How to host a website on your Android device

As you may already know, there are plenty of hosting companies out there, some expensive, some not. Some are dependable, some have terrible up time, and some simply shouldn’t be allowed to offer hosting. Even after looking through a list of some of the best options, finding the perfect hosting company can be a rather difficult thing to do. So why not host your site yourself?

Thanks to your Android device’s capabilities you can host a website by yourself. Note this is not meant to be the perfect solution for anyone and everyone. But, it’s helpful for developers who want to test their website or people who want to learn and test capabilities of their Android.
Here’s how to host a website on your Android device:

Setting up the Server

1. Install and run KSWEB on your Andriod device. The app allows a 6-day free trial, after which you will be required to pay $2.99 for the full version in-order to keep your site running. Other alternatives include My FTP Server (Free) and Pixel Media Server (Free). For the purpose of this article we will use KSWEB.

2. Once opened, locate the IP Address given on the KSWEB and access it through your computer, or access the ‘localhost:8080′ link through your phone.

3. Go to “Tools” and click on Start, your browser should now open. The default username and password is ‘admin’ for both.

 

 

4. (Optional but Recommended) Select ‘system settings’ and change password from ‘admin’ to something else. Do this again for MySQL. Go on KSWEB settings and enter a MySQL Password.

Making your Server accessible though the Web

1. Enter your router’s IP Address in a browser to access it’s admin page.

2. Create a Static IP available for your Android Device. Access your DHCP settings and select an IP range that your router allows you to use.


3. Access ‘port forwarding’ and change the ports to 80 and 8080. This allows your router to communicate with your Android device and it’s server.

4. Access the WiFi settings on your Android Device, and long press the name of your WiFi network until you see the pop-up. Click ‘Modify network,’ and check advanced settings. Change IP Settings to Static and IP Address to the Static IP set in step 2.


5. Find out your IP Address. An easy way to this is by Googling “What is my IP.” People will use the IP Address to access your site so make sure to capture it correctly.


For now your site will show blank; you have to give out IP to people in-order for them to access your site. Also, your Android device has to be on at all times in order for this to work.
By installing Keep Screen On Free you can allow your server to be on almost always. As for the content of your site, install FTP Server, you can now add files to your site after you change the ports for FTP. This method obviously doesn’t even come close to some of the best hosting services available, but it’s “free” and simple to set-up.
Have you hosted a website from your Android before? Did we miss anything? What would you recommend to others hoping to do something similar?

(androidguys)

Top 20 Things Every First-Time Android User Should Know

Choosing a new device like a new phone or tablet should be fun. But there are so many choices out there, and it can be hard to know where to start. If you’re thinking about anAndroid device, or if you’ve just bought one and want to get the most out of it, we have some basic tips to get you started.






