Introduction to Android Programming

Contents Basic Concepts Environment Setup Creating and Building Android App

Android Android apps are written in Java The Android OS is a multi-user Linux system Android app lives in its own security sandbox System assigns each app a unique Linux user ID Each process has its own virtual machine Every application runs in its own Linux process

Application Components Android Application .apk : Android package Four Application Components Activity Service Content Provider Broadcast Receiver Communication among components except Content Provider Intent extension

Activity Activity Lifecycle Implement Lifecycle Callbacks

Activity Start an Activity Start an Activity for a Result Caller Activity Callee Activity

Activities and Stack

Services A service is a component that runs in the background to perform long-running operations A service does not provide a user interface Activity can start the service and let it run or bind to it in order to interact with it e.g., a service might play music in the background while the user is in a different app

Broadcast Receivers A broadcast receiver is a component that responds to system-wide broadcast announcements Apps can also initiate broadcasts Although broadcast receivers don't display a UI, they may create a status bar notification to alert the user when a broadcast event occurs

Content Providers A content provider manages a shared set of app data Through the content provider, other apps can query or even modify the data Any app with the proper permissions can query part of the content provider

Intent An intent is an abstract description of an operation to be performed startActivity sendBroadcast startService (bindService) …

Environment Setup Step 1: Install JDK

JDK Installation Can download the JDK for your OS at http://java.oracle.com Alternatively, OS X: Open "Terminal” Type javac at command line Install Java when prompt appears Linux: Type sudo apt–get install default–jdk at command line (Debian, Ubuntu) Other distributions: consult the documentation JDK and JRE are different!

Environment Setup Step 2: Configure the Android SDK

SDK Configuration Download Android SDK from http://developer.android.com Or Simplest: Download and install Android Studio bundle (including Android SDK) Software development kit

Eclipse IDE- Official IDE for Android development Integrated development environment Eclipse IDE- Official IDE for Android development Apache Ant for building projects

Android focused IDE, designed specifically for Android development. Contains all SDK tools for develop, debug, or test.

Android Studio Android Development Environment based on IntelliJ IDEA Software development kit

Android Studio Android uses Gradle Gradle is an open source build system that combines the power of Ant and Maven Software development kit

Android Studio Software development kit

Run Android SDK Manager Recommended: Install Android 2.2, 2.3.3 APIs and 4.x API Do not worry about Intel x86 Atom, MIPS system images Settings

Now you are ready for Android development!

Create New Android Project

Create Activity

The Manifest File Identify any user permissions the application requires Declare the minimum API level required by the application Declare hardware and software features used or required by the application API libraries the application needs to be linked

The Manifest File

The Manifest File Do not forget to declare Components in the Manifest

Permission Add following permissions to the Manifest file

Sample Code

UI – Declaring Layout Initiated when called setContentView() on onCreate() Use Visual Layout Editor for initial layout design Edit XML file extensively

Editing Sample Code “@+id/helloId” Add id to main.xml Edit HelloWorldActivity.java

A Sample Code Important points UI Element has an Id Variables in our code link to UI elements Update UI element content from the program 1 2 Hello world! 3

UI – Handling UI Events onClick, onLongClick, onKey, onTouch, …

Sample Implementation MainActivity Option menu Context menu Capture Play click CaptureActivity Upload Service Capture Button Click PlayerActivity Background Upload

Building Process Running

Running Sample App

App Failure

Debugging, look at DDMS !!! “Dalvik Debug Monitor Service”

Enabling USB Debugging

Thank You! Any questions *These slides are based on the slides from http://www.comp.nus.edu.sg/~cs5248/l03/L3-ProgrammingInAndroid.pdf