android application development for tresmaxasia

Android Application Development101

Mike Rivera

TresMax AsiaMarch 12, 2010

What’s in store today?

• What is Android?• Android Architecture• Getting Android?• Application Components• User Interfaces• Resources• The Manifest File• Understanding Hello Android

What’s in store today?

• What is Android? • Android Architecture• Getting Android?• Application Components• User Interfaces• Resources• The Manifest File• Understanding Hello Android

What is Android• Android is a software stack for mobile devices

that includes:– Operating System• Linux version 2.6– Services include hardware drivers; power, process and memory

management; security and network.

– Middleware• Libraries (i.e. SQLite, OpenGL, WebKit, etc.)• Android Runtime (Dalvik Virtual Machine and core libraries)• Application Framework– Abstraction for hardware access; manages application resources and the UI;

provides classes for developing applications for Android

– Applications • Native apps: Contacts, Phone, Browser, etc.• Third-party apps: developer’s applications.

Next is the...

• What is Android?• Android Architecture • Getting Android?• Application Components• User Interfaces• Resources• The Manifest File• Understanding Hello Android

Android Architecture

Next is ...

• What is Android?• Android Architecture • Getting Android?• Application Components• User Interfaces• Resources• The Manifest File• Understanding Hello Android

Getting Android

Install JDK (5 or 6) & Eclipse (3.4 or 3.5) Download & Install the Android SDK (2.1)

- http://developer.android.com/sdk/index.html

- simply unpack the starter package to a safe location and then add the location to your PATH. Install and Configure ADT (Android Development Tool) plug-in for Eclipse Add Android Platforms & other components to your SDK

Next is the...

• What is Android?• Android Architecture • Getting Android?• Application Components• User Interfaces• Resources• The Manifest File• Understanding Hello Android

Application Components• Components of your application:– Activities• Presentation layer for the application you are building • For each screen you have, their will be a matching

Activity • An Activity uses Views to build the user interface

– Services• Components that run in the background• Do not interact with the user• Can update your data sources and Activities, and trigger

specific notifications

Application Components• Components of your application:– Content Providers• Manage and share application databases

– Intents• Specify what intentions you have in terms of a specific

action being performed

– Broadcast Receivers• Listen for broadcast Intents that match some defined filter

criteria• Can automatically start your application as a response to

an intent

Next is the...

• What is Android?• Android Architecture • Getting Android?• Application Components• User Interfaces• Resources• The Manifest File• Understanding Hello Android

User Interfaces• Views– The basic UI component– Responsible for drawing and event handling– Define your View through:• Layout Resources (i.e. defined in main.xml file):

<ListView android:id="@+id/myListView" android:layout_width="fill_parent" android:layout_height="wrap_content" />

From your Activity class code:setContentView(R.layout.main);ListView myListView = (ListView)findViewById(R.id.myListView);

• Inside your code:ListView myListView = new ListView(this);setContentView(myTextView);

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User Interfaces (cont.)• Layouts– Specify the position of child views (controls) on the

screen– Common Layout Objects:• FrameLayout: all child views are pinned to the top left corner of the

screen• LinearLayout: each child view is added in a straight line (vertically

or horizontally) • TableLayout: add views using a grid of rows and columns• RelativeLayout: add views relative to the position of other views

or to its parent. • AbsoluteLayout: for each view you add, you specify the exact

screen coordinate to display on the screen

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User Interfaces (cont.)• Implement layouts in XML using external resources:<?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"><EditText

android:id="@+id/myEditText" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="" /> <ListView android:id="@+id/myListView" android:layout_width="fill_parent" android:layout_height="wrap_content" /></LinearLayout>

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User Interfaces (cont.)• Dialogs – a small window that appears in front

of the current Activity (Alert,Progress,DatePicker, TimePicker and a custom one)

• Menus– Concerned about having to much functionality on

the screen => use menus– Three menu types:• Icon Menu: appears at the bottom of the screen when

the user presses the Menu button. It can display icons and text for up to six menu items.

• Expanded Menu: displays a scrollable list of menu items not previously displayed in the icon menu.

• Submenu: displayed as a floating window.

Next is the...

• What is Android?• Android Architecture • Getting Android?• Application Components• User Interfaces• Resources• The Manifest File• Understanding Hello Android

Resources

External files (that is, non-code files) that are used by your code and compiled into your application at build time. Android supports a number of different kinds of resource files, including XML, PNG, and JPEG files.

• res/anim - XML files for animations• res/drawable – image files• res/layout – XML files for screen layouts• res/values – XML files that can be compiled into many kinds of resources• res/xml – Arbitrary XML files that are compiled and can be read at run time.• res/raw – Arbitrary files to copy directly to the device

At compile time, Android generates a class named R that contains resource identifiers to all the resources in your program. This class contains several subclasses, one for each type of resource supported by Android, and for which you provided a resource file.

What’s in store today? What is Android? Android Architecture Getting Android? Application Components User Interfaces Resources The Manifest File Understanding Hello Android

The Manifest File

• a structured XML file and is always named AndroidManifest.xml for all applications.

• It does a number of things in addition to declaring the application's components, such as naming any libraries the application needs to be linked against (besides the default Android library) and identifying any permissions the application expects to be granted.

<?xml version="1.0" encoding="utf-8"?><manifest . . . > <application . . . > <activity android:name="com.example.project.FreneticActivity" android:icon="@drawable/small_pic.png" android:label="@string/freneticLabel" . . . > </activity> . . . </application></manifest>

What’s in store today? What is Android? Android Architecture Getting Android? Application Components User Interfaces Resources The Manifest File Understanding Hello Android

Understanding Hello Android

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);}}

HelloAndroid Activity

Understanding Hello Android

<?xml version="1.0" encoding="utf-8"?>

<LinearLayoutxmlns: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>

main.xml

Understanding Hello Android

<?xml version="1.0" encoding="utf-8"?>

<resources>

<string name="hello">Hello Android !!!</string><string name="app_name">Hello Android Demo</string></resources>

strings.xml

Understanding Hello Android<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"package="asia.tresmax" android:versionCode="1"android:versionName="1.0.0">

<application android:icon="@drawable/icon"android:label="@string/app_name"><activity android:name=".HelloAndroid" 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> AndroidManifest.xml

Reference

• http://developer.android.com/guide/index.html

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