Post on 19-May-2015
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Android Apps for Absolute Beginners
Vaclav Hnizdavaclav.cz@gmail.com
Who am I?Vaclav HnizdaBackground● BS in Music Education - 2005 ● MS in Software Engineering - 2014● First coded in ‘98 in QBasic! ● Currently focus in Java & Android● Attended Google IO - 2012
Met Vic GundotraSenior VP of Google Engineering
Contact● email: vaclav.cz@gmail.com● linkedin: www.linkedin.com/in/vaclavhnizda● twitter: @Vaclav_Moravak
Android Past● Dalvik VM on top of Linux-based OS
● designed with touch mobility in mind
● Initially developed by Android, Inc., backed by Google
● In 2005 purchased & publicly displayed in 2007
● Also in 2007 Open Handset Alliance created
● The first Android-powered phone was sold in October
2008.
Android Present● Cupcake: 1.5 (2009)● Donut: 1.6● Eclair: 2.0-1● Froyo: 2.2● Gingerbread: 2.3● Honeycomb: 3.0-2● Ice Cream Sandwich: 4.0● Jelly Bean: 4.1-3● KitKat: 4.4 (2013)
images from http://developer.android.com/
Why Android ?● Portability ● IDE Improvement
Android System Architecture
( source: http://developer.android.com/images/system-architecture.jpg )
Linux Kernel
( source: http://developer.android.com/images/system-architecture.jpg )
Linux device drivers● where all hardware is
managed
Android specific drivers: ● wake lock logger● logger● lowmemorykiller● Paranoid network-ing
The vast Libraries
( source: http://developer.android.com/images/system-architecture.jpg )
Custom Java● Library is a
custom made collection of classes optimized for the mobile platform
Android Runtime
( source: http://developer.android.com/images/system-architecture.jpg )
Dalvik● Just in time● optimized for
mobile devices● Just because it’s a
VM does not mean it runs slow, very efficient and fast
Application Framework
( source: http://developer.android.com/images/system-architecture.jpg )
The legos!● Building blocks● Many Features for
you to make use of rather than having to build it from scratch
Last but not least, Applications !
( source: http://developer.android.com/images/system-architecture.jpg )
<Your App Here>
● All things visible to you and any Android user are located on this layer
Application lifecycle - It’s alive?Resume(visible)
Started(visible)
Paused(partially visible)
CreatedStopped(hidden)
onResume()
onStart()
onResume()
onStart()
onRestart()
onStop()
onPause()
onDestroy()
Destroyed
onCreate()
Launched
Android? New problems to solve!● What happens when the user receives a phone call or
switches to another app from yours?● Does your app consume valuable system resources
when the user is not actively using it?● What happens to the user's progress if they leave your
app and return to it at a later time?● Will you allow screen rotation? If so, will your app
crash?● Many, many more!
Other questions to ask..
● Will the app be stand alone?● Will it need a dedicated network connection?● Will a Phone data plan be enough?● Will data be stored locally, somewhere else?● Do I need something to run in the
background?
Android make it easy to start now.
Want more Visual Power?
● Canvas and Drawables● Hardware Acceleration● OpenGL
Media? Got that too.
There are libraries already built in to:● play videos & music● capture an image from the camera● find your location with the GPS● manage what the volume rocker does● voice activation? ready for you!
Storage - so many options!
● Shared Preferences
● Internal Storage
● External Storage
● SQLite Databases
● Network Connection
Which Screen will you support?
Application lifecycle RevisitedResume(visible)
Started(visible)
Paused(partially visible)
CreatedStopped(hidden)
onResume()
onStart()
onResume()
onStart()
onRestart()
onStop()
onPause()
onDestroy()
Destroyed
onCreate()
Launched
Android Skeleton
Android Skeleton
Android Skeleton
Android Skeleton
Application lifecycle RevisitedResume(visible)
Started(visible)
Paused(partially visible)
CreatedStopped(hidden)
onResume()
onStart()
onResume()
onStart()
onRestart()
onStop()
onPause()
onDestroy()
Destroyed
onCreate()
Launched
Other considerations.. HTML5 ?HTML vs Java
Budget - All vs OneUser reach vs User Experience
Browser vs FullscreenOnline vs Offline
Alerts - Email vs local NotificationsOpenGL vs Even more
Future topics ● HTML5 apps vs native Android apps
● Building that first native app right
● Android framework basics
● How to get Android to work with you
● Exploring the Rich libraries of Android OS
● APIs and how they can supercharge your app
?vaclav.cz@gmail.com
●www.linkedin.com/in/vaclavhnizda/
●@Vaclav_Moravak
QUESTIONS
Thanks for coming!
More talks to come!