e1e029d26d
* Adds MD3 animations to MenuAnchor. * Adds a "hoverOpenDelay" parameter on `SubmenuButton` * Moves the layout algorithm from SingleChildLayoutDelegate to a custom render object. <s>This was done because I needed to access the dry layout of the menu panel for the best effect. I'll demonstrate below.</s> Turns out using dry layout significantly limits what children you can use with a widget. As a result, I'm calculating the final height using the inverse height factor. Fixes https://github.com/flutter/flutter/issues/135025 I don't have access to the internal Google documentation, so I did my best to deduce the spec from https://github.com/material-components/material-web/blob/main/menu/internal/menu.ts. This change is currently opt-in via an `animated` parameter on `MenuAnchor` and `SubmenuButton`. As a result, this is not a breaking change. Because the PR is already quite large, I chose to not add animation customization to this PR. I also didn't change any theming files or `DropdownMenu`. The only other API addition is a `hoverOpenDelay` parameter on `SubmenuButton`. This parameter delays the start of a submenu opening by the specified duration. It is independent of the `animated` parameter. When `animated == false`, the menu runs its forward and reverse animations with a duration of 0. I originally disposed of all animation assets when `animated` was false, but found that the code/testing complexity to be unwieldy. <s>Blocked by https://github.com/flutter/flutter/pull/176503</s> ## Examples * Basic example adapted from material-web https://github.com/user-attachments/assets/e6d02fab-e11c-4dce-ab82-2fb39c1111e0 * Example showing scrollbar https://github.com/user-attachments/assets/847054ba-7218-4e73-9835-019bfa7b5521 * MenuBar usage https://github.com/user-attachments/assets/8231b1cd-c40c-4f18-af87-1b77b43ecb7b Thanks to @QuncCccccc and @dkwingsmt for [their work on this issue.](https://github.com/flutter/flutter/pull/143416) Sorry for throwing a wrench into the original PR by introducing `RawMenuAnchor`... ## 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], 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]. **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 [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
Flutter Examples
This directory contains several examples of using Flutter. To run an example,
use flutter run inside that example's directory. See the getting started
guide to install the flutter tool.
For additional samples, see the
flutter/samples repo.
Available examples include:
-
Hello, world The hello world app is a minimal Flutter app that shows the text "Hello, world!"
-
Flutter gallery The flutter gallery app no longer lives in this repo. Please see the gallery repo.
-
Layers The layers vignettes show how to use the various layers in the Flutter framework. For details, see the layers README.
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Platform Channel The platform channel app demonstrates how to connect a Flutter app to platform-specific APIs. For documentation, see https://flutter.dev/to/platform-channels/.
-
Platform Channel Swift The platform channel swift app is the same as platform channel but the iOS version is in Swift and there is no Android version.
Notes
Note on Gradle wrapper files in .gitignore:
Gradle wrapper files should normally be checked into source control. The example projects don't do that to avoid having several copies of the wrapper binary in the Flutter repo. Instead, the Gradle wrapper is injected by Flutter tooling, and the wrapper files are .gitignore'd to avoid making the Flutter repository dirty as a side effect of running the examples.