-g

LGTM

stuartmorgan-g · 2026-08-27T14:23:33Z

  int64_t viewId = [args[@"id"] longLongValue];
  // A missing argument arrives as nil and an explicit Dart null as NSNull, neither of which can be
  // converted to a view type.
  NSString* viewTypeString = args[@"viewType"];


Optional nit: you could rename this viewType, since it looks like calling it viewTypeString was probably just to give it a distinct name from viewType (although that's arguably the least useful suffix that could have been added...)

stuartmorgan-g · 2026-08-27T14:25:16Z

  } else if ([gestureBlockingPolicyValue
                 isEqualToString:kGestureBlockingPolicyFallbackToPluginDefault]) {
-    gestureBlockingPolicy = self.gestureRecognizersBlockingPoliciesByType[viewType];
+    gestureBlockingPolicy = static_cast<FlutterPlatformViewGestureRecognizersBlockingPolicy>(


(It's a shame we're losing type information on the value, but that's worth avoiding the actual data conversion on the key. If only there were some language we could use for this file where we didn't have to make that tradeoff 😉 )

flutter/flutter@e8dca90...8d8c1aa 2026-08-28 engine-flutter-autoroll@skia.org Roll Packages from bd3cbc1 to cd4cdd0 (15 revisions) (flutter/flutter#191965) 2026-08-28 matthiasngeo@gmail.com Bump customer testing version to pick up forui tests (flutter/flutter#191931) 2026-08-28 victorsanniay@gmail.com Use leading scroll offset instead of infinite offset to reveal pinned slivers (flutter/flutter#191329) 2026-08-28 engine-flutter-autoroll@skia.org Roll Skia from 21f71051e749 to fe0b9a5261f9 (1 revision) (flutter/flutter#191960) 2026-08-28 robert.ancell@canonical.com Share the common Linux window controller code in mixins (flutter/flutter#191930) 2026-08-28 engine-flutter-autoroll@skia.org Roll Dart SDK from 2cf2f69fd9f0 to ae63a6eca3f1 (1 revision) (flutter/flutter#191953) 2026-08-28 engine-flutter-autoroll@skia.org Roll Skia from 11e3a7cb0fd0 to 21f71051e749 (3 revisions) (flutter/flutter#191942) 2026-08-28 engine-flutter-autoroll@skia.org Roll Dart SDK from e030e77d5413 to 2cf2f69fd9f0 (2 revisions) (flutter/flutter#191934) 2026-08-28 32538273+ValentinVignal@users.noreply.github.com Remove no-shuffle in flutter tools overall experience test (flutter/flutter#191861) 2026-08-28 bkonyi@google.com [flutter_tools] Gracefully handle Windows Application Control and security policy execution blocks (flutter/flutter#191912) 2026-08-28 bkonyi@google.com [tool] Migrate ConfigCommand to modular dependency injection (flutter/flutter#190743) 2026-08-28 engine-flutter-autoroll@skia.org Roll Skia from 37459da0a755 to 11e3a7cb0fd0 (9 revisions) (flutter/flutter#191929) 2026-08-28 robert.ancell@canonical.com Connect to moved-to-rect after the window is realized (flutter/flutter#191773) 2026-08-28 chris@bracken.jp macOS: Compare accessibility strings as NSStrings in tests (flutter/flutter#191853) 2026-08-28 chris@bracken.jp macOS: Record test accessibility notifications in a dictionary (flutter/flutter#191854) 2026-08-28 engine-flutter-autoroll@skia.org Roll Fuchsia Test Scripts from 6SXRz6wsA2Zm_rAqP... to u_fSMsPU22VvUsvSo... (flutter/flutter#191927) 2026-08-28 engine-flutter-autoroll@skia.org Roll Dart SDK from cb4c39d067f3 to e030e77d5413 (3 revisions) (flutter/flutter#191923) 2026-08-27 okorohelijah@google.com Migrate ios driver tests batch 2 to simulators (flutter/flutter#190930) 2026-08-27 bkonyi@google.com [flutter_test] Ensure LiveTestWidgetsFlutterBinding executes frame and pointer callbacks in the test zone (flutter/flutter#191595) 2026-08-27 36861262+QuncCccccc@users.noreply.github.com Deprecate legacy gen_defaults tool (flutter/flutter#191911) 2026-08-27 robert.ancell@canonical.com Fix black window in the subsurface view renderer (flutter/flutter#191850) 2026-08-27 engine-flutter-autoroll@skia.org Roll Skia from 82e972ea84b1 to 37459da0a755 (10 revisions) (flutter/flutter#191906) 2026-08-27 chris@bracken.jp iOS: Key the platform view factory registries by NSString (flutter/flutter#191855) 2026-08-27 154381524+flutteractionsbot@users.noreply.github.com Sync CHANGELOG.md from stable (flutter/flutter#191895) 2026-08-27 bkonyi@google.com [flutter_tools] Honor configured build-dir across flutter project and build targets (flutter/flutter#191592) 2026-08-27 154381524+flutteractionsbot@users.noreply.github.com Revert: Handle linear and radial gradients in UberSDF (flutter/flutter#191913) 2026-08-27 34871572+gmackall@users.noreply.github.com Explicitly disable HCPP in hybrid_android_views integration test (flutter/flutter#191894) If this roll has caused a breakage, revert this CL and stop the roller using the controls here: https://autoroll.skia.org/r/flutter-packages Please CC bmparr@google.com,stuartmorgan@google.com on the revert to ensure that a human is aware of the problem. To file a bug in Packages: https://github.com/flutter/flutter/issues/new/choose To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

