To display a What’s New dialog, we can compare  current application version number with the previous version number. If the current version number is greater then previous, that means the application is newer or recently updated then we should display the dialog and save the current version number .

Code implementation in Android:

public class MainActivity extends Activity {
	private static final String PRIVATE_PREF = "myapp";
	private static final String VERSION_KEY = "version_number";

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

        setContentView(R.layout.main);

        init();
    }

    private void init() {
    	SharedPreferences sharedPref  	= getSharedPreferences(PRIVATE_PREF, Context.MODE_PRIVATE);
    	int currentVersionNumber		= 0;

		int savedVersionNumber			= sharedPref.getInt(VERSION_KEY, 0);

		try {
   	 		PackageInfo pi 			= getPackageManager().getPackageInfo(getPackageName(), 0);
    	 	currentVersionNumber	= pi.versionCode;
   	 	} catch (Exception e) {}

   	 	if (currentVersionNumber > savedVersionNumber) {
   	 		showWhatsNewDialog();

   	 		Editor editor	= sharedPref.edit();

   	 		editor.putInt(VERSION_KEY, currentVersionNumber);
   	 		editor.commit();
   	 	}
	}

    private void showWhatsNewDialog() {
    	LayoutInflater inflater = LayoutInflater.from(this);

        View view				= inflater.inflate(R.layout.dialog_whatsnew, null);

  	  	Builder builder			= new AlertDialog.Builder(this);

	  	builder.setView(view).setTitle("Whats New")
	  	.setPositiveButton("OK", new DialogInterface.OnClickListener() {
	  		@Override
	  		public void onClick(DialogInterface dialog, int which) {
	  			dialog.dismiss();
	  		}
	    });

	  	builder.create().show();
    }
}

Look at init() method (line 14):

• currentVersionNumber is the current application version number which is obtained from PackageInfo (line 21,22). This version number is set in AndroidManifest.xml on android:versionCode attribute.

try {
   	 		PackageInfo pi 	= getPackageManager().getPackageInfo(getPackageName(), 0);
    	 	currentVersionNumber = pi.versionCode;
   	 	} catch (Exception e) {}

• savedVersionNumber is used to save latest version number and saved in SharedPreferences with default value is 0 (line 18).

int savedVersionNumber	= sharedPref.getInt(VERSION_KEY, 0);

• When application starts for the first time, it compares currentVersionNumber with savedVersionNumber. Because there was no value set for savedVersionNumber before, the value is set to 0 (line 18) so currentVersionNumber is greater then savedVersionNumber then the What’s New dialog displayed (line 26). The value of currentVersionNumber then saved into SharedPreferences for later use (28-31) so the dialog will not be displayed anymore until the application is updated. Next time when the application updated, currentVersionNumber value will be greater than savedVersionNumber so the What’s New dialog is displayed again.

if (currentVersionNumber > savedVersionNumber) {
   	 		showWhatsNewDialog();

   	 		Editor editor	= sharedPref.edit();

   	 		editor.putInt(VERSION_KEY, currentVersionNumber);
   	 		editor.commit();
   	 	}

Download source code

My solution was simple, since my friend didn’t use Gmail on his Blackberry i had to backup the contacts using Blackberry Desktop Software into a CSV file (comma separated) then import it into Gmail contact. Android then will automatically sync the contacts from Gmail into phone’s contact list using Android Account Sync feature. In this tutorial i’ll try to explain the import steps in a simple way so it can be easily understood by people who are new to Android .

Note that there is another way to import contacts from Blackberry. If you already use Gmail on your Blackberry, you can turn on the Contact Sync option on Email settings so your contacts will be synced automatically with Gmail contact. This tutorial is suitable for people who do not use Gmail on their Blackberry.

1. Backup Blackberry contacts to computer.

The first step is to backup your Blackberry contacts to computer using Blackberry Desktop Software. If you don’t have the software installed, go to this link and download the appropriate version for your computer (Windows PC or Mac).

• Run the Blackberry Desktop Software and connect your Blackberry device to computer using USB cable.