1. What is Android?
Android is an operating system, like Windows for computers or iOS for iPhones and iPads
2. Who makes Android?
Google makes Android, and a lot of manufacturers such as Samsung, HTC and Motorola put it on their phones, tablets and now even cameras.
3. Why does everyone keep talking about desserts?
As well as regular version numbers, every time Google makes a significant update to Android, it names the update after a dessert. The desserts run alphabetically, so you can keep track of different Android versions. In the past few years, devices have upgraded from Eclair, to Froyo, to Gingerbread, to Honeycomb, to Ice Cream Sandwich. The latest devices to be released are currently running Jelly Bean.
4. Does Android have apps?
Yes. Android has a huge app market called Google Play, where you can download books, music and movies as well as apps, all from one place. Amazon also has its own app store for Android phones, giving you even more choice.
5. Can I use Twitter and Facebook on Android phones?
Yes. Pretty much every phone released nowadays is a smartphone with Internet capabilities. Whether you choose a BlackBerry, an iPhone, a Windows phone or a phone running Android, you’ll be able to use Facebook and Twitter.
6. How do I download apps to my Android device?
You can install new apps on your Android device in two ways. First, you can use the Google Play app that you’ll find on your device when you power it up the first time. No need to be connected to a computer; Android devices can install apps all by themselves. Second, you can use the Google Play website on your computer. If you log in with the Google Account you used on your Android device, Google Play will give you the option to install straight to your device. This can be handy when you want a big screen to browse through lots of apps.
7. Wait, I don’t have to tether my phone to my computer to install new apps?
Nope! You can do it via cellular data or Wi-Fi directly to your phone or tablet. No cables.
8. Okay, I understand apps now, but what if I want to put some pictures or a movie on my phone?
There are a couple of super-simple ways to move your personal files on and off an Android device. First, you can use a Dropbox account plus the Dropbox app. Upload everything to Dropbox via your computer, log into Dropbox on your phone or tablet, and they’ll all be there waiting for you. Even easier, connect your phone to your computer and treat it like a fancy USB stick — just drag and drop the files, and Android will know how to organize them.
9. I have lots of music in iTunes. Can I listen to it on my Android phone?
Yes. There’s a piece of software called doubleTwist that works just like iTunes, letting you install your iTunes music collection on your Android phone or tablet. If you store your music collection outside of iTunes, then the drag-and-drop method of file transfer should work just fine.
10. There’s a game called Angry Birds that I keep hearing about. Can I play it on Android?
Yes. It’s one of the top free games on Android. Download Angry Birds from Google Play.
11. My friend has an Android phone from Samsung, and my Android phone is from HTC. Why does Android look a bit different on our phones?
Google makes the Android software and then lets hardware manufacturers such as HTC and Samsung install it on their phones and tablets. Device manufacturers usually add their own design tweaks to the standard Android operating system. These design tweaks are known as skins, and manufacturers use them to help Android devices stand out from the competition.
12. What if I just want pure Android without a skin?
If you want the pure Android experience straight from Google, then you should choose a device with “Nexus” in the title, such as the Nexus 7 tablet or the Galaxy Nexus phone. These devices always get updated to the latest version of Android first, too, because they don’t use any extra tweaks from the hardware manufacturers that might hold up the upgrade process.
13. What’s the difference between home screens and the app drawer?
The app drawer is where you can find all of the apps installed on your device. On Apple devices, all of your apps are live on your home screens. But Android devices have (up to) seven home screens that you can fill with your favorite apps and widgets for quick access — any apps you don’t choose to keep on your home screen will still be in your app drawer.
14. Widgets? What are widgets?
Widgets are one of our favorite features of Android. Super useful at both displaying information and saving power, they are a little like snapshots of apps that live on your home screens. Widgets come in all different sizes. They can display simple things like how much data you’ve used this month or show more complex things like your Facebook news feed. Because they’re designed for basic interactions like posting updates to Facebook or Twitter, widgets can help you save battery power because you don’t need to open up the full app every time you want to make a simple update or reply to comments.
15. Do I need a Google account to use Android?
Yes. Just like you need an Apple ID to use an iDevice, you need a Google account to use Android. You don’t have to use any of the specific Google services like Gmail on a daily basis if you don’t want to, and Google lets you add other email accounts to your Android phone or tablet. But if you really don’t want a Google account, Android might not be right for you. Google’s software and cloud services are really slickly integrated into the Android experience, and you’ll miss out on some of the best features of Android if you don’t want to use them.
16. What’s the easiest way to move all my contacts onto my phone?
You can enter them as contacts into Gmail, and they’ll be automatically synced to your phone, or you can transfer saved numbers off your SIM card.
17. How do I save battery power on my Android device?
We’ve got some battery-saving tips right here for you.
18. Are there any good Android productivity apps?
Yes, loads! Here are some of our favorite Android productivity apps.
19. Which Android games do you recommend?
We’ve got a list of cool (and free) Android games.
20. How do I keep my Android phone secure?
Android has plenty of security features. We make understanding Android security featuressimple.

Have you got any pointers for first-time Android users? Let us know in the comments!

Image courtesy of Flickr, Johan Larsson
This article originally published at Tecca here

What Is Android Rooting?

You must have wondered people talking about Android Rooting. But do you know what is Android Rooting? In this article we will discuss all aspects of rooting your Android.

What is Android Rooting?

Android Rooting or getting root or rooting your Android phone is nothing but the process to modify the operating system which is shipped with your purchased Android device so as to award you complete control over it.

Manufacturers and carriers put certain limitations on the phone while selling them in the market. B rooting you can overcome those limitations and extend the system functionalities. Rooting also helps in removing bloatware and installing Custom ROMs.

Word ‘root’ is actually used in Linux OS for the most privileged user just like an Administrator in Windows.

Rooting is usually simple. For most of the cases you will get useful videos and articles on internet that will explain how to root a specific phone model. To search how to root your Android device just search “Yourphonemodel root”.
Rooting process is not something permitted by manufacturers or carriers but they can’t even avert it from happening because the process of rooting usually exploits susceptibility in the Android OS code or in the device drivers which permits the ‘hacker’ to upload a program known as su where su stands for switch user. Su is the program which provides root access to the programs.
There is another program named Superuser Permissions which is usually bundled with all of the root methods. Superuser Permissions gives user a chance to approve or deny requests from any app that requests to utilize root. This program replaces the conventional root password and puts a simple approve/deny prompt for the same. This is not as secure as the password but it is definitely convenient on a mobile device.

WARNING: Rooting has potential risks of bricking the phone which means it could leave your phone non-functional. So before rooting your phone do your homework.

