content: /**
   * Copyright 2010-present Facebook.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *    http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.facebook;
  
  import android.app.Activity;
  import android.content.Intent;
  import android.os.Bundle;
  import android.util.Log;
  import android.view.View;
  import com.facebook.android.R;
  
  /**
   * This Activity is a necessary part of the overall Facebook login process
   * but is not meant to be used directly. Add this activity to your
   * AndroidManifest.xml to ensure proper handling of Facebook login.
   * <pre>
   * {@code
   * <activity android:name="com.facebook.LoginActivity"
   *           android:theme="@android:style/Theme.Translucent.NoTitleBar"
   *           android:label="@string/app_name" />
   * }
   * </pre>
   * Do not start this activity directly.
   */
  public class LoginActivity extends Activity {
      static final String RESULT_KEY = "com.facebook.LoginActivity:Result";
  
      private static final String TAG = LoginActivity.class.getName();
      private static final String NULL_CALLING_PKG_ERROR_MSG =
              "Cannot call LoginActivity with a null calling package. " +
                      "This can occur if the launchMode of the caller is singleInstance.";
      private static final String SAVED_CALLING_PKG_KEY = "callingPackage";
      private static final String SAVED_AUTH_CLIENT = "authorizationClient";
      private static final String EXTRA_REQUEST = "request";
  
      private String callingPackage;
      private AuthorizationClient authorizationClient;
      private AuthorizationClient.AuthorizationRequest request;
  
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.com_facebook_login_activity_layout);
  
          if (savedInstanceState != null) {
              callingPackage = savedInstanceState.getString(SAVED_CALLING_PKG_KEY);
              authorizationClient = (AuthorizationClient) savedInstanceState.getSerializable(SAVED_AUTH_CLIENT);
          } else {
              callingPackage = getCallingPackage();
              authorizationClient = new AuthorizationClient();
              request = (AuthorizationClient.AuthorizationRequest) getIntent().getSerializableExtra(EXTRA_REQUEST);
          }
  
          authorizationClient.setContext(this);
          authorizationClient.setOnCompletedListener(new AuthorizationClient.OnCompletedListener() {
              @Override
              public void onCompleted(AuthorizationClient.Result outcome) {
                  onAuthClientCompleted(outcome);
              }
          });
          authorizationClient.setBackgroundProcessingListener(new AuthorizationClient.BackgroundProcessingListener() {
              @Override
              public void onBackgroundProcessingStarted() {
                  findViewById(R.id.com_facebook_login_activity_progress_bar).setVisibility(View.VISIBLE);
              }
  
              @Override
              public void onBackgroundProcessingStopped() {
                  findViewById(R.id.com_facebook_login_activity_progress_bar).setVisibility(View.GONE);
              }
          });
      }
  
      private void onAuthClientCompleted(AuthorizationClient.Result outcome) {
          request = null;
  
          int resultCode = (outcome.code == AuthorizationClient.Result.Code.CANCEL) ?
                  RESULT_CANCELED : RESULT_OK;
  
          Bundle bundle = new Bundle();
          bundle.putSerializable(RESULT_KEY, outcome);
  
          Intent resultIntent = new Intent();
          resultIntent.putExtras(bundle);
          setResult(resultCode, resultIntent);
  
          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);
              finish();
              return;
          }
  
          authorizationClient.startOrContinueAuth(request);
      }
  
      @Override
      public void onPause() {
          super.onPause();
  
          authorizationClient.cancelCurrentHandler();
          findViewById(R.id.com_facebook_login_activity_progress_bar).setVisibility(View.GONE);
      }
  
      @Override
      public void onSaveInstanceState(Bundle outState) {
          super.onSaveInstanceState(outState);
  
          outState.putString(SAVED_CALLING_PKG_KEY, callingPackage);
          outState.putSerializable(SAVED_AUTH_CLIENT, authorizationClient);
      }
  
      @Override
      protected void onActivityResult(int requestCode, int resultCode, Intent data) {
          authorizationClient.onActivityResult(requestCode, resultCode, data);
      }
  
      static Bundle populateIntentExtras(AuthorizationClient.AuthorizationRequest request) {
          Bundle extras = new Bundle();
          extras.putSerializable(EXTRA_REQUEST, request);
          return extras;
      }
  }
  