getting started with android 1.5

Android

By: Gaurav Kohli

Agenda

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History

• In July 2005, Google acquired Android, Inc., a small startup company based in Palo Alto, CA.

• Android's co-founders who went to work at Google included Andy Rubin (co-founder of Danger), Rich Miner (co-founder of Wildfire Communications, Inc.), Nick Sears (once VP at T-Mobile), and Chris White (one of the first engineers at WebTV).

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Introduction- What is Android ?

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Android is a software platform for mobile devices, powered by the Linux operating system, initially developed by Google and later the Open Handset Alliance[1].It allows developers to write managed code in the Java language, controlling the device via Google-developed Java libraries.

[1] http://en.wikipedia.org/wiki/Google_Android

Introduction- Why Android ?

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Mobile Computing is next big thing

Google is behind it

Not limited to mobiles only

Open-Handset Alliance

Community support

Open/Free/Java Syntax/Tools support

Open Handset alliance

Architecture of Android

Architecture of Android

• Linux Kernel based• Libraries (Open sourced/ Custom)

• Open GL • Android Runtime

• Dalvik VM• Application Framework• Applications

• Highly optimized VM, compiled byte is optimized for mobile devices

• End result is NOT the same byte code as Java,o dx in the sdk takes compiled Java class files and converts them into .dex

• No JIT• Built with security and performances (battery life) in mind

Dalvik VM

Applications

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• SDK o Available at http://developer.android.com/sdk/1.1_r1/index.html

• Eclipseo  3.3(Europa) or 3.4 (Ganymede)

• Eclipse Plugino  XP,Vista, Linux, x86 Mac 10.4.8 or latero http://developer.android.com/sdk/1.1_r1/installing.html

• Leave the emulator running!  o Exact opposite to J2ME and BREW, your app will be deployed each

subsequent run or debug

Installing and Using the SDK

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Building Blocks of Application

Activity An activity presents a visual user interface for one focused endeavor the user can undertake.

Intent An intent is an abstract description of an operation to be performed. It can be used with startActivity to launch an  Activity, broadcastIntent to send it to any interested BroadCastReceiver components

Services A service doesn't have a visual user interface, but rather runs in the background for an indefinite period of time

Content Provider A content provider makes a specific set of the application's data available to other applications.

• Emulator (comes with SDK)

• Eclipse Plugin

• Android SDK

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Developer Tool Chain

First Simple Application

package com.example.hello;

import android.app.Activity;import android.os.Bundle;import android.widget.TextView;

public class HelloAndroid extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) {

……….

} }

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Android Development flow 

Android Manifest

• Describes the Application• Describes the building blocks of an application that it

exposes: activities, services, broadcast receivers and content providers

• Intent filters allow the platform to find the best application for the request

Comparison to other platforms

• Iphone

• Symbian

• Palm Pre

Advantages / Disadvantages 

• iPhone o has a lot of iHype, easier to get publicity in the short termo only allows one application to run at a given timeo Apple are the gatekeepero no telephony access from within the SDK

• Androido Content providers and intents allow applications to

communicate with each othero GPS as a content provider o unregulated marketplaceo Potential hardware fragmentation

• Android 1.5 SDK Released.

• Samsung I7500 annouced yesterday.

• Aceratec to release an android Notebook.

• HTC planning to launch G1 in India soon.

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Latest News

Google groups:For application development: http://groups.google.com/group/android-developers

For platform development:http://groups.google.com/group/android-platform

IRC: #android on freenode

anddev.org is a good source for example and tutorials

References

Q&A

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