Questions before we Start

1
Questions before we Start?

• Questions from previous lecture?
• Questions on HW?
• Note to Self Check to be sure pictures are
  working in Olin 106
• FINISH EARLY to leave time for class project
• Not responsible for
• WindowListener
• Displaying Images in Labels
• Changing Fonts

2
Week 08 - b

• BordersDrawing in PanelsJCheckBox,
  ItemListenerJRadioButton, ButtonGroupJComboBox

3
Sample Programs Referenced(code located in
course folder)

• BorderedTemperature
• ColorfulDots
• CheckBoxDemo
• with without pictures
• RadioButtonDemo
• with without pictures

• ComboBoxDemo
• Restaurant Menu
• Whiteboard

4
Adding Borders to Panels

• Border object describes how to draw
• Empty Border -- Empty space around panel
• Line Border -- Plain, Etched, Beveled
• Titled Border -- Add text to above
• import javax.swing.border.
• . . .
• Border line BorderFactory.createLineBorder(c,w)
  
• // c a Color, w width in pixels
• Border etched BorderFactory.createEtchedBorder()
  
• Border titled BorderFactory.createTitledBorder(l
  ine,"Title")
• samplePanel.setBorder(titled)

5
Temperature Conversion(with Borders)

• Run BorderedTemperature in BlueJ
• Changed Etched border to Thick RED Line

6
Drawing in a JFrame (1 of 3)

• Created JFrame in main program
• Adding ColorfulDots Object to Frame
• Instead of paint method used in Applets
• Graphics g container.getGraphics()
• import javax.swing.
• /
• Create ColorfulDots object.
• _at_author Dave Hannay
• _at_version 2/25/2004
• /
• public class ColorfulDotsClient
• public static void main(String args)
• JFrame myFrame new JFrame()
• myFrame.setTitle("CONFETTI")
• myFrame.setContentPane(new ColorfulDots())
• myFrame.pack() // as opposed to setSize

7
Drawing in a JFrame (2 of 3)

• import javax.swing.
• import java.awt.event.
• import java.awt.
• // Dave Hannay 2/25/2004
• class ColorfulDots extends JPanel implements
  ActionListener
• JButton show new JButton("show")
• JButton erase new JButton("erase")
• JPanel theButtons new JPanel()
• JPanel board new JPanel()
• ColorfulDots()
• setLayout(new BorderLayout())
• theButtons.add(show) theButtons.add(erase)
• add(theButtons, BorderLayout.NORTH)
• board.setPreferredSize(new Dimension(200,
  200))
• board.setBackground(Color.white)
• add(board, BorderLayout.CENTER)
• show.addActionListener(this)
• erase.addActionListener(this)
• // end of ColorfulDots constructor

8
Drawing in a JFrame (3 of 3)

• public void actionPerformed(ActionEvent e)
• Object source e.getSource()
• if (source show)
• Graphics g board.getGraphics()
• int red (int)(256Math.random())
• int green (int)(256Math.random())
• int blue (int)(256Math.random())
• g.setColor(new Color(red,green,blue))
• g.fillOval((int)(200Math.random()),(int)(20
  0Math.random()),5,5)
• // end of show button
• else if (source erase)
• board.repaint() // in this case, erases
  graphics
• // end of actionPerformed method
• // end of ColorfulDots class

9
CheckBoxes

• Used to allow user to select one or more items
• Checkbox always has a built-in label
• Program often needs to react to the user
  selection(s)
• Declaration example
• JCheckBox brakes new JCheckBox(Power Brakes)
• JCheckBox steering new JCheckBox(Power
  Steering)
• JCheckBox ac new JCheckBox(Air Conditioning)
• container.add(brakes)
• container.add(steering)
• container.add(ac)

10
Programming Checkboxes

• Program is declared with implements ItemListener
  
• Checkbox is registered by calling addItemListener
  
• Event is handled using itemStateChanged argument
  type ItemEvent
• The ItemEvent argument is used to tell which item
  triggered the event by calling getSource

11
Processing Checkboxes

• CheckboxDemo
• Run version without pictures first in BlueJ
• Simplified version on next slides

12
CheckBoxDemo (1 of 3)

• // Dave Hannay 2/22/2004
• import java.awt.
• import java.awt.event.
• import javax.swing.
• public class CheckBoxDemo extends JFrame
  implements ItemListener
• JCheckBox chinButton new JCheckBox("Chin")
• JCheckBox glassesButton new
  JCheckBox("Glasses")
• JCheckBox hairButton new JCheckBox("Hair")
• JCheckBox teethButton new JCheckBox("Teeth")
• JTextField description new JTextField(20)
• public CheckBoxDemo()
• setDefaultCloseOperation( EXIT_ON_CLOSE )
• Container frame this.getContentPane()
• // Register a listener for the check boxes.
• chinButton.addItemListener(this)
• glassesButton.addItemListener(this)
• hairButton.addItemListener(this)