Benefits of Android Rooting

There are many benefits of rooting and few of them are discussed below:
1. Full Control
Android Rooting gives you the power to edit anything in the Android OS. After rooting you can do following things:

• Use themes
• Alter system files
• Change boot images
• Remove bloatware

To do this just use Titanium backup and delete apps from there. Although there are other methods also available on the web but we prefer using Titanium backup for this purpose.
2. Backup and Restore
Most of the rooted phones have this facility of taking back up of entire system to an SD card. In fact this is a very convenient feature. Say, if you try a new ROM, as you take back up of your phone, wipe it & flash the new ROM and if you don’t like it, simply restore from your backup to get all the same old features back.
One can use ROM Manager, the easiest tool to do this; developed by Koush (famous Android developer). With the ROM Manager you can easily flash a custom recovery image which will be required in order to take backup of your phone and will be used while restoring it.
Recovery image is a unique program which can be booted into outside device’s OS juts like an OS recovery console used in PC. BY default recovery image gives only provide a few options that too mainly related to wiping the phone. Whereas, in comparison to default recovery image; custom recovery image offers a wide variety of options for the same job. It includes scripts that can help in doing things like backup and restore system, fix file permissions, allow you to flash and install custom ROMs.
Normally some command line work is required on PC or on the terminal emulator on phone to flash a custom recovery image but with Koush’s ROM Manager this won’t be required as it should automatically flash a custom recovery image known as ClockworkMod Recovery. The only catch is that it supported only on some of the supported phones which is by the way a long list . You can find your phone’s name in this supported phone’s list which is constantly updated by Koush himself.

How To Use ROM Manager?

Its pretty simple to use ROM manager. You just need to download and install the application from Google Play store. Start the application and you will be prompted to allow the application superuser permissions which you have to make sure that you approve it. The very first thing which will be required is flash the ClockworkMod recovery image which we mentioned earlier. It can be done with the help of first option from the app. ROM Manager will then automatically find the latest version of the right custom image for your Android handset, download and install it. Once this is done, you can take backup or restore from an existing backup by using these two options – ‘Manage and Restore Backups’ & ‘Backup current ROM’.

3. Increase Memory Space on Your Phone
Even though Google did introduce Apps2SD officially in Android 2.2 Froyo update still it is up to developers to manually add support for this feature in their apps. Because of this reason it is fairly possible to overflow your device internal memory space.
The easiest way to overcome this problem is to enable most applications to be transferable or movable to SD card. For example, CyanogenMod one of the most popular custom ROM for Android allows its users to force most of the apps to SD even if developers didn’t add this feature. It doesn’t work on all the apps, especially if we talk about keyboard apps and other apps with widgets.
4. Run Applications Meant for Rooted Phones
Yes, it’s true that there are apps with some uniquely enhanced features that can be used on rooted phones only. Few of them are Titanium Backup, ROM Manager, Quick boot, Move2SD Enabler and many more such apps can be used on rooted devices.
5. Remove Bloatware
If your phone is rooted then you can also remove bloatware. Bloatware are nothing but pre-installed apps which comes from  manufacturer or carrier of the device. Most of these pre-installed apps are not useful and if they are removed then it can hellp you in saving some memory.
6. Use Custom ROMs
Well we have already covered, what custom ROMs are. Through the years, Android ROM community has grown greatly and ROMs have been developed for almost all the phones out there in the market. These days custom ROMs are coming major tweaks that can give you an entirely new look, feel and performance. The ROMs can make your Android phone fly by replacing the kernel with highly optimized versions or they can even over-clock the CPU.
Here at Android Trickz, we are developing a series of custom ROM reviews for various phones. So stay tuned for updates.

(Satyesh Kumar Singh)

Android - Shell & Deployment

 Android Debugging Bridge - Shell

You can access your Android emulator also via the console. Open a shell, switch to your "android-sdk" installation directory into the folder "tools". Start the shell via the following command "adb shell".

adb shell 

You can also copy a file from and to your device via the following commands.

// Assume the gesture file exists on your Android device
adb pull /sdcard/gestures ~/test
// Now copy it back
adb push ~/test/gesture /sdcard/gestures2 

This will connect you to your device and give you Linux command line access to the underlying file system, e.g. ls, rm, mkdir, etc. The application data is stored in the directory "/data/data/package_of_your_app".
If you have several devices running you can issue commands to one individual device.

# Lists all devices
adb devices
#Result
List of devices attached
emulator-5554 attached
emulator-5555 attached
# Issue a command to a specific device
adb -s emulator-5554 shell 

Uninstall an application via adb

You can uninstall an android application via the shell. Switch the data/app directory (cd /data/app) and simply delete your android application.
You can also uninstall an app via adb with the package name.

adb uninstall <packagename> 

Emulator Console via telnet

Alternatively to adb you can also use telnet to connect to the device. This allows you to simulate certain things, e.g. incoming call, change the network "stability", set your current geocodes, etc. Use "telnet localhost 5554" to connect to your simulated device. To exit the console session, use the command "quit" or "exit".
For example to change the power settings of your phone, to receive an sms and to get an incoming call make the following.

