Download An Introduction to Control Structures

Components and Facilities
for Rich Graphical User
Interfaces
Chapter 7
Java Programming: Advanced Topics
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Objectives
• Become familiar with the extensive library of GUI
components offered by the Swing API
• Write code that uses the methods of the
javax.swing.JComponent class
• Learn to add windows, dialog boxes, and panels
to a GUI application
• Learn to add labels, buttons, and check boxes to
a GUI application
• Learn to add menus, toolbars, and actions to a
GUI application
• Learn to add sliders, spinners, progress bars, and
scrollbars to a GUI application
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Objectives (Cont.)
• Learn to add lists and combo boxes to a GUI
application
• Learn to add text-entry components to a GUI
application
• Learn to add file and color choosers to a GUI
application
• Learn to add tables and trees to a GUI
application
• Add printing support to a GUI application using
the 2D API
• Learn how to discover what print facilities are
available to an application using the Java Print
Service API
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Programming with the JFC
• To create applets or application that have
graphical user interfaces (GUIs), use the Java
Foundation Classes (JFC) of the Java platform
• Support for the development of GUIs for the Java
platform is provided by a combination of the AWT
and Swing APIs
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Packages of the AWT
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Packages of the AWT (Cont.)
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The Swing Packages
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The Swing Packages (Cont.)
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Swing API Components
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Windows
Dialog boxes
Panels
Labels
Buttons
Check Boxes
Menus
Toolbars
Sliders
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Spinners
Progress bars
Scrollbars
Lists
Combo boxes
Text-entry components
Tables
Trees
File and color choosers
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JComponent Class
• The JComponent class is the abstract
superclass for all Swing components
• Methods:
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void addxxxListener(xxxListener object )
void repaint( )
void repaint ( long msec)
void repaint (int x, int y, int height, int width)
void repaint ( long msec, int x, int y, int height, int
width)
– void setVisible( boolean b )
– void update( Graphics context )
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Windows, Dialog Boxes, and
Panels
• Containers: components that hold other
components
• Swing provides several top-level container
components:
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JApplet
JDialog
JFrame
JWindow
• To add a component to a JApplet, JDialog,
JFrame, or JWindow object, call the method
getContentPane
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Windows, Dialog Boxes, and
Panels (Cont.)
• An application runs in a JFrame object
• An applet runs in a JApplet object
• You build a GUI adding containers and
components to the JFrame object of an
application or the panel of an applet
• JDesktopPane, JInternalFrame, JOptionPane,
and JPanel are lightweight components that
extend JComponent
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Methods of the Container Class
• The Container class provides several methods
for adding and removing components or working
with layouts:
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void add( Component comp )
void add( Component comp, Object constraint )
Component[ ] getComponents()
LayoutManager getLayout()
void remove( Component comp )
void setLayout( LayoutManager mgr )
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Labels, Buttons, and Check
Boxes
• Labels add text that typically explains the
purpose of the other elements of a user
interface
• Buttons and check boxes provide the
opportunity to make selections and trigger
actions
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AbstractButton and Its
Subclasses
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Menus, Toolbars, and Actions
• To add menus to your GUI, use the classes:
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JMenuBar
JMenuItem
Jmenu
JPopupMenu
JRadioButtonMenuItem
JCheckBoxMenuItem
• Swing provides support for toolbars through the
JToolBar class
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Menus, Toolbars, and Actions
(Cont.)
• Swing provides a mechanism, the Action
interface, for defining objects that can be put
into toolbars and menus
• Actions that are common to both menus and
toolbars can be created as subclasses of
AbstractAction to provide a single point of
control
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Menus, Toolbars, and Actions
(Cont.)
• To create a main menu for an application, use a
JMenuBar object
• Use the add method to add menus to the menu
bar and the setJMenuBar method to add the
menu bar to its window
• For a menu that is associated with a component
and pops up when the user clicks a component,
create a JPopupMenu object
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Menus, Toolbars, and Actions
(Cont.)
• For every item in a menu, use an instance of
JMenuItem or a subclass of JMenuItem
• To nest menus, use JMenu objects. A JMenu
object is a JMenuItem object that is itself a menu
• For a menu item that is also a check box, use a
JCheckBoxMenuItem object
• For a menu item that is also a radio button, use
a JRadioButtonMenuItem object.
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Menu Classes in javax.swing
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Sliders, Spinners, Progress Bars,
and Scrollbars
• JProgressBar, JScrollBar, JSlider, and JSpinner
allow users to select or display a value within a
bounded range
• Programs use JProgressBar objects to indicate
the progress of a long-running operation
• Use a JScrollBar object to control the visible
contents of a component
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Sliders, Spinners, Progress Bars,
and Scrollbars (Cont.)
• Use a JScrollPane object to display a
component with contents that are likely to
exceed the available visible area
• The JScrollPane class adds scrollbars
automatically to control scrolling operations
• Use a JSlider object to allow selection of a
value within a bounded range
• Use a JSpinner object to allow selection of a
value within a bounded range from a
predetermined list of legal values
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Output of the FontSliderSpinner
Class
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Lists and Combo Boxes
• The JComboBox component is a drop-down list
that is useful for lists with a small number of
items
• A JList object displays a list of choices from
which it is possible to select one or multiple
items
• JList objects can be contained within
JScrollPane and scrolled to view the entire list
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Text-Entry Components
• A JEditorPane object is a region that is
designed to parse and edit specific types of
structured text content
• A JFormattedTextField object is an entry field in
which the data that the user enters must meet
the specified formatting rules
• A JPasswordField field can display a single line
of text and lets the user enter or edit the text
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Text-Entry Components (Cont.)
• JTextArea is a region that can contain several
lines of text
• JTextField can display a single line of text and
lets the user enter or edit the text
• A JTextPane object is a region that can contain
several lines of text
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TextComponent and Its
Subclasses
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Color and File Choosers
• Swing includes the standard classes
JFileChooser and JColorChooser that
implement panels and that can be embedded in
dialogs or internal frames
• JColorChooser is a panel that allows users to
browse a palette of available colors and select
one
• JFileChooser is a panel that allows users to
browse the contents of the file system and
select a file to open or a file to save
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Tables and Trees
• Swing provides two sophisticated controls for
structured information:
– JTable
– JTree
• The JTable class is best suited for tabular
information
• The JTree class is ideal for hierarchical
information
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Output of the JTree Example
Class
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The JTable Constructors
• Table()
• Table(int rows, int columns )
• Table( Object[][] rowData, Object[]
columnNames )
• Table( Vector rowData, Vector columnNames )
• Table( TableModel model )
• Table( TableModel model, TableColumnModel
tcModel )
• Table( TableModel model, TableColumnModel
tcModel, ListSelectionModel lsModel )
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The Output of the JTable Class
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Printing with the 2D API
• The Java 2D API introduced the java.awt.print
package to provide printing support on the Java
platform
• The java.awt.print.PrinterJob class provides the
control point for displaying print-related dialog
boxes, indicating what will print, and actually
starting the print job
• The PageFormat class provides information
about the size, orientation, and area available
for printing for a page of printed output
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java.awt.print.PrinterJob
• Methods of the class java.awt.print.PrinterJob:
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PageFormat defaultPage( )
PrintService getPrintService()
PageFormat pageDialog( PageFormat format )
PageFormat pageDialog( PrintRequestAttributeSet
attrs )
void print()
void print( PrintRequestAttributeSet attrs )
boolean printDialog()
boolean printDialog( PrintRequestAttributeSet attrs )
void setPrintable( Printable painter )
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The Page Setup Dialog Box
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Java Print Service API
• The Java Print Service API can be used for
printing text and graphics that are displayed
within an application
• The Java Print Service API is used to handle
many flavors of documents, to search and
discover print services for handling these
document flavors
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Java Print Service API (Cont.)
• The Doc interface encapsulates the interface for
an object that supplies a piece of print data for a
print job
• The DocFlavor class encapsulates the format in
which data will be supplied to a DocPrintJob
object
• The javax.print.DocPrintJob interface represents
a print job that can print a specified document
with a set of job attributes
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Summary
• The AWT API provides the infrastructure for
layout managers, events, event listeners, and
basic 2D graphics support
• The Swing API provides a comprehensive set
of GUI components to produce professional
applications
• JComponent is the superclass of all Swing
components, and JApplet, JDialog, JFrame,
and JWindow are the top-level containers
• An application runs in a JFrame object, and an
applet runs in a JApplet object
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Summary (Cont.)
• Swing provides classes to support buttons,
check boxes, menus, toolbars, sliders, spinners,
progress bars, scrollbars, lists, combo boxes,
text-entry components
• Swing includes the standard classes
JFileChooser and JColorChooser that
implement panels
• JTable is used for tabular information, and JTree
for hierarchical information
• Print capability can be added to an application
by using either the Printing API from the 2D API
or by using the Java Print Service API
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