Kotlin logic conversion to Java problem with method “contains”

Question

I'm trying to use the following piece of code posted on goo.gl/av3tJD

val supportsDistortionCorrection = characteristics.get(

    CameraCharacteristics.DISTORTION_CORRECTION_AVAILABLE_MODES)?.contains(

    CameraMetadata.DISTORTION_CORRECTION_MODE_HIGH_QUALITY) ?: false

I see the code is in Kotlin, which I know very little about. I want to convert the code to Java.

I'm trying the following:

Boolean hasNoiseReduction = false;
//cc is my previously defined CameraCharacteristics object
if(cc.get(CameraCharacteristics.DISTORTION_CORRECTION_AVAILABLE_MODES).contains("some string"))hasNoiseReduction = true;

The method contains is throwing me off. I don't believe is the method contains used in the String class.

Any advice is needed

Answer 1

it.first at that point in the code is referring to the first element of the Pair created above, containing a CameraCharacteristics instance. The get on this returns an IntArray ( int[] in Java terms), and the contains method from the Kotlin standard library checks whether the given constant is in that array.

val cameraCharacteristics: CameraCharacteristics = it.first
val capabilities: IntArray = cameraCharacteristics.get(CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES)!!
capabilities.contains(CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES_LOGICAL_MULTI_CAMERA)

You could check this in Java by - for example - looping through the array elements and seeing if you find the value. A primitive implementation for this:

CameraCharacteristics cameraCharacteristics = ...;
final int[] capabilities = cameraCharacteristics.get(CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES);

boolean contains = false;
for (final int capability : capabilities) {
    if (capability == CameraCharacteristics.REQUEST_AVAILABLE_CAPABILITIES_LOGICAL_MULTI_CAMERA) {
        contains = true;
        break;
    }
}

// use result