RuntimePermissionsExtended

Kotlin Serbia meetup #4

Talk about Kotlin and its usage in Android Runtime permission handling.

Transcript

1. RuntimePermissionsExtended Nebojša Vukšić
2. Nebojša Vukšić Android developer @ codecentric Founder of Kotlin User Group Serbia TheTechW0lf nebojsa92vuksic@gmail.com
3. Kotlin User Group Serbia https://www.meetup.com/Serbia-Kotlin-User-Group https://www.facebook.com/kotlinserbia/ https://twitter.com/kotlin_serbia
4. Android permissions definition • part of Android security system • used to control access to system features, data, etc. • apps are in sandbox • needed permission needs to be annotated in AndroidManifest.xml <uses-permission android:name="android.permission.CAMERA" />
5. Pre-Marshmallow • targetSdkVersion < 23 • all permissions are granted in install time • less control for user • no explanation for permission usage • when app is updated we need to check additional permissions
6. After Marshmallow • targetSdkVersion >= 23 • permissions are requested in runtime • all edge cases need to be covered • User can revoke permission from settings screen • Process is revoked
7. After Marshmallow • targetSdkVersion >= 23 • permissions are requested in runtime • all edge cases need to be covered • User can revoke permission from settings screen • Process is revoked
8. Permission protection level • Normal permissions • Dangerous permissions • Signature permissions • Signature and system permissions
9. Permission protection level • Normal permissions • Dangerous permissions • Signature permissions • Signature and system permissions
10. Normal permissions • granted when app is installed • they are not risk for users data privacy and can’t affect other apps Permission list: • ACCESS_NETWORK_STATE • BLUETOOTH • INTERNET • NFC • VIBRATE • WAKE_LOCK • etc...
11. Permission protection level • Normal permissions • Dangerous permissions • Signature permissions • Signature and system permissions
12. Permission protection level • Normal permissions • Dangerous permissions • Signature permissions • Signature and system permissions
13. Dangerous permissions • requested in runtime • when permission from one group is granted, all permissions in group are granted • they are risk for data privacy and can affect other apps
14. Runtime permission user flow
16. Twitter user flow example
19. Let’s see some code...
20. Pre-Marshmallow - targetSdk < 23 import kotlinx.android.synthetic.main.activity_camera.* class CameraActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_camera) setSupportActionBar(toolbar) //Start camera preview startCameraPreviewScreen() } }
21. After Marshmallow - targetSdk >= 23 class CameraActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_camera) setSupportActionBar(toolbar) //Start camera preview if (PermissionChecker.checkSelfPermission(this, android.Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) { startCameraPreviewScreen() } } }
22. After Marshmallow - targetSdk >= 23 class CameraActivity : AppCompatActivity() { private val REQUEST_CAMERA_PERMISSION: Int = 1 override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_camera) setSupportActionBar(toolbar) //Start camera preview if (PermissionChecker.checkSelfPermission(this, android.Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) { startCameraPreviewScreen() } else { ActivityCompat.requestPermissions(this, arrayOf<String>(android.Manifest.permission.CAMERA), REQUEST_CAMERA_PERMISSION) } } }
23. After Marshmallow - targetSdk >= 23 override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) { when (requestCode) { REQUEST_CAMERA_PERMISSION -> { if (grantResults.filterNot { it == PackageManager.PERMISSION_GRANTED }.isEmpty()) { startCameraPreviewScreen() } else { if (ActivityCompat.shouldShowRequestPermissionRationale(this, android.Manifest.permission.CAMERA)) { showSnackBarWithExplanation() } else { startGoToSettingsScreenIntent() } } } } }
24. After Marshmallow - targetSdk >= 23 class CameraActivity : AppCompatActivity() { private val REQUEST_CAMERA_PERMISSION: Int = 1 override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_camera) setSupportActionBar(toolbar) //Start camera preview if (PermissionChecker.checkSelfPermission(this, android.Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) { startCameraPreviewScreen() } else { if (ActivityCompat.shouldShowRequestPermissionRationale(this, android.Manifest.permission.CAMERA)) { showSnackBarWithExplanation() } else { ActivityCompat.requestPermissions(this, arrayOf(android.Manifest.permission.CAMERA), REQUEST_CAMERA_PERMISSION) } } } }
