design patterns summer course 2009-2010 - session#1

Session # 1Ahmed Safwat

Muhamad HeshamAbdelrahman Al-Ogail

Where are we? Someone has already solved your problems! History of design patterns. Why design patterns? How to start ? Road Map. Introduction to session’s project. Why all of this?

Where are we

Start

• A small program to save customer information on MS DOS

Last Decade

• Each Bank has a system connected to the internet so that you can access your account from any branch

Now

• A full automation banking all around the world with secure payments over the internet, trading in stock markets, money withdrawal from any ATM in the world

Software Scale and Size

Where are we

“While component technology was a great framework for reuse, Developers didn’t put the effort into making sure the components themselves were actually designer for reuse”MS Architecture Journal Motivation

Service Based Computing {SOA}

Where are we

Global architecture

Enterprise architecture

System architecture

Application architecture

Macro-architecture

Micro-architecture

Objects

The seven layers of architecture

ORB

OO architecture

Frameworks

Subsystem

Design patterns

OO programming

Where are we

1. Make sure your software does what

customer wants it to do

Great Software

Where are we

1. Make sure your software does what

customer wants it to do

Great Software

2. Apply basic OO princibles to add

more flexibility

Where are we

1. Make sure your software does what

customer wants it to do

Great Software

2. Apply basic OO princibles to add

more flexibility

3. Strive for maintainability and

reusable design

What is Design Patterns

•Pattern: A solution to a problem in a context.

•Well-structured object-oriented systems have recurring patterns ofclasses and objects

• old men always know a solution

Problem

Context

Forces

Solution

Benefits Related patterns consequences

Someone has already solved your problems

1987 - Cunningham and Beck used Alexander’s ideas to develop a small pattern language for Smalltalk

1990 - The Gang of Four (Gamma, Helm, Johnson and Vlissides) begin work compiling a catalog of design patterns

1991 - Bruce Anderson gives first Patterns Workshop at OOPSLA

1993 - Kent Beck and Grady Booch sponsor the first meeting of what is now known as the Hillside Group

1994 - First Pattern Languages of Programs (PLoP) conference

1995 - The Gang of Four (GoF) publish the Design Patterns book

Why Design Patterns? Job Requirements

Why Design Patterns

•"Designing object-oriented software is hard and designing reusable object-oriented software is even harder." - Erich Gamma

•Knowledge of the patterns that have worked in the past allows a designer to be more productive and the resulting designs to be more flexible and reusable

This can be you

Run successful projects

Is willing to teach others

Has the respect of her

peers

Is an important part of the

development community

Earn A lot of money

This Can Be YOU

How does it work?

How does it work?

Here is my game. Change the game theme Here is the game assets. I will come by tommorow.

Who Wins ?

VS

He won

Abdelrahman wins

But …………….2al by2oly

design patterns

Guess what?

“The one constant in software development”

Guess what?

“The one constant in software development”

CHANGE

Never Stop Changing his mind

My sons likes different themes.

My sons want to be able to change theme while playing.

Change it Today.

Our Clients

AGAIN

VS

Who wins

MEEEEEEEEEEEEEEEEE

Conclusion

Zikas MuhamadWhy did I win ?• Genius ?

• Super speed writer ?

• Teneeen ?!

How to start?

Acceptance Recognition Initialization

there is a slow induction period after we’ve read about a pattern followed by the proverbial “Aha!” when we see how we can apply them in our work

Road Map

How to read patterns?

Classifications pattern

Some GOF patterns Factory. Singleton. Adapter. Façade. Command. Observer. State. Mediator. Composite.

We’ll Study:

1. Factory.

2. Singleton.

3. Observer.

4. State.

Our Sessions Content

Road Map

We’ve non-patterned feature. CHANGE. Let’s Google it. Pattern it! CHANGE. Conclusion. Break. Pattern details.

Session’s Approach

Session’s Project

Learning through Game Programming

Why Game Programming ?

Session’s Project

Learning through Game Programming

Why Game Programming ?

1.Fun & Interesting

OOD & Design patterns in action

Session’s Project Platformer Skeleton

Main Actors • Level• Player• Enemy• Gem

Finally

Where are our scientists? HF & DS authors. Taha & Elmasri. Previous:

▪ Algorithm, Algebra, 1,2,3, Camera, NASA.

Hospital. Nueclar scientist. Stat.

What about efforts? Thomas Edison. Reading books. Ebn Makhld. Quotes.

“No pain, no gain”Anonymous.

”ال ُيستطاع العلم براحة الجسم“يحى بن كثير

“My inventions comes from 2% inspiration and 98% of efforts”Thomas Edison.

“Science is what we understand well enough to explain to a computer. Art is everything else we do”Donald Knuth.

Why all of this?

Questions??Ahmedaliyossef@acm.orgMhesham.fcis@gmail.com

Zikas_zak@hotmail.com