# connects to device
telnet localhost 5554
# set the power level
power status full
power status charging
# make a call to the device
gsm call 012041293123
# send a sms to the device
sms send 12345 Will be home soon
# set the geo location
geo fix 48 51 

For more information on the emulator console please see Emulator Console manual

* Deployment

Overview

In general there are you restrictions how to deploy an Android application to your device. You can use USB, email yourself the application or use one of the many Android markets to install the application. The following describes the most common ones.

Deployment via Eclipse

Turn on "USB Debugging" on your device in the settings. Select in the settings of your device Applications → Development, then enable USB debugging.
You may also need to install the a driver for your mobile phone. Linux and Mac OS usually work out of the box while an Windows OS typically requires
For details please see Developing on a Device . Please note that the Android version you are developing for must be the installed version on your phone.
To select your phone, select the "Run Configurations", select "Manual" selection and select your device.

Android application must be signed before they can get installed on an Android device. During development Eclipse signs your application automatically with a debug key.
If you want to install your application without the Eclipse IDE you can right click on it and select Android Tools → Export Signed Application Package.
This wizard allows to use an existing key or to create a new one.
Please note that you need to use the same signature key in Google Play (Google Market) to update your application. If you loose the key you will NOT be able to update your application ever again.
Make sure to backup your key.

Via external sources

Android allow to install applications also directly. Just click on a link which points to an .apk file, e.g. in an email attachment or on a webpage. Android will prompt you if you want to install this application.
This requires a setting on the Android device which allows the installation of non-market application. Typically this setting can be found under the "Security" settings.

Google Play (Market)

Google Play requires a one time fee, currently 25 Dollar. After that the developer can directly upload his application and the required icons, under Google Play Publishing .
Google performs some automatic scanning of applications, but no approval process is in place. All application, which do not contain malware, will be published. Usually a few minutes after upload, the application is available.

(vogella.com)

Fragments

Fragments Overview

Fragment components allow you to organize your application code so that it is easier to support different sized devices.
Fragments are components with their own lifecycle and their own user interface. They can be defined via layout files or via coding.
Fragments always run in the context of an Activity. If an Activity is stopped its Fragments will also be stopped; if an Activity is destroyed its Fragments will also get destroyed.
If a Fragment component is defined in an XML layout file, the android:name attribute points to the Fragments class.
The base class for Fragments is android.app.Fragment. For special purposes you can also use more special classes, like ListFragment or DialogFragment.
The onCreateView() method is called by Android once the Fragment should create its user interface. Here you can inflate an layout. The onStart() method is called once the Fragment gets visible.
Fragments can be dynamically added and removed from an Activity via Fragment transactions. This will add the action to the history stack of the Activity, i.e. this will allow to revert the Fragment changes in the Activity via the back button.

When to use Fragments

Fragments make it easy to re-use components in different layouts, e.g. you can build single-pane layouts for handsets (phones) and multi-pane layouts for tablets.
This is not limited to tablets; for example you can use Fragments also to support different layout for landscape and portrait orientation. But as tablets offer significantly more space you typically include more views into the layout and Fragments makes that easier.
The typical example is a list of items in an activity. On a tablet you see the details immediately on the same screen on the right hand side if you click on item. On a handset you jump to a new detail screen. The following discussion will assume that you have two Fragments (main and detail) but you can also have more. We will also have one main activity and one detailed activity. On a tablet the main activity contains both Fragments in its layout, on a handheld it only contains the main fragment.
To check for an fragment you can use the FragmentManager.

DetailFragment fragment = (DetailFragment) getFragmentManager().
  findFragmentById(R.id.detail_frag);
if (fragment==null || ! fragment.isInLayout()) {
 // start new Activity
 }
else {
 fragment.update(...);
} 

To create different layouts with Fragments you can:

• Use one activity, which displays two Fragments for tablets and only one on handsets devices. In this case you would switch the Fragments in the activity whenever necessary. This requires that the fragment is not declared in the layout file as such Fragments cannot be removed during runtime. It also requires an update of the action bar if the action bar status depends on the fragment.
  
• Use separate activities to host each fragment on a handset. For example, when the tablet UI uses two Fragments in an activity, use the same activity for handsets, but supply an alternative layout that includes just one fragment. When you need to switch Fragments, start another activity that hosts the other fragment.
  

The second approach is the most flexible and in general preferable way of using Fragments. In this case the main activity checks if the detail fragment is available in the layout. If the detailed fragment is there, the main activity tells the fragment that is should update itself. If the detail fragment is not available the main activity starts the detailed activity.
It is good practice that Fragments do not manipulate each other. For this purpose a Fragment typically implements an interface to get new data from its host Activity.

# Fragments Tutorial

Overview

The following tutorial demonstrates how to use Fragments. The entry Activity (called MainActivity of our application) will use different layouts for portrait and for landscape mode.
In portrait mode MainActivity will show one Fragment with a list of names. If the user touches an item in the list, a second Activity called DetailActivity will start and show the selected text.
In landscape mode MainActivity will show two Fragments. The first is again the Fragments which shows the list of names. The second Fragment shows the text of the current selected item. This is similar to the portrait mode, but the whole information will be shown on one screen.

Create project

Create a new project de.vogella.android.fragments with an Activity called MainActivity.

Create layouts for portrait mode

Create or change the following layout files in the "res/layout/" folder.
First create the following file called "details.xml". This layout will be used by the DetailFragment.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/detailsText"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="center_horizontal|center_vertical"
        android:layout_marginTop="20dip"
        android:text="Large Text"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:textSize="30dip" />

</LinearLayout> 

Change the existing main.xml file. This layout will be used by MainActivity in landscape mode and shows two Fragments.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal" >

    <fragment
        android:id="@+id/listFragment"
        android:layout_width="150dip"
        android:layout_height="match_parent"
        android:layout_marginTop="?android:attr/actionBarSize"
        class="de.vogella.android.fragments.ListFragment" ></fragment>

    <fragment
        android:id="@+id/detailFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        class="de.vogella.android.fragments.DetailFragment" >
        <!-- Preview: layout=@layout/details -->
    </fragment>

</LinearLayout> 

Create Fragment classes

Create now the Fragment classes. Create the ListFragment class.

package de.vogella.android.fragments;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;

public class ListFragment extends android.app.ListFragment {
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);

 }

 @Override
 public void onActivityCreated(Bundle savedInstanceState) {
  super.onActivityCreated(savedInstanceState);
  String[] values = new String[] { "Android", "iPhone", "WindowsMobile",
    "Blackberry", "WebOS", "Ubuntu", "Windows7", "Max OS X",
    "Linux", "OS/2" };
  ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity(),
    android.R.layout.simple_list_item_1, values);
  setListAdapter(adapter);
 }

 @Override
 public void onListItemClick(ListView l, View v, int position, long id) {
  String item = (String) getListAdapter().getItem(position);
  DetailFragment fragment = (DetailFragment) getFragmentManager()
    .findFragmentById(R.id.detailFragment);
  if (fragment != null && fragment.isInLayout()) {
   fragment.setText(item);
  } else {
   Intent intent = new Intent(getActivity().getApplicationContext(),
     DetailActivity.class);
   intent.putExtra("value", item);
   startActivity(intent);

  }

 }
} 

Create the DetailFragment class.

package de.vogella.android.fragments;

import android.app.Fragment;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class DetailFragment extends Fragment {
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  Log.e("Test", "hello");
 }

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

 }

 @Override
 public View onCreateView(LayoutInflater inflater, ViewGroup container,
   Bundle savedInstanceState) {
  View view = inflater.inflate(R.layout.details, container, false);
  return view;
 }

 public void setText(String item) {
  TextView view = (TextView) getView().findViewById(R.id.detailsText);
  view.setText(item);
 }
} 

Create layouts for landscape mode

We want that Android uses a different main.xml file in portrait model then in landscape mode.
For this reason create the "res/layout-port" folder.
In portrait mode Android will check the "layout-port" folder for fitting layout files. Only if we would not have a main.xml file in "layout-port", Android would check the "layout" folder.
Therefore create the following main.xml layout file in "res/layout-port".

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal" >

    <fragment
        android:id="@+id/listFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginTop="?android:attr/actionBarSize"
        class="de.vogella.android.fragments.ListFragment" />
</LinearLayout> 

Also create the "details_activity_layout.xml" layout file. This layout will be used in the DetailActivity which is only used in portrait mode. Please note that we could have create this file also in the "layout" folder, but as it is only used in portrait mode it is best practise to place it into this folder.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <fragment
        android:id="@+id/detailFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        class="de.vogella.android.fragments.DetailFragment" />

</LinearLayout> 

Activities

Create a new Activity called DetailActivity with the following class.

package de.vogella.android.fragments;

import android.app.Activity;
import android.content.res.Configuration;
import android.os.Bundle;
import android.widget.TextView;

public class DetailActivity extends Activity {
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);

  // Need to check if Activity has been switched to landscape mode
  // If yes, finished and go back to the start Activity
  if (getResources().getConfiguration().orientation == 
    Configuration.ORIENTATION_LANDSCAPE) {
   finish();
   return;
  }

  setContentView(R.layout.details_activity_layout);
  Bundle extras = getIntent().getExtras();
  if (extras != null) {
   String s = extras.getString("value");
   TextView view = (TextView) findViewById(R.id.detailsText);
   view.setText(s);
  }
 }
} 

MainActivity will remain unmodified.

package de.vogella.android.fragments;

import android.app.Activity;
import android.os.Bundle;

public class MainActivity extends Activity {
 

/** Called when the activity is first created. */
@Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
 }
} 

Run

Run your example. If you run the application in portrait mode you should see only one Fragment. Use Ctrl+F11 to switch the orientation. In horizontal mode you should see two Fragments. If you select an item in portrait mode a new Activity should get started with the selected item. In horizontal mode your second Fragment should display the select item.

