Example showing how to request for permissions

[charleschege]

Is there an example showing how to request for example STORAGE permissions using jni and ndk-context like:

let ctx = ndk_context::android_context();
    let vm = unsafe { jni::JavaVM::from_raw(ctx.vm().cast()) }.unwrap();
    let context = unsafe { JObject::from_raw(ctx.context().cast()) };
    let env = vm.attach_current_thread().unwrap();

    // Query the global Audio Service
    let class_ctx = env.find_class("android/content/Context").unwrap();
    let storage_service = env
        .get_static_field(class_ctx, "AUDIO_SERVICE", "Ljava/lang/String;")
        .unwrap();

    let storage_manager = env
        .call_method(
            context,
            "getSystemService",
            "(Ljava/lang/String;)Ljava/lang/Object;",
            &[storage_service],
        )
        .unwrap()
        .l()
        .unwrap();

    // Request storage permission
    let permission_read = env
        .new_string("android.permission.READ_EXTERNAL_STORAGE")
        .unwrap();
    let permission_write = env
        .new_string("android.permission.WRITE_EXTERNAL_STORAGE")
        .unwrap();

env.call_method(
        storage_manager,
        "requestPermissions",
        "([Ljava/lang/String;I)V",
        &[
            permission_read.into(),
            JValue::from(permission_request_code),
        ],
    )
    .unwrap();

With the strict Rust types enforced it can be difficult to know exactly what to do and where the errors occured like the example above results in error:

02-20 12:35:17.831 15654 15693 I RustStdoutStderr: thread '<unnamed>' panicked at 'called `Result::unwrap()` on an `Err` value: JavaException', src/lib.rs:66:6
02-20 12:35:17.831 15654 15693 I RustStdoutStderr: note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Which doesn't say much.

[MarijnS95]

@charleschege That indeed doesn't say much, as we don't know which line in your example corresponds to line 66 in lib.rs :)

[charleschege]

Sorry about that.

Its

permission_read.into(),

[charleschege]

An example to show how to request for permissions would be more ideal though.

Like the audio example is well done

[MarijnS95]

Right, yes, you are calling requestPermissions on the storage_manager variable which contains https://developer.android.com/reference/android/media/AudioManager (from the string AUDIO_SERVICE), it doesn't have that method :)

EDIT: Neither does https://developer.android.com/reference/android/os/storage/StorageManager, I think that method has to be called on an Activity/AppCompatActivity?

[charleschege]

Sorry I missed that while copy pasting.

Changing it to STORAGE_SERVICE, still same error

[MarijnS95]

Changing it to STORAGE_SERVICE, still same error

Again, as mentioned above requestPermissions doesn't exist on StorageManager either. Perhaps you're interested in reading https://github.com/matthunz/permissions / rust-mobile/android-activity#66? Feel free to converse there, this issue has nothing to do with cargo-apk (aside from borrowing a few lines from a runtime example) so I'll close it.

[charleschege]

Thanks for pointing me to the permissions repo

[iincity]

Thanks for pointing me to the permissions repo
this code can not buid for me:

error[E0308]: mismatched types
--> src\lib.rs:217:15
|
217 | &[storage_service],
| ^^^^^^^^^^^^^^^ expected JValueGen<&JObject<'_>>, found JValueGen<JObject<'_>>
|
= note: expected enum JValueGen<&jni::objects::JObject<'_>>
found enum JValueGen<jni::objects::JObject<'_>>