kotlin_support.md

Fully Kotlin support

From 3.0.0 we started support .kt file generation.

Let's think about the same example as described in README.md.

0. Prepare AndroidManifest

Add the following line to AndroidManifest.xml:

<uses-permission android:name="android.permission.CAMERA" />

1. Attach annotations

NOTE: Annotated methods must not be private.

@RuntimePermissions
class MainActivity : AppCompatActivity(), View.OnClickListener {

    @NeedsPermission(Manifest.permission.CAMERA)
    fun showCamera() {
        supportFragmentManager.beginTransaction()
                .replace(R.id.sample_content_fragment, CameraPreviewFragment.newInstance())
                .addToBackStack("camera")
                .commitAllowingStateLoss()
    }

    @OnShowRationale(Manifest.permission.CAMERA)
    fun showRationaleForCamera(request: PermissionRequest) {
        showRationaleDialog(R.string.permission_camera_rationale, request)
    }

    @OnPermissionDenied(Manifest.permission.CAMERA)
    fun onCameraDenied() {
        Toast.makeText(this, R.string.permission_camera_denied, Toast.LENGTH_SHORT).show()
    }

    @OnNeverAskAgain(Manifest.permission.CAMERA)
    fun onCameraNeverAskAgain() {
        Toast.makeText(this, R.string.permission_camera_never_askagain, Toast.LENGTH_SHORT).show()
    }
}

2. Delegate to generated functions

Now generated functions become much more concise and intuitive than Java version!

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        findViewById(R.id.button_camera).setOnClickListener {
            // NOTE: delegate the permission handling to generated function
            showCameraWithPermissionCheck()
        }
    }

    override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
        // NOTE: delegate the permission handling to generated function
        onRequestPermissionsResult(requestCode, grantResults)
    }

Check out the sample for more details.