Week 3: Android App Programming
Jeff Gray, Ph.D. - Associate Professor
Carnegie Foundation Professor of the Year (Alabama, 2008)
University of Alabama
Department of Computer Science
gray@cs.ua.edu
http://www.cs.ua.edu/~gray
Agenda for Week
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Today
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General intro
Introduction to App Inventor
Various Demos and Hands-on Exercises
Lunch: Ms. Lynsey Dill
Rest of week
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See end of slides
Camp Introduction
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Liability forms
Photos throughout the week
Lunch each day – 11:30am-12:45pm
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Today: Pizza lunch (Shelby 3438)
Tue-Thu: Lunch in the Freshens Food Court
Fri: Catered lunch
Restrooms
USB Stick
Assumption
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Java background
Camp rules
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Camp Rules
 No cell phone usage in class except for
emergencies
 No headphones while instructor is speaking
 No surfing the web or playing games during
lectures
 No food or drink are allowed in the lab
 Pay attention during class exercises; do not
jump ahead and let us know if you fall
behind
General Info
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Bleeding edge – may encounter various
“issues” throughout the week; App Inventor
barely a year old
Sharing of various Android phones
Much different than week 1
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Focus is on motivating you to practice Java on
fun exercises
Developing
your
own
creativity
while
implementing a customized app
Why Smartphones?
Motivation: Teaching CS – 1980s style
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Typical example was text-based, trivial, and
uninspiring
Motivation: New and Exciting Contexts
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Media Computation (Georgia Tech)
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Robots
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Programming in a more exciting context by
manipulating images and sounds
Lego NXT
2D/3D Animation Environments
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Alice, Scratch, AgentSheets
Motivation: Newest Context
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Teen cell phone adoption at 84%
March 3, 2011
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Android marketshare (29%) passes Apple (27%)
Android sales soar 888%
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Social networking and
crowd sourcing a daily
activity
Increasing adoption of
smartphones in science
and medical applications
Android Overview
Brief History
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2005
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2007
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Google acquires startup Android Inc. to start Android
platform
Work on Dalvik VM begins
Open Handset Alliance announced
Early look at SDK
2008
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Google sponsors 1st Android Developer Challenge
T-Mobile G1 announced
SDK 1.0 released
Android released open source (Apache License)
Android Dev Phone 1 released
Brief History cont.
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2009
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SDK 1.5 (Cupcake)
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SDK 1.6 (Donut)
SDK 2.0/2.0.1/2.1 (Eclair)
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Gartner Inc. predicts 14% in 2012
2010
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Nexus One released to the public
SDK 2.2 (Froyo)
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wifi tethering, Flash
SDK 2.3 (Gingerbread)
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Exchange support; refine UI
Android runs on 3.5% of all smartphones
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new soft keyboard with an "Autocomplete" feature
refine UI; improve keyboard copy/paste
Q4 Android passes Symbia as best-selling smartphone platform
2011
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SDK 3.0 (Honeycomb)
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Table only release; Motorola Xoom in 2 weeks
Ice-cream Sandwich (mid-2011)
http://en.wikipedia.org/wiki/Android_(operating_system)
Android Facts
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From Wikipedia
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Modified version of Linux kernel
Android is composed of 12 millions lines of code
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3M SLOCs pertaining to XML
2.8M SLOCS in C
2.1M SLOCS in Java
1.75M SLOCS in C++
Linux kernel tensions
Oracle lawsuit
Android Developer Challenge
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http://code.google.com/android/adc/
2008:
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10 teams received $275k
10 teams received $100k
Each of top 50 finalists received $25k
2009
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10 first prizes at $100k
10 2nd prizes at $50k
10 3rd prizes at 25k
Overall: 1st-$250k, 2nd- $50k, 3rd- $25k
Open Handset Alliance
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Established November 2007
Competes against Microsoft, Apple, Nokia
(Symbia), Palm, RIM, and Samsung (Bada)
Composed of 79 software and hardware
companies
URLs:
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http://www.openhandsetalliance.com/
http://en.wikipedia.org/wiki/Open_Handset_Alliance
Key Differences: Android vs. iPhone
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iPhone
OS is proprietary
OS runs on iPhone or
iPod Touches only
Apps written in ObjectiveC
Apple must approve all
apps  Application Store
Some apps are more
important than others
(Safari is your browser)
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Android
OS is open source
OS can be licensed for
any mobile device
Apps written in Java
No approval process for
apps  Android Market
All apps considered equal
(choose your browser)
What is Google Android?
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A software stack for mobile devices that includes
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An operating system
Middleware
Key Applications
Uses Linux to provide core system services
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Security
Memory management
Process management
Power management
Hardware drivers
App Inventor Overview
App Inventor Overview
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URL: http://appinventor.googlelabs.com
Purpose
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Teaching
Prototyping
Components of App Inventor
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Designer
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GUI builder
Block Editor
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Provide behavior behind the GUI
Based on MIT OpenBlocks and Scratch
App Inventor Overview
Installing and Running
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http://appinventor.googlelabs.com/learn/setup
/index.html#setupComputer
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App Inventor environment loads in a web
browser
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Requires Java 1.6
Install App Inventor setup
Login using Google account
Run from a phone or the Android emulator
Stores programs in the cloud
Designer
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Provides a WYSIWYG editor for designing the
visual parts of the app
Also provides ability to attach non-visual
components
Blocks Editor
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Provides an ability to give
behavior to an app; the
programming part
Typical and expected basic
predefined constructs (logic,
conditionals, iteration)
Ability to refer to the
components and their
properties from the Designer
Very similar to Scratch
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Built on Open Blocks library
from MIT
Limitations
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File I/O
Custom objects
Printing your code!
Reliability
Examples
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Many tutorials available:
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Standard Google Kitty app (embarrassing!)
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Developed by Dave Wolber (Univ. San Francisco)
http://appinventor.googlelabs.com/learn/tutorials/index.html
http://appinventor.googlelabs.com/learn/setup/hellopurr/hellopurr
emulatorpart1.html
Other Examples
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Where’s My Car, No Text While Driving
Schedule
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Monday
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Tuesday
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Intro to App Inventor
Think about an app idea
More on App Inventor
Java-based intro to writing Android Apps
Prepare project presentation (3 minutes each)
Wednesday
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Start at 8:30am
Project proposal presentation
More Java-based Android
Start project implementation
Schedule
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Thursday
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Project implementation
Late Afternoon: CS AP GridWorld
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Mr. Martin and Mrs. Woessner
Friday
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Project wrap-up and final presentations
Lunch
Say good-byes