JPanel

1
JPanel

• contained container
• lightweight
• typically used as top level container in content
  pane
• also for controlling layout
• default layout manager FlowLayoutManager
• constructor
• JPanel()

2
JButton

• button widget
• button with label
• press generates ActionEvent
• constructor
• JButton ( String label )
• methods
• addActionListener ( ActionListener l )
• setActionCommand ( String actionCommand )
• setEnabled ( boolean b )
• setText ( String text )

3
JMenuBar

• associated with a JFrame
• frame.setJMenuBar ( JMenuBar mBar )
• constructor
• JMenuBar ( )
• methods
• add ( JMenu menu )

4
JMenu

• menu in a JMenuBar
• constructor
• JMenu ( String label )
• methods
• add ( JMenuItem item )
• addSeparator ( )
• insert ( JMenuItem item, int pos)
• insertSeparator ( int pos )
• remove ( JMenuItem item )
• remove ( int pos )
• removeAll ( )

5
JMenuItem

• selectable item in a JMenu
• constructors
• JMenuItem ( String text )
• methods
• addActionListener ( ActionListener listener )
• setActionCommand ( String command )
• setEnabled ( boolean b )

6
Example

• public MyFrame()
• JMenuBar myBar new JMenuBar()
• JMenu fileMenu new JMenu("File")
• JMenuItem startItem new JMenuItem("Start
  Game")
• startItem.setEnabled(false)
• fileMenu.add(startItem)
• JMenuItem quitItem new JMenuItem("Quit")
• quitItem.addActionListener(new AbstractAction()
  
• public void actionPerformed(ActionEvent e)
• System.exit(0)
• )
• fileMenu.add(quitItem)
• myBar.add(fileMenu)
• setJMenuBar(myBar)
• setSize(500,300)
• setLocation(200,200)
• setVisible(true)

7
JRadioButton

• buttons that can be grouped
• ButtonGroup
• constructor
• ButtonGroup ( )
• methods
• add ( AbstractButton b )
• ButtonModel getSelection ( )
• constructors
• JRadioButton ( String label )
• JRadioButton ( String label, boolean state )
• methods
• addActionListener ( Actionlistener listener )
• setActionCommand ( String actionCommand )
• setEnabled ( boolean b )
• boolean isSelected ( )
• setSelected ( boolean state )

8
JDialog

• dialog window
• has a parent (owner)
• modal or non-modal
• content pane
• constructors
• JDialog ( )
• JDialog ( Dialog owner )
• JDialog ( Frame owner )
• JDialog ( Dialog owner, boolean modal )
• JDialog ( Frame owner, boolean modal )
• methods
• Container getContentPane ( )
• dispose ( ) // from Window
• pack ( ) // from Window
• setResizable ( boolean b ) // from Dialog
• setTitle ( String title ) // from Dialog
• setDefaultCloseOperation ( int operation )

9
Example

• public MyDialog(JFrame parent)
• super(parent,true)
• setSize(220,160)
• setTitle("Select number of players")
• ButtonGroup group new ButtonGroup()
• JRadioButton one new JRadioButton("One",true)
• JRadioButton two new JRadioButton("Two",false
  )
• JRadioButton three new JRadioButton("Three",fal
  se)
• JRadioButton four new JRadioButton("Four",false
  )
• group.add(one) group.add(two)
  group.add(three) group.add(four)
• JPanel selectPanel new JPanel()
• selectPanel.setLayout(new GridLayout(4,1))
• selectPanel.add(one) selectPanel.add(two)
• selectPanel.add(three) selectPanel.add(four)
• getContentPane().add(selectPanel,BorderLayout.NOR
  TH)

10
Example (contd)

• JPanel buttonPanel new JPanel()
• JButton ok new JButton("OK")
• ok.addActionListener(new AbstractAction()
• public void actionPerformed(ActionEvent e)
• setVisible(false)
• )
• buttonPanel.add(ok,BorderLayout.CENTER)
• getContentPane().add(buttonPanel,BorderLayout.SOU
  TH)
• setVisible(false)
• In MyFrame private MyDialog dialog new
  MyDialog(this)
• ...
• startItem.addActionListener(new AbstractAction()
  
