[ios] Filter UIScene events to those relating to Flutter VC scene#187987
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This pull request introduces a mechanism to filter out scene lifecycle notifications originating from unrelated scenes (such as an out-of-process system keyboard scene) to prevent unexpected app pausing. However, the changes in FlutterEngine.mm introduce a critical bug: if self.viewController is nil (which is common for headless or pre-warmed engines), messaging it returns NO, which negates to YES and causes an unintended early return. This would break lifecycle transitions entirely. To resolve this, the engine should only filter notifications when self.viewController is non-nil.
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This pull request introduces a mechanism to filter out scene lifecycle notifications originating from unrelated scenes in multi-scene environments. It adds a shouldHandleSceneNotification: check to FlutterEngine and FlutterViewController lifecycle methods, and includes a unit test to verify that auxiliary scene notifications are ignored. The review feedback suggests adding the API_AVAILABLE(ios(13.0)) attribute to the implementation of shouldHandleSceneNotification: to prevent compiler warnings, and correcting a typo in the test documentation.
Fixes a bug where FlutterViewController and FlutterEngine would globally intercept UIScene lifecycle notifications (such as UISceneDidEnterBackgroundNotification) originating from any scene in the process, rather than just the scene hosting the Flutter view controller. This can be triggered in multi-scene environments (e.g. iPadOS multi-window or inside App Extensions where `isAvailable = NO` forces scene observers to register). Unrelated scenes (like an out-of-process system keyboard scene or secondary window) transitioning to the background can cause the Flutter view to incorrectly switch to a paused lifecycle state and destroy the rendering surface. This updates FlutterViewController/FlutterEngine to verify that the notification's sender matches the UIWindowScene instance that hosts the Flutter view before propagating deactivation/activation events. Fixes: flutter#187986 Fixes: flutter#187844
| * In multi-scene environments (such as iPadOS split view, macOS Catalyst multi-window, or App | ||
| * Extensions), multiple UIWindowScene instances can exist in the same process space. Because the | ||
| * scene observers register to listen for all targets, they may receive lifecycle notifications | ||
| * from unrelated auxiliary or secondary scenes. |
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Ah this reminds me of #185690
Which should help get rid of this class of problem entirely.
hellohuanlin
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Jun 15, 2026
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Roll Flutter from b7cb925419e6 to 5827d5fd2b8d (35 revisions) flutter/flutter@b7cb925...5827d5f 2026-06-15 [email protected] Roll Skia from 7128af60575a to c8d9f80f13e4 (1 revision) (flutter/flutter#188015) 2026-06-15 [email protected] In the APNG decoder, validate the chunk data length before calling GetChunkSize to avoid potential overflow in the chunk size calculation (flutter/flutter#187949) 2026-06-15 [email protected] Roll Skia from 6b4ac3bfb39d to 7128af60575a (1 revision) (flutter/flutter#188011) 2026-06-15 [email protected] Roll Skia from 0a3b8549cbf0 to 6b4ac3bfb39d (7 revisions) (flutter/flutter#188007) 2026-06-15 98614782+auto-submit[bot]@users.noreply.github.com Reverts "[a11y] Map some framework semantics roles to android classes. (#185217)" (flutter/flutter#188008) 2026-06-15 [email protected] [ios] Filter UIScene events to those relating to Flutter VC scene (flutter/flutter#187987) 2026-06-15 [email protected] [a11y] Map some framework semantics roles to android classes. (flutter/flutter#185217) 2026-06-15 [email protected] Roll Skia from f46928e7f50c to 0a3b8549cbf0 (1 revision) (flutter/flutter#188004) 2026-06-14 [email protected] Rework docs for flutter/packages changelogs (flutter/flutter#187666) 2026-06-14 [email protected] Roll Fuchsia Linux SDK from nvzMQAmuRSzo7-wAP... to TbB86Po_HDe1dvXvT... (flutter/flutter#187997) 2026-06-14 [email protected] Roll Skia from 4e2c9b5e4dad to f46928e7f50c (1 revision) (flutter/flutter#187996) 2026-06-14 [email protected] Roll Skia from c52667607242 to 4e2c9b5e4dad (1 revision) (flutter/flutter#187990) 2026-06-14 [email protected] Improve RenderTargetCache docs (flutter/flutter#187893) 2026-06-13 [email protected] [Test cross_imports] Check cross imports in flutter_test/** (flutter/flutter#187587) 2026-06-13 [email protected] Fixing corrupted window size OnEmptyFrameGenerated due to transpsed width/height (flutter/flutter#187954) 2026-06-13 [email protected] Roll Skia from 42355271a335 to c52667607242 (2 revisions) (flutter/flutter#187979) 2026-06-13 [email protected] Roll Fuchsia Linux SDK from A3eaUn9mQ_EkSNxVI... to nvzMQAmuRSzo7-wAP... (flutter/flutter#187975) 2026-06-13 [email protected] Roll Skia from 9ef46390c2d1 to 42355271a335 (1 revision) (flutter/flutter#187974) 2026-06-13 [email protected] [Flutter GPU] Make ShaderLibrary.fromAsset asynchronous (flutter/flutter#187716) 2026-06-13 [email protected] Roll Skia from 8c89bf2b0ee3 to 9ef46390c2d1 (6 revisions) (flutter/flutter#187968) 2026-06-12 [email protected] [Flutter GPU] Add surface API for framework presentation (flutter/flutter#187358) 2026-06-12 [email protected] [gen_l10n] Exclude inherited keys from untranslated-messages-file (flutter/flutter#187950) 2026-06-12 [email protected] Update `MediaQueryData` docs for devicePixelRatio overriding (flutter/flutter#187542) 2026-06-12 [email protected] [Impeller] Fix dirty-range race in DeviceBufferGLES uploads (flutter/flutter#187932) 2026-06-12 [email protected] Compare isModifiedAfter against the given time (flutter/flutter#187727) 2026-06-12 [email protected] Enable unit tests for compilation of compute shaders on non-metal backends (flutter/flutter#179683) 2026-06-12 [email protected] [flutter_tools] Add doctor validator warning for multiple adb installations (flutter/flutter#186031) 2026-06-12 [email protected] Optimize SHA hash calculation of generated APK (flutter/flutter#187184) 2026-06-12 [email protected] Scope widget inspector overlay to the selected widget's modal route (flutter/flutter#186784) 2026-06-12 [email protected] Switches Windows to OpenGLESSDF (flutter/flutter#187877) 2026-06-12 [email protected] [integration_test] Update README to support modern Kotlin-based setups by default (flutter/flutter#186080) 2026-06-12 [email protected] Convert the PNG signature constant in APNGImageGenerator to a std::array and use it in the APNG tests (flutter/flutter#187930) 2026-06-12 [email protected] Correct backoff retry time cap unit and add regression tests (flutter/flutter#187250) 2026-06-12 [email protected] Fix std::vector out-of-bounds access in Flutter Android JNI and Delegate (flutter/flutter#187218) 2026-06-12 [email protected] [Android] Adding 30-second timeouts to adb stopApp and uninstallApp (flutter/flutter#187876) 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 [email protected],[email protected] 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 ...
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…utter#187987) Fixes a bug where FlutterViewController and FlutterEngine would globally intercept UIScene lifecycle notifications (such as UISceneDidEnterBackgroundNotification) originating from any scene in the process, rather than just the scene hosting the Flutter view controller. This can be triggered in multi-scene environments (e.g. iPadOS multi-window or inside App Extensions where `isAvailable = NO` forces scene observers to register). Unrelated scenes (like an out-of-process system keyboard scene or secondary window) transitioning to the background can cause the Flutter view to incorrectly switch to a paused lifecycle state and destroy the rendering surface. This updates FlutterViewController/FlutterEngine to verify that the notification's sender matches the UIWindowScene instance that hosts the Flutter view before propagating deactivation/activation events. Fixes: flutter#187986 Fixes: flutter#187844 <!-- Thanks for filing a pull request! Reviewers are typically assigned within a week of filing a request. To learn more about code review, see our documentation on Tree Hygiene: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md --> ## Pre-launch Checklist - [X] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [X] I read the [AI contribution guidelines] and understand my responsibilities, or I am not using AI tools. - [X] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [X] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [X] I signed the [CLA]. - [X] I listed at least one issue that this PR fixes in the description above. - [X] I updated/added relevant documentation (doc comments with `///`). - [X] I added new tests to check the change I am making, or this PR is [test-exempt]. - [X] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [X] All existing and new tests are passing. If you need help, consider asking for advice on the #hackers-new channel on [Discord]. If this change needs to override an active code freeze, provide a comment explaining why. The code freeze workflow can be overridden by code reviewers. See pinned issues for any active code freezes with guidance. **Note**: The Flutter team is currently trialing the use of [Gemini Code Assist for GitHub](https://developers.google.com/gemini-code-assist/docs/review-github-code). Comments from the `gemini-code-assist` bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed. <!-- Links --> [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [AI contribution guidelines]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#ai-contribution-guidelines [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md
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Fixes a bug where FlutterViewController and FlutterEngine would globally intercept UIScene lifecycle notifications (such as UISceneDidEnterBackgroundNotification) originating from any scene in the process, rather than just the scene hosting the Flutter view controller.
This can be triggered in multi-scene environments (e.g. iPadOS multi-window or inside App Extensions where
isAvailable = NOforces scene observers to register). Unrelated scenes (like an out-of-process system keyboard scene or secondary window) transitioning to the background can cause the Flutter view to incorrectly switch to a paused lifecycle state and destroy the rendering surface.This updates FlutterViewController/FlutterEngine to verify that the notification's sender matches the UIWindowScene instance that hosts the Flutter view before propagating deactivation/activation events.
Fixes: #187986
Fixes: #187844
Pre-launch Checklist
///).If you need help, consider asking for advice on the #hackers-new channel on Discord.
If this change needs to override an active code freeze, provide a comment explaining why. The code freeze workflow can be overridden by code reviewers. See pinned issues for any active code freezes with guidance.
Note: The Flutter team is currently trialing the use of Gemini Code Assist for GitHub. Comments from the
gemini-code-assistbot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed.