mirror of
https://github.com/flutter/flutter.git
synced 2026-02-20 02:29:02 +08:00
8796ecd15c
Fixes https://github.com/flutter/flutter/issues/129085 ## Changes to `FlutterMouseCursorPlugin` - `none` cursor is not handled by hiding the cursor anymore. That was too big of a hammer as it also affects other views (and platform views). Instead empty cursor is created from empty `NSImage`. - Cursor plugin now notifies the engine when cursor has changed. The engine forwards the change to last `FlutterView` that handled mouse event. This is necessary because on occasion `FlutterView` needs to be able to restore cursor without framework being involved. ## Preventing PlatformView from changing cursor when it is obscured by Flutter Content. Generally in Cocoa cursor changes are done as response to `mouseMoved` event, which is driven by a `NSTrackingArea`. The issue here is that this is not affected by hit testing and tracking areas form a hierarchy parallel to view hierarchy and are not affected by being obscured by another view (or tracking area). This means that platform view will receive `mouseMoved` event even when is obscured by Flutter content. To work around this, the mutator view puts a tracking area above platform view, which means it gets the mouseMove event first, and when it decides that mouse is over Flutter content, it will prevent platform view from changing the cursor for the rest of RunLoop turn (see `NSCursor+IgnoreChange`). ## Actual hit testing This part is rather straightforward, the area where FlutterContent obscures mutator view is provided to the mutator view, which will return `nil` from `hitTest:` when the point is in the obscured area. ## Example of hit testing https://github.com/flutter/engine/assets/96958/bbac0cfd-8c44-44d3-addd-921c91a8a539 ## Pre-launch Checklist - [X] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [X] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [X] I read and followed the [Flutter Style Guide] and the [C++, Objective-C, Java style guides]. - [X] I listed at least one issue that this PR fixes in the description above. - [X] I added new tests to check the change I am making or feature I am adding, or Hixie said the PR is test-exempt. See [testing the engine] for instructions on writing and running engine tests. - [X] I updated/added relevant documentation (doc comments with `///`). - [X] I signed the [CLA]. - [X] All existing and new tests are passing. If you need help, consider asking for advice on the #hackers-new channel on [Discord]. <!-- Links --> [Contributor Guide]: https://github.com/flutter/flutter/wiki/Tree-hygiene#overview [Tree Hygiene]: https://github.com/flutter/flutter/wiki/Tree-hygiene [Flutter Style Guide]: https://github.com/flutter/flutter/wiki/Style-guide-for-Flutter-repo [C++, Objective-C, Java style guides]: https://github.com/flutter/engine/blob/main/CONTRIBUTING.md#style [testing the engine]: https://github.com/flutter/flutter/wiki/Testing-the-engine [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/wiki/Tree-hygiene#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/wiki/Chat