Creating Android Phone Tablet application in a single apk

Guys!! It was very difficult to believe that Android had introduced an entirely new API (Fragment API) for Tablet App Development. Coming from Activity background, it was really tough to digest this fragments concept while coding; even if it is very interesting and more generalized one. Soon, i got to hear that we can create a single apk file for both phone and Tablets by using Fragment API itself. On digging more into it, it became quite easy and interesting to implement.

Functional Concept

Basically, in such type of apps, we need to separate all components of our application, and then convert each component to fragments. For example- Dashboard Fragment for Dashboard screen, two fragments for List and Details. Then, as our need, we can combine them to fit on the screens of both phone and tablet based on the Space available and required functionality.

Technical Concept

The earlier concept (for mobile versions) was to have activity class for each screen having business logic written for the respective screen functionality. Here we will write the business logic once but only different main screen layouts for both phone and tablet screens. Now, we will have smaller components as Fragment classes & layouts and their respective business logic in them.

As we know, we cannot show fragment directly on screen as it needs to be in the form of Activity class.  So for phone, we will convert the fragment to FragmentActivity class and for tablet we will have separate layouts containing two or more fragments and their respective FragmentActivity classes.

Now, on deploying the same apk file to both phone and tablet, it should take respective layouts for both.

Sample Application

So here is what i have created a way or you can say a ‘BASE STRUCTURE’ for any Phone-Tablet Android Application.

Application Name: TestPhoneTablet

Deployment platforms: Phone and Tablet versions both, i.e. Android 2.x & 3.x

External Jar file: android-support-v4.jar (When we need to deploy our application on both phone and tablet, all Fragment and Fragment Activity classes in our project should extend from this jar).

Description: In the application for phone, a list of countries will be displayed on first screen; on clicking any of them, the country name will be displayed on the second screen.

On the other hand in case of Tablet, on a single screen, the list of countries will be displayed on left hand side and on clicking any of them; the country name will be displayed on right side.

Brief Description for every element (classes and xmls) in the above project:

·         com.deepak.test : This package is for all the classes which will be common elements for both phone and tablet build.

§  BaseActivity.java: This class extended by FragmentActivity class is the base class for our whole project. A base activity that defers common functionality across app activities to an ActivityHelper. This class shouldn't be used directly; instead, activities should inherit from BaseSinglePaneActivity or BaseMultiPaneActivity.

§  BaseMultiPaneActivity.java: This class extended by BaseActivity class and all Tablet activities will extend to this class. It can contain multiple panes, and has the ability to substitute fragments for activities when intents are fired using BaseActivity#openActivityOrFragment(android.content.Intent).

§  BaseSinglePaneActivity.java: This class extended by BaseActivity class and all Phone activities will extend to this class. It simply contains a single fragment. The intent used to invoke this activity is forwarded to the fragment as arguments during fragment instantiation.

§  Home Activity.java: This Activity class is the launcher activity for our application and is only class which directly extends to the BaseActivity class after BaseSinglePaneActivity and BaseMultiPaneActivity classes. It sets the layout activity_home.xml on screen which is defined for both phone and tablet in their respective layout folders.

§  List_Fragment.java: This is List Fragment class, containing a list of countries which is the first screen of our application.

§  DetailFragment.java: This is a Fragment class which shows the selected country name.

·         com.deepak.test.phone : The package for all phone activity classes.

§  DetailActivity.java: The FragmentActivity class on converting the DetailFragment class to an activity and used to show only on Phone.

·         com.deepak.test.tablet : The package for all tablet activity classes.

·         com.deepak.test.Utils : The package for utility/helper classes in our project.

§  ActivityHelper.java: A class that handles some common activity-related functionality in the app, such as setting up the action bar. This class provides functionality useful for both phones and tablets, and does not require any Android 3.0-specific features.

§  ActivityHelperHoneycomb.java: An extension of ActivityHelper that provides Android 3.0-specific functionality for Honeycomb tablets. It thus requires API level 11.

§  SimpleMenu.java: An implementation of Menu Interface to show the action bar and Options menu in tablet and phone respectively.

§  SimpleMenuItem.java: An implementation of MenuItem interface.

§  UIUtils.java: A utility class which can have many UI helper functions like- to know the version of device OS on which the app is deployed so that it could render respective activities and layouts.

·         res/layout: The layout files used for Fragments and Phone screens or we can say that common layout files for phone and tablets.

·         res/layout-xlarge-v11: the layout files for tablet screens.

If we want to make the same layout look different on both phone and tablet, we can put the same layout with same name and different design in both layout folders. On  deployment, we will automatically render to the respective folder. Similary for  drawable & drawable-xlarge-v11 and menu & menu-xlarge-v11 folders

App Screenshots:

Tablet Screen

Phone Screen:

Here is link for source code. Enjoy doing some creative stuff and meeting your requirements.
http://code.google.com/p/testphonetablet-androidapp/downloads/list

Folks!! This is all about the project structure and files for this particular requirement. Please provide your comments, ques and suggestions J