FacebookActivity.java

package com.geored.gui;

import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

import com.facebook.LoggingBehaviors;
import com.facebook.Session;
import com.facebook.SessionState;
import com.facebook.Settings;
import com.facebook.android.R;
import com.geored.rest.Main;
import com.geored.rest.ServicioRestAutenticacion;
import com.geored.rest.exception.RestBlowUpException;
import com.geored.rest.exception.UnauthorizedException;

public class FacebookActivity extends GenericActivity {
	//static final String URL_PREFIX_FRIENDS = "https://graph.facebook.com/me/friends?access_token=";
	TextView textInstructionsOrLink;
	Button buttonLoginLogout;
	Session.StatusCallback statusCallback = new SessionStatusCallback();

	@Override
	protected void goToPreviousActivity(){	
        Intent setIntent = new Intent(this,Main.class);
        startActivity(setIntent); 
	}
	
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_facebook);
		buttonLoginLogout = (Button) findViewById(R.id.buttonLoginLogout);
		textInstructionsOrLink = (TextView) findViewById(R.id.instructionsOrLink);
		Settings.addLoggingBehavior(LoggingBehaviors.INCLUDE_ACCESS_TOKENS);
		Session session = Session.getActiveSession();
		if (session == null) {
			if (savedInstanceState != null) {
				session = Session.restoreSession(this, null, statusCallback,
						savedInstanceState);
			}
			if (session == null) {
				session = new Session(this);
			}
			Session.setActiveSession(session);
			if (session.getState().equals(SessionState.CREATED_TOKEN_LOADED)) {
				session.openForRead(new Session.OpenRequest(this)
						.setCallback(statusCallback));
			}
		}
		updateView();
	}

	@Override
	public void onStart() {
		super.onStart();
		Session.getActiveSession().addCallback(statusCallback);
	}

	@Override
	public void onStop() {
		super.onStop();
		Session.getActiveSession().removeCallback(statusCallback);
	}

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

	@Override
	protected void onSaveInstanceState(Bundle outState) {
		super.onSaveInstanceState(outState);
		Session session = Session.getActiveSession();
		Session.saveSession(session, outState);
	}

	private void updateView() {
		Session session = Session.getActiveSession();
		if (session.isOpened()) {
			textInstructionsOrLink.setText("Bienvenido a Geored.uy, usted se a autenticado por Facebook, estamos chequeando esta sea una cuenta valida.");
			buttonLoginLogout.setText(R.string.logout);
			buttonLoginLogout.setOnClickListener(new OnClickListener() {
				public void onClick(View view) {
					onClickLogout();
				}
			});
		} else {
			textInstructionsOrLink.setText(R.string.instructions);
			buttonLoginLogout.setText(R.string.login);
			buttonLoginLogout.setOnClickListener(new OnClickListener() {
				public void onClick(View view) {
					onClickLogin();
				}
			});
		}
	}

	private void onClickLogin() {
		final Session session = Session.getActiveSession();
		if (!session.isOpened() && !session.isClosed()) {
			session.openForRead(new Session.OpenRequest(this).setCallback(statusCallback));
		} else {
			Session.openActiveSession(this, true, statusCallback);
		}
	}

	private void onClickLogout() {
		Session session = Session.getActiveSession();
		if (!session.isClosed()) {
			session.closeAndClearTokenInformation();
		}
	}

	private class SessionStatusCallback implements Session.StatusCallback {
		@Override
		public void call(final Session session, SessionState state, Exception exception) {
			if (state.isOpened()) {
				AsyncTask<Void, Void, Void> serverLoginTask = new AsyncTask<Void, Void, Void>() {
					@Override
					protected Void doInBackground(Void... params) {
						try {
							ServicioRestAutenticacion.loginFacebook(session.getAccessToken());
							goToActivity(UsuarioActivity.class);
						} catch (RestBlowUpException e) {
							Log.e("Error", e.getMessage(), e);
						} catch (UnauthorizedException e) {
							Log.e("Warning", "Unauthorized - " + e.getMessage(), e);
						}
						return null;
					}
				};
				serverLoginTask.execute();
			}
			updateView();
		}
	}
}