• Go to Organizer menu then click the Configure settings button



• A new dialog will be opened then click the Address Book option



• After clicking the Address book option, a new dialog will be opened. Choose the ASCII Importer/Exporter option then click Next



• On Synchronization options dialog, choose the one way sync from Device option then click Next




• On ASCII Importer/Exporter options for Address Book dialog, click the Options button then choose Comma on options dialog.




• Still on the same dialog, click the Browse button then point to the directory where you want to put the exported contacts file. Give it any name you want with csv extension (ex: contacts.csv). Note that the csv extension is not mandatory, you can use .txt or any type you want.



• Click the Next button then Finish, your final Organizer menu display should be like this:



• Click the Sync button to start syncing. When the sync completes, click the Accept button on the dialog that appears after it. Go to the directory where you save the contact file. If you have Microsoft Excel installed, try to double click on the file then it will be opened on Excel, you can see the list of your contacts there. You can also open the file using notepad or other text editing softwares.
• Now you already have the Blackberry contacts on a comma separated format file (csv). It is time to import the file into Gmail contact.

2. Import contacts into Gmail

The next step is to load the contacts from csv file into Gmail contact list.

• Go to gmail.com then log in using your Gmail account.
• Open the Contact menu


Gmail Contact on Old Layout



Gmail Contact on New Layout

• Click the Import Contacts menu then select the csv file.



• Click the Import button and wait untill the process completes. If no error occured, you should see your Blackberry contacts now on your Gmail contact list.

3. Sync Gmail contact from Android

Ok now you’ve almost done, it is time to sync Gmail contact into your shiny new Android phone. There are two cases when you want to import Gmail contact:

a. If you already use the Gmail account that contains imported contacts as your Android primary account:

• Go to Settings -> Account & sync




• Make sure the Background data and Auto-sync option enabled



• Click on your primary account
• Enable the Sync Contacts option

b. If the Gmail account that contains imported contacts differs from your Android primary account, you have to add the account into Account & Sync settings:

• Go to Settings -> Account & sync [see case-a,step-1]
• Click Add account button [see case-1, pic-2]
• Choose Google and follow the wizard



• Enable the contacts sync as described on step-a pic-3.

Now just wait for several minutes, your contacts will be loaded automatically into your Android contact list.  Note that the above images taken from Nexus S with Gingebread OS version. Your menu settings may differ from images above if you use different android version or custom manufacturer UI.

How to use custom transition animation:

• Create two animation files (xml), one for incoming activity (/anim/incoming.xml) and one for outgoing activity (/anim/outgoing.xml).
  

  incoming.xml

  <?xml version="1.0" encoding="UTF-8"?>
  <set xmlns:android="http://schemas.android.com/apk/res/android">
  
  	<translate
  		android:interpolator="@android:anim/accelerate_interpolator"
          android:fromXDelta="0"
          android:toXDelta="0"
          android:duration="300"/>
  
      <scale
  	    android:pivotX="50%"
  	    android:pivotY="50%"
  	    android:fromXScale="0"
  	    android:fromYScale="0"
  	    android:toXScale="1.0"
  	    android:toYScale="1.0"
  	    android:startOffset="300"
  	    android:duration="300" />
  </set>
  

  outgoing.xml

  <?xml version="1.0" encoding="UTF-8"?>
  <set xmlns:android="http://schemas.android.com/apk/res/android">
  
  	<translate
          android:fromXDelta="0"
          android:toXDelta="-50%p"
          android:duration="300" />
  
      <scale
  	    android:pivotX="50%"
  	    android:pivotY="50%"
  	    android:fromXScale="1.0"
  	    android:fromYScale="1.0"
  	    android:toXScale=".1"
  	    android:toYScale=".1"
  	    android:startOffset="300"
  	    android:duration="400" />
  </set>
  

• Call method overridePendingTransition (int enterAnim, int exitAnim) right after startActivity(intent) to override default transition animation between current activity and next activity.

  Intent intent = new Intent(this, NextActivity.class);
  
  startActivity(intent);
  overridePendingTransition (R.anim.incoming, R.anim.outgoing)
  

• To use custom transition animation between current activity and previous activity (when user press the back key to get back to previous activity) override the onBackPressed () method and call the overridePendingTransition (int enterAnim, int exitAnim) method. 