ActionBar navigation with Fragments

Fragments can also be used in combination with the ActionBar for navigation. For this your main Activity needs to implement a TabListener which is responsible for moving between the tabs.
The ActionBar allows to add tabs to it via the newTab() method. The following code shows such an Activity. It uses two Fragments, called DetailFragment and ImageFragment. At this point you should be able to create these two Fragments yourself.

package de.vogella.android.fragment;

import android.app.ActionBar;
import android.app.ActionBar.Tab;
import android.app.ActionBar.TabListener;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.os.Bundle;

public class MainActivity extends Activity {
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  // setup action bar for tabs
  ActionBar actionBar = getActionBar();
  actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
  actionBar.setDisplayShowTitleEnabled(false);

  Tab tab = actionBar
    .newTab()
    .setText("First tab")
    .setTabListener(new MyTabListener<DetailFragment>(this, "artist",
        DetailFragment.class));
  actionBar.addTab(tab);

  tab = actionBar
    .newTab()
    .setText("Second Tab")
    .setTabListener(new MyTabListener<ImageFragment>(this, "album",
        ImageFragment.class));
  actionBar.addTab(tab);

 }

 public static class MyTabListener<T extends Fragment> implements
   TabListener {
  private Fragment mFragment;
  private final Activity mActivity;
  private final String mTag;
  private final Class<T> mClass;

  

/**
   * Constructor used each time a new tab is created.
   * 
   * @param activity
   *            The host Activity, used to instantiate the fragment
   * @param tag
   *            The identifier tag for the fragment
   * @param clz
   *            The fragment's Class, used to instantiate the fragment
   */
public MyTabListener(Activity activity, String tag, Class<T> clz) {
   mActivity = activity;
   mTag = tag;
   mClass = clz;
  }

  /* The following are each of the ActionBar.TabListener callbacks */

  public void onTabSelected(Tab tab, FragmentTransaction ft) {
   // Check if the fragment is already initialized
   if (mFragment == null) {
    // If not, instantiate and add it to the activity
    mFragment = Fragment.instantiate(mActivity, mClass.getName());
    ft.add(android.R.id.content, mFragment, mTag);
   } else {
    // If it exists, simply attach it in order to show it
    ft.setCustomAnimations(android.R.animator.fade_in,
      R.animator.animationtest);
    ft.attach(mFragment);
   }
  }

  public void onTabUnselected(Tab tab, FragmentTransaction ft) {
   if (mFragment != null) {
    ft.setCustomAnimations(android.R.animator.fade_in,
      R.animator.test);
    ft.detach(mFragment);
   }
  }

  public void onTabReselected(Tab tab, FragmentTransaction ft) {
  }
 }
} 

 (vogella.com)

Layout Manager- ViewGroups & ScrollView

Available Layout Manager

A layout manager is a subclass of ViewGroup and is responsible for the layout of itself and its child Views. Android supports different default layout managers.
As of Android 4.0 the most relevant layout managers are LinearLayout, FrameLayout, RelativeLayout and GridLayout.
All layouts allow the developer to define attributes. Children can also define attributes which may be evaluated by their parent layout.
AbsoluteLayoutLayout is deprecated and TableLayout can be implemented more effectively via GridLayout

LinearLayout

LinearLayout puts all its child elements into a single column or row depending on the android:orientation attribute. Possible values for this attribute are horizontal and vertical, horizontal is the default value.
LinearLayout can be nested to achieve more complex layouts.

RelativeLayout

RelativeLayout allow to position the widget relative to each other. This allows for complex layouts.
A simple usage for RelativeLayout is if you want to center a single component. Just add one component to the RelativeLayout and set the android:layout_centerInParent attribute to true.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <ProgressBar
        android:id="@+id/progressBar1"
        style="?android:attr/progressBarStyleLarge"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
         />

</RelativeLayout> 

GridLayout

GridLayout was introduced with Android 4.0. This layout allows you to organize a view into a Grid. GridLayout separates its drawing area into: rows, columns, and cells.
You can specify how many columns you want for define for each View in which row and column it should be placed and how many columns and rows it should use. If not specified GridLayout uses defaults, e.g. one column, one row and the position of a View depends on the order of the declaration of the Views.