13
CheckBoxDemo (2 of 3)

• // Put the check boxes in a column in a panel
• JPanel checkPanel new JPanel()
• checkPanel.setLayout(new GridLayout(0, 1))
• checkPanel.add(chinButton)
• checkPanel.add(glassesButton)
• checkPanel.add(hairButton)
• checkPanel.add(teethButton)
• frame.setLayout(new FlowLayout())
• frame.add(checkPanel)
• frame.add(description)
• pack()
• // end CheckBoxDemo constructor

14
CheckBoxDemo (3 of 3)

• / Listens to the check boxes. /
• public void itemStateChanged(ItemEvent e)
• // don't care which one was selected in this
  case...
• String descStr ""
• if (chinButton.isSelected())
• descStr " chin "
• if (glassesButton.isSelected())
• descStr " glasses "
• if (hairButton.isSelected())
• descStr " hair "
• if (teethButton.isSelected())
• descStr " teeth "
• description.setText(descStr)
• // end of itemStateChanged method
• // end of CheckBoxDemo class

15
Radio ButtonsStation Presets
16
Radio Buttons

• A group in which only one item can be selected at
  a time
• Implemented using a Java ButtonGroup
• Items are declared initially as selected (true)
  or unselected (false)
• Example
• ButtonGroup gender
• JRadioButton maleCheck new JRadioButton(Male)
  
• JRadioButton femaleCheck new JRadioButton(Femal
  e)
• gender.add(maleCheck)
• gender.add(femaleCheck)
• maleCheck.setSelected(true) // only one can be
  true

17
Processing Radio Buttons

• RadioButtonDemo
• Run no images version first in BlueJ
• Simplified version on next slides

18
RadioButtonDemo (1 of 3)

• import java.awt.
• import java.awt.event.
• import javax.swing.
• public class RadioButtonDemo extends JFrame
  implements ActionListener
• private JRadioButton birdButton new
  JRadioButton("Bird")
• private JRadioButton catButton new
  JRadioButton("Cat")
• private JRadioButton dogButton new
  JRadioButton("Dog")
• private JRadioButton rabbitButton new
  JRadioButton("Rabbit")
• private JRadioButton pigButton new
  JRadioButton("Pig")
• private JTextField description new
  JTextField(6)
• public RadioButtonDemo()
• Container frame this.getContentPane()
• // Group the radio buttons.
• ButtonGroup group new ButtonGroup()
• group.add(birdButton)
• group.add(catButton)

19
RadioButtonDemo (2 of 3)

• // Register a listener for the radio buttons.
• birdButton.addActionListener(this)
• catButton.addActionListener(this)
• dogButton.addActionListener(this)
• rabbitButton.addActionListener(this)
• pigButton.addActionListener(this)
• // Put the radio buttons in a column in a
  panel
• JPanel radioPanel new JPanel()
• radioPanel.setLayout(new GridLayout(0, 1))
• radioPanel.add(birdButton)
• radioPanel.add(catButton)
• radioPanel.add(dogButton)
• radioPanel.add(rabbitButton)
• radioPanel.add(pigButton)
• frame.setLayout(new FlowLayout())
• frame.add(radioPanel)
• frame.add(picture)

20
RadioButtonDemo (3 of 3)

• / Listens to the radio buttons. /
• public void actionPerformed(ActionEvent e)
• Object btn e.getSource()
• if (birdButton.isSelected())
• description.setText("BIRD")
• else if (catButton.isSelected())
• description.setText("CAT")
• else if (dogButton.isSelected())
• description.setText("DOG")
• else if (rabbitButton.isSelected())
• description.setText("RABBIT")
• else if (pigButton.isSelected())
• description.setText("PIG")
• // end of actionPerformed method
• // end of RadioButtonDemo class

21
Java BREAK
22
ComboBoxes

• Similar to Radio Buttons
• Allows selection of one of several choices
• Features Beyond Radio Buttons
• Choose text rather than true/false
• Can enter new text at run time
• See next slide then
• run ComboBoxDemo in BlueJ

23
Using a ComboBox

• String choices
• "Chevy",
• "Ford",
• "Jeep",
• "Toyota",
• "Honda"
• JComboBox choiceList new JComboBox(choices)
• choiceList.addActionListener(this)
• choiceList.setEditable(true) // false to
  restrict
• In ActionListener
• JComboBox cb (JComboBox)e.getSource()
• String newSelection (String)cb.getSelectedItem()
  

