Swing

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Swing GUI Design
AWT Swing GUI Design Using IDE Tool
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What is GUI

• Graphic User Interface
• Outer Interface of Program
• GUI is Built by GUI Components
• GUI Component Visual Object to Interact With
  Outside such as Mouse, Keyboard, etc.
• Ex) AWT, Swing Components
• Interfaces Provided by Java
• Graphic line, rectangle, polygon, arc, .
• Interaction Elements button, textfield, menu,
• Image image files

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GUI and AWT

• Abstract Window Toolkit (AWT)
• Java.awt package
• Component Class Button, List, Menu, TextArea,
  Window, MenuBar, Dialog
• Graphics Related Classes Graphics Context, Font
  , Color
• Event Class For Event Handling
• Layout Management Class Size and Position of
  Component

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GUI Component Hierarchy

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GUI Operation Outline

• Procedure for Making GUI in Java
• Select the Container Component and Arrange the
  Basic Components within this container. Select
  the Layout Manager Also.
• Make the Event Handling Routine and Register it.
• Event Listener
• Insert the Drawing Code to Override the paint()
  method in order to draw some figure on component
• Paint(), repaint(), update()

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Make the GUI Component

• Procedure to put the GUI components into Frame or
  Panel which is container
• Make the container object
• Declare and create the component object.
• Put the objects created into container
• Layout Manager
• FlowLayout From Left to Right in Panel, Default
  Manager
• GridLayout With Grid, Arrange in Lattice Type
• GridBagLayout Arrange Different Size Component
  on Grid
• BorderLayout Up, Down, Left, Right, Center
• CardLayout Arrange Several Cards

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Graphics User Interface (I)

• Component Class
• Abstract Class which provides
• Methods to control size and position on the
  screen
• Methods to setup cursor and return the cursor
  position
• Methods for drawing such as paint(),update(),repai
  nt()
• Methods to determine keyboard input, visibility
• Function for providing event handling
  registration
• Methods related with Font and Color

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Graphics User Interface (I)

• Label
• Not able to change
• Describes Text information
• Button
• When user presses
• Occur events to make some action.
• Check Box
• Has two states of ON and OFF
• When user selects one of two
• For multiple selection, CheckboxGroup can be used

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Graphics User Interface (I)

• Choice Button
• Select one of several items to select
• When user clicks arrow button, then the selection
  list is displayed.
• When user select one, Action event occurred.
• Select List
• Used to select one or more item(s)
• Text Field
• A line of text area to input
• It is possible to disable/enable input
• Text Area
• Multi-lines of text area to input

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Graphics User Interface (I)

• TextComponent Class
• Super class of TextField and TextArea
• Scroll Bar
• To input an integer within some range
• Canvas
• To create display area for graphic
• Building a customized component by user

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Graphics User Interface (II)

• Panel
• Inherited from Container class (Super of Applet)
• Components can be added into Panel
• Frame
• Window to have Title Bar and Border
• Independent of Window( compare to Dialog)
• Dialog Box
• Window to have Title Bar
• Dependent on Parent Window
• Modal Dialog (Can do work only after terminating
  the Dialog)
• Non-Modal Dialog

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Graphics User Interface (II)

• Scroll Pane
• To make an area to be scrolled easily
• To display the child component as large as
  possible
• If child component is larger than Scroll Pane,
  it adds the horizontal or vertical scroll bar.
• Menu
• MenuItem Each Item of Menu
• CheckboxMenuItem
• Menu
• MenuBar
• PopupMenu

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Events

• Event
• Event Listener
• Delegation Model
• Adaptor
• Low Level Event
• Mouse, MouseMotion, Key, Component, Container,
  Focus, Window
• High Level (Have Semantics) Event
• Action, Adjustment, Item, Text

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Events
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JFC Swing

• JFC (Java Foundation Class)
• Give a group of class to help people build GUI
• Things Contains
• Swing Components
• Pluggable Look and Feel Support
• Accesibility API
• Java 2D API
• Drag and Drop Support

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JFC Swing

• Differences between AWT and Swing
• Swing components are implemented with absolutely
  no native code gt can be present on every
  platform.
• Swing component which their names start with J
  can be identified
• Have capabilities beyond what the AWT components
  offer

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JFC Swing

• Capabilities beyond AWT
• Swing buttons and labels can display images
  instead of, or in addition to, text.
• You can easily add or change borders drawn around
  most Swing components.
• You can easily change the behavior or appearance
  of a Swing component by either invoking methods
  on it or creating a subclass of it
• Swing components need not be rectangular.
• Assistive technologies such as screen readers can
  easily get information from Swing components.

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Swing Components

• Content URL
• http//java.sun.com/docs/books/tutorial/uiswing/co
  mponents/components.html
• Top Level Containers
• The components at the top of any Swing
  containment hierarchy
• General Purpose Containers
• Intermediate containers that can be used under
  many different circumstances

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Swing Components

• Special Purpose Containers
• Intermediate containers that play specific roles
  in the UI.
• Basic Controls
• Atomic components that exist primarily to get
  input from the user they generally also show
  simple state
• Uneditable Information Displays
• Atomic components that exist solely to give the
  user information
• Editable Displays for Formatted Information
• Atomic components that display highly formatted
  information that (if you choose) can be edited by
  the user

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Swing Application Code

• Importing Swing Packages ( and AWT packages)
• ltSwingApplication.javagt
• Import javax.swing.
• Import java.awt. Import java.awt.event.
• Choosing the Look and Feel
• Java Look and Feel, Windows Look and Feel,
  CDE/Motif Look and Feel
• public static void main(String args) try
  UIManager.setLookAndFeel(
• UIManager.getCrossPlatformLookAndFeelClass
  Name()) catch (Exception e)
• ...//Create and show the GUI...

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Swing Application Code

• Setting Up a Top-Level Container
• Instances of JFrame, JDialog, JApplet
• JFrame implements a single main window
• JDialog implements a secondary window
• JApplet implements an applets display area
  within a browser windows
• Ex)
• JFrame frame new JFrame(SwingApplication)

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Swing Application Code

• Setting Up Buttons and Labels
• Make component objects and set up attribute
• Ex)
• JButton button new JButton("I'm a Swing
  button!") button.setMnemonic(KeyEvent.VK_I)
  //use Alt-i button.addActionListener(...create an
  action listener...)
• final JLabel label new JLabel(labelPrefix
  "0 ") ... label.setLabelFor(button) ...//in the
  event handler for button clicks
  label.setText(labelPrefix numClicks)

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Swing Application Code

• Adding Components to Containers
• To group a label and button in a container (a
  JPanel) before adding components to the frame
• Ex)
• JPanel pane new JPanel() pane.setBorder(Bord
  erFactory.createEmptyBorder(30, 30, 10, 30))
• pane.setLayout(new GridLayout(0, 1))
  pane.add(button) pane.add(label)

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Swing Application Code

• Adding Borders Around Components
• Provides some empty space around the panels
  contents
• Ex)
• pane.setBorder(BorderFactory.createEmptyBorder(
• 30, //top
• 30, //left
• 10, //bottom
• 30) //right )

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Swing Application Code

• Handling Events
• Make Event Handler
• Ex)
• button.addActionListener(new ActionListener()
• public void actionPerformed(ActionEvent e)
  numClicks label.setText(labelPrefix
  numClicks)
• ) ...
• frame.addWindowListener(new WindowAdapter()
  public void windowClosing(WindowEvent e)
  System.exit(0)
• )

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Swing Application Code

• Dealing with Thread Issues
• Because the event handler runs in the same thread
  that performs all event handling and painting for
  the application, there's no possibility that two
  threads will try to manipulate the GUI at once
• All manipulation of the GUI such as setText,
  getText, etc, is performed in event handlers such
  as actionPerformed()

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Swing Application Code

• Supporting Assistive Technologies
• Support for assistive technologies -- devices
  such as screen readers that provide alternate
  ways of accessing information in a GUI -- is
  already included in every Swing component.
• The only code in SwingApplication that exists
  solely to support assistive technologies is this
  label.setLabelFor(button)

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GUI Design Using IDE TOOL

• There are several Integrated Development
  Environment (IDE) Tools
• Jbuilder of Borland
• Visual Age of IBM
• Visual J of Microsoft
• Visual Café of Symantec (faded out)
• Demonstration