Android Development- the basics

Tomáš Kypta@TomasKypta

Outline

● Android platform● Android ecosystem● Android SDK and development tools● Hello World● Building blocks & the manifest file● Activities, widgets, intents● Dialog, toast

Android platform

● Linux-based operating system● open-source● originally phone OS● tablet (since Honeycomb)● Google TV● hundreds of devices

History

● 2003, Android inc.● 2005 acquired by Google● 2008 first Android phone – T-Mobile G1

● since then rapid development of the platform

Android ecosystem

● the world's most popular mobile platform● over 850 000 new devices activated each day● total number of devices ~ 300 million

● play.google.com (market.android.com)● more than 450 000 applications● ~ 70% free apps

Problems

● fragmentation● manufacturer/carrier enhancements● updates & support● openness – low quality apps● malware (users)

Sources

● developer.android.com● android-developers.blogspot.com● source.android.com● stackoverflow.com● youtube.com/androiddevelopers● svetandroida.cz

Development

● programming in “Java”● native apps possible (C++)

● development tools platform friendly● Windows, Linux, Mac OS X● IDE support – ADT plugin for Eclipse,

Netbeans, IntelliJ IDEA, ...

Android SDK● android – Android SDK and AVD Manager● adb – Android Debug Bridge● ddms – Dalvik Debug Monitor● emulator● hierarchyviewer● ProGuard● Traceview● docs

Libraries

● compatibility libraries● licensing library

● AdMob● Google Analytics, Flurry● C2DM

Android internals

Hello World

Android Building Blocks

● Activity● Service● Content provider● Broadcast receiver

● AndroidManifest.xml

Activity

● screen with user interface● the only visual component

● examples:– list of emails

– email detail

– email composition

Service

● runs in background● long-running tasks

● examples:– music playback service

– download service

– sync service

Content Provider

● manages and shares application data● data storage doesn't matter – database, web,

filesystem● apps can query and modify data through

content provider● read/write permissions can be defined● examples:

– all system databases

– contacts

– SMS

Broadcast Receiver

● responds to broadcasts● broadcasts are system wide● can be registered statically or dynamically● system or custom messages● examples:

– incoming SMS, incoming call

– screen turned off

– low baterry

– removed SD card

AndroidManifest.xml

● defines what parts the app have● defines which endpoints are exposed● minimum API level● permissions● declare hardware and software features● required configuration

Intent

● asynchronous message● binds components together (all of them

except ContentProvider)● starting activities● starting services and binding to services● sending broadcasts

User Interface

● defined by hierarchy of views● layouts = containers

– LinearLayout

– RelativeLayout

– FrameLayout

● widgets = UI objects– Button, TextView, EditText

– WebView

Activity Lifecycle

● activities managed in a stack● activity can be in different states during it's

lifecycle:– foreground

– visible

– stopped

– killed

Intent & Activity

● starting activity explicitly

● starting activity implicitly

● starting activity for result

List Widgets

● displays a list of items (some view)– ListView, Spinner, GridView, Gallery

● use adapter to bind list to data

Dialogs and Toasts

● Dialog – displays modal information– standard dialogs

– custom dialogs

● Toast – non-modal information – doesn't have user focus

THE END