Android Manifest for Login demo app

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.ccny.semanticweb"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="14"
        android:targetSdkVersion="17" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.ccny.semanticweb.LoginActivity"
            android:label="@string/title_activity_login"
            android:windowSoftInputMode="adjustResize|stateVisible" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name="com.ccny.semanticweb.MainActivity"
            android:label="@string/title_activity_main" >
        </activity>
        <activity
            android:name="com.ccny.semanticweb.SettingsActivity"
            android:label="@string/title_activity_settings"
            android:parentActivityName="com.ccny.semanticweb.MainActivity" >
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value="com.ccny.semanticweb.MainActivity" />
        </activity>
    </application>

</manifest>

LoginActivity.java

package com.ccny.semanticweb;

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Build;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.View;
import android.view.inputmethod.EditorInfo;
import android.widget.EditText;
import android.widget.TextView;

/**
 * Activity which displays a login screen to the user, offering registration as
 * well.
 */
public class LoginActivity extends Activity {
  /**
	 * A dummy authentication store containing known user names and passwords.
	 * TODO: remove after connecting to a real authentication system.
	 */
	private static final String[] DUMMY_CREDENTIALS = new String[] {
			"foo@example.com:hello", "bar@example.com:world" };

	/**
	 * The default email to populate the email field with.
	 */
	public static final String EXTRA_EMAIL = "com.example.android.authenticatordemo.extra.EMAIL";

	/**
	 * Keep track of the login task to ensure we can cancel it if requested.
	 */
	private UserLoginTask mAuthTask = null;

	// Values for email and password at the time of the login attempt.
	private String mEmail;
	private String mPassword;

	// UI references.
	private EditText mEmailView;
	private EditText mPasswordView;
	private View mLoginFormView;
	private View mLoginStatusView;
	private TextView mLoginStatusMessageView;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);

		setContentView(R.layout.activity_login);

		// Set up the login form.
		mEmail = getIntent().getStringExtra(EXTRA_EMAIL);
		mEmailView = (EditText) findViewById(R.id.email);
		mEmailView.setText(mEmail);

		mPasswordView = (EditText) findViewById(R.id.password);
		mPasswordView
				.setOnEditorActionListener(new TextView.OnEditorActionListener() {
					@Override
					public boolean onEditorAction(TextView textView, int id,
							KeyEvent keyEvent) {
						if (id == R.id.login || id == EditorInfo.IME_NULL) {
							attemptLogin();
							return true;
						}
						return false;
					}
				});

		mLoginFormView = findViewById(R.id.login_form);
		mLoginStatusView = findViewById(R.id.login_status);
		mLoginStatusMessageView = (TextView) findViewById(R.id.login_status_message);

		findViewById(R.id.sign_in_button).setOnClickListener(
				new View.OnClickListener() {
					@Override
					public void onClick(View view) {
						attemptLogin();
					}
				});
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		super.onCreateOptionsMenu(menu);
		getMenuInflater().inflate(R.menu.login, menu);
		return true;
	}

	/**
	 * Attempts to sign in or register the account specified by the login form.
	 * If there are form errors (invalid email, missing fields, etc.), the
	 * errors are presented and no actual login attempt is made.
	 */
	public void attemptLogin() {
		if (mAuthTask != null) {
			return;
		}

		// Reset errors.
		mEmailView.setError(null);
		mPasswordView.setError(null);

		// Store values at the time of the login attempt.
		mEmail = mEmailView.getText().toString();
		mPassword = mPasswordView.getText().toString();

		boolean cancel = false;
		View focusView = null;

		// Check for a valid password.
		if (TextUtils.isEmpty(mPassword)) {
			mPasswordView.setError(getString(R.string.error_field_required));
			focusView = mPasswordView;
			cancel = true;
		} else if (mPassword.length() < 4) {
			mPasswordView.setError(getString(R.string.error_invalid_password));
			focusView = mPasswordView;
			cancel = true;
		}