  @Override
  public void onBackPressed() {
    super.onBackPressed();
    overridePendingTransition(R.anim.customanim1, R.anim.customanim2)
  }
  

• Copy your custom font files into assets directory. The font files can be a True Type (ttf) font or Open Type font (.otf)
• From your application code, load the font using Typeface.createFromAsset(getAssets(), “fontname.otf”) method

  Typeface font = Typeface.createFromAsset(getAssets(), "helvetica.otf");
  

• To use the loaded custom font, use setTypeface method on the widget you want to apply, for example, to use it on TextView, use textViewObj.setTypeface(customfont).

  TextView myTextView = (TextView) findViewById(R.id.tv_mytext);
  
  myTextView.setTypeface(font);
  

1. JSONView
   This extension is a porting from original JSONView Firefox extension and supports JSONP. It validates JSON using a client-side javascript implementation of JSONLint and compliant with rfc 4627.
   JSONView  supports syntax highlighting and displays JSON in tree view where the nodes on the tree can be collapsed and expanded by clicking on the plus (+) or minus (-) sign on  the left of each node.
   
2. JSONFormatter
   JSONFormatter supports syntax highlighting and displays JSON in tree view where the nodes on the tree can be collapesed and expanded by clicking on the triangle icon on the left of each node. It also provides a button for switching to original (raw) data.
   
3. PrettyJSON
   PrettyJSON supports syntax highlighting and displays JSON in tree view. Unlike the two previous extensions, the nodes on the tree can not be collapsed and expanded. And because of it doesn’t check for a valid content type (application/json), it will not format JSON data that comes from a URL without ‘json’ appended. For example, it will display correctly the JSON data that comes from http://example.com/data.json but will not work if the JSON data comes from http://example.com/data.php.
   
   
4. JSON Prettifier
   JSON Prettifier  supports syntax highlighting and displays JSON in tree view where the nodes on the tree can be collapsed and expanded by clicking on the plus (+) or minus (-) sign on  the left of each node. It also has a button for switching to original (raw) data.
   

• Login into Android shell, you can use adb tool or terminal application such as Android Terminal Emulator .
• Type su to login as root
• Type mount -o rw,remount -t yaffs2 /dev/block/mtdblock3 /system to enable read-write mode
• Type cd /system/app, to enter the applications directory
• Tyle ls to view the list of existing applications
• Type rm AppilicationName.apk to delete an application. For example, to delete Facebook app, just type rm Facebook.apk

As many other social media, Twitpic also provides RESTful API to enable developers to post image to Twitpic. The current version at the time of this writing is version 2 (V2). Using this API, we can build an Android application that features an image upload to Twitpic so we don’t have to create a new infrastructure for image hosting server.

In this tutorial i’ll explain how to send image to Twitpic from an Android application using Twitter4j library. The source code for this tutorial can be downloaded from my github page (see the download link at the bottom of this post).

I. Register Application

To enable an Android application to send image to Twitpic, first you have to register your application to get an API Key. To get an API Key:

• Go to Twitpic developer page and click the Register link. If you’re not logged in before, you have to sign in to Twitpic using your Twitter account.
  
• Register your application.
  
• Save the API Key.
  

II. Android Integration

In my sample project i use Twitter4j library to send image to Twitpic. You can download the latest version from Twitter4j download page or use the library package  i’ve provided in this tutorial. To enable Android to send image to Twitpic, first you have to connect to Twitter first using a Twitter account. How to connect to Twitter will not be explained here, you can read my previous tutorial on how to post Twitter status from Android. So basically to be enable to send image to Twitpic, first you have to sign in to Twitter, get the access token and use the access token along with Twitter consumer key, secret key and Twitpic API key.

In my sample project, i create two packages. The first is for Twitter library, which can be found also on my previous Twitter tutorial sample project and the second is the main application page.

Connect to Twitter (ConnectActivity.java)

This activity displays the Twitter login page and  authenticates user to get the access token. More comprehensive explanation can be found on my previous tutorial.

