1-1 Copyright © 2009 Pearson Education, Inc. Publishing as Pearson Addison-Wesley 1-1 Programmering 7.5 hp Programmering är... creativ, fascinerande, roligt, användbart – och tidskrävande. E 304, Gör?, Är? Kursens hemsida:

1-2 Copyright © 2009 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Vad är programmering? När vi vill att en maskin(processor) skall åstadkomma något åt oss använder vi en form av kod för att instruera maskinen om vad som skall utföras. För att processorn skall förstå de instruktioner som du vill ge måste de instruktioner som du ger vara i formatet ettor och nollor i en rad olika kombinationer. Det sliper vi idag genom att använda högnivåspråk (java) för att skriva instruktioner och sedan omvandla (kompilera) det till ettor och nollor ( maskin språk). Det moderna att programmera är objekt-orienterat, dvs man utgår ifrån den verkliga världen som består av objekt ( student, bord, stol) som har egenskaper ( namn, antal_ben, färg) och kan göra saker ( tänka, rotera, bytta_färg).

1-3 Copyright © 2009 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Alice and Java Alice is a computer environment in which you create virtual worlds containing three-dimensional characters and objects that move and interact. Both Alice and Java use an object-oriented approach. Java is a general-purpose programming language. 1-3

1-4 Copyright © 2009 Pearson Education, Inc. Publishing as Pearson Addison-Wesley The Alice Environment Alice is an integrated development environment (IDE) – a program used to create and run another program. Versions for Windows and Mac OS are available from the Alice website:  run a tutorial;  open a world that has been opened recently;  start a new world;  explore several example worlds;  open a world that has been stored.

1-5 Copyright © 2009 Pearson Education, Inc. Publishing as Pearson Addison-Wesley The Alice Environment (continued) 1-5 toolbar world view events editor object tree details panel method editor

1-6 Copyright © 2009 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Objects All objects contained in the Alice world are listed in the object tree. All Alice worlds have objects that represent camera and light source. Most worlds have a ground surface. Camera controls set the initial point of view. 1-6 The object tree The camera controls

1-7 Copyright © 2009 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Classes An object is created from a class. Class determines the methods and properties the object has. Classes are organized into galleries. There are built-in galleries; they are also available through the Web. 1-7

1-8 Copyright © 2009 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Methods A method is a set of statements that can be called. Methods define every object’s behavior. The world object in every animation has a method called my first method. There are several control statements available in Alice. Calling a method – sending a message to an object. Methods can accept parameters. 1-8 object parameters method

1-9 Copyright © 2009 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Methods (continued) Built-in methods exist for almost all objects in Alice Other methods can be developed and added. Some useful methods are: –say –think –sound Special methods—functions are used to get some information about an object 1-9

1-10 Copyright © 2009 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Properties Properties describe an object’s state at any point in time. The value of the property can be changed directly or during animation, using method call. There are hidden properties for the objects. 1-10

1-11 Copyright © 2009 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Do Together Statement The Do Together statement allows several things to be done simultaneously. 1-11

1-12 Copyright © 2009 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Do In Order Statement The Do In Order statement forces the statements it contains to be executed in order. 1-12

1-13 Copyright © 2009 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Composite Objects A composite object is an object that contains other objects. It is possible to control the whole object or any of its parts. 1-13