WHAT IS ANDROID?

Android is a mobile operating system that is based on a modified version of Linux. It was originally developed by a startup of the same name, Android, Inc. In 2005, as part of its strategy to enter the mobile space, Google purchased Android and took over its development work (as well as its development team).

Google wanted Android to be open and free; hence, most of the Android code was released under the open-source Apache License, which means that anyone who wants to use Android can do so by downloading the full Android source code. Moreover, vendors (typically hardware manufacturers) can add their own proprietary extensions to Android and customize Android to differentiate their products from others. This simple development model makes Android very attractive and has thus piqued the interest of many vendors. This has been especially true for companies affected by the phenomenon of Apple’s iPhone, a hugely successful product that revolutionized the smartphone industry. Such companies include Motorola and Sony Ericsson, which for many years have been developing their own mobile operating systems. When the iPhone was launched, many of these manufacturers had to scramble to find new ways to revitalize their products. These manufacturers see Android as a solution — they will continue to design their own hardware and use Android as the operating system that powers it.

The main advantage of adopting Android is that it offers a unified approach to application development. Developers need only develop for Android, and their applications should be able to run on numerous different devices, as long as the devices are powered using Android. In the world of smartphones, applications are the most important part of the success chain. Device manufacturers therefore see Android as their best hope to challenge the onslaught of the iPhone, which already commands a large base of applications.

Android Versions

Android has gone through quite a number of updates since its first release. Table 1-1 shows the various versions of Android and their codenames.

TABLE 1-1: A Brief History of Android Versions

In February 2011, Google released Android 3.0, a tablet-only release supporting wide-screen devices. The key changes in Android 3.0 are as follows:

• New user interface optimized for tablets
• 3D desktop with new widgets
• Refined multi-tasking
• New web browser features, such as tabbed browsing, form auto-fill, bookmark syncing, and private browsing
• Support for multicore processors

Applications written for versions of Android prior to 3.0 are compatible with Android 3.0 devices, and they run without modifications. Android 3.0 tablet applications that make use of the newer features available in 3.0, on the other hand, will not be able to run on older devices. If you want to ensure that an Android tablet application is able to run on all versions of devices, you must programmatically ensure that you only make use of features that are supported in specific versions of Android. To do so, you can make use of the android.os.Build.VERSION.SDK constant. The following code snippet shows how you can determine the version of the device during runtime:

int version =
     Integer.parseInt(android.os.Build.VERSION.SDK);
switch (version) {
case 8:
    //---use features specific to Android 2.2---
    break;
case 9:
    //---use features specific to Android 2.3.1---
    break;
case 10:
    //---use features specific to Android 2.3.3---
    break;
case 11:
    //---use features specific to Android 3.0---
    break;
}

Android Devices in the Market

Android devices come in all shapes and sizes. As of late May 2010, the Android OS powers all of the following types of devices:

• Smartphones
• Tablets
• E-reader devices
• Netbooks
• MP4 players
• Internet TVs

Increasingly, manufacturers are rushing out to release Android tablets. Tablet sizes typically start at seven inches, measured diagonally. Figure 1-1 shows the Samsung Galaxy Tab (top), a seven-inch tablet, and the Dell Streak (bottom), a five-inch tablet.

FIGURE 1-1

While the Samsung Galaxy Tab and the Dell Streak run the older Android 2.x, the newer tablets run the latest Android 3.0 Honeycomb. Figure 1-2 shows the Motorola Xoom.

FIGURE 1-2

Besides the Motorola Xoom, the LG Optimus Pad, shown in Figure 1-3, is another Android 3.0 device, running the latest Android Honeycomb OS.

FIGURE 1-3

The Android Market

As mentioned earlier, one of the main factors determining the success of a smartphone platform is the applications that support it. It is clear from the success of the iPhone that applications play a very vital role in determining whether a new platform swims or sinks. In addition, making these applications accessible to the general user is extremely important.

As such, in August 2008, Google announced the Android Market, an online application store for Android devices, and made it available to users in October 2008. Using the Market application that is preinstalled on their Android device, users can simply download third-party applications directly onto their devices. Both paid and free applications are supported on the Android Market, though paid applications are available only to users in certain countries due to legal issues.

Similarly, in some countries, users can buy paid applications from the Android Market, but developers cannot sell in that country. As an example, at the time of writing, users in India can buy apps from the Android Market, but developers in India cannot sell apps on the Android Market. The reverse may also be true; for example, users in South Korea cannot buy apps on the Android Market, but developers in South Korea can sell apps on it.