Send Image to Twitpic (SendImageActivity.java)

In this activity, using an image picker, the image to be sent can be from existing images on sdcard or directly taking a picture from camera. You can read my previous tutorial on how to create image picker on Android to get more deep understanding on how it works. The classes from Twitter4j that are used to send image to Twitpic are:

import twitter4j.conf.Configuration;
import twitter4j.conf.ConfigurationBuilder;
import twitter4j.http.AccessToken;
import twitter4j.http.OAuthAuthorization;
import twitter4j.util.ImageUpload;

 private class ImageSender extends AsyncTask<URL, Integer, Long> {
    	private String url;

    	protected void onPreExecute() {
			mProgressDialog = ProgressDialog.show(SendImageActivity.this, "", "Sending image...", true);

			mProgressDialog.setCancelable(false);
			mProgressDialog.show();
		}

        protected Long doInBackground(URL... urls) {
            long result = 0;

            TwitterSession twitterSession	= new TwitterSession(SendImageActivity.this);
            AccessToken accessToken 		= twitterSession.getAccessToken();

			Configuration conf = new ConfigurationBuilder()
            .setOAuthConsumerKey(twitter_consumer_key)
            .setOAuthConsumerSecret(twitter_secret_key)
            .setOAuthAccessToken(accessToken.getToken())
            .setOAuthAccessTokenSecret(accessToken.getTokenSecret())
            .build();

			OAuthAuthorization auth = new OAuthAuthorization (conf, conf.getOAuthConsumerKey (), conf.getOAuthConsumerSecret (),
	                new AccessToken (conf.getOAuthAccessToken (), conf.getOAuthAccessTokenSecret ()));

	        ImageUpload upload = ImageUpload.getTwitpicUploader (twitpic_api_key, auth);

	        Log.d(TAG, "Start sending image...");

	        try {
	        	url = upload.upload(new File(mPath));
	        	result = 1;

	        	Log.d(TAG, "Image uploaded, Twitpic url is " + url);
	        } catch (Exception e) {
	        	Log.e(TAG, "Failed to send image");

	        	e.printStackTrace();
	        }

            return result;
        }

        protected void onProgressUpdate(Integer... progress) {
        }

        protected void onPostExecute(Long result) {
        	mProgressDialog.cancel();

        	String text = (result == 1) ? "Image sent successfully.\n Twitpic url is: " + url : "Failed to send image";

        	Toast.makeText(getApplicationContext(), text, Toast.LENGTH_LONG).show();
        }
    }

In this example, i use asynchronous task to send image to Twitpic, you can use more convenience way to send the image such as using background service with queue to manage uploading multiple images. The main code for sending image to Twitpic defined in doInBackground() method.

line 14: create an object of TwitterSession class to get the accsess token that was previously saved when user was successfully authenticated.

line 15: get the access token object.

line 16: create the configuration object with Twitter consumer key, secret key, access token and access token secret as parameters.

line 24: create the authorization object.

line 27: create the Twitpic image uploader object.

line 32: upload the image file to Twitpic, the method uses file path to the image that was selected from image picker.

lin3 35: if success, the upload method will return the Twitpic url to the uploaded image, ex: http://twitpic.com/6hqd44

Download

• Download source code from my github page
• Download Twitter external jars (Twitter4j and signpost)

public class MainActivity extends Activity {
	private Uri mImageCaptureUri;
	private ImageView mImageView;

	private static final int PICK_FROM_CAMERA = 1;
	private static final int PICK_FROM_FILE = 2;

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

        setContentView(R.layout.main);

        final String [] items			= new String [] {"From Camera", "From SD Card"};
		ArrayAdapter<String> adapter	= new ArrayAdapter<String> (this, android.R.layout.select_dialog_item,items);
		AlertDialog.Builder builder		= new AlertDialog.Builder(this);

		builder.setTitle("Select Image");
		builder.setAdapter( adapter, new DialogInterface.OnClickListener() {
			public void onClick( DialogInterface dialog, int item ) {
				if (item == 0) {
					Intent intent 	 = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
					File file		 = new File(Environment.getExternalStorageDirectory(),
							   			"tmp_avatar_" + String.valueOf(System.currentTimeMillis()) + ".jpg");
					mImageCaptureUri = Uri.fromFile(file);