ScrollView

The ScrollView class can be used to contain one View that might be to big too fit on one screen. ScrollView will is this case display a scroll bar to scroll the context.
Of course this View can be a layout which can then contain other elements.

** Tutorial: ScrollView

Create an android project "de.vogella.android.scrollview" with the activity "ScrollView". Create the following layout and class.

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fillViewport="true"
    android:orientation="vertical" >

    <LinearLayout
        android:id="@+id/LinearLayout01"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical" >

        <TextView
            android:id="@+id/TextView01"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:paddingLeft="8dip"
            android:paddingRight="8dip"
            android:paddingTop="8dip"
            android:text="This is a header"
            android:textAppearance="?android:attr/textAppearanceLarge" >
        </TextView>

        <TextView
            android:id="@+id/TextView02"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:layout_weight="1.0"
            android:text="@+id/TextView02" >
        </TextView>

        <LinearLayout
            android:id="@+id/LinearLayout02"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" >

            <Button
                android:id="@+id/Button01"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1.0"
                android:text="Submit" >
            </Button>

            <Button
                android:id="@+id/Button02"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1.0"
                android:text="Cancel" >
            </Button>
        </LinearLayout>
    </LinearLayout>

</ScrollView> 

package de.vogella.android.scrollview;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

public class ScrollView extends Activity {
    

/** Called when the activity is first created. */
@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        TextView view = (TextView) findViewById(R.id.TextView02);
        String s="";
        for (int i=0; i < 100; i++) {
         s += "vogella.com ";
        }
        view.setText(s);
    }
} 

The attribute "android:fillViewport="true"" ensures that the scrollview is set to the full screen even if the elements are smaller then one screen and the "layout_weight" tell the android system that these elements should be extended.

(vogella.com)

OptionMenu and ActionBar

ActionBar

The ActionBar is located at the top of the Activity that may display the Activity title, navigation modes, and other interactive items.
The following picture show the ActionBar of a typical Google Application with interactive items and a nagivation bar.

OptionsMenu

The application can also open a menu which shows actions via a popup menu. This OptionsMenu is only available if the phone has a hardware "Options" button. Even if the hardware button is available, it is recommended to use the ActionBar, which is available for phones as of Android 4.0.
The following picture highlights the hardware button and the resulting menu as popup.

One of the reasons why the ActionBar is superior to the OptionsMenu, if that it is clearly visible, while the OptionsMenu is only shown on request and the user may not recognize that options are available.

Creating the menu

The OptionsMenu and the ActionBar is filled by the onCreateOptionsMenu() method of your Activity.
In the onCreateOptionsMenu() method you can create the menu entries. You can add menu entries via code or via the inflation of an existing XML resources.
The MenuInflator class allows to inflate menu entries defined in XML to the menu. MenuInflator can get accessed via the getMenuInflator() method in your Activity.
The onCreateOptionsMenu() method is only called once. If you want to influence the menu later you have to use the onPrepareOptionsMenu() method. onPrepareOptionsMenu() is not called for entries in the ActionBar for these entries you have to use the invalidateOptionsMenu() method.

Reacting to menu entry selection

If a menu entry is selected then the onOptionsItemSelected() method is called. As parameter you receive the menu entry which was selected so that you can react differently to different menu entries.

Using the home icon

The ActionBar also shows an icon of your application. You can also add an action to this icon. If you select this icon the onOptionsItemSelected() method will be called with the value android.R.id.home. The recommendation is to return to the main Activity in your program.

// If home icon is clicked return to main Activity
case android.R.id.home:
 Intent intent = new Intent(this, OverviewActivity.class);
 intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
 startActivity(intent);
 break; 

ActionBar tabs

It is also possible to add tabs to the ActionBar which can be used for navigation. Typically Fragments are used for this purpose. We demonstrate this in the Fragments chapter.

Custom Views in the ActionBar

You can also add a custom View to the ActionBar. The following code snippet demonstrates that.

@Override
public void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.main);
 
 ActionBar actionBar = getActionBar();
 // add the custom view to the action bar
 actionBar.setCustomView(R.layout.actionbar_view);
 actionBar.setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM
  | ActionBar.DISPLAY_SHOW_HOME);
} 

Contextual action mode

A contextual action mode activates a temporary ActionBar that overlays the application ActionBar for the duration of a particular sub-task.
The contextual action mode is typically activated by selecting an item or by long clicking on it.
To implemented this, call the startActionMode() method on a View or on your Activity. This method gets an ActionMode.Callback object which is responsible for the lifecycle of the contextual ActionBar.

Context menus

You can also assign a context menu to a View. A context menu is also activated if the user "long presses" the view.
If possible the contextual action mode should be preferred over a context menu.
A context menu for a view is registered via the registerForContextMenu(view) method. The onCreateContextMenu() method is called every time a context menu is activated as the context menu is discarded after its usage. The Android platform may also add options to your View, e.g. EditText provides context options to select text, etc.

