@UseExperimental should take multiple marker classes [145137892]

Fixed

Feature Request

Status Update

No update yet.

Description

tr...@google.com

created issue #1

Nov 25, 2019 07:01PM

The AndroidX UseExperimental annotation only takes a single markerClass. This means only a single Experimental API can be used within the same scope. Taking an array of marker classes may be one way to fix this behavior.

By comparison, the kotlin UseExperimental annotation takes a vararg markerClass argument which allows for multiple experimental APIs in the same scope.

Comments

tr...@google.com <tr...@google.com> Nov 26, 2019 12:44AM

Assigned to al...@google.com.

al...@google.com <al...@google.com> #2Dec 3, 2019 05:33PM

I don't think I'll be able to change it from a single Class to a vararg or array, but I might be able to change it to a single Class followed by a default null array. Not ideal, but at least it doesn't require a 2.0.

tr...@google.com <tr...@google.com> #3Dec 3, 2019 09:00PM

Whatever works to allow for multiple experimental classes.

Is it considered a breaking change to add a default value to markerClass? Could you do something like this:

public @interface UseExperimental {
Class<?> markerClass() default void.class;
Class<?>[] value() default {};
}

Then @UseExperimental could be used like:

@UseExperimental(markerClass = MyExperimental.class)
or
@UseExperimental(MyExperimental.class)
or
@UseExperimental({MyExperimental.class, MyOtherExperimental.class})

It would also be ok (but a little weird) to use it like:
@UseExperimental(markerClass = MyExperimental.class, value = {MyOtherExperimental.class})

al...@google.com <al...@google.com> #4Dec 4, 2019 04:38PM

That should work -- https://wiki.eclipse.org/Evolving_Java-based_APIs_2 says that adding default to an existing annotation type element is binary compatible.

al...@google.com <al...@google.com> Dec 6, 2019 08:21PM

Accepted by al...@google.com.

ap...@google.com <ap...@google.com> #5Dec 20, 2019 07:36PM

Marked as fixed.

Project: platform/frameworks/support
Branch: androidx-master-dev

commit 07ff9477a2fd998662ebb11447b3a5291a6fd087
Author: Alan Viverette <alanv@google.com>
Date: Mon Dec 09 17:17:14 2019

Add support for multiple marker classes by migrating to Kotlin

Fixes: 145137892
Test: ExperimentalDetectorTest
Change-Id: I762a525bfc1e78aac4fa6458daa979b2fb3800e1

A annotation/annotation-experimental-lint/integration-tests/src/main/java/sample/ExperimentalLocation.java
A annotation/annotation-experimental-lint/integration-tests/src/main/java/sample/ExperimentalLocationKt.kt
A annotation/annotation-experimental-lint/integration-tests/src/main/java/sample/LocationProvider.java
A annotation/annotation-experimental-lint/integration-tests/src/main/java/sample/LocationProviderKt.kt
M annotation/annotation-experimental-lint/integration-tests/src/main/java/sample/UseJavaExperimentalFromJava.java
M annotation/annotation-experimental-lint/integration-tests/src/main/java/sample/UseJavaExperimentalFromKt.kt
M annotation/annotation-experimental-lint/integration-tests/src/main/java/sample/UseJavaPackageFromKt.kt
M annotation/annotation-experimental-lint/integration-tests/src/main/java/sample/UseKtExperimentalFromJava.java
M annotation/annotation-experimental-lint/src/main/java/androidx/annotation/experimental/lint/ExperimentalDetector.kt
M annotation/annotation-experimental-lint/src/test/kotlin/androidx/annotation/experimental/lint/ExperimentalDetectorTest.kt
A annotation/annotation-experimental/api/1.1.0-alpha01.ignore
M annotation/annotation-experimental/api/1.1.0-alpha01.txt
A annotation/annotation-experimental/api/api_lint.ignore
M annotation/annotation-experimental/api/current.txt
M annotation/annotation-experimental/api/public_plus_experimental_1.1.0-alpha01.txt
M annotation/annotation-experimental/api/public_plus_experimental_current.txt
A annotation/annotation-experimental/api/restricted_1.1.0-alpha01.ignore
M annotation/annotation-experimental/api/restricted_1.1.0-alpha01.txt
M annotation/annotation-experimental/api/restricted_current.txt
M annotation/annotation-experimental/build.gradle
M annotation/annotation-experimental/src/main/java/androidx/annotation/experimental/Experimental.kt
D annotation/annotation-experimental/src/main/java/androidx/annotation/experimental/UseExperimental.java
A annotation/annotation-experimental/src/main/java/androidx/annotation/experimental/UseExperimental.kt

https://android-review.googlesource.com/1185577

Issue 145137892