					try {
						intent.putExtra(android.provider.MediaStore.EXTRA_OUTPUT, mImageCaptureUri);
						intent.putExtra("return-data", true);

						startActivityForResult(intent, PICK_FROM_CAMERA);
					} catch (Exception e) {
						e.printStackTrace();
					}

					dialog.cancel();
				} else {
					Intent intent = new Intent();

	                intent.setType("image/*");
	                intent.setAction(Intent.ACTION_GET_CONTENT);

	                startActivityForResult(Intent.createChooser(intent, "Complete action using"), PICK_FROM_FILE);
				}
			}
		} );

		final AlertDialog dialog = builder.create();

		mImageView = (ImageView) findViewById(R.id.iv_pic);

		((Button) findViewById(R.id.btn_choose)).setOnClickListener(new View.OnClickListener() {
			@Override
			public void onClick(View v) {
				dialog.show();
			}
		});
    }

    @Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
	    if (resultCode != RESULT_OK) return;

		Bitmap bitmap 	= null;
		String path		= "";

		if (requestCode == PICK_FROM_FILE) {
			mImageCaptureUri = data.getData();
			path = getRealPathFromURI(mImageCaptureUri); //from Gallery

			if (path == null)
				path = mImageCaptureUri.getPath(); //from File Manager

			if (path != null)
				bitmap 	= BitmapFactory.decodeFile(path);
		} else {
			path	= mImageCaptureUri.getPath();
			bitmap  = BitmapFactory.decodeFile(path);
		}

		mImageView.setImageBitmap(bitmap);
	}

	public String getRealPathFromURI(Uri contentUri) {
        String [] proj 		= {MediaStore.Images.Media.DATA};
        Cursor cursor 		= managedQuery( contentUri, proj, null, null,null);

        if (cursor == null) return null;

        int column_index 	= cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);

        cursor.moveToFirst();

        return cursor.getString(column_index);
	}
}

The code from my sample project above shows how to create a dialog that shows two options to select the image source. The first is from Camera, where the picture is taken directly from camera, and the second is from saved images on sdcard.

line 14: Define two image source options, From Camera and From SD Card.

line 16-48: Setup the image picker dialog.

line 22: If user choose to take picture from Camera, create an intent to open Camera app with MediaStore.ACTION_IMAGE_CAPTURE action.

line 23: Create temporary file to hold the image from Camera.

line 24: Get the uri of temporary file

line 39: If user choose to select image from sdcard, start the intent to open image chooser dialog. The image chooser dialog will display list File Manager (if exist) apps and default Gallery app.

line 55: show the image picker dialog.

line 61: Override the onActivityResult method to handle the selected image.

line 67: If user selects image from sdcard, get the uri of selected image (line 68)

line 69: Assume user selects the image from sdcard using Gallery app. The uri from Gallery app does not give the real path to selected image, so it has to be resolved on content provider. Method getRealPathFromURI used to resolve the real path from the uri.

line 71: If the path is null, assume user selects the image using File Manager app. File Manager app returns different information than Gallery app. To get the real path to selected image, use getImagePath method from the uri (line 72).

line 75: Get the bitmap.

line 77: If user choose to take picture from camera, get the real path of temporary file that previously defined on line 24-25.

line 78: Get the bitmap.

line 81: Display the bitmap on image view.

Download source code of this tutorial on my github page

Facebook has an official SDK for Android platform that can be used easily by developers to integrate their application. In this tutorial, i’ll explain how to use Facebook SDK for Android to post status to Facebook wall from an Android application. I have written similar tutorial for Twitter to show how to post status to Twitter from Android and for Foursquare to show how to connect and use Foursquare API on Android.

I. Register Facebook Application

To enable user to post status to Facebook, first you have to create a Facebook application:

• Login to Facebook and go to Facebook Developer page then register your application by clicking the Create New App button on top right of the page.
  
• Fill the App Name with your application name.
  
• Note the App ID, we will use it later on Android code. Note that you don’t have to select how app integrate with Facebook option, just click the Save Changes button.
  

II. Android Integration

To integrate Facebook with Android, you can use official Facebook SDK for Android that can be downloaded from github page. For sample project in this tutorial, i use old version of Facebook SDK downloaded from the github page with some small modification. If you want to use the latest version, just download the SDK from the link above.

