Gui Interfaces a la Swing

1
Gui Interfacesa la Swing

• Up to speed with Swing by
• Steven Gutz is a good source
• It dont mean a thing
• if it aint got that swing
• Duke Ellington

2
Simple Gui layout Design

• Four main decisions
• 1. User Interactions
• what to gather from user, what to show
  him
• 2. Particular objects on screen
• JTextField, TextArea, JButton, JPanels,
  JLabels, JFrame...
• 3. General layout of Screen
• borderlayout, gridlayout, flowlayout,.
• 4. Listeners
• connect user actions with program
  activities
• WindowListeners, ActionListeners,
  ItemListeners, .

3
Minimal Objects and methods

• JFrame where you start
• Container mainPane getContentPane() is where
  you add other components.
• JPanels
• container for other objects including Jpanels
• setLayoutManager(..)
• JTextField(int size) setText, getText,
  addActionListener
• TextArea(int row, int col) append
• JButton(String s) named button,
  addActionListener
• JLabel(String s) just a string
• More JTabbedPane, ScollBars, Lists, Checkboxes,
  Menus, Dialogs, PopUps, Sliders,Toolbars..and on
  and on

4
Layout Managers

• FlowLayout()
• right to left with wrap around
• default manager for JPanel
• BorderLayout()
• north, south, east, west, center
• default for contentPane
• GridLayout(int row, int columns)
• row and columns
• GridBag Layout (..)
• hurts my head
• Layout Managers can be nested.

5
Listeners are Interfaces

• WindowListeners
• respond to window events, such as miniminizing
  window, closing, moving, maximizing, etc.
• Window will not Close! Need to add a listener.
• Has 7 methods, I.e. obligations.
• ActionListeners
• For JButtons, responds to clicking on buttons
• For JTextFields, responds to enter
• Still need to define the activity
• Only 1 method actionPerformed(ActionEvent ae)
• ItemListeners, MouseListeners, KeyListeners,.
• 11 listeners at last count.

6
Events

• ActionEvent
• button pressed, text entered, .
• WindowEvent
• windowIconified, windowClosed, windowOpened,
• Key Events
• keyTyped, keyPressed, keyReleased
• MouseEvents
• mouseClicked, mousePressed, mouseReleased,
  mouseDragged, mouseMoved,...
• TextEvent
• textValue changed,..
• And on and on

7
Closeable Hello World

• import javax.swing. // for J stuff
• import java.awt.event. // for listeners
• import java.awt. // for the layout managers
• class Driver extends JFrame
• public static void main(String args)
• Driver driver new Driver()
• driver.show() // without this, you get
  nothing
• Driver()
• addWindowListener(new WindowDestroyer())
  //needed to close window
• Container mainPane getContentPane()
  // default border layout
• mainPane.add(new Jlabel(Hello World))

8
Window Destroyer

• import java.awt.event.
• class WindowDestroyer extends WindowAdapter
• public void windowClosing(WindowEvent we)
• System.exit(0)
• WindowListener has 7 methods to define.
• WindowAdapter defines them all to do nothing.