Professional Android Application Development- Reto Meier

Whether you’re an experienced mobile engineer, a desktop or web developer, or a complete programming novice, Android represents an exciting new opportunity to write innovative applications for mobile devices.

Despite the name, Android will not help you create an unstoppable army of emotionless robot warriors on a relentless quest to cleanse the earth of the scourge of humanity. Instead, Android is an open source software stack that includes the operating system, middleware, and key applications along with a set of API libraries for writing mobile applications that can shape the look, feel, and function of mobile handsets.

Small, stylish, and versatile, modern mobile phones have become powerful tools that incorporate cameras, media players, GPS systems, and touch screens. As technology has evolved, mobile devices have become about more than simply making calls, but their software and development platforms have struggled to keep pace.

Until recently, mobile phones were largely closed environments built on proprietary operating systems that required proprietary development tools. The phones themselves often prioritized native applications over those written by third parties. This has introduced an artificial barrier for developers hoping to build on increasingly powerful mobile hardware.

In Android, native and third-party applications are written using the same APIs and executed on the same run time. These APIs feature hardware access, location-based services, support for background services, map-based activities, relational databases, interdevice peer-to-peer messaging, and 2D and 3D graphics.

Using this series of articles, you will learn how to use these APIs to create your own Android applications. In this chapter, you’ll learn some mobile development guidelines and be introduced to the features available from the Android development platform.

Android has powerful APIs, excellent documentation, a thriving developer community, and no development or distribution costs. As mobile devices continue to increase in popularity, this is an exciting opportunity to create innovative mobile phone applications no matter what your development background.

In the days before Twitter and Facebook, when Google was still a twinkle in its founders’ eyes and dinosaurs roamed the earth, mobile phones were just that — portable phones small enough to fit inside a briefcase, featuring batteries that could last up to several hours; they offered the freedom to make calls without being physically connected to a landline.

Increasingly small, stylish, and powerful mobile phones are now as ubiquitous as they are indispensable. Hardware advancements have made mobiles smaller and more efficient while including an increasing number of peripherals.

Beginning with cameras and media players, mobiles now include GPS systems, accelerometers, and touch screens. While these hardware innovations should prove fertile ground for software development, the applications available for mobile phones have generally lagged behind the hardware.

Historically, developers, generally coding in low-level C or C++, have needed to understand the specific hardware they were coding for, generally a single device or possibly a range of devices from a single manufacturer. As hardware technology has advanced, this closed approach has struggled to keep pace.

More recently, platforms like Symbian have been created to provide developers a wider target audience. These systems have proved more successful in encouraging mobile developers to provide rich applications that better leverage the hardware available.

These platforms offer some access to the device hardware, but require writing complex C/C++ code and making heavy use of proprietary APIs that are notoriously difficult to use. This difficulty is amplified when developing applications that must work on different hardware implementations and is particularly true when developing for a particular hardware feature like GPS.

In recent years, the biggest advance in mobile phone development has been the introduction of Javahosted MIDlets. MIDlets are executed on a Java virtual machine, abstracting the underlying hardware and letting developers create applications that run on the wide variety of hardware that supports the Java run time. Unfortunately, this convenience comes at the price of restricted access to the device hardware.

In mobile development, it’s considered normal for third-party applications to receive different hardware access and execution rights compared to native applications written by the phone manufacturers, with MIDlets often receiving few of either.

The introduction of Java MIDlets has expanded developers’ audiences, but the lack of low-level hardware access and sandboxed execution have meant that most mobile applications are desktop programs designed to run on a smaller screen rather than take advantage of the inherent mobility of the handheld platform.

Android sits alongside a new wave of mobile operating systems designed for increasingly powerful mobile hardware. Windows Mobile and Apple’s iPhone now provide a richer, simplified development environment for mobile applications. However, unlike Android, they’re built on proprietary operating systems that often prioritize native applications over those created by third parties and restrict communication among applications and native phone data. Android offers new possibilities for mobile applications by offering an open development environment built on an open source Linux kernel. Hardware access is available to all applications through a series of API libraries, and application interaction, while carefully controlled, is fully supported.

In Android, all applications have equal standing. Third-party and native Android applications are written using the same APIs and are executed on the same run time. Users can remove and replace any native application with a third-party developer alternative; even the dialer and home screens can be replaced.

Google describes Android as:

The first truly open and comprehensive platform for mobile devices, all of the software to run a mobile hone but without the proprietary obstacles that have hindered mobile innovation.
http://googleblog.blogspot.com/2007/11/wheres-my-gphone.html

Android is made up of several necessary and dependent parts including the following:

What really makes Android compelling is its open philosophy, which ensures that any deficiencies in user interface or native application design can be fixed by writing an extension or replacement. Android provides you, as a developer, the opportunity to create mobile phone interfaces and applications designed to look, feel, and function exactly as you image them.

The data stored and used by the native applications — like contact details — are also available to third-party applications. Similarly, your applications can handle events such as an incoming call or a new SMS message.

The exact makeup of the applications available on new Android phones is likely to vary based on the hardware manufacturer and/or the phone carrier or distributor. This is especially true in the United States, where carriers have significant influence on the software included on shipped devices.