Permissions in marshmallow

I expect you to first go and have a look at this page in the Android Bible about permissions in marshmallow. Especially have a look at how to:

• Request the permissions you need
• Handle the permissions request response

Requesting for permission

You might have seen a code snippet like below in the training page.

// Here, thisActivity is the current activity
if (ContextCompat.checkSelfPermission(thisActivity,
                Manifest.permission.READ_CONTACTS)
        != PackageManager.PERMISSION_GRANTED) {
    // Should we show an explanation?
    if (ActivityCompat.shouldShowRequestPermissionRationale(thisActivity,
            Manifest.permission.READ_CONTACTS)) {
        //show user the reason for permission
    } else {
        //request permission
    }
}

Pay Attention

Lets just dive into the only tricky part here - shouldShowRequestPermissionRationale() returns

• true if
  • The app has requested this permission previously and the user denied the request in the dialog
  • User has toggled off the permission in the settings (Even if the app hasn't requested the permission yet, if the user just has toggled the switch on and off in the settings page, you are expected to show the rationale)
• false if
  • The app didn't request for this permission yet
  • The user denied the permission and chose Don't ask again option
  • The device policy prohibits the app from having that permission (Mostly in enterprise cenarios)

Consider this possible case

The above code works pretty much in most practical cases. Let us consider this case:

• The user has chosen Don't ask again for contacts access in the past (which will most probably never happen if you have requested permissions gracefully and if the user made the decision conciously)
• And now the user wants to send a contact to his friend

There is no way to detect using the above code that we were denied the permission, and ask him to grant the permission via application settings.

The way out

Check for shouldShowRequestPermissionRationale() before and after asking permission. If it returns false both the times then the user chose 'Don't ask again' in the past or the device policy doesn't allow for that permission.

  boolean before, after;
  
  public void requestContactsPermission() {
      if (ContextCompat.checkSelfPermission(thisActivity,
                      Manifest.permission.READ_CONTACTS)
              != PackageManager.PERMISSION_GRANTED) {
          // Should we show an explanation?
+         before = ActivityCompat.shouldShowRequestPermissionRationale(thisActivity,
+                 Manifest.permission.READ_CONTACTS);
+         if (before) {
              //show user the reason for permission
          } else {
              //request permission
          }
      }
  }
  
  @Override
  public void onRequestPermissionsResult(int requestCode,
          String permissions[], int[] grantResults) {
      switch (requestCode) {
          case MY_PERMISSIONS_REQUEST_READ_CONTACTS: {
              if (grantResults.length > 0
                  && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                  // permission was granted, yay! Do the
                  // contacts-related task you need to do.
              } else {
+                 after = ActivityCompat.shouldShowRequestPermissionRationale(
+                 thisActivity,
+                 Manifest.permission.READ_CONTACTS);
+                 boolean goToSettings = !(after || before);
+                 showRationale(goToSettings);
              }
              return;
          }
      }
  }

If both before and after are false, then show the user a dialog explaining that we need the contacts permission with a 'GO TO SETTINGS' button. On click take him to your application in the settings like this :

private void goToSettings() {
    Intent intent = new Intent();
    intent.setAction(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
    Uri uri = Uri.parse("package:" + getPackageName());
    intent.setData(uri);
    startActivity(intent);
}