24
ComboBoxDemo (1 of 4)

• import java.awt.
• import java.awt.event.
• import javax.swing.
• import javax.swing.border.
• import java.util.
• import java.text.
• public class ComboBoxDemo extends JFrame
  implements ActionListener
• JLabel result
• String currentPattern
• String patternExamples
• "dd MMMMM yyyy",
• "dd.MM.yy",
• "MM/dd/yy",
• "yyyy.MM.dd G 'at' hhmmss z",
• "EEE, MMM d, ''yy",
• "hmm a",
• "HmmssSSS",
• "Kmm a,z",

25
ComboBoxDemo (2 of 4)

• public ComboBoxDemo()
• Container frame getContentPane()
• this.setSize(250,150)
• currentPattern patternExamples0
• // Set up the UI for selecting a pattern.
• JLabel patternLabel1 new JLabel("Enter the
  pattern string or")
• JLabel patternLabel2 new JLabel("select one
  from the list")
• JComboBox patternList new
  JComboBox(patternExamples)
• patternList.addActionListener(this)
• patternList.setEditable(true)
• patternList.setAlignmentX(Component.LEFT_ALIGN
  MENT)
• // Create the UI for displaying result
• JLabel resultLabel new JLabel("Current
  Date/Time")
• result new JLabel(" ")

26
ComboBoxDemo (3 of 4)

• // Lay out everything
• JPanel patternPanel new JPanel()
• patternPanel.setLayout(new GridLayout(0,1))
• patternPanel.add(patternLabel1)
• patternPanel.add(patternLabel2)
• patternPanel.add(patternList)
• JPanel resultPanel new JPanel()
• resultPanel.setLayout(new GridLayout(0,1))
• resultPanel.add(resultLabel)
• resultPanel.add(result)
• frame.setLayout(new FlowLayout())
• patternPanel.setAlignmentX(Component.LEFT_ALIG
  NMENT)
• resultPanel.setAlignmentX(Component.LEFT_ALIGN
  MENT)
• frame.add(patternPanel)
• frame.add(resultPanel)
• reformat()

27
ComboBoxDemo (4 of 4)

• / Formats and displays today's date. /
• public void reformat()
• Date today new Date()
• SimpleDateFormat formatter new
  SimpleDateFormat(currentPattern)
• try
• String dateString formatter.format(today)
  
• result.setForeground(Color.black)
• result.setText(dateString)
• catch (IllegalArgumentException iae)
• result.setForeground(Color.red)
• result.setText("Error "
  iae.getMessage())
• // end try/catch
• // end of reformat method
• public void actionPerformed(ActionEvent e)
• JComboBox cb (JComboBox)e.getSource()
• String newSelection (String)cb.getSelectedIt
  em()
• currentPattern newSelection
• reformat()

28
Restaurant Menu

• Check Boxes
• Radio Buttons
• Run in BlueJ
• then look at code

29
Restaurant Menu (1 of 7)

• import java.awt.
• import java.awt.event.
• import javax.swing.
• import java.text.
• /
• Customer Selects Dinner from a Menu
• _at_author Dave Hannay
• _at_version 19 February 2003
• /
• public class Menu extends JFrame
• implements ItemListener
• JPanel p, p2
• JRadioButton radSteak new JRadioButton("Steak"
  ),
• radChicken new
  JRadioButton("Chicken"),
• radTacos new JRadioButton("Tacos"
  ),
• radVeggie new JRadioButton("Veget
  arian")
• JTextField txtChicken new JTextField("9.95",6)
  ,
• txtVeggie new JTextField("12.95",6)
  ,
• txtSteak new JTextField("14.95",6),
  

30
Restaurant Menu (2 of 7)

• JCheckBox chkSoup new JCheckBox("Soup"),
• chkSalad new JCheckBox("Salad"),
• chkBeverage new JCheckBox("Beverage"
  ),
• chkDessert new JCheckBox("Dessert")
  
• JTextField txtSoup new JTextField("2.50",6),
• txtSalad new JTextField("3.00",6),
• txtBeverage new JTextField("1.99",6
  ),
• txtDessert new JTextField("5.50",6)
  
• JLabel lblTotal new JLabel("Total Bill Comes
  Out Here!")
• double mainCourse 0.00,
• soup 0.00,
• salad 0.00,
• beverage 0.00,
• dessert 0.00,
• totalBill 0.00
• NumberFormat currency
  NumberFormat.getCurrencyInstance()