In my sample project, i create two packages, one for Facebook SDK and the other for application main package.

Code implementation

1. Facebook Connection (TestConnect.java)

This example shows how to connect to Facebook, display webview dialog to authorize user then save the access token and username on shared preference for later use.

public class TestConnect extends Activity {
	private Facebook mFacebook;
	private CheckBox mFacebookBtn;
	private ProgressDialog mProgress;

	private static final String[] PERMISSIONS = new String[] {"publish_stream", "read_stream", "offline_access"};

	private static final String APP_ID = "*****app id ******";

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

        setContentView(R.layout.main);

        mFacebookBtn	= (CheckBox) findViewById(R.id.cb_facebook);

        mProgress		= new ProgressDialog(this);
        mFacebook		= new Facebook(APP_ID);

        SessionStore.restore(mFacebook, this);

        if (mFacebook.isSessionValid()) {
			mFacebookBtn.setChecked(true);

			String name = SessionStore.getName(this);
			name		= (name.equals("")) ? "Unknown" : name;

			mFacebookBtn.setText("  Facebook (" + name + ")");
			mFacebookBtn.setTextColor(Color.WHITE);
		}

        mFacebookBtn.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				onFacebookClick();
			}
		});

        ((Button) findViewById(R.id.button1)).setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				startActivity(new Intent(TestConnect.this, TestPost.class));
			}
		});
    }

    private void onFacebookClick() {
		if (mFacebook.isSessionValid()) {
			final AlertDialog.Builder builder = new AlertDialog.Builder(this);

			builder.setMessage("Delete current Facebook connection?")
			       .setCancelable(false)
			       .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
			           public void onClick(DialogInterface dialog, int id) {
			        	   fbLogout();
			           }
			       })
			       .setNegativeButton("No", new DialogInterface.OnClickListener() {
			           public void onClick(DialogInterface dialog, int id) {
			                dialog.cancel();

			                mFacebookBtn.setChecked(true);
			           }
			       });

			final AlertDialog alert = builder.create();

			alert.show();
		} else {
			mFacebookBtn.setChecked(false);

			mFacebook.authorize(this, PERMISSIONS, -1, new FbLoginDialogListener());
		}
	}

    private final class FbLoginDialogListener implements DialogListener {
        public void onComplete(Bundle values) {
            SessionStore.save(mFacebook, TestConnect.this);

            mFacebookBtn.setText("  Facebook (No Name)");
            mFacebookBtn.setChecked(true);
			mFacebookBtn.setTextColor(Color.WHITE);

            getFbName();
        }

        public void onFacebookError(FacebookError error) {
           Toast.makeText(TestConnect.this, "Facebook connection failed", Toast.LENGTH_SHORT).show();

           mFacebookBtn.setChecked(false);
        }

        public void onError(DialogError error) {
        	Toast.makeText(TestConnect.this, "Facebook connection failed", Toast.LENGTH_SHORT).show();

        	mFacebookBtn.setChecked(false);
        }

        public void onCancel() {
        	mFacebookBtn.setChecked(false);
        }
    }

	private void getFbName() {
		mProgress.setMessage("Finalizing ...");
		mProgress.show();

		new Thread() {
			@Override
			public void run() {
		        String name = "";
		        int what = 1;

		        try {
		        	String me = mFacebook.request("me");

		        	JSONObject jsonObj = (JSONObject) new JSONTokener(me).nextValue();
		        	name = jsonObj.getString("name");
		        	what = 0;
		        } catch (Exception ex) {
		        	ex.printStackTrace();
		        }

		        mFbHandler.sendMessage(mFbHandler.obtainMessage(what, name));
			}
		}.start();
	}

	private void fbLogout() {
		mProgress.setMessage("Disconnecting from Facebook");
		mProgress.show();

		new Thread() {
			@Override
			public void run() {
				SessionStore.clear(TestConnect.this);

				int what = 1;

		        try {
		        	mFacebook.logout(TestConnect.this);

		        	what = 0;
		        } catch (Exception ex) {
		        	ex.printStackTrace();
		        }

		        mHandler.sendMessage(mHandler.obtainMessage(what));
			}
		}.start();
	}

	private Handler mFbHandler = new Handler() {
		@Override
		public void handleMessage(Message msg) {
			mProgress.dismiss();

			if (msg.what == 0) {
				String username = (String) msg.obj;
		        username = (username.equals("")) ? "No Name" : username;

