Android Activity, Fragment Permission Request Snippet

CheckPermissionLauncher.kt

import android.app.Activity
import androidx.activity.result.ActivityResultLauncher
import androidx.core.app.ActivityCompat
import androidx.core.content.PermissionChecker

typealias PermissionRequest = () -> Unit

class CheckPermissionLauncher(
	private val launcher: ActivityResultLauncher<Array<String>>,
	private val permissions: Array<String>,
	private val onShowRationale: ((request: PermissionRequest) -> Unit)? = null,
	private val requiresPermission: (() -> Unit)
) {

	fun launch(activity: Activity) {
		if (permissions.all { PermissionChecker.checkSelfPermission(activity, it) == PermissionChecker.PERMISSION_GRANTED }) {
			requiresPermission.invoke()
		} else {
			if (permissions.any { ActivityCompat.shouldShowRequestPermissionRationale(activity, it) }) {
				val request = { launcher.launch(permissions) }
				onShowRationale?.invoke(request)
			} else {
				launcher.launch(permissions)
			}
		}
	}
}

example.kt

private val legacyPermissions = arrayOf(
  Manifest.permission.CAMERA,
  Manifest.permission.READ_EXTERNAL_STORAGE,
  Manifest.permission.WRITE_EXTERNAL_STORAGE
)

@RequiresApi(Build.VERSION_CODES.Q)
private val permissionsVersionQ = arrayOf(
  Manifest.permission.CAMERA,
  Manifest.permission.READ_EXTERNAL_STORAGE
)

@RequiresApi(Build.VERSION_CODES.TIRAMISU)
private val permissions = arrayOf(
  Manifest.permission.CAMERA,
  Manifest.permission.READ_MEDIA_IMAGES
)

private val requestPermissions =
  registerRequestPermissions(
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) permissions
    else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) permissionsVersionQ
    else legacyPermissions,
    onShowRationale = ::onCameraShowRationale,
    onPermissionDenied = ::onCameraPermissionDenied,
    onNeverAskAgain = ::onCameraNeverAskAgain,
    requiresPermission = ::takePicture
  )
  
private fun onCameraShowRationale(request: PermissionRequest) {
		request.invoke()
	}

private fun takePicture() {
  tempFile = try {
    ImageUtils.createTempFile(requireContext())
  } catch (e: IOException) {
    Snackbar.make(
      contentBinding.root,
      getString(R.string.common_error_create_capture_file_failed),
      Snackbar.Type.WARNING
    ).show()
    return
  }

  val fileUri = FileProvider.getUriForFile(
    requireContext(),
    "${requireActivity().applicationInfo.packageName}.FileProvider", tempFile!!
  )

  requestActivity.launch(fileUri)
}

private fun onCameraPermissionDenied() {
  DialogFactory.createDeniedPermissions(requireContext()) {
    findNavController().navigateUp()
  }.show()
}

private fun onCameraNeverAskAgain() {
  DialogFactory.createNeverAskPermissions(requireContext()) {
    findNavController().navigateUp()
  }.show()
}

extensions.kt

fun AppCompatActivity.registerRequestPermissions(
	permissions: Array<String>,
	onShowRationale: ((PermissionRequest) -> Unit)? = null,
	onPermissionDenied: (() -> Unit)? = null,
	onNeverAskAgain: (() -> Unit)? = null,
	requiresPermission: (() -> Unit)
): CheckPermissionLauncher {
	val activityResultLauncher = registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) { permissionResult ->
		if (permissionResult.entries.all { result -> result.value }) {
			requiresPermission.invoke()
		} else {
			if (!permissionResult.entries.any { result -> ActivityCompat.shouldShowRequestPermissionRationale(this, result.key) }) {
				onNeverAskAgain?.invoke()
			} else {
				onPermissionDenied?.invoke()
			}
		}
	}

	return CheckPermissionLauncher(activityResultLauncher, permissions, onShowRationale, requiresPermission)
}

fun Fragment.registerRequestPermissions(
	permissions: Array<String>,
	onShowRationale: ((PermissionRequest) -> Unit)? = null,
	onPermissionDenied: (() -> Unit)? = null,
	onNeverAskAgain: (() -> Unit)? = null,
	requiresPermission: (() -> Unit)
): CheckPermissionLauncher {
	val activityResultLauncher = registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) { permissionResult ->
		if (permissionResult.entries.all { result -> result.value }) {
			requiresPermission.invoke()
		} else {
			if (!permissionResult.entries.any { result -> shouldShowRequestPermissionRationale(result.key) }) {
				onNeverAskAgain?.invoke()
			} else {
				onPermissionDenied?.invoke()
			}
		}
	}

	return CheckPermissionLauncher(activityResultLauncher, permissions, onShowRationale, requiresPermission)
}

fun PermissionChecker.verifyPermissions(vararg grantResults: Int): Boolean {
	if (grantResults.isEmpty()) return false

	for (result in grantResults) {
		if (result != PermissionChecker.PERMISSION_GRANTED) return false
	}
	return true
}