source: http://en.wikipedia.org/wiki/Android_software_development
Android software development is the process by which new applications are created for the
Android operating system. Applications are usually developed in the
Java programming language using the Android
Software Development Kit
The Android
software development kit (SDK) includes a comprehensive set of development tools.
[5] These include a
debugger,
libraries, a handset
emulator based on
QEMU, documentation, sample code, and tutorials. Currently supported development platforms include computers running
Linux (any modern desktop
Linux distribution),
Mac OS X 10.5.8 or later,
Windows XP or later. The officially supported
integrated development environment (IDE) is
Eclipse
using the Android Development Tools (ADT) Plugin, though developers may
use any text editor to edit Java and XML files then use
command line tools (
Java Development Kit and
Apache Ant
are required) to create, build and debug Android applications as well
as control attached Android devices (e.g., triggering a reboot,
installing software package(s) remotely).
[6]
Android applications are packaged in
.apk format and stored under
/data/app folder on the Android OS (the folder is accessible only to root user for security reasons). APK package contains .dex files
[8] (compiled byte code files called
Dalvik executables), resource files, etc.
others
Native development kit
Libraries written in
C and other languages can be compiled to
ARM or
x86 native code and installed using the Android
Native Development Kit. Native classes can be called from Java code running under the Dalvik VM using the
System.loadLibrary call, which is part of the standard Android Java classes.
[9][10]
Complete applications can be
compiled and installed using traditional development tools.
[11] The ADB debugger gives a root shell under the Android Emulator which allows native
ARM code or
x86 code to be uploaded and executed. ARM or x86 code can be compiled using
GCC on a standard PC.
[11] Running native code is complicated by the fact that Android uses a non-standard C library (libc, known as
Bionic). The underlying graphics device is available as a
framebuffer at
/dev/graphics/fb0.
[12] The graphics library that Android uses to arbitrate and control access to this device is called the
Skia Graphics Library (SGL), and it has been released under an open source licence.
[13] Skia has backends for both
win32 and
Unix, allowing the development of cross-platform applications, and it is the graphics engine underlying the
Google Chrome web browser.
[14]
Unlike Java App development based on the
Eclipse
IDE, the NDK is based on command-line tools and requires invoking them
manually to build, deploy and debug the apps. Several third-party tools
allow integrating the NDK into Eclipse
[15] and Visual Studio
[16].
Android Open Accessory Development Kit
The Android 3.1 platform (also backported to Android 2.3.4)
introduces Android Open Accessory support, which allows external USB
hardware (an Android USB accessory) to interact with an Android-powered
device in a special "accessory" mode. When an Android-powered device is
in accessory mode, the connected accessory acts as the USB host (powers
the bus and enumerates devices) and the Android-powered device acts as
the USB device. Android USB accessories are specifically designed to
attach to Android-powered devices and adhere to a simple protocol
(Android accessory protocol) that allows them to detect Android-powered
devices that support accessory mode.
[17]
App Inventor for Android
On 12 July 2010, Google announced the availability of App Inventor
for Android, a Web-based visual development environment for novice
programmers, based on MIT's Open Blocks Java library and providing
access to Android devices' GPS, accelerometer and orientation data,
phone functions, text messaging, speech-to-text conversion, contact
data, persistent storage, and Web services, initially including Amazon
and Twitter.
[18] "We could only have done this because Android’s architecture is so open," said the project director, MIT's
Hal Abelson.
[19] Under development for over a year,
[20]
the block-editing tool has been taught to non-majors in computer
science at Harvard, MIT, Wellesley, Trinity College (Hartford,) and the
University of San Francisco, where Professor David Wolber developed an
introductory computer science course and tutorial book for non-computer
science students based on App Inventor for Android.
[21][22]
HyperNext Android Creator
HyperNext Android Creator (HAC) is a software development system
aimed at beginner programmers that can help them create their own
Android apps without knowing Java and the Android SDK. It is based on
HyperCard
that treated software as a stack of cards with only one card being
visible at any one time and so is well suited to mobile phone
applications that have only one window visible at a time. HyperNext
Android Creator's main programming language is simply called
HyperNext and is loosely based on Hypercard's
HyperTalk
language. HyperNext is an interpreted English-like language and has
many features that allow creation of Android applications. It supports a
growing subset of the Android SDK including its own versions of the GUI
control types and automatically runs its own background service so apps
can continue to run and process information while in the background.
The Simple project
The goal of Simple is to bring an easy-to-learn-and-use language to the Android platform.
[23] Simple is a
BASIC
dialect for developing Android applications. It targets professional
and non-professional programmers alike in that it allows programmers to
quickly write Android applications that use the Android runtime
components.
Similar to Microsoft Visual Basic 6, Simple programs are form
definitions (which contain components) and code (which contains the
program logic). The interaction between the components and the program
logic happens through events triggered by the components. The program
logic consists of event handlers which contain code reacting to the
events.
The Simple project is not very active
[24], the last source code update being in August 2009.
Basic4android
Basic4android is a commercial product similar to Simple.
[25] It is inspired by Microsoft
Visual Basic 6 and Microsoft
Visual Studio. Basic4android is very active, and there is a strong online community of Basic4android developers.
