Android Application Development DevFest event 2012 @ Pear Continental, Karachi

Android Application DevelopmentDevFest event 2012

@Pear Continental, Karachi

Presenter: Imam Raza

Speaker.bio.toString()

Monday, September 19, 2011

• Senior Software Architect @ Folio3.• Specialties: Enterprise Software

Architecture, Mobile Software Architecture, Software Best Practices(TDD,CI ,AOP, IOC).

• Master in computer science from KU• B.E (Mechanical) from NED University

Me.loveQuestions==true



رفعنالک ذکرکو

Agenda• Market Statistics• The Android Work in Pakistan• Android Basics• Hello World• Main Building Blocks• Android Best Practices

SmartPhone Vs PC sales 2011Category Q4 2011

shipments(millions)

Growth Q4’11/Q4’10

Full year 2011 shipments(millions)

Growth2011/2010

Smart Phones

158.5 56.6% 487.7 62.7%

Total Client Pcs

120.2 16.3% 414.6 14.8%

-pads 26.5 186.2% 63.2 274.2%

-netbooks 6.7 -32.4% 29.4 -25.3%

-notebooks 57.9 7.3% 209.6 7.5%

-Desktops 29.1 -3.6% 112.4 2.3%

Market Share Q2 2012Smart Phone %percentage Unit sold (millions)

Android 68.1% 104.8

iOS 16.9% 26

Black Berry 4.8% 7.4

Symbian 4.4% 6.8

Windows 3.5% 5.4

AgendaMarket StatisticsThe Android Work in PakistanAndroid BasicsHello WorldMain Building BlocksAndroid Best Practices

Android Apps• Myomo MyProgress • Sony Socom Android App• Bitzer• NSDroid (NetSuite CRM)• Hiplink

Sony Socom App

BEAM(Bitzer Enterprise)

NSDroid(NetSuite CRM)

Hiplink

Android Stack

The Stack

Linux Kernel• Android runs on Linux.

Linux provides: – Hardware

abstraction layer – Memory

management – Process

management – Networking

• Users never see Linux sub system

• The adb shell command opens Linux shell

Native Libraries• Pieces borrowed from

other open source projects:

– Bionic, a super fast and small license-friendly libc library optimized for Android

• WebKit library for fast HTML rendering

• OpenGL for graphics • Media codecs offer

support for major audio/video codecs

• SQLite database ..Much more…

Question: Difference between Java VM and Dalvik VM?

Dalvik VM• Dalvik VM is Android implementation of

Java VM • Dalvik is optimized for mobile devices:

–   Battery consumption –   CPU capabilities

• Key Dalvik differences: – Register-based versus stack-based VM – Dalvik runs .dex files – More efficient and compact

implementation – Different set of Java libraries than JDK

Application Framework• The rich set of system services wrapped

in an intuitive Java API. • This ecosystem that developers can

easily tap into is what makes writing apps for Android easy.

• Location, web, telephony, WiFi, Bluetooth, notifications, media, camera, just to name a few.

Applications

Applications• Dalvik Executable

+ Resources = APK

• Must be signed (but debug key is okay

for development) • Many markets

with different policies

Question: What is the difference between Android and Java?

Android and JavaAndroid Java = Java SE – AWT/Swing + Android API

Android SDK- what is in box?

SDK Tools Docs Platforms

– Data – Skins – Images – Sample

sAdd-ons

– Google

Hello World-Create New ProjectUse the Eclipse tool to create a new

Android project. Here are some key constructs:

Step-1

Step-2

Step-3

Step-4

Hello World-Anatomy of App

Java Code + XML / OtherResources + Manifest File = Android App

HelloWorld-Manifest File

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.folio3" android:versionCode="1" android:versionName="1.0"> <uses-sdk android:minSdkVersion="10" /> <application android:icon="@drawable/icon" android:label="@string/app_name"> <activity android:name=".HelloworldActivity" android:label="@string/app_name"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application></manifest>

HelloWorld- Layout Resource File<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" ><TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/hello" /></LinearLayout>

HelloWorld-JAVA Filepackage com.folio3; import android.app.Activity; import android.os.Bundle; public class HelloAndroid extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); } }

Main Building Blocks• Activities• Intents• Services• Content Providers• Broadcast Receivers• Fragments

ActivitiesAn activity represents a screen or windows

Activity LifeCycleActivity have well-defined lifecycle. The android OS manages your activity by changing its state.You fill in the blanks

Intents• Intents represent

events or actions. • They are to

Android apps what hyperlinks are to websites. Sort of.