• public void actionPerformed(ActionEvent e)
• dialog.setVisible(true)
• )

11
JScrollBar

• constructors
• JScrollBar (int orientation, int value,
  int extent, int min, int max )
• methods
• addAdjustmentListener( AdjustmentListener
  listener )
• getOrientation( )
• getValue( )
• setValue( int value )

12
JLabel

• text label
• constructors
• JLabel ( String text )
• JLabel ( String text, int align )
• JLabel ( Icon icon )
• JLabel ( String text, Icon icon, int align )
• alignment
• JLabel.LEFT
• JLabel.RIGHT
• JLabel.CENTER
• methods
• setText ( String text )
• setIcon ( Icon icon )

13
Example

• private JLabel widthLabel new JLabel("
  Width 5000")
• private JLabel heightLabel new JLabel("
  Height 5000")
• private JScrollBar widthScrollbar
• new JScrollBar(JScrollBar.HORIZONTAL,5000,0,0,320
  00)
• private JScrollBar heightScrollbar
• new JScrollBar(JScrollBar.HORIZONTAL,5000,0,0,320
  00)
• ?
• widthScrollbar.addAdjustmentListener(new
  AdjustmentListener()
• public void adjustmentValueChanged(AdjustmentEven
  t e)
• widthLabel.setText(" Width "
  widthScrollbar.getValue())
• )
• heightScrollbar.addAdjustmentListener(new
  AdjustmentListener()
• public void adjustmentValueChanged(AdjustmentEven
  t e)
• heightLabel.setText(" Height "
  heightScrollbar.getValue())
• )

14
JOptionPane

• easy pop-up of standard dialogs
• modal
• methods (static)
• int showMessageDialog ( Component parent, Object
  msg)
• int showMessageDialog ( Component parent, Object
  msg, String title, int
  type )
• int showOptionDialog ( )
• int showConfirmDialog ( )
• String showInputDialog ( )

15
JFileChooser

• file selection dialog
• can specify subdirectory and file filter
• constructor
• JFileChooser ( )
• JFileChooser ( File currentDirectory )
• methods
• File getSelectedFile
• setCurrentDirectory ( File dir )
• setFileFilter ( FileFilter filter )
• showOpenDialog ( Component Parent )
• showSaveDialog ( Component Parent )

16
JTextComponent

• text entry areas
• new lines (\n)
• JTextField
• editable single-line text
• JTextField ( int cols )
• JTextArea
• editable multi-line text
• JTextArea ( int rows, int cols )
• methods
• setText ( String text )
• String getText ( )
• setEditable ( boolean b )
• JPasswordField
• setEchoChar ( char echo )
• char getPassword ( )

17
JCheckbox

• a checkbox
• generates ActionEvent
• constructors
• JCheckbox ( String label )
• JCheckbox ( String label, boolean state )
• methods
• addActionListener ( Actoinlistener listener )
• setActionCommand ( String actionCommand )
• setEnabled ( boolean b )
• boolean isSelected ( )
• setSelected ( boolean state )

18
JList

• list selector
• generates ListSelectionEvent
• constructor
• JList ( Object items )
• JList ( ListModel dataModel )
• methods
• setVisibleRowCount ( int rows )
• setFixedCellWidth ( int width)
• setSelectionMode ( int mode )
• JList.SINGLE_SELECTION, JList.SINGLE_INTERVAL_SELE
  CTION, JList.MULTIPLE_INTERVAL_SELECTION
• addListSelectionListener ( ListSelectionListener
  l )
• Object getSelectedValues ( )
• Object getSelectedValue ( )

19
ListSelectionListener

• javax.swing.event
• method
• valueChanged ( ListSelectionEvent e )
• ListSelectionEvent
• boolean getValueIsAdjusting ( )
• Object getSource ( )

20
JScrollPane

• scrolling for other components
• place component in JScrollPane and then add
  scroll pane to container
• constructor
• JScrollPane ( Component c )