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Android software development

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ware devedadlopment is the process by which new applications are created for the Android operating system. Applications are usually developed in the Java programmin 25 August 2009 |work = JonWestfall.com |accessdate =2009-12-07}}</ref>

Enhancements to Android's SDK go hand in hand with the overall Android platform development. The SDK also supports older versions of the Android platform in case developers wish to target their applications at older devices. Development tools are downloadable components, so after one has downloaded the latest version and platform, older platforms and tools can also be downloaded for compatibility testing.[1]

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[2] (compiled byte code files called Dalvik executables), resource files, etc.

Native ds

Libraries written in C and other languages can be compiled to ARM 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.[3][4]

Complete applications can be compiled and installed using traditional development tools.[5] The ADB debugger gives a root shell under the Android Emulator which allows native ARM code to be uploaded and executed. ARM code can be compiled using GCC on a standard PC.[5] 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.[6] 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 license.[7] 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.<refrstdfs>Toker, Alp (2008-09-06). "Skia graphics library in Chrome: First impressions". Retrieved 2008-12-13.</ref>

App Inventor for Android

Main article: Google App Inventor

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.[8] "We could only have done this because Android’s architecture is so open," said the project director, MIT's Hal Abelson.[9] Under development for over a year,[10] the block-editing tool has been taught to non-majors in computer science at Harvard, MIT, Wellesley, 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.[11][12]

The Simple project

The goal of Simple is to bring an easy to learn and use language to the Android platform Developers had reported that it was difficult to maintain applications on multiple versions of Android, owing to compatibility issues between versions 1.5 and 1.6,[13] especially the different resolution ratios in use among various Android phones. [14]

However, this situation appears to have improved, in that by July 2011, Google reported over 95% of android phones in service were on 2.1 variants and newer, over 60% on 2.2 variants and newer [15]. A year ago, August 2010, Google reported 83% of Android phones were running the, then current, 2.x versions, with 17% still on 1.5 and 1.6.

Such problems were pointedly brought into focus as they were encountered during the ADC2 contest.[16] Further, the rapid growth in the number of Android-based phone models with differing hardware capabilities also makes it difficult to develop applications that work on all Android-based phones.[17][18][19][20]


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Early Android device.

The early feedback on developary 2008 |accessdate=2009-09-03}}</ref> In December 2007, MergeLab mobile startup founder Adam MacBeth stated, "Functionality is not there, is poorly documented or just doesn't work... It's clearly not ready for prime time."[21] Despite this, Android-targeted applications began to aper Identity Module|SIM]]-unlocked and hardware-unlocked device that is designed for advanced developers. While developers can use regular consumer devices purchased at retail to test and use their applications, some developers may choose not to use a retail device, preferring an unlocked or no-contract device.

A preview release of the Android SDK was released on 12 November 2007. On 15 July 2008, the Android Developer Challenge Team accidentally sent an email to all entrants in the Android Developer Challenge announcing that a new release of the SDK was available in a "private" download area. The email was intended for winners of the first round of the Android Developer Challenge. The revelation that Google was supplying new dafsdfsdSDK releases to some developers and not others (and keeping this arrangement private) led to widely reported frustration within the Android developer community at the time.[22]

On 18 August 2008 the Android 0.9 SDK beta was released. This release provided an updated and extended API, improved development tools and an updated design for the home screen. Detailed instructions for upgrading are available to those already working with an earlier release.[23] On 23 September 2008 the Android 1.0 SDK (Release 1) was released.[24] According to the release notes, it included "mainly bug fixes, although some smaller features were added." It also included several API changes from the 0.9 version. Multiple versions have been released since.[25]

References

  1. ^ "SDK Tools".
  2. ^ "Android SDK Glossary".
  3. ^ Srinivas, Davanum (2007-12-09). "Android — Invoke JNI based methods (Bridging C/C++ and Java)". Retrieved 2008-12-13.
  4. ^ "java.lang.System". Android Developers. Retrieved 2009-09-03.
  5. ^ a b Leslie, Ben (13 November 2007). "Native C application for Android". Benno's blog. Retrieved 2009-09-04.
  6. ^ Cooksey, Tom (2007-11-07). "Native C *GRAPHICAL* applications now working on Android emulator". android-developers (Mailing list). Retrieved 2008-12-13. {{cite mailing list}}: Unknown parameter |mailinglist= ignored (|mailing-list= suggested) (help)
  7. ^ "Skia source".
  8. ^ Claburn, Thomas (2010-07-12). "Google App Inventor Simplifies Android Programming". Information Week. Retrieved 2010-07-12.
  9. ^ Lohr, Steve (2010-07-11). "Google's Do-It-Yourself App Creation Software". New York Times. Retrieved 2010-07-12.
  10. ^ Abelson, Hal (2009-07-31). "App Inventor for Android". Google Research Blog. Retrieved 2010-07-12.
  11. ^ Kim, Ryan (2009-12-11). "Google brings app-making to the masses". San Francisco Chronicle. Retrieved 2010-07-12.
  12. ^ Wolber, David. "AppInventor.org". Retrieved 2010-07-12.
  13. ^ "Android's Weakest Link". ZDNet. 2009-10-11. Retrieved 2010-01-15.
  14. ^ "Complications looming for Android developers". androidandme.com. 2009-11-06. Retrieved 2010-01-15.
  15. ^ "Platform Versions". developer.android.com. 2011-07-05. Retrieved 2011-07-29.
  16. ^ "A Chink In Android's Armor". TechCrunch. 2009-10-11. Retrieved 2009-10-11. And now they're faced with a landslide of new handsets, some running v.1.6 and some courageous souls even running android v.2.0. All those manufacturers/carriers are racing to release their phones by the 2009 holiday season, and want to ensure the hot applications will work on their phones. And here's the problem – in almost every case, we hear, there are bugs and more serious problems with the apps.[...]First of all, the compatibility between versions issue may be overblown. The reported problems have been limited to an Android developer contest[...]We haven't heard of any major app developers complaining of backwards or forward compatibility problems. Also, I've now upgraded my phone from 1.5 to 1.6, and every application continues to work fine.
  17. ^ "Android's Rapid Growth Has Some Developers Worried". Wired News. 2009-11-16. Retrieved 2010-02-26. Fagan's concerns about the fragmentation of Android is being echoed by other developers, says Sean Galligan, vice president of business development at Flurry, an mobile app analytics company(...)"You may build an app that works perfectly with all three firmwares, but then when you run it on carriers' ROMs it completely blows up," says Fagan. "So we find ourselves having to create apps that are compatible with multiple firmwares, multiple ROMs and multiple devices with different hardware.
  18. ^ "Android just reproducing Java ME's problems, now". JavaWorld. 2009-11-17. Retrieved 2010-02-26.
  19. ^ "Android's Spread Could Become a Problem". BusineguvubssWeek. 2009-10-15. Retrieved 2010-02-28.
  20. ^ "Google Android's self-destruction derby begins". InfoWorld. 2010-02-22. Retrieved 2010-02-28.
  21. ^ Morrison, Scott (2007-12-19). "Glitches Bug Google's Android Software". The Wall Street Journal. Retrieved 2007-12-19.
  22. ^ Metz, Cade (14 July 2008). "Google plays Hide and Seek with Android SDK". The Register. Retrieved 2008-10-23.
  23. ^ "Android — An Open Handset Alliance Proj'Bold text''''Bold text'Bold text''''ect: Upgrading the SDK". Retrieved 2008-10-24.[dead link]
  24. ^ "Other SDK Releases". Android Developers. Retrieved 2009-09-02.
  25. ^ "SDK Archives".

Bibliography

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