Java Swing - Lecture 1 An Introduction Milena Radenkovic slides originally by Chris Coleman

G5BUID - Java Swing Timeline 26 th Oct (Now) - Java Necessaries, Swing Basics 27 th Oct - Components and Containers 3 rd Oct - Layout Management 9 th Nov - Event Handling and Listeners 10 th Nov - Graphics with Swing Java Labs TBA

G5BUID - Java Swing Before we Start… (1) Swing is all Java. You must know about, and understand:  Classes / Objects  Method Overloading  Inheritance  Polymorphism  Interfaces  How to read the Java2 API Documents

G5BUID - Java Swing Before We Start… (2) If Java is a problem – learn NOW, not later when the coursework is due!  Labs  Come to the labs and help is there for both Java and Swing.  Web  Use the Sun/Java tutorials  Plenty of web resources out there, even the PRG notes  Read a book?

G5BUID - Java Swing D interface programming toolkits Tcl/Tk Motif/UIL IDEs (e.g. VB, MSVC++/MFC) Java AWT – the beginnings Java JFC Swing (Java2 - JDK >= 1.2) JBuilder and other Java IDEs etc…

G5BUID - Java Swing What is Swing? A part of The Java Foundation Classes  Swing  Look and feel  Accessibility  Java 2D (Java 2 onwards)  Drag and Drop  etc Can be used to build Standalone Apps as well as Servlets and Applets

G5BUID - Java Swing On-line reading and reference The Java Swing trail: Swing articles: Developer Technical Articles & Tips:

G5BUID - Java Swing Books Java Swing (1998), Robert Eckstein, Mark Loy, Dave Wood, O'Reilly JFC Swing Tutorial, The: A Guide to Constructing GUIs, 2nd Edition (2004); K. Walrath and M. Campione, Addison Wesley

G5BUID - Java Swing Getting started with Swing (1) Compiling & running programs  Swing is standard in Java 2 (JDK >= 1.2)  Use:  ‘javac ’ && ‘java ’  Or JCreator / IDE

G5BUID - Java Swing Getting started with Swing (2) Computer Science Department Stuff…  PCs  Java 2 (1.5.0) on hard disk at \cs\java  Unix (tuck and much):  Java 2 (1.5.0) in /usr/bin (or /usr/java)  Differences between previous versions    Coursework marked on Win XP & JDK 1.5.0

G5BUID - Java Swing Getting started with Swing (3) Swing, like the rest of the Java API is subdivided into packages:  javax.swing, javax.accessibility, javax.swing.border … At the start of your code - always  import javax.swing;  import javax.swing.event; Most Swing programs also need  import java.awt.*;  import java.awt.event.*;

G5BUID - Java Swing Differences between Swing and AWT (1) Never mix Swing and AWT components If you know AWT, put ‘J’ in front of everything  AWT: Button  Swing: JButton Swing does all that AWT does, but better and there’s much more of it.

G5BUID - Java Swing Differences between Swing and AWT (2) Buttons and labels can display images Behaviour and appearance of components Component shape Borders Assistive technologies Look and feel of the program’s GUI  Windows – (but only on Windows, M$ issues….)  UNIX  GTK  etc

G5BUID - Java Swing A typical Swing program Consists of multiple parts  Containers  Components  Events  Graphics  (Threads) Now look at each in turn

G5BUID - Java Swing A simple Swing program - Containers Containers

G5BUID - Java Swing Remember this about Containers: The structure of containers is your design decision and should always be thought through in advance  particularly for managing components  nesting containers Failure to do so usually either results in a messy interface, messy code or both.

G5BUID - Java Swing A simple Swing program - Components Components

G5BUID - Java Swing Remember this about Components: There are many components that make your job much easier. Often, you will be able to customise an existing Swing component to do a job for you, instead of having to start from scratch  Eg can extend (inherit from) the JButton class and ‘paint’ a new button over the top

G5BUID - Java Swing A simple Swing program - Events Events

G5BUID - Java Swing Remember this about events: ‘Events’ as seen by GUIs do not happen all that often in an application Consider what is happening between events as well as during them

G5BUID - Java Swing A simple Swing program - Graphics Graphics Complex drawing and shading API. Can do far more than display images.

G5BUID - Java Swing Remember this about Graphics: There are many aspects of Swing that allow you to achieve graphics-like things without actually using ‘Graphics’. Therefore, you don’t have to use them most of the time, and it is often easier not to.

G5BUID - Java Swing A simple Swing program - Threads Most simple Swing GUI applications don’t require use of any (extra) threads As Swing creates event-driven programs, all code is executed on the event- dispatching thread

G5BUID - Java Swing Remember this about Threads:  The single-thread rule “Once a Swing component has been realized, all code that might affect or depend on the state of that component should be executed in the event-dispatching thread”  (with some exceptions)

G5BUID - Java Swing How to Learn Swing Don’t even try. Learn general framework principles and design styles. Then use the API reference, and Swing Tutorials to discover detailed usage of each component.

G5BUID - Java Swing How to read Java Docs (1) Java 2 (J2SE 1.5.0) API Reference:  Split into 3 Sections (html frames):  Top Left: Packages  Bottom Left: Classes in Packages  Main Frame: Information about selected Class

G5BUID - Java Swing How to read Java Docs (2) General idea is find class, and examine main frame for information. Main frame pages split into sections:  Package hierarchy & implemented interfaces  Class Description, and links to more info  Nested Class Summary – Detail in separate page  Fields - 2 types Class (static) and instance, plus fields inherited from parent classes / interfaces  Constructor Summary  Method Summary & inherited methods from parents  Detailed info on all summary sections

G5BUID - Java Swing Summary Do you know enough Java? 2D interface programming toolkits JFC/Swing AWT and Swing Getting started with Swing Parts of a simple Swing program Tomorrow: Components and Containers Some source code, and design styles