LoginFragment.java

/**
 * Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
 *
 * You are hereby granted a non-exclusive, worldwide, royalty-free license to use,
 * copy, modify, and distribute this software in source code or binary form for use
 * in connection with the web services and APIs provided by Facebook.
 *
 * As with any software that integrates with the Facebook platform, your use of
 * this software is subject to the Facebook Developer Principles and Policies
 * [http://developers.facebook.com/policy/]. This copyright notice shall be
 * included in all copies or substantial portions of the software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package com.facebook.login;

import android.app.Activity;
import android.content.ComponentName;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.facebook.R;

/**
 * This Fragment is a necessary part of the overall Facebook login process
 * but is not meant to be used directly.
 *
 * @see com.facebook.FacebookActivity
 */

public class LoginFragment extends Fragment {
    static final String RESULT_KEY = "com.facebook.LoginFragment:Result";
    static final String REQUEST_KEY = "com.facebook.LoginFragment:Request";
    static final String EXTRA_REQUEST = "request";

    private static final String TAG = "LoginFragment";
    private static final String NULL_CALLING_PKG_ERROR_MSG =
            "Cannot call LoginFragment with a null calling package. " +
                    "This can occur if the launchMode of the caller is singleInstance.";
    private static final String SAVED_LOGIN_CLIENT = "loginClient";

    private String callingPackage;
    private LoginClient loginClient;
    private LoginClient.Request request;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (savedInstanceState != null) {
            loginClient = savedInstanceState.getParcelable(SAVED_LOGIN_CLIENT);
            loginClient.setFragment(this);
        } else {
            loginClient = createLoginClient();
        }

        loginClient.setOnCompletedListener(new LoginClient.OnCompletedListener() {
            @Override
            public void onCompleted(LoginClient.Result outcome) {
                onLoginClientCompleted(outcome);
            }
        });

        Activity activity = getActivity();
        if (activity == null) {
            return;
        }

        initializeCallingPackage(activity);
        if (activity.getIntent() != null) {
            Intent intent = activity.getIntent();
            Bundle bundle = intent.getBundleExtra(REQUEST_KEY);
            request = bundle.getParcelable(EXTRA_REQUEST);
        }
    }

    protected LoginClient createLoginClient() {
        return new LoginClient(this);
    }

    @Override
    public void onDestroy() {
        loginClient.cancelCurrentHandler();
        super.onDestroy();
    }

    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
                             @Nullable Bundle savedInstanceState) {
        final View view = inflater.inflate(R.layout.com_facebook_login_fragment, container, false);

        loginClient.setBackgroundProcessingListener(
                new LoginClient.BackgroundProcessingListener() {
                    @Override
                    public void onBackgroundProcessingStarted() {
                        view.findViewById(R.id.com_facebook_login_activity_progress_bar)
                                .setVisibility(View.VISIBLE);
                    }

                    @Override
                    public void onBackgroundProcessingStopped() {
                        view.findViewById(R.id.com_facebook_login_activity_progress_bar)
                                .setVisibility(View.GONE);
                    }
                });

        return view;
    }

    private void onLoginClientCompleted(LoginClient.Result outcome) {
        request = null;

        int resultCode = (outcome.code == LoginClient.Result.Code.CANCEL) ?
                Activity.RESULT_CANCELED : Activity.RESULT_OK;

        Bundle bundle = new Bundle();
        bundle.putParcelable(RESULT_KEY, outcome);

        Intent resultIntent = new Intent();
        resultIntent.putExtras(bundle);

        // The activity might be detached we will send a cancel result in onDetach
        if (isAdded()) {
            getActivity().setResult(resultCode, resultIntent);
            getActivity().finish();
        }
    }

    @Override
    public void onResume() {
        super.onResume();

        // If the calling package is null, this generally means that the callee was started
        // with a launchMode of singleInstance. Unfortunately, Android does not allow a result
        // to be set when the callee is a singleInstance, so we log an error and return.
        if (callingPackage == null) {
            Log.e(TAG, NULL_CALLING_PKG_ERROR_MSG);
            getActivity().finish();
            return;
        }

        loginClient.startOrContinueAuth(request);
    }

    @Override
    public void onPause() {
        super.onPause();

        getActivity().findViewById(R.id.com_facebook_login_activity_progress_bar).setVisibility(
                View.GONE);
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        loginClient.onActivityResult(requestCode, resultCode, data);
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);

        outState.putParcelable(SAVED_LOGIN_CLIENT, loginClient);
    }

    private void initializeCallingPackage(final Activity activity) {
        ComponentName componentName = activity.getCallingActivity();
        if (componentName == null) {
            return;
        }
        callingPackage = componentName.getPackageName();
    }

    LoginClient getLoginClient() {
        return loginClient;
    }
}