Connect smart device

Recently facebook released new feature to support user authorization from Smart devices. Smart TV, for example.

The doc: https://developers.facebook.com/docs/facebook-login/for-devices

The flow

1. Enable Login from Devices in OAuth Settings pane from app settings dashboard.

2. Connect Device

   Here, we don't need to login or anything with this lib. We can just call for this method. Just set a permissions (scope), that user that is connected via the device will need.

   Permission[] permissions = new Permission[] {
       Permission.PUBLIC_PROFILE,
   };	
   
   SimpleFacebook.getInstance().connectDevice(permissions, new OnConnectDeviceListener() {
   
   	@Override
       public void onComplete(Device device) {
           
           // this is the code, that user should use in next step
           String userCode = device.getUserCode();
   
           // this is internal code for us to check if user made the next step
           String authorizationCode = device.getAuthorizationCode();
       }
   });

3. Now, user should take the userCode from previous step and put manually in https://www.facebook.com/device

4. Poll periodically with intervals of min 5 seconds to get Access Token.

   Use authorizationCode from step (2)

   SimpleFacebook.getInstance().pollDeviceAuthorization(authorizationCode, new OnAuthorizationDeviceListener() {
   
       @Override
       public void onComplete(String accessToken) {
       	// boom!, you have real access token
       }
   
       @Override
       public void onException(Throwable throwable) {
           String errorMessage = throwable.getMessage();
           // this error message means something
       }
   });

#### Error messages that can be retrieved from polling
Error message | Description
--------------|------------
authorization_pending | User has not yet authorized your application. Continue polling at the rate specified in the response (device)
authorization_declined | User has declined to authorize your application. Your device should stop polling, cancel out of the Login flow and send the user back to the initial screen.
slow_down | Your device is polling too frequently. Slow down the polling to the interval specified in the first API call.
code_expired | The device code has expired. Cancel the Device Login flow and send the user back to the initial screen.