31
Restaurant Menu (3 of 7)

• public Menu()
• setTitle("Chez UpperClass")
• setFont(new Font("Helvetica", Font.BOLD,
  14))
• Container frame this.getContentPane()
• ButtonGroup grpEntree new ButtonGroup()
• grpEntree.add(radChicken)
• grpEntree.add(radSteak)
• grpEntree.add(radTacos)
• grpEntree.add(radVeggie)
• frame.setLayout(new GridLayout(8, 1))
• pan new JPanel()
• pan.add(new JLabel(
• "Select one Main Course, add
  Soup/Salad/Beverage/Dessert"))
• frame.add(pan)

32
Restaurant Menu (4 of 7)

• pan new JPanel()
• pan.add(radChicken) pan.add(txtChicken)
• frame.add(pan)
• pan new JPanel()
• pan.add(radVeggie) pan.add(txtVeggie)
• frame.add(pan)
• pan new JPanel()
• pan.add(radSteak) pan.add(txtSteak)
• frame.add(pan)
• pan new JPanel()
• pan.add(radTacos) pan.add(txtTacos)
• frame.add(pan)
• pan new JPanel()
• pan.add(chkSoup) pan.add(txtSoup)
• pan.add(chkSalad) pan.add(txtSalad)
• frame.add(pan)
• pan new JPanel()
• pan.add(chkBeverage) pan.add(txtBeverage)
• pan.add(chkDessert) pan.add(txtDessert)

33
Restaurant Menu (5 of 7)

• // Register the Component Listener
• radChicken.addActionListener(this)
• radVeggie.addActionListener(this)
• radSteak.addActionListener(this)
• radTacos.addActionListener(this)
• chkSoup.addItemListener(this)
• chkSalad.addItemListener(this)
• chkBeverage.addItemListener(this)
• chkDessert.addItemListener(this)
• // end of Menu constructor
• // Respond to Action/Item Events clicking on
  buttons
• public void actionPerformed (ActionEvent e)
• JRadioButton choice (JRadioButton)(e.getSour
  ce())
• if (choiceradChicken)
• mainCourse Double.parseDouble(txtChicken.g
  etText())
• if (choiceradSteak)
• mainCourse Double.parseDouble(txtSteak.get
  Text())
• if (choiceradVeggie)
• mainCourse Double.parseDouble(txtVeggie.ge
  tText())

34
Restaurant Menu (6 of 7)

• public void itemStateChanged (ItemEvent e)
• JCheckBox box (JCheckBox) (e.getSource())
• if (boxchkSoup)
• if (box.isSelected())
• soup Double.parseDouble(txtSoup.getText(
  ))
• else
• soup 0.00
• if (boxchkSalad)
• if (box.isSelected())
• salad Double.parseDouble(txtSalad.getTex
  t())
• else
• salad 0.00
• if (boxchkBeverage)
• if (box.isSelected())
• beverage Double.parseDouble(txtBeverage.
  getText())
• else
• beverage 0.00
• if (boxchkDessert)
• if (box.isSelected())

35
Restaurant Menu (7 of 7)

• private void setTotal()
• totalBill mainCourse
• soup
• salad
• beverage
• dessert
• lblTotal.setText("Total (before Tax and Tip)
  "
• currency.format(totalBill)
  )
• // end of setTotal method
• // end of Menu class

36
Virtual Whiteboard (1 of 3)Combining
RadioButtons with Drawing

• import javax.swing.
• import java.awt.event.
• import java.awt.
• // Dave Hannay 2/25/2004
• class Whiteboard extends JPanel
• implements MouseMotionListener
  
• JRadioButton radRed new JRadioButton("Red")
• JRadioButton radGreen new JRadioButton("Green"
  )
• JRadioButton radBlue new JRadioButton("Blue")
  
• JRadioButton radBlack new JRadioButton("Black"
  )
• ButtonGroup colorGroup new ButtonGroup()
• JPanel theButtons new JPanel()
• JPanel board new JPanel()
• Point start new Point()

37
Virtual Whiteboard (2 of 3)

• public Whiteboard()
• setLayout(new BorderLayout())
• radRed.setBackground(Color.RED)
• radGreen.setBackground(Color.GREEN)
• radBlue.setBackground(Color.BLUE)
• radBlack.setBackground(Color.BLACK)
• radBlue.setForeground(Color.WHITE)
• radBlack.setForeground(Color.WHITE)
• radBlack.setSelected(true)
• theButtons.add(radRed)
• theButtons.add(radGreen)
• theