Programming YOURMobile Phone

Professor Simon M. LucasSchool of Computer Science and

Electronic Engineering

Mobile (Cell) Phones

• First prototype: Motorola 1973• Commercial cell phones :– NTT Japan 1979– Motorola 1983– DynaTAC 8000X ($4,000)

• Subscribers:– 300,000 in 1984

• Over 3,000,000,000 now!• So much more than just a telephone…

Samsung Galaxy S II (2011)

• Android phone• GPS, Motion Sensors, Video etc• Powerful processor• 3G WIFI Router!• 1gb RAM + 8 GB Flash mem + SD• 1.2Ghz dual core processor (licenced

from ARM)• 800 x 480 Super AMOLED Plus screen• Kindle!• Programmable in Java• Very open marketplace for apps

Tetris

• Developed by Alexei Pajitnov in 1985– With the help of Dmitry

Pavlovsky and Vadim Gerasimov

– Popular in the west in 1986• The classic ‘casual game’

of all time

EA Mobile

• Tetris is frequently top of the sales charts for mobile games

• But seems to be losing out on smartphones (e.g. iPhone, Android)

• Why?

Run Demo

Tetris and JavaWORA: Write Once, Run Anywhere?

Well, almost…

• The Java language may vary slightly between versions available for each platform

• New platforms such as Android have significant new APIs– API = Application Programmer Interface

• Some effort needed to port an application to a new platform

• But at least with Android, you can use the familiar Java language

Developing Mobile Java Apps

• Write Java for mobile platform– Using suitable API / platform e.g. Android

• Test on emulator or device• Deploy to mobile marketplace?– Or direct to phone

• E.g. Android Market• Can be free or paid-for apps• Get detailed download and usage stats– Use the stats to refine your app…

Android Market

Software Design

Divide and Conquer

Modelling Tetris: Object Oriented Approach

• Objects group together:– Data– Actions that can be performed on

them:• Methods

• In Java, each object is of a particular class

• Programming: design classes – Make objects of those classes

• What sort of classes might you design for Tetris?

And we get …

• Controller – Main loop + event handling

• View– Only concerned with display of game objects

• Model– Game model (2d array of blocks)– Shape model

Class Diagram

Main Loop

Event Handling

move() method of Shape

Careful: how not to wait!

Summary

• Mobile phones: incredible technology– RF, hardware, telecoms, software

• Programming should be (and is!) lots of fun• Java’s a great language – Android is a great

mobile platform• Modern IDEs take the pain out of software

development• Study computing and electronics: be part of a

bright future!