Swinging in Your Java Playground

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Swinging in Your Java Playground
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Background

• Swing is a part of the Java Foundation Classes
  (JFC).
• The JFC is made up of features intended to give a
  programmer all the tools necessary to build
  enterprise applications.
• Swing Components
• Pluggable Look and Feel
• Accessibility API
• Java 2D API
• Drag and Drop Support

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Swing Features

• Built on top of AWT 1.1, taking your 1995 school
  playground into 2000 and beyond
• New components exist in Swing
• Tables, Trees, Sliders, Progress Bars, Internal
  Frames, and Text Components.
• Tooltips can appear over GUI Components
• Bind Keyboard events to GUI Components
• Easily extendible to create Customized Components

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Swing DesignModel/View/Controller Architecture

• Model - The state data for a component. For
  example, a Choice would contain all the items
  that could be chosen. This data remains constant
  no matter what its representation is on the
  screen.
• View - The way a component actually appears when
  it is drawn on the screen
• Controller - The way a component interacts with
  the events that occur.

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Taking Turns on a Swing Component(Event
Handling)

• When a component receives input, it fires events.
  An Object can register to receive those events by
  being added as a Listener to the Component.
• A Component can have multiple objects listening
  for its events.
• When the listening Object handles an event, it
  can do something to the Component or something
  else entirely.

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Taking Turns on a Swing Component(Event
Handling)Example
public class ClickEvent extends JFrame implements
ActionListener private JButton click new
JButton("Click Me") private JTextField
welcomeText new JTextField() private JPanel
thePanel new JPanel() public ClickEvent()
super("Event Example")
setSize(400,300) thePanel.setLayout(new
GridLayout(2,1)) //this.getContentPane().add(
click,BorderLayout.NORTH) thePanel.add(click)
thePanel.add(welcomeText)
this.getContentPane().add(thePanel,BorderLayout.CE
NTER) click.addActionListener(this)
this.setVisible(true)
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Taking Turns on a Swing Component(Event
Handling)Example
public void actionPerformed(ActionEvent e)
welcomeText.setHorizontalAlignment(JTextField.CENT
ER) welcomeText.setText("Hello Linux User's
Group") public static void main(String
args) ClickEvent clickEvent1 new
ClickEvent()
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JTree Component

• The visual representation of data that is
  organized in tree format
• Root, there is only 1 of these for a tree
• Node, any entry in the tree
• Leaf, any node without a child node
• Two Interfaces
• TreeModel - how to work with the data
• TreeSelectionModel - how to select nodes within
  the tree

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JTree ComponentContinued

• Node Interface TreeNode, The basic piece of the
  tree
• Contains the basic methods needed by the
  TreeModel to manipulate the data
• All of the interfaces have Default
  implementations so that you dont have to start
  from scratch

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JTree Component Continued

• Events
• TreeExpansionEvent, When a node has been expanded
  or collapsed
• TreeSelectionEvent, A row (path) has been
  selected or, if multiple rows can be selected, a
  row has been added or removed from that group
  selection.

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JTable Component

• The visual representation of data in a table
  format. It is very useful to display data from
  databases in this format.
• Column is the basic unit of the Table. The data
  represented in it is consistent
• Row the collection of columns that uniquely
  identifies an entity.
• Cell the location at a particular row and column
  of data.

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JTable ComponentContinued

• Two Interfaces
• TableColumnModel manages selection in the column
  and spacing of the column in the table.
• TableModel provides all the information
  concerning the rows and columns in the table as
  well as access to the data found in the cells.
• Again, both interfaces have Default
  implementations.

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JTable ComponentContinued

• Events
• TableColumnEvent used to notify that a column
  model has changed. For example, that a column has
  been added, removed, or moved.
• TableModelEvent used to notify that the
  TableModel has changed and/or that rows/column
  data has changed

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Other Details

• Components are lightweight
• Swing runs on any JDK 1.1.5 or higher does not
  need to be downloaded for JDK 1.2 it is part of
  the core JDK.
• Java.swing.border package which contain 8
  predefined classes for borders that can be placed
  around a component.
• Lots of classes exist to provide editing within
  the complex components.