		        SessionStore.saveName(username, TestConnect.this);

		        mFacebookBtn.setText("  Facebook (" + username + ")");

		        Toast.makeText(TestConnect.this, "Connected to Facebook as " + username, Toast.LENGTH_SHORT).show();
			} else {
				Toast.makeText(TestConnect.this, "Connected to Facebook", Toast.LENGTH_SHORT).show();
			}
		}
	};

	private Handler mHandler = new Handler() {
		@Override
		public void handleMessage(Message msg) {
			mProgress.dismiss();

			if (msg.what == 1) {
				Toast.makeText(TestConnect.this, "Facebook logout failed", Toast.LENGTH_SHORT).show();
			} else {
				mFacebookBtn.setChecked(false);
	        	mFacebookBtn.setText("  Facebook (Not connected)");
	        	mFacebookBtn.setTextColor(Color.GRAY);

				Toast.makeText(TestConnect.this, "Disconnected from Facebook", Toast.LENGTH_SHORT).show();
			}
		}
	};
}

line 6: Define the Facebook permission list, publish_stream, read_stream, and offline_access is enough to enable Android app to write status on Facebook wall. If you want more permissions, just add them into the PERMISSIONS array.

line 8:  Set the Facebook application id, use the App ID from Facebook application settings page as described above.

line 19:  Instantiate the Facebook class with APP_ID as the parameter. Facebook class is the main class for interacting with Facebook API endpoint.

line 23: Check if user has been authenticated before. Method isSessionValid is used to check if there is already access token saved on preference file. If user has been successfully authenticated, the access token and the name of authenticated user will be saved on preference file. The name of preference file is defined within SessionStore class on KEY variable. You can change the name of preference file as you want.

line 33+48: Check if user has been authenticated, if yes, display the confirmation dialog to log out from current session (also delete the access token from preference file). If not, display the authentication dialog (webview dialog).

line 77: Define the listener for authentication dialog and override the four methods to handle four different events: onComplete: is called when user successfully authenticated, here we save the access token to preference file (line 79), onFacebookError: is called when there is an error while authenticating user, onError: is called when there is an error on dialog and the last is onCancel: is called when user cancel the dialog.

2. Post Status (TestPost.java)

This example shows how to post status to Facebook wall.

public class TestPost extends Activity{
	private Facebook mFacebook;
	private CheckBox mFacebookCb;
	private ProgressDialog mProgress;

	private Handler mRunOnUi = new Handler();

	private static final String APP_ID = "*** put app id here";

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

		setContentView(R.layout.post);

		final EditText reviewEdit = (EditText) findViewById(R.id.revieew);
		mFacebookCb				  = (CheckBox) findViewById(R.id.cb_facebook);

		mProgress	= new ProgressDialog(this);

		mFacebook 	= new Facebook(APP_ID);

		SessionStore.restore(mFacebook, this);

		if (mFacebook.isSessionValid()) {
			mFacebookCb.setChecked(true);

			String name = SessionStore.getName(this);
			name		= (name.equals("")) ? "Unknown" : name;

			mFacebookCb.setText("  Facebook  (" + name + ")");
		}

		((Button) findViewById(R.id.button1)).setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View v) {
				String review = reviewEdit.getText().toString();

				if (review.equals("")) return;

				if (mFacebookCb.isChecked()) postToFacebook(review);
			}
		});
	}

	private void postToFacebook(String review) {
		mProgress.setMessage("Posting ...");
		mProgress.show();

		AsyncFacebookRunner mAsyncFbRunner = new AsyncFacebookRunner(mFacebook);