…r#12679) flutter/flutter@e8dca90...8d8c1aa 2026-08-28 engine-flutter-autoroll@skia.org Roll Packages from bd3cbc1 to cd4cdd0 (15 revisions) (flutter/flutter#191965) 2026-08-28 matthiasngeo@gmail.com Bump customer testing version to pick up forui tests (flutter/flutter#191931) 2026-08-28 victorsanniay@gmail.com Use leading scroll offset instead of infinite offset to reveal pinned slivers (flutter/flutter#191329) 2026-08-28 engine-flutter-autoroll@skia.org Roll Skia from 21f71051e749 to fe0b9a5261f9 (1 revision) (flutter/flutter#191960) 2026-08-28 robert.ancell@canonical.com Share the common Linux window controller code in mixins (flutter/flutter#191930) 2026-08-28 engine-flutter-autoroll@skia.org Roll Dart SDK from 2cf2f69fd9f0 to ae63a6eca3f1 (1 revision) (flutter/flutter#191953) 2026-08-28 engine-flutter-autoroll@skia.org Roll Skia from 11e3a7cb0fd0 to 21f71051e749 (3 revisions) (flutter/flutter#191942) 2026-08-28 engine-flutter-autoroll@skia.org Roll Dart SDK from e030e77d5413 to 2cf2f69fd9f0 (2 revisions) (flutter/flutter#191934) 2026-08-28 32538273+ValentinVignal@users.noreply.github.com Remove no-shuffle in flutter tools overall experience test (flutter/flutter#191861) 2026-08-28 bkonyi@google.com [flutter_tools] Gracefully handle Windows Application Control and security policy execution blocks (flutter/flutter#191912) 2026-08-28 bkonyi@google.com [tool] Migrate ConfigCommand to modular dependency injection (flutter/flutter#190743) 2026-08-28 engine-flutter-autoroll@skia.org Roll Skia from 37459da0a755 to 11e3a7cb0fd0 (9 revisions) (flutter/flutter#191929) 2026-08-28 robert.ancell@canonical.com Connect to moved-to-rect after the window is realized (flutter/flutter#191773) 2026-08-28 chris@bracken.jp macOS: Compare accessibility strings as NSStrings in tests (flutter/flutter#191853) 2026-08-28 chris@bracken.jp macOS: Record test accessibility notifications in a dictionary (flutter/flutter#191854) 2026-08-28 engine-flutter-autoroll@skia.org Roll Fuchsia Test Scripts from 6SXRz6wsA2Zm_rAqP... to u_fSMsPU22VvUsvSo... (flutter/flutter#191927) 2026-08-28 engine-flutter-autoroll@skia.org Roll Dart SDK from cb4c39d067f3 to e030e77d5413 (3 revisions) (flutter/flutter#191923) 2026-08-27 okorohelijah@google.com Migrate ios driver tests batch 2 to simulators (flutter/flutter#190930) 2026-08-27 bkonyi@google.com [flutter_test] Ensure LiveTestWidgetsFlutterBinding executes frame and pointer callbacks in the test zone (flutter/flutter#191595) 2026-08-27 36861262+QuncCccccc@users.noreply.github.com Deprecate legacy gen_defaults tool (flutter/flutter#191911) 2026-08-27 robert.ancell@canonical.com Fix black window in the subsurface view renderer (flutter/flutter#191850) 2026-08-27 engine-flutter-autoroll@skia.org Roll Skia from 82e972ea84b1 to 37459da0a755 (10 revisions) (flutter/flutter#191906) 2026-08-27 chris@bracken.jp iOS: Key the platform view factory registries by NSString (flutter/flutter#191855) 2026-08-27 154381524+flutteractionsbot@users.noreply.github.com Sync CHANGELOG.md from stable (flutter/flutter#191895) 2026-08-27 bkonyi@google.com [flutter_tools] Honor configured build-dir across flutter project and build targets (flutter/flutter#191592) 2026-08-27 154381524+flutteractionsbot@users.noreply.github.com Revert: Handle linear and radial gradients in UberSDF (flutter/flutter#191913) 2026-08-27 34871572+gmackall@users.noreply.github.com Explicitly disable HCPP in hybrid_android_views integration test (flutter/flutter#191894) If this roll has caused a breakage, revert this CL and stop the roller using the controls here: https://autoroll.skia.org/r/flutter-packages Please CC bmparr@google.com,stuartmorgan@google.com on the revert to ensure that a human is aware of the problem. To file a bug in Packages: https://github.com/flutter/flutter/issues/new/choose To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

cbracken requested a review from a team as a code owner August 27, 2026 04:01

flutter-dashboard Bot added the CICD Run CI/CD label Aug 27, 2026

github-actions Bot added platform-ios iOS applications specifically engine flutter/engine related. See also e: labels. team-ios Owned by iOS platform team labels Aug 27, 2026

gemini-code-assist Bot reviewed Aug 27, 2026

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Comment thread engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViewsController.mm

stuartmorgan-g approved these changes Aug 27, 2026

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cbracken added the autosubmit Merge PR when tree becomes green via auto submit App label Aug 27, 2026

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Merged via the queue into flutter:master with commit ff663c6 Aug 28, 2026
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iOS: Key the platform view factory registries by NSString - #191855

iOS: Key the platform view factory registries by NSString#191855
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cbracken commented Aug 27, 2026

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