Java Swing Lecture 1 An Introduction

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Java Swing - Lecture 1An Introduction

• Chris Coleman
• (cqc_at_cs.nott.ac.uk)
• http//www.cs.nott.ac.uk/cqc/G5BUID

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Timeline

• 27th Oct (Now) - Java Necessaries, Swing Basics
• 28th Oct - Components and Containers
• 3rd Oct - Layout Management
• 17th Nov - Event Handling and Listeners
• 18th Nov - Graphics with Swing
• 8th Nov Problem Class Session
• Labs Start Week Beginning 7th Nov. Time TBA.

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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

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Before We Start (2)

• If Java is a problem learn NOW, not in a month
  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?

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2D interface programming toolkits

• Tcl/Tk
• Motif/UIL
• IDEs (e.g. VB, MSVC/MFC)
• Java AWT the beginnings
• Java JFC Swing (Java2 - JDK gt 1.2)
• JBuilder and other Java IDEs
• etc

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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

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On-line reading and reference

• The Swing connection - http//java.sun.com/product
  s/jfc/tsc/
• The JFC Swing trail - http//java.sun.com/docs/boo
  ks/tutorial/uiswing/
• Fundamentals of JFC/Swing I II
  - http//developer.java.sun.com/developer/onlineTr
  aining/

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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

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Getting started with Swing (1)

• Compiling running programs
• Swing is standard in Java 2 (JDK gt 1.2)
• Use
• javac ltprogram.javagt java ltprogramgt
• Or JCreator / IDE

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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 (1.4.2) in /usr/bin (or /usr/java)
• Differences between previous versions
• http//java.sun.com/j2se/1.4.2/docs/guide/swing/Sw
  ingChanges.html
• http//java.sun.com/j2se/1.5.0/docs/guide/swing/Sw
  ingChanges.html
• Coursework marked on Win XP JDK 1.5.0

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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.

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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
  theres much more of it.

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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 programs GUI
• Windows (but only on Windows, M issues.)
• UNIX
• GTK
• etc

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A typical Swing program

• Consists of multiple parts
• Containers
• Components
• Events
• Graphics
• (Threads)
• Now look at each in turn

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A simple Swing program - Containers

• Containers

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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.

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A simple Swing program - Components

• Components

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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

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A simple Swing program - Events

• Events

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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

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A simple Swing program - Graphics

• Graphics
• Complex drawing and
• shading API.
• Can do far more than
• display images.

      
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Remember this about Graphics

• There are many aspects of Swing that allow you to
  achieve graphics-like things without actually
  using Graphics.
• Therefore, you dont have to use them most of the
  time, and it is often easier not to.

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A simple Swing program - Threads

• Most simple Swing GUI applications dont require
  use of any (extra) threads
• As Swing creates event-driven programs, all code
  is executed on the event-dispatching thread

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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)

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How to Learn Swing

• Dont even try.
• Learn general framework principles and design
  styles.
• Then use the API reference, and Swing Tutorials
  to discover detailed usage of each component.

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How to read Java Docs (1)

• Java 2 (1.5.0) API Reference available at
• http//java.sun.com/j2se/1.5.0/docs/api/
• Split into 3 Sections (html frames)
• Top Left Packages
• Bottom Left Classes in Packages
• Main Frame Information about selected Class

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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

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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