Android Studio's "expected resource of type" checks?

Question

Android Studio Beta (0.8) has a nifty new feature where it checks that some int parameters are not arbitrary integers, but rather have some properties.

For example, calling something like:

setContentView(R.id.textView1);

will correctly report that R.id.textView1 is not a layout id (the message is "expected resource of type layout"). There are other cases of this peppered around.

Understandably, this protection is lost as soon as you add your own methods into the mix, e.g.

private void mySetContentView(int resourceId) {
    setContentView(resourceId);
}

I can then call mySetContentView() with any arbitrary integer and it will not complain.

So, I have two (related) questions:

How is this achieved -- are the special checks "baked" into lint?
Is there any way to annotate the mySetContentView() method so that it will also report a resource type error when calling it with an invalid value?

I'm pretty sure it's an annotation -- I think they may have covered this in the developer tools presentation at Google I|O. — CommonsWare, Jul 12 '14 at 19:47
@CommonsWare You're right! Do you want to answer this, or shall I do it myself? — matiash, Jul 12 '14 at 20:04
Since I don't remember the annotation, you had better answer it. :-) — CommonsWare, Jul 12 '14 at 20:05

score 40 · Accepted Answer · edited Aug 15 '14 at 09:03

40

(Thanks to @CommonsWare for the heads up).

There are Java annotations to support these checks in your own code. They can all be found in the android.support.annotations package:

IdRes
DrawableRes
LayoutRes
StringRes
&c

In this case, for example, I could use:

private void mySetContentView(@LayoutRes int resourceId) {
    setContentView(resourceId);
}

and Android Studio will check that the provided resource id is indeed for a layout.

Moreover, these annotations are exported, so they can be especially useful when designing a library.

Sources:

Video from Google I/O 2014: What's new in Android development tools

edited Aug 15 '14 at 09:03

Andrea Turri

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answered Jul 12 '14 at 20:11

matiash

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Thanks! The same exeption ... InputStream is = getResources().openRawResource(getResourceID(R.drawable.greenbal)); .... private int getResourceID(@DrawableRes int resID) { return resID; } – contributorpw Jan 30 '15 at 06:03

score 22 · Answer 2 · answered Sep 27 '14 at 11:57

This are all Annotations:

@AnimatorRes
@AnimRes
@AnyRes
@ArrayRes
@AttrRes
@BoolRes
@ColorRes
@DimenRes
@DrawableRes
@FractionRes
@IdRes
@IntDef
@IntegerRes
@InterpolatorRes
@LayoutRes
@MenuRes
@NonNull
@Nullable
@PluralsRes
@RawRes
@StringDef
@StringRes
@StyleableRes
@StyleRes
@XmlRes

score 8 · Answer 3 · answered Apr 26 '16 at 06:36

8

Try this answer: Its working... Put this code into your build.gradle

android {
 lintOptions {
    disable "ResourceType"
  }
}

answered Apr 26 '16 at 06:36

Mahendran Candy

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I think the question was just the opposite: he wants to have those checks even if intermediate functions are used. Beware: Disabling checks is usually a bad idea. The Android developers are usually smarter than us ;) – Raúl Salinas-Monteagudo Jun 07 '17 at 08:57

score 0 · Answer 4 · answered Oct 16 '15 at 11:37

0

All annotations, that you can use with android.support.annotation you can find here.

And technical doc about supporting annotations.

answered Oct 16 '15 at 11:37

Volodymyr Yatsykiv

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Android Studio's "expected resource of type" checks?

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