• Intents can be implicit or explicit.

ServicesServices are code that runs in the

background. They can be started and stopped. Services doesn’t have UI.

Service LifeCycle• Service also has a

lifecycle, but it’s much simpler than activity’s.

• An activity typically starts and stops a service to do some work for it in the background, such as play music, check for new tweets, etc.

Content Provider• Content Providers

share content with

applications across application boundaries. • Examples of built-in Content Providers are:

– Contacts, – MediaStore, – Settings and

more.

Broadcast ReceiversAn Intent-based publish-subscribe

mechanism. Great for listening system events such as SMS messages.

Fragments A Fragment represents a behavior or a

portion of user interface in an Activity.

Fragments• Fragments were introduced in Android

3.0 (API level 11), primarily to support more dynamic and flexible UI designs on large screens, such as tablets.

• Fragments are lot like an activity but it must exists within the activity.

• DialogFragment makes it easy to show a Dialog that is managed as part of the Activity lifecycle.

• ListFragment makes it easy to show a list of data.


Best Practices• Use RoboGuice(DI based framework)• Learn Activity Life Cycle• Avoid getting activities thick• Design views for multiple

size/orientation.• Use Fragments to better manage sub-

portion of Activity.• Practice Good MVC. • Use Source Code Analyzer Tools

(findbugs, checkstyle,PMD and CPD). Integrate these tools with CI Tools like Teamcity.


RoboGuice• It’s based on dependency injection

pattern just like Spring Framework in enterprise apps

• It takes the guesswork out of development. e.g checking null for getIntent().getExtras(). Casting findViewById().

• Make your writing unit test case easy• It reduces your lines of code and hence

the number of bugs see next slide for code.


class AndroidWay extends Activity { TextView name; ImageView thumbnail; LocationManager loc; Drawable icon; String myName;

public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); name = (TextView) findViewById(R.id.name); thumbnail = (ImageView) findViewById(R.id.thumbnail); loc = (LocationManager) getSystemService(Activity.LOCATION_SERVICE); icon = getResources().getDrawable(R.drawable.icon); myName = getString(R.string.app_name); name.setText( "Hello, " + myName ); } }


class RoboWay extends RoboActivity { @InjectView(R.id.name) TextView name; @InjectView(R.id.thumbnail) ImageView thumbnail; @InjectResource(R.drawable.icon) Drawable icon; @InjectResource(R.string.app_name) String myName; @Inject LocationManager loc;

public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); name.setText( "Hello, " + myName ); } }


Compatibility• Ability to install and run app on device.• Huge variety of devices so developer

need to make sure about the Hardware/Software feature his application needed to run.


Compatibility• Specify uses-feature node for every

API you use• Mark essential features as required.• Mark optional features as not required.<uses-featureAndroid:name=“android.hardware.g

ps”Android:required=“true”/>Monday, September 19,

2011

Compatibility• Check for API existence in code.PackageManager pm = getPackageManager();Boolean hasCompass=

pm.hasSystemFeature( PackageManager.FEATURE_SENSOR_COMPASS)

;If(hasCompass){//enable things are needed}Monday, September 19,

2011

CompatibilityUse dp and sp instead of px:<Button

android:layout_width=“wrap_content”

Android:layout_height=“wrap_content”

Android:layout_marginTop=“20dp”/><TextView

android:layout_width=“match_parent”

Android:layout_height=“wrap_content”Android:textsize=“20sp”/>


Compatibility


Advance Task Killer App is among 50

millions or more install apps

Why?


Performance • Avoid creating objects. (e.g use

StringBuffer) .• Prefer static over virtual.• Use static final for constants.• Avoid internal getter/Setter (with

Proguard you don’t need it.)• Use Enhanced For Loop Syntax e.g:

for (Foo a : mArray) { sum += a.mSplat; }• Use native methods. • Avoid using Float and enums

Responsiveness


Responsiveness• “Application Not Responding”

• Respond to user within 5 seconds• Broadcast Receiver must complete within

10 seconds• Use Threads and AsyncTasks within

Services


Source Code Analyzer Tools• FindBugs• PMD• CheckStyle • CPD : Shows code duplication• You can integrate them with CI Server

like Teamcity to get consolidated reports of code quality of your team. We have been using it on our company and its really helped us in monitoring quality of code.


Questions

Android Application Development DevFest event 2012 @ Pear Continental, Karachi

Documents

Transcript of Android Application Development DevFest event 2012 @ Pear Continental, Karachi