Android API level annotation for Android libraries

Question

I am writing an Android library. The vast majority of the interface in the lbirary supports Android API level 10 or above. Some functionality, though, requires a higher API

Answer 1

I have recently done this on a custom view class, which needed special constructor for some api levels.

I have done it with the @TargetApi annotation.

If a method is available only since api level 16:

@TargetApi(16)
public void someMethod () {}

This should do the trick, including lint errors.

Answer 2

There is no need to create your own annotation, the android support library's @RequiresApi annotation is what you are looking for. For example:

@RequiresApi(Build.VERSION_CODES.LOLLIPOP)
public void someMethod() {}

This annotation tells lint to warn if someMethod() is used in a context that may have a lower API level.

Note that @TargetApi is different: It's used to assure the linter that the annotated method will only be called with the targeted API, in a situation where it would otherwise warn you not to use that method. So @TargetApi can be used to silence the lint warning triggered by @RequiresApi.