Android Application Development

Adam Gerber, PhD, SCJPgerber@cs.uchicago.edu

Office: Ryerson 154 Office Hours: Mon 8:20pm-10:00pm

TA: Jonathan Nieder

jrnieder@cs.uchicago.edu

Evaluations

20% homework assignments (4@ 5% each) 20% midterm exam 50% individual final project (take home) 10% class participation

Late homework/final project is penalized 10% every day late, for three days; after that, you get a zero.

lec 01

The Android Computing Platform and Architecture

Setting Up Your Development Environment

Tour of Eclipse/ADT

First App: HelloWorld

Understanding Android Resources

The Android Computing Platform

Android

• Comprehensive open-source platform for mobile devices

• Owned by Open Handset Alliance

• Championed by Google

• Stated goal: "accelerate innovation in mobile and offer consumers a richer, less expensive, and better mobile experience."

Vision for Android

Version API Level Nickname

Android 1.0 1 Android

Android 1.1 2 Android

Android 1.5 3 Cupake

Android 1.6 4 Donut

Android 2.0 5 Eclair

Android 2.01 6 Eclair

Android 2.1 7 Eclair

Android 2.2 8 FroYo

Android 2.3 9 Gingerbread

Android 2.3.3 10 Gingerbread

Android 3.x 11,12,13 Honeycomb

Android 4.0.1 – 4.0.2 14 Ice Cream Sandwich

Android 4.0.3 – 4.0.4 15 Ice Cream Sandwich

http://developer.android.com/resources/dashboard/platform-versions.html

Mods (skins)

Open Handset Alliance

http://en.wikipedia.org/wiki/Android_(operating_system)

http://en.wikipedia.org/wiki/Open_Handset_Alliance

The OHA was established on 5 November 2007, led by Google with 34 members including mobile handset makers, application developers, some mobile carriers and chip makers.

Android, the flagship software of the alliance, is based on an open source license and competes against mobile platforms from Apple, Microsoft, Nokia (Symbian), HP (formerly Palm), Research In Motion, and Samsung Electronics (bada).

Headquarters: South Korea

Setting up your dev enviroment

Getting/Using the tools

Google-search-> java jdk || java se downloads || JDK version 6 || install to c:\java || set the path env variable. C:\path\to\jdk\bin || java -version from command line.

Google-search-> android sdk || install to c:\java\android-sdk || path to C:\java\android-sdk\platform-tools;C:\java\android-sdk\tools; adb devices to test.

Google-search-> eclipse ide | right-side download eclipse get the SE version || portable version so no need to "install" || dnd in root of c

Google-search-> adt eclipse || half way down to red url, and copy it. | within eclispe help || install new software || paste in there.

within eclipse || little-down arrow || opens And SdK manager 4.0.3

within eclipse || little=phone-icon || pulls up AVDM new

http://www.classes.cs.uchicago.edu/archive/2012/summer/51031-1/android-src.zip C:\java\android-sdk\platforms\android-15\sources\android-src.zip

Quick Java Review

Java Primitives (integers)Type Signed? Bits Bytes Lowest Highest

byte signed 8 1 -27

-128 27-1+127 

short signed 16 2 -215

-32,768 215-132,767 

int signed 32 4-231

-2,147,483,648 231-1 2,147,483,647 

long signed 64 8

-263

-9, 223,372,036,854,775,808

263-19,223,372,036,854,775,807  

How Java Stores positive Integers

-2(bits -1) to 2(bits -1) – 1•0001 0011•The above is a binary representation of the number 19 stored in a byte (8 bits).•The range of a byte is: -128 to 127.

Type Signed? Bits Bytes Lowest Highest

boolean n/a 1 1 false true

char unsigned Unicode 16 2 0

'\u0000' 216-1'\uffff' 

float

signed exponent and mantissa

32 4 ±1.40129846432481707e-45

±3.40282346638528860e+38with 6 to 7 significant digits of accuracy.

double

signed exponent and mantissa

64 8 ±4.94065645841246544e-324

±1.79769313486231570e+308with 14 to 15 significant digits of accuracy.

Java Primitives (others)

Primitives versus ObjectsmemoryPrimitives Objects

Variables store values and are allocated memory depending on their type. How much?...refer to Java Primitives slide.

References store memory addresses. The size of the allocation for the object reference is VM specific, but is usually the native pointer size; 32bits in 32-bit VM, and 64bits in a 64-bit VM.

Garbage collected when out-of-scope. Garbage collected when out-of-scope.

Passed into methods by value Passed into methods by reference (value of the address is passed)

primitive objectpass by value pass by reference

Action: Tell my accountant how much I intend to spend on a new car next year. Change in bank account: no change.

Action: Swipe debit card and enter pin at the Bently dealership. Change in bank account: -125k.

Class Objects

Class Objects

Spot the “class” here

Naming conventions

Naming local variables - suggestions

boolean bFlagbyte yAgechar cFirstshort sRosterSizeint nStudent; nClong lPopulationfloat fPricedouble dDistanceToMoon

Naming local references - suggestions

Person per perDirectorString str strFirstNameRectangle rec recShapeBee bee beeDrone

Naming local arrays and collections - suggestions

Array of boolean bAnswersArray of byte yAgesArray of int nIdentitiesArray of Person perStudentsArray of String strCountriesCollection of Bee such as ArrayList<Bee> beeDronesCollection of Athlete athPlayers

Why use a naming convention? metadata is immediately discernible just by looking

at the local variable or local reference name. This makes your code easy to read and debug.

Primitives always have one letter prefix; nNumber References have three letter prefix; perDirector. Arrays and collections have s postfix: beeDrones;

strCountries, nLevels. Avoid ending with s for variables or references that

are NOT collections/arrays; e.g. nRadiux, or nRadius_

Overridden methods in Android come with their own set of params.

Eclipse IDE

Shortucts:

New class and browse to superclass ActivityCntrl-numeric 1 is QuickFix!Control click to source.

Source || override/implements methods

Extract method Create getters and setters

Templates || see videoWindow || preferences || Java || Editor || Templates

Ctrl-Shift-L

Using the debugger

Perspectives; Java and Debug Setting breakpoints Step-over F6, and Step-in F5 Watch expressions Conditional breakpoints

Resources in Android

Alt-Shift-A to externalize strings

<st + ctrl space Create many xml resources, but don't name the actual resources the same

Add resources from the Add Resources from the graphical editor and also manually. #FFFFFF white

getResources(). getStringArray(R.array.whatever)

Building Blocks of an App

• Activities

• Intents

• Services

• Content Providers

• Broadcast Recievers

Some Developer Resources

Dev Guide

• http://developer.android.com/guide/topics/fundamentals.html

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

Turning in AssignmentsUse git