		// Check for a valid email address.
		if (TextUtils.isEmpty(mEmail)) {
			mEmailView.setError(getString(R.string.error_field_required));
			focusView = mEmailView;
			cancel = true;
		} else if (!mEmail.contains("@")) {
			mEmailView.setError(getString(R.string.error_invalid_email));
			focusView = mEmailView;
			cancel = true;
		}

		if (cancel) {
			// There was an error; don't attempt login and focus the first
			// form field with an error.
			focusView.requestFocus();
		} else {
			// Show a progress spinner, and kick off a background task to
			// perform the user login attempt.
			mLoginStatusMessageView.setText(R.string.login_progress_signing_in);
			showProgress(true);
			mAuthTask = new UserLoginTask();
			mAuthTask.execute((Void) null);
		}
	}

	/**
	 * Shows the progress UI and hides the login form.
	 */
	@TargetApi(Build.VERSION_CODES.HONEYCOMB_MR2)
	private void showProgress(final boolean show) {
		// On Honeycomb MR2 we have the ViewPropertyAnimator APIs, which allow
		// for very easy animations. If available, use these APIs to fade-in
		// the progress spinner.
		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR2) {
			int shortAnimTime = getResources().getInteger(
					android.R.integer.config_shortAnimTime);

			mLoginStatusView.setVisibility(View.VISIBLE);
			mLoginStatusView.animate().setDuration(shortAnimTime)
					.alpha(show ? 1 : 0)
					.setListener(new AnimatorListenerAdapter() {
						@Override
						public void onAnimationEnd(Animator animation) {
							mLoginStatusView.setVisibility(show ? View.VISIBLE
									: View.GONE);
						}
					});

			mLoginFormView.setVisibility(View.VISIBLE);
			mLoginFormView.animate().setDuration(shortAnimTime)
					.alpha(show ? 0 : 1)
					.setListener(new AnimatorListenerAdapter() {
						@Override
						public void onAnimationEnd(Animator animation) {
							mLoginFormView.setVisibility(show ? View.GONE
									: View.VISIBLE);
						}
					});
		} else {
			// The ViewPropertyAnimator APIs are not available, so simply show
			// and hide the relevant UI components.
			mLoginStatusView.setVisibility(show ? View.VISIBLE : View.GONE);
			mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
		}
	}

	/**
	 * Represents an asynchronous login/registration task used to authenticate
	 * the user.
	 */
	public class UserLoginTask extends AsyncTask<Void, Void, Boolean> {
		@Override
		protected Boolean doInBackground(Void... params) {
			// TODO: attempt authentication against a network service.

			try {
				// Simulate network access.
				Thread.sleep(2000);
			} catch (InterruptedException e) {
				return false;
			}

			for (String credential : DUMMY_CREDENTIALS) {
				String[] pieces = credential.split(":");
				if (pieces[0].equals(mEmail)) {
					// Account exists, return true if the password matches.
					return pieces[1].equals(mPassword);
				}
			}

			// TODO: register the new account here.
			return true;
		}

		@Override
		protected void onPostExecute(final Boolean success) {
			mAuthTask = null;
			showProgress(false);

			if (success) {
				//finish();
				Intent intent = new Intent(LoginActivity.this, MainActivity.class)
					.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
				startActivity(intent);
			} else {
				mPasswordView
						.setError(getString(R.string.error_incorrect_password));
				mPasswordView.requestFocus();
			}
		}

		@Override
		protected void onCancelled() {
			mAuthTask = null;
			showProgress(false);
		}
	}
}

MainActivity.java

package com.ccny.semanticweb;

import java.util.Locale;

import android.app.ActionBar;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.app.NavUtils;
import android.support.v4.view.ViewPager;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class MainActivity extends FragmentActivity implements
  	ActionBar.TabListener {