===   Tutorial: ActionBar   ===

Project

Create a project called "de.vogella.android.socialapp" with the Activity called OverviewActivity.

Add a menu XML resource

Select your project, right click on it and select New → Other → Android → Android XML File to create a new XML resource.
Select the Menu option, enter mainmenu.xml as filename and press the Finish button.

This will create a new mainmenu.xml file in the res/menu folder of your project. Open this file and select the Layout tab of the Android editor.
Press the Add button and select the Item entry. Maintain a entry similar to the following screenshot. Via the ifRoom attribute you define that the menu entry is displayed in the ActionBar if there is sufficient space available.

Add a similar entry to the menu with the ID attribute set to "@+id/menuitem2", and the Title attribute set to "Test". Also set the ifRoom flag.
The resulting XML will look like the following.

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android" >

    <item
        android:id="@+id/menuitem1"
        android:showAsAction="ifRoom"
        android:title="Prefs">
    </item>
    <item
        android:id="@+id/menuitem2"
        android:showAsAction="ifRoom"
        android:title="Test">
    </item>

</menu> 

Change your OverviewActivity class to the following.

package de.vogella.android.socialapp;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.Toast;

public class OverviewActivity extends Activity {
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
 }

 @Override
 public boolean onCreateOptionsMenu(Menu menu) {
  MenuInflater inflater = getMenuInflater();
  inflater.inflate(R.menu.mainmenu, menu);
  return true;
 }

 @Override
 public boolean onOptionsItemSelected(MenuItem item) {
  switch (item.getItemId()) {
  case R.id.menuitem1:
   Toast.makeText(this, "Menu Item 1 selected", Toast.LENGTH_SHORT)
     .show();
   break;
  case R.id.menuitem2:
   Toast.makeText(this, "Menu item 2 selected", Toast.LENGTH_SHORT)
     .show();
   break;

  default:
   break;
  }

  return true;
 }
} 

Run your application. As there is enough space in the ActionBar otherwise you may see the Overflow menu or you have to use the Option menu button on your phone. If you select one item, you should see a small info message.

Tutorial: Using the contextual action mode

Add a EditText element your main.xml layout file.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <EditText
        android:id="@+id/myView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:ems="10" >

        <requestFocus />
    </EditText>

</LinearLayout> 

Create a new menu XML resource with the file name "contextual.xml"

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android" >
    <item
        android:id="@+id/toast"
        android:title="Toast">
    </item>

</menu> 

Change your Activity to the following.

package de.vogella.android.socialapp;

import android.app.Activity;
import android.os.Bundle;
import android.view.ActionMode;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.Toast;

public class OverviewActivity extends Activity {
 protected Object mActionMode;
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  // Define the contextual action mode
  View view = findViewById(R.id.myView);
  view.setOnLongClickListener(new View.OnLongClickListener() {
   // Called when the user long-clicks on someView
   public boolean onLongClick(View view) {
    if (mActionMode != null) {
     return false;
    }

    // Start the CAB using the ActionMode.Callback defined above
    mActionMode = OverviewActivity.this
      .startActionMode(mActionModeCallback);
    view.setSelected(true);
    return true;
   }
  });
 }

 @Override
 public boolean onCreateOptionsMenu(Menu menu) {
  MenuInflater inflater = getMenuInflater();
  inflater.inflate(R.menu.mainmenu, menu);
  return true;
 }

 @Override
 public boolean onOptionsItemSelected(MenuItem item) {
  Toast.makeText(this, "Just a test", Toast.LENGTH_SHORT).show();
  return true;
 }

 private ActionMode.Callback mActionModeCallback = new ActionMode.Callback() {

  // Called when the action mode is created; startActionMode() was called
  public boolean onCreateActionMode(ActionMode mode, Menu menu) {
   // Inflate a menu resource providing context menu items
   MenuInflater inflater = mode.getMenuInflater();
   // Assumes that you have "contexual.xml" menu resources
   inflater.inflate(R.menu.contextual, menu);
   return true;
  }

  // Called each time the action mode is shown. Always called after
  // onCreateActionMode, but
  // may be called multiple times if the mode is invalidated.
  public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
   return false; // Return false if nothing is done
  }

  // Called when the user selects a contextual menu item
  public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
   switch (item.getItemId()) {
   case R.id.toast:
    Toast.makeText(OverviewActivity.this, "Selected menu",
      Toast.LENGTH_LONG).show();
    mode.finish(); // Action picked, so close the CAB
    return true;
   default:
    return false;
   }
  }

  // Called when the user exits the action mode
  public void onDestroyActionMode(ActionMode mode) {
   mActionMode = null;
  }
 };

} 

If you run this example and long press the EditText widget, your contextual ActionBar is displayed.

(vogella.com)