Swing Components III
This guide covers essential aspects of using JFrame and Dialog components in Java Swing. It explains the significance of JFrame for creating windows, generic methods, and key functionalities like dispose(), pack(), and setVisible(). It also explores constructing JFrame windows, setting layout managers, adding components, and managing closing behaviors. Additionally, the document provides an overview of Dialogs, including constructors, modal types, and the importance of user interactions. Examples demonstrate practical implementation, making it easier for programmers to create GUI applications in Java.
Swing Components III
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Presentation Transcript
Swing Components III Chapter 12 - Student JFrame, Component Methods
Window • Mostly used for ____________ • Generic type that _______ and Dialog inherit • 3 important methods: • dispose() – eliminate ___________ when done • pack() – __________ to fit added components • setVisible(boolean) – make the window appear (c) 2005 by Elizabeth Sugar Boese
JFrame • Uses ____________ by default • Possible ornaments: • Title • ____________ • Menu • ____________ • Widgets to hide/minimize/grow • Methods: • Constructors: • JFrame() • JFrame( String title) • setBounds( w, h ) • setSize( w, h ) (c) 2005 by Elizabeth Sugar Boese
JFrame text is the title on the JFrame • Create a JFrame window JFrame frame; frame = new JFrame( text ); • Set the ____________ on the screen (optional) frame.setLocation( 500, 600 ); • Major Steps 1. ______________________. JFrame frame; frame = new JFrame("FrameDemo"); 2. Set ________________ frame.setLayout( new BorderLayout( ) ); 3. Create components and _________________________ JButton go = new JButton( "Go for it!" ); frame.add(universe, BorderLayout.SOUTH); 4. _________ the frame. frame.pack(); OR frame.setSize( 200, 500 ); 5. Show it. frame.setVisible(true); Calling the .pack( ) method will size the frame based on the minimum size to fit all the components added to the frame. (c) 2005 by Elizabeth Sugar Boese
JFrame – Simple Example import javax.swing.*; public class JFrameDefault extends JApplet { JFrame frame; public void init( ) { frame = new JFrame( "Testing JFrame stuff" ); frame.setSize( 200,100 ); frame.setVisible( true ); } } (c) 2005 by Elizabeth Sugar Boese
JFrame – Example with components import java.awt.*; import javax.swing.*; public class JFrameStuff extendsJApplet { JFrame frame; JLabel myname, universe; JButton go, skiing; public void init( ) { //1. Create the frame. frame = new JFrame("FrameDemo"); //2. Set layout manager frame.setLayout( new BorderLayout( ) ); //3. Create components and put them in the frame. myname = new JLabel( "<HTML>My <BR>Stuff", JLabel.CENTER ); go = new JButton( "Go for it!" ); skiing = new JButton( "Do you like skiing too?" ); universe = new JLabel( "I live at the borders of the universe where fact and fiction collide" ); frame.add(myname, BorderLayout.NORTH); frame.add(go, BorderLayout.WEST); frame.add(skiing, BorderLayout.EAST); frame.add(universe, BorderLayout.SOUTH); //4. Size the frame. frame.pack( ); //5. Show it. frame.setVisible(true); } } (c) 2005 by Elizabeth Sugar Boese
JFrame Closing Behaviors • When user selects window manager Close option for JFrame, has default behavior • JFrame did nothing • JFrame hides itself • setDefaultCloseOperation (operation) • DO_NOTHING_ON_CLOSE • HIDE_ON_CLOSE • DISPOSE_ON_CLOSE • No EXIT_ON_CLOSE operation (c) 2005 by Elizabeth Sugar Boese
JFrame - Events • usually want to pop open a JFrame based on an event (e.g. a button click) • Example (c) 2005 by Elizabeth Sugar Boese
Dialogs (extra material)
JOptionPane Examples (c) 2005 by Elizabeth Sugar Boese
Dialog • For simple _______________ with user • Uses _______________ by default • Are _____ by default (can change to modeless setModal(false) • Constructors: • Dialog( Frame parent ) • Dialog( Frame parent, String title ) • Dialog( Frame parent, boolean isModal ) • Call to super( ) (c) 2005 by Elizabeth Sugar Boese
Dialog Example Frame frame = new Frame( ); Dialog d = new Dialog( frame, “Hi there”, true ); JButton button = new JButton( “Okay?” ); JPanel panel = new JPanel(); p.add( button ); d.add( panel ); d.setSize( 400,100 ); d.setVisible( true ); (c) 2005 by Elizabeth Sugar Boese
Menu (extra material)
Menu • MenuBar • Collection of Menus • Associated with a Frame • Menu • Collection of MenuItems and separators • Can be a MenuItem for hierarchical menus • MenuItem • Enabled or disabled • May be checkable (c) 2005 by Elizabeth Sugar Boese
Component Methods • Common methods works on most components (e.g. JLabel, JButton, JPanel, etc.) • setBackground ( Color ) • setForeground ( Color ) • setBorder ( Border ) • setFont ( Font ) • setToolTipText( String ) • setVisible ( boolean ) (c) 2005 by Elizabeth Sugar Boese
Component Methods - JButton • JButton • addActionListener ( this ) • setBorderPainted ( boolean ) • setContentAreaFilled ( boolean ) • setDisabledIcon ( ImageIcon ) • setIcon ( ImageIcon ) • setHorizontalAlignment ( int ) • setHorizontalTextPosition ( int ) • setRolloverIcon ( ImageIcon ) • setText ( String ) Parameter int one of: JButton.LEFT JButton.CENTER JButton.RIGHT (c) 2005 by Elizabeth Sugar Boese
Component Methods – JCheckbox, JRadioButton • JCheckbox and JRadioButton • addItemListener ( this ) • isSelected ( ) Returns true if currently selected, false if not selected (c) 2005 by Elizabeth Sugar Boese
Component Methods - JLabel • JLabel • setIcon ( ImageIcon ) • setText ( String ) (c) 2005 by Elizabeth Sugar Boese
Component Methods - text • JTextField • getText ( ) • setText ( ) • JTextArea • append ( String ) • getText ( ) • setLineWrap ( boolean ) • setText ( String ) • setWrapStyleWord ( boolean ) (c) 2005 by Elizabeth Sugar Boese
Summary • JFrame • Dialogs • Menu • Component methods (c) 2005 by Elizabeth Sugar Boese