	/**
	 * The {@link android.support.v4.view.PagerAdapter} that will provide
	 * fragments for each of the sections. We use a
	 * {@link android.support.v4.app.FragmentPagerAdapter} derivative, which
	 * will keep every loaded fragment in memory. If this becomes too memory
	 * intensive, it may be best to switch to a
	 * {@link android.support.v4.app.FragmentStatePagerAdapter}.
	 */
	SectionsPagerAdapter mSectionsPagerAdapter;

	/**
	 * The {@link ViewPager} that will host the section contents.
	 */
	ViewPager mViewPager;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		// Set up the action bar.
		final ActionBar actionBar = getActionBar();
		actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

		// Create the adapter that will return a fragment for each of the three
		// primary sections of the app.
		mSectionsPagerAdapter = new SectionsPagerAdapter(
				getSupportFragmentManager());

		// Set up the ViewPager with the sections adapter.
		mViewPager = (ViewPager) findViewById(R.id.pager);
		mViewPager.setAdapter(mSectionsPagerAdapter);

		// When swiping between different sections, select the corresponding
		// tab. We can also use ActionBar.Tab#select() to do this if we have
		// a reference to the Tab.
		mViewPager
				.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
					@Override
					public void onPageSelected(int position) {
						actionBar.setSelectedNavigationItem(position);
					}
				});

		// For each of the sections in the app, add a tab to the action bar.
		for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
			// Create a tab with text corresponding to the page title defined by
			// the adapter. Also specify this Activity object, which implements
			// the TabListener interface, as the callback (listener) for when
			// this tab is selected.
			actionBar.addTab(actionBar.newTab()
					.setText(mSectionsPagerAdapter.getPageTitle(i))
					.setTabListener(this));
		}
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}

	@Override
	public void onTabSelected(ActionBar.Tab tab,
			FragmentTransaction fragmentTransaction) {
		// When the given tab is selected, switch to the corresponding page in
		// the ViewPager.
		mViewPager.setCurrentItem(tab.getPosition());
	}

	@Override
	public void onTabUnselected(ActionBar.Tab tab,
			FragmentTransaction fragmentTransaction) {
	}

	@Override
	public void onTabReselected(ActionBar.Tab tab,
			FragmentTransaction fragmentTransaction) {
	}

	/**
	 * A {@link FragmentPagerAdapter} that returns a fragment corresponding to
	 * one of the sections/tabs/pages.
	 */
	public class SectionsPagerAdapter extends FragmentPagerAdapter {

		public SectionsPagerAdapter(FragmentManager fm) {
			super(fm);
		}

		@Override
		public Fragment getItem(int position) {
			// getItem is called to instantiate the fragment for the given page.
			// Return a DummySectionFragment (defined as a static inner class
			// below) with the page number as its lone argument.
			Fragment fragment = new DummySectionFragment();
			Bundle args = new Bundle();
			args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
			fragment.setArguments(args);
			return fragment;
		}

		@Override
		public int getCount() {
			// Show 3 total pages.
			return 3;
		}

		@Override
		public CharSequence getPageTitle(int position) {
			Locale l = Locale.getDefault();
			switch (position) {
			case 0:
				return getString(R.string.title_section1).toUpperCase(l);
			case 1:
				return getString(R.string.title_section2).toUpperCase(l);
			case 2:
				return getString(R.string.title_section3).toUpperCase(l);
			}
			return null;
		}
	}

	/**
	 * A dummy fragment representing a section of the app, but that simply
	 * displays dummy text.
	 */
	public static class DummySectionFragment extends Fragment {
		/**
		 * The fragment argument representing the section number for this
		 * fragment.
		 */
		public static final String ARG_SECTION_NUMBER = "section_number";

		public DummySectionFragment() {
		}

		@Override
		public View onCreateView(LayoutInflater inflater, ViewGroup container,
				Bundle savedInstanceState) {
			View rootView = inflater.inflate(R.layout.fragment_main_dummy,
					container, false);
			TextView dummyTextView = (TextView) rootView
					.findViewById(R.id.section_label);
			dummyTextView.setText(Integer.toString(getArguments().getInt(
					ARG_SECTION_NUMBER)));
			return rootView;
		}
	}

}