		Bundle params = new Bundle();

		params.putString("message", review);
		params.putString("name", "Dexter");
		params.putString("caption", "londatiga.net");
		params.putString("link", "http://www.londatiga.net");
		params.putString("description", "Dexter, seven years old dachshund who loves to catch cats, eat carrot and krupuk");
		params.putString("picture", "http://twitpic.com/show/thumb/6hqd44");

		mAsyncFbRunner.request("me/feed", params, "POST", new WallPostListener());
	}

	private final class WallPostListener extends BaseRequestListener {
        public void onComplete(final String response) {
        	mRunOnUi.post(new Runnable() {
        		@Override
        		public void run() {
        			mProgress.cancel();

        			Toast.makeText(TestPost.this, "Posted to Facebook", Toast.LENGTH_SHORT).show();
        		}
        	});
        }
    }
}

line 46: Instantiate the Facebook asynchronous thread that will be used to send status to Facebook.
line 52: Use Bundle as data wrapper to send data
line 54: message, is  the Facebook status message
line 55: name, is the link title
line 56: caption, is the caption text below the link
line 57: link, is the link to go when user clicks on the title
line 58: description, is the desciption text below the caption
line 59: picture, is the image link. The image will be displayed on the left of description
line 61: post the status to facebook. me/feed parameter means the status will be posted on current authenticated user’s wall. WallPostListener is the listener to be called when the asynchronous thread finished sending the post to Facebook.

Facebook Wall

You can download  the source code on my github page

This  2-steps verification requires two independent factors for authentification. This is much like you might see on your e-banking transaction, your website password and a key obtained from your phone or a dedicated key generator device. Once this 2-steps verification enabled on your account, you will see an extra page prompting for a code after you signing in with username and password. You can use your Android, Iphone or Blackberry as the code generator device or  use SMS to send the code to your phone. In this tutorial, i’ll explain how to use 2-step verification with Android as the code generator device.

How to setup:

• Log in to your Gmail and go to Account settings page
  
• On Account Settings page, click the Using 2-step verification link.
  
• Click the Start setup button.
  
• On Set up 2-verification page, choose Android as device where you’ll get the verification code.
• Install Google Authenticator app from Android market.
  
• Now it is time to configure your Android device, run the Google Authenticator app.
• There are two ways to configure Google Authenticator: by scanning a barcode or manually add account if you have no barcode scanner app installed.
• If you choose to scan barcode, click the Scan a barcode button to scan the barcode displayed on setup page.
• Enter the code displayed on Google Authenticator app into the Code field then click the Verify button.
  
• If you choose to add account manually, click the Can’t scan the barcode to expand the hidden instruction page.
• On Google Authenticator app, click the Manually add account button. Enter account name with your Gmail address, key with the key from setup page (step 3 on picture above) and choose time based key type.
  
• Enter the code displayed on Google Authenticator app into the Code field then click the Verify button.
• Click Next on the next page.
• Now you can backup some codes to be used in case the phone isn’t available. Each code will allow you to sign in one time. Click the  Save to text file to save the codes to local disk.
• Click Next to continue.
• You can also have the codes sent to your backup phone number if your primary phone is unavailable or lost. Fill in your phone number and choose which way the codes will be sent, you can choose between SMS or Voice Call. Click Next to continue.
  
• On next page, you’ll get a warning page shows that you need to generate and enter an application specific password. Application specific password will be used when you log in to several Google apps such as Adsense, Adwords, Google Talk or your Android device. Note that if you enable this 2-step verification, you will never be able to use your current password to login to those applications, you have to use separate application specific password. This password need to be entered only once for each application. We will setup it later, click Next to continue.
• Now the setup is done, click the Turn on 2-step verification button to turn on the 2-step verification. You will be signed out of your Google Account on all devices including mobile applications. The next time you sign in, Google will ask for your password and your verification code.
• After logged out, try to log in to your Gmail. After entering your password, you’ll will be asking for verification code. Use verification code from your Google Authenticator application to verify.
• You have done the 2-step verification setup. You will be noticed that you have been logged out automatically from some Google applications such as Google Talk, Gmail and Market on your Android phone. It means you have to sign in again with new application specific password.
• Go to Account Settings page then enter the Using 2-step verification
• Click the  Manage application-specific password link.
  
• Enter the name that will help you remember what application is for then click Generate password
• Use the generated password to sign in to Google application. For example, to login into Gtalk on Android, use your email as username and your generated app-specific password as your password.
• Done.