01-11-2012, 04:04 PM
Android Application Development Tutorial
AndroidTutorial.ppt (Size: 3.6 MB / Downloads: 497)
Introduction to Android
Software platform from Google and the Open Handset Alliance
July 2005, Google acquired Android, Inc.
November 2007, Open Handset Alliance formed to develop open standards for mobile devices
October 2008, Android available as open source
December 2008, 14 new members joined Android project
April 30, 2009: Official 1.5 Cupcake release
September 15, 2009: 1.6 SDK Donut release
October 26, 2009: 2.0 SDK Éclair release
Updates to the Éclair release:
2.0.1 on December 3, 2009
2.1 on January 12, 2010
Android and the Hardware
Reuse and replacement of components
Dalvik virtual machine
Integrated browser
Optimized graphics
SQLite
Media support
GSM Telephony
Bluetooth, EDGE, 3G, and WiFi
Camera, GPS, compass, and accelerometer
Rich development environment
Android Architecture
Apps are written in Java
Bundled by Android Asset Packaging Tool
Every App runs its own Linux process
Each process has it’s own Java Virtual Machine
Each App is assigned a unique Linux user ID
Apps can share the same user ID to see each other’s files
Hardware-oriented Features
Sensor type (Sensor class)
Orientation, accelerometer, light, magnetic field, proximity, temperature, etc.
Sampling rate
Fastest, game, normal, user interface.
When an application requests a specific sampling rate, it is really only a hint, or suggestion, to the sensor subsystem. There is no guarantee of a particular rate being available.
Accuracy
High, low, medium, unreliable.
Internet Layers
A server machine is identified on the Internet by some IP address
Daemons are the processes running in the background which are listening all the time for connection requests from clients on a particular port number.
Once a connection request comes into the server on a given port, the corresponding daemon can choose to accept it, and if so, a connection is established.
Then the application layer protocol is typically used for the client to get or send data to the server.