25. Lots of boilerplate code
26. It’s time to become extended!
27. RuntimePermissionExtended class CameraActivity : AppCompatActivity() { private val REQUEST_CAMERA_PERMISSION: Int = 1 override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_camera) setSupportActionBar(toolbar) //Start camera preview if (PermissionChecker.checkSelfPermission(this, android.Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) { startCameraPreviewScreen() } else { if (ActivityCompat.shouldShowRequestPermissionRationale(this, android.Manifest.permission.CAMERA)) { showSnackBarWithExplanation() } else { ActivityCompat.requestPermissions(this, arrayOf(android.Manifest.permission.CAMERA), REQUEST_CAMERA_PERMISSION) } } } } OnPermissionGranted Block OnExplanationNeeded Block OnPermissionDenied Block
28. RuntimePermissionExtended inline fun handlePermission(onGranted: () -> Unit, onExplanationNeeded: () -> Unit, onDenied: () -> Unit) { if (PermissionChecker.checkSelfPermission(this, android.Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) { onGranted() } else { if (ActivityCompat.shouldShowRequestPermissionRationale(this, android.Manifest.permission.CAMERA)) { onExplanationNeeded() } else { onDenied() } } } inline modifier - inlines onGranted, onDenied an onExplanationNeeded functions on call site
29. RuntimePermissionExtended class CameraActivity : AppCompatActivity() { private val REQUEST_CAMERA_PERMISSION: Int = 1 override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_camera) setSupportActionBar(toolbar) //Start camera preview handlePermission( onGranted = { startCameraPreviewScreen() }, onExplanationNeeded = { //Show explanation }, onDenied = { ActivityCompat.requestPermissions(this, arrayOf(android.Manifest.permission.CAMERA), REQUEST_CAMERA_PERMISSION) } ) } }
30. RuntimePermissionExtended inline fun handlePermission(permission: AppPermission, onGranted: () -> Unit, onExplanationNeeded: () -> Unit, onDenied: () -> Unit) { if (PermissionChecker.checkSelfPermission(this, permission.permissionName) == PackageManager.PERMISSION_GRANTED) { onGranted() } else { if (ActivityCompat.shouldShowRequestPermissionRationale(this, permission.permissionName)) { onExplanationNeeded() } else { onDenied() } } } sealed class AppPermission(val permissionName: String, val requestCode: Int, val deniedMessageId: Int, val explanationMessageId: Int) { companion object { val permissions: List<AppPermission> by lazy { listOf(CAMERA) } } object CAMERA: AppPermission(permissionName = Manifest.permission.CAMERA, requestCode = 1, deniedMessageId = R.string.permission_camera_denied, explanationMessageId = R.string.permission_camera_explanation) }
31. RuntimePermissionExtended class CameraActivity : AppCompatActivity() { private val REQUEST_CAMERA_PERMISSION: Int = 1 override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_camera) setSupportActionBar(toolbar) //Start camera preview handlePermission(AppPermission.CAMERA, onGranted = { startCameraPreviewScreen() }, onExplanationNeeded = { //Show explanation }, onDenied = { ActivityCompat.requestPermissions(this, arrayOf(android.Manifest.permission.CAMERA), REQUEST_CAMERA_PERMISSION) } ) } } No information about requested permission
32. RuntimePermissionExtended inline fun handlePermission(permission: AppPermission, onGranted: () -> Unit, onExplanationNeeded: (AppPermission) -> Unit, onDenied: (AppPermission) -> Unit) { if (PermissionChecker.checkSelfPermission(this, permission.permissionName) == PackageManager.PERMISSION_GRANTED) { onGranted() } else { if (ActivityCompat.shouldShowRequestPermissionRationale(this, permission.permissionName)) { onExplanationNeeded(permission) } else { onDenied(permission) } } } sealed class AppPermission(val permissionName: String, val requestCode: Int, val deniedMessageId: Int, val explanationMessageId: Int) { companion object { val permissions: List<AppPermission> by lazy { listOf(CAMERA) } } object CAMERA: AppPermission(permissionName = Manifest.permission.CAMERA, requestCode = 1, deniedMessageId = R.string.permission_camera_denied, explanationMessageId = R.string.permission_camera_explanation) }
33. RuntimePermissionExtended class CameraActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_camera) setSupportActionBar(toolbar) //Start camera preview handlePermission(AppPermission.CAMERA, onGranted = { startCameraPreviewScreen() }, onExplanationNeeded = { permission -> showSnackBarWithExplanation(permission.explanationMessageId) }, onDenied = { permission -> ActivityCompat.requestPermissions(this, arrayOf(permission.permissionName), permission.requestCode) } ) } }
34. RuntimePermissionExtended class CameraActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_camera) setSupportActionBar(toolbar) //Start camera preview handlePermission(AppPermission.CAMERA, onGranted = { startCameraPreviewScreen() }, onExplanationNeeded = { showSnackBarWithExplanation(it.explanationMessageId) }, onDenied = { ActivityCompat.requestPermissions(this, arrayOf(it.permissionName), it.requestCode) } ) } }
35. RuntimePermissionExtended inline fun handlePermission(permission: AppPermission, onGranted: () -> Unit, onExplanationNeeded: (AppPermission) -> Unit, onDenied: (AppPermission) -> Unit) { if (PermissionChecker.checkSelfPermission(this, permission.permissionName) == PackageManager.PERMISSION_GRANTED) { onGranted() } else { if (ActivityCompat.shouldShowRequestPermissionRationale(this, permission.permissionName)) { onExplanationNeeded(permission) } else { onDenied(permission) } } }
36. RuntimePermissionExtended inline fun Activity.handlePermission(permission: AppPermission, onGranted: () -> Unit, onExplanationNeeded: (AppPermission) -> Unit, onDenied: (AppPermission) -> Unit) { if (PermissionChecker.checkSelfPermission(this, permission.permissionName) == PackageManager.PERMISSION_GRANTED) { onGranted() } else { if (ActivityCompat.shouldShowRequestPermissionRationale(this, permission.permissionName)) { onExplanationNeeded(permission) } else { onDenied(permission) } } } fun Activity.isPermissionGranted(permission: AppPermission) = (PermissionChecker.checkSelfPermission(this, android.Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) fun Activity.isExplanationNeeded(permission: AppPermission) = ActivityCompat.shouldShowRequestPermissionRationale(this, permission.permissionName)
37. RuntimePermissionExtended inline fun Activity.handlePermission(permission: AppPermission, onGranted: () -> Unit, onExplanationNeeded: (AppPermission) -> Unit, onDenied: (AppPermission) -> Unit) { if (isPermissionGranted(this, permission.permissionName) == PackageManager.PERMISSION_GRANTED) { onGranted() } else { if (isExplanationNeeded(this, permission.permissionName)) { onExplanationNeeded(permission) } else { onDenied(permission) } } } fun Activity.isPermissionGranted(permission: AppPermission) = (PermissionChecker.checkSelfPermission(this, android.Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) fun Activity.isExplanationNeeded(permission: AppPermission) = ActivityCompat.shouldShowRequestPermissionRationale(this, permission.permissionName)
38. RuntimePermissionExtended inline fun Activity.handlePermission(permission: AppPermission, onGranted: () -> Unit, onExplanationNeeded: (AppPermission) -> Unit, onDenied: (AppPermission) -> Unit) { if (isPermissionGranted(this, permission.permissionName) == PackageManager.PERMISSION_GRANTED) { onGranted() } else { if (isExplanationNeeded(this, permission.permissionName)) { onExplanationNeeded(permission) } else { onDenied(permission) } } } fun Activity.isPermissionGranted(permission: AppPermission) = (PermissionChecker.checkSelfPermission(this, android.Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) fun Activity.isExplanationNeeded(permission: AppPermission) = ActivityCompat.shouldShowRequestPermissionRationale(this, permission.permissionName)
39. RuntimePermissionExtended inline fun Activity.handlePermission(permission: AppPermission, onGranted: () -> Unit, onExplanationNeeded: (AppPermission) -> Unit, onDenied: (AppPermission) -> Unit) { when { isPermissionGranted(permission) -> onGranted() isExplanationNeeded(permission) -> onExplanationNeeded(permission) else -> onDenied(permission) } } fun Activity.isPermissionGranted(permission: AppPermission) = (PermissionChecker.checkSelfPermission(this, android.Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) fun Activity.isExplanationNeeded(permission: AppPermission) = ActivityCompat.shouldShowRequestPermissionRationale(this, permission.permissionName)
40. RuntimePermissionExtended class CameraActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_camera) setSupportActionBar(toolbar) //Start camera preview handlePermission(AppPermission.CAMERA, onGranted = { startCameraPreviewScreen() }, onExplanationNeeded = { showSnackBarWithExplanation(it.explanationMessageId) }, onDenied = { ActivityCompat.requestPermissions(this, arrayOf(it.permissionName), it.requestCode) } ) } } fun Activity.requestPermission(permission: AppPermission) = ActivityCompat.requestPermissions(this, arrayOf(permission.permissionName), permission.requestCode)
