Andriod Session.ppt
- 1. Android
- 2. Overview • Android is an open source platform designed for mobile devices. Android is founded in the year 2003 by Andy Rubin,Rich miner,Nick sears and Chris white and names it as “Android Inc” . Then the company is acquired by Google and now it is aligned with “open Handset Alliance” . First Android mobile is G1 Phone manufactured by HTC and sold by wireless carrier T-mobile USA.
- 3. Android Versions: Versions Nick Name Android 1.0 NA Android 1.1 NA Android 1.5 Cup Cake Android 1.6 DoNut Android 2.0 Eclair Android 2.2 Froyo Android 2.3 GingerBread Android 3.0 HoneyComb Android 4.0 IceCream Sandwich
- 5. Android Stack overview : Android is built in the top of LINUX operating system. Other Libraries are Web-kit (Web rendering engine) SqlLite (Sql DataBase) OpenGL (3D graphics Library) OpenSSL (Secured Socket Layer)
- 6. Dalvik Architecture • Dalvik is an virtual machine designed specifically for Android by Dan Bornstein from Google. Reasons for replacing Java VM : Dalvik focus strictly on mobile devices one of these are battery power consumptions and other is processing power Though Java Language,Java tools and Java libraries are open source , Java VM is not . To make it license friendly Android introduces Dalvik VM. Dalvik VM is closest to Java libraries but removes interface (awt and swing).
- 7. How it works ? In Java , we write Java source code and compile to Java byte code using Java compiler , then byte code is run on Virtual machine. In Android , we write Java code and still convert byte code using Java compiler and recompiled again with Dalvik virtual machine.
- 9. Activity Life-cycle Introduction : An activity is a single screen that user sees on the screen. Launching an activity is an expensive , it creates a new Linux process and allocates memory for the UI objects and loads the XML layout .To do load an activity it takes lot of task , if user switches the screen to persist the activity state Android introduces Activity manager.
- 11. Activity State's : Start state (Activity doesn't exist in memory and starts loading it ) Running state (user Interaction state) Paused state (App is visible but not used ) Stopped state.(App is invisible and still exist in the memory) Destroy state. (App removed from the memory)
- 12. Intent Intents are messages that are sent among major building blocks. They trigger an activity to start up, a service to start or stop, or are simply broadcasts. Intents are asynchronous, meaning the code that is sending them doesn’t have to wait for them to be completed. Intent can be explicit or implicit command.
- 13. Intent Diagram
- 14. Content Providers Content Providers are interfaces for sharing data between applications. Android by default runs each application in its own sandbox so that all data that belongs to an application is totally isolated from other applications on the system. While small amounts of data can be passed between applications via Intents
- 16. Android User Interface • Android UI : Declarative Approach (XML based Layout). Programmatic Approach (Java Code To develop the UI)