* This Activity requests permissions to access the camera ({@link android.Manifest.permission#CAMERA}) * when the 'Show Camera' button is clicked to display the camera preview. * Contacts permissions (({@link android.Manifest.permission#READ_CONTACTS} and ({@link * android.Manifest.permission#WRITE_CONTACTS})) are requested when the 'Show and Add Contacts' * button is * clicked to display the first contact in the contacts database and to add a dummy contact * directly to it. Permissions are verified and requested through compat helpers in the support v4 * library, in this Activity using {@link ActivityCompat}. * First, permissions are checked if they have already been granted through {@link * ActivityCompat#checkSelfPermission(Context, String)}. * If permissions have not been granted, they are requested through * {@link ActivityCompat#requestPermissions(Activity, String[], int)} and the return value checked * in * a callback to the {@link android.support.v4.app.ActivityCompat.OnRequestPermissionsResultCallback} * interface. *
* Before requesting permissions, {@link ActivityCompat#shouldShowRequestPermissionRationale(Activity, * String)} * should be called to provide the user with additional context for the use of permissions if they * have been denied previously. *
* If this sample is executed on a device running a platform version below M, all permissions * declared * in the Android manifest file are always granted at install time and cannot be requested at run * time. *
* This sample targets the M platform and must therefore request permissions at runtime. Change the * targetSdk in the file 'Application/build.gradle' to 22 to run the application in compatibility * mode. * Now, if a permission has been disable by the system through the application settings, disabled * APIs provide compatibility data. * For example the camera cannot be opened or an empty list of contacts is returned. No special * action is required in this case. *
* (This class is based on the MainActivity used in the SimpleFragment sample template.) */ public class MainActivity extends AppCompatActivity implements ActivityCompat.OnRequestPermissionsResultCallback { public static final String TAG = "MainActivity"; /** * Id to identify a camera permission request. */ private static final int REQUEST_CAMERA = 0; /** * Id to identify a contacts permission request. */ private static final int REQUEST_CONTACTS = 1; /** * Permissions required to read and write contacts. Used by the {@link ContactsFragment}. */ private static String[] PERMISSIONS_CONTACT = {Manifest.permission.READ_CONTACTS, Manifest.permission.WRITE_CONTACTS}; /** * Root of the layout of this Activity. */ private View mLayout; /** * Called when the 'show camera' button is clicked. * Callback is defined in resource layout definition. */ public void showCamera(View view) { Log.i(TAG, "Show camera button pressed. Checking permission."); // BEGIN_INCLUDE(camera_permission) // Check if the Camera permission is already available. if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) { // Camera permission has not been granted. requestCameraPermission(); } else { // Camera permissions is already available, show the camera preview. Log.i(TAG, "CAMERA permission has already been granted. Displaying camera preview."); showCameraPreview(); } // END_INCLUDE(camera_permission) } /** * Requests the Camera permission. * If the permission has been denied previously, a SnackBar will prompt the user to grant the * permission, otherwise it is requested directly. */ private void requestCameraPermission() { Log.i(TAG, "CAMERA permission has NOT been granted. Requesting permission."); // BEGIN_INCLUDE(camera_permission_request) if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.CAMERA)) { // Provide an additional rationale to the user if the permission was not granted // and the user would benefit from additional context for the use of the permission. // For example if the user has previously denied the permission. Log.i(TAG, "Displaying camera permission rationale to provide additional context."); Snackbar.make(mLayout, R.string.permission_camera_rationale, Snackbar.LENGTH_INDEFINITE) .setAction(R.string.ok, new View.OnClickListener() { @Override public void onClick(View view) { ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.CAMERA}, REQUEST_CAMERA); } }) .show(); } else { // Camera permission has not been granted yet. Request it directly. ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CAMERA}, REQUEST_CAMERA); } // END_INCLUDE(camera_permission_request) } /** * Called when the 'show camera' button is clicked. * Callback is defined in resource layout definition. */ public void showContacts(View v) { Log.i(TAG, "Show contacts button pressed. Checking permissions."); // Verify that all required contact permissions have been granted. if (ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_CONTACTS) != PackageManager.PERMISSION_GRANTED || ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_CONTACTS) != PackageManager.PERMISSION_GRANTED) { // Contacts permissions have not been granted. Log.i(TAG, "Contact permissions has NOT been granted. Requesting permissions."); requestContactsPermissions(); } else { // Contact permissions have been granted. Show the contacts fragment. Log.i(TAG, "Contact permissions have already been granted. Displaying contact details."); showContactDetails(); } } /** * Requests the Contacts permissions. * If the permission has been denied previously, a SnackBar will prompt the user to grant the * permission, otherwise it is requested directly. */ private void requestContactsPermissions() { // BEGIN_INCLUDE(contacts_permission_request) if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.READ_CONTACTS) || ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_CONTACTS)) { // Provide an additional rationale to the user if the permission was not granted // and the user would benefit from additional context for the use of the permission. // For example, if the request has been denied previously. Log.i(TAG, "Displaying contacts permission rationale to provide additional context."); // Display a SnackBar with an explanation and a button to trigger the request. Snackbar.make(mLayout, R.string.permission_contacts_rationale, Snackbar.LENGTH_INDEFINITE) .setAction(R.string.ok, new View.OnClickListener() { @Override public void onClick(View view) { ActivityCompat .requestPermissions(MainActivity.this, PERMISSIONS_CONTACT, REQUEST_CONTACTS); } }) .show(); } else { // Contact permissions have not been granted yet. Request them directly. ActivityCompat.requestPermissions(this, PERMISSIONS_CONTACT, REQUEST_CONTACTS); } // END_INCLUDE(contacts_permission_request) } /** * Display the {@link CameraPreviewFragment} in the content area if the required Camera * permission has been granted. */ private void showCameraPreview() { getSupportFragmentManager().beginTransaction() .replace(R.id.sample_content_fragment, CameraPreviewFragment.newInstance()) .addToBackStack("contacts") .commit(); } /** * Display the {@link ContactsFragment} in the content area if the required contacts * permissions * have been granted. */ private void showContactDetails() { getSupportFragmentManager().beginTransaction() .replace(R.id.sample_content_fragment, ContactsFragment.newInstance()) .addToBackStack("contacts") .commit(); } /** * Callback received when a permissions request has been completed. */ @Override public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { if (requestCode == REQUEST_CAMERA) { // BEGIN_INCLUDE(permission_result) // Received permission result for camera permission. Log.i(TAG, "Received response for Camera permission request."); // Check if the only required permission has been granted if (grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED) { // Camera permission has been granted, preview can be displayed Log.i(TAG, "CAMERA permission has now been granted. Showing preview."); Snackbar.make(mLayout, R.string.permision_available_camera, Snackbar.LENGTH_SHORT).show(); } else { Log.i(TAG, "CAMERA permission was NOT granted."); Snackbar.make(mLayout, R.string.permissions_not_granted, Snackbar.LENGTH_SHORT).show(); } // END_INCLUDE(permission_result) } else if (requestCode == REQUEST_CONTACTS) { Log.i(TAG, "Received response for contact permissions request."); // We have requested multiple permissions for contacts, so all of them need to be // checked. if (PermissionUtil.verifyPermissions(grantResults)) { // All required permissions have been granted, display contacts fragment. Snackbar.make(mLayout, R.string.permision_available_contacts, Snackbar.LENGTH_SHORT) .show(); } else { Log.i(TAG, "Contacts permissions were NOT granted."); Snackbar.make(mLayout, R.string.permissions_not_granted, Snackbar.LENGTH_SHORT) .show(); } } else { super.onRequestPermissionsResult(requestCode, permissions, grantResults); } } public void onBackClick(View view) { getSupportFragmentManager().popBackStack(); } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mLayout = findViewById(R.id.sample_main_layout); if (savedInstanceState == null) { FragmentTransaction transaction = getSupportFragmentManager().beginTransaction(); RuntimePermissionsFragment fragment = new RuntimePermissionsFragment(); transaction.replace(R.id.sample_content_fragment, fragment); transaction.commit(); } } }