41. RuntimePermissionExtended class CameraActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_camera) setSupportActionBar(toolbar) //Start camera preview handlePermission(AppPermission.CAMERA, onGranted = { startCameraPreviewScreen() }, onExplanationNeeded = { showSnackBarWithExplanation(it.explanationMessageId) }, onDenied = { requestPermission(it) } ) } } fun Activity.requestPermission(permission: AppPermission) = ActivityCompat.requestPermissions(this, arrayOf(permission.permissionName), permission.requestCode)
42. Don’t forget about onRequestPermissionResult
43. override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) { when (requestCode) { REQUEST_CAMERA_PERMISSION -> { if (grantResults.filterNot { it == PackageManager.PERMISSION_GRANTED }.isEmpty()) { startCameraPreviewScreen() } else { if (ActivityCompat.shouldShowRequestPermissionRationale(this, android.Manifest.permission.CAMERA)) { showSnackBarWithExplanation() } else { startGoToSettingsIntent() } } } } } RuntimePermissionExtended
44. fun Activity.onPermissionRequestResultReceived(requestCode: Int, grantResults: IntArray, onGranted: () -> Unit, onExplanationNeeded: (AppPermission) -> Unit, onDenied: (AppPermission) -> Unit) { AppPermission.permissions.find { requestCode == it.requestCode }?.let { when { arePermissionsGranted(grantResults) -> onGranted() isExplanationNeeded(it) -> onExplanationNeeded(it) else -> onDenied(it) } } } private fun arePermissionsGranted(grantResults: IntArray) = grantResults.filterNot { it == PackageManager.PERMISSION_GRANTED }.isEmpty() RuntimePermissionExtended
45. override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) { onPermissionRequestResultReceived(requestCode, grantResults, onGranted = { startCameraPreviewScreen() }, onExplanationNeeded = { showSnackBarWithExplanation(it.explanationMessageId) }, onDenied = { startGoToSettingsScreenIntent() } ) } RuntimePermissionExtended
46. Overview and summary
47. Overview - before and now class CameraActivity : AppCompatActivity() { private val REQUEST_CAMERA_PERMISSION: Int = 1 override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_camera) setSupportActionBar(toolbar) //Start camera preview if (PermissionChecker.checkSelfPermission(this, android.Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) { startCameraPreviewScreen() } else { if (ActivityCompat.shouldShowRequestPermissionRationale(this, android.Manifest.permission.CAMERA)) { showSnackBarWithExplanation() } else { ActivityCompat.requestPermissions(this, arrayOf(android.Manifest.permission.CAMERA), REQUEST_CAMERA_PERMISSION) } } } override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) { when (requestCode) { REQUEST_CAMERA_PERMISSION -> { if (grantResults.filterNot { it == PackageManager.PERMISSION_GRANTED }.isEmpty()) { showCameraPreviewScreen() } else { if (ActivityCompat.shouldShowRequestPermissionRationale(this, android.Manifest.permission.CAMERA)){ showSnackBarWithExplanation() } else { startGoToSettingsScreenIntent() } } } } } } class CameraActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_camera) setSupportActionBar(toolbar) handlePermission(AppPermission.CAMERA, onGranted = { startCameraPreviewScreen() }, onExplanationNeeded = { showSnackbarExplanation }, onDenied = { requestPermission(it) } ) } override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) { onPermissionRequestResultReceived(requestCode, grantResults, onGranted = { startCameraPreviewScreen() }, onExplanationNeeded = { showSnackbarExplanation() }, onDenied = { startGoToSettingsScreenIntent() } ) } } Before Now
48. Summary • use PermissionChecker • extension functions • higher order functions • use combination of two concepts to reduce amount of boilerplate code • use inline modifier
49. Resources • RuntimePermissionsExtended • Official Kotlin documentation • Official Kotlin Github • Kotlin koans • Awesome Kotlin – collection of materials • Slack kanal • #droidconpl2015 - Shintaro Katafuchi 'Managing Runtime Permissions' • Sonja Kesić from Endava: May I? - droidcon Zagreb 2016 • Runtime Permissions - official Android documentation • PermissionsDispatcher library
50. Android Serbia Slack team of local Android community Join us: https://android-serbia.slack.com/
51. Questions?.Answers!!
52. Thank you!
53. Nebojša Vukšić Android developer @ codecentric Founder of Kotlin User Group Serbia nebojsa92vuksic@gmail.com Kotlin User Group Serbia https://www.meetup.com/Serbia-Kotlin-User-Group https://www.facebook.com/kotlinserbia/ https://twitter.com/kotlin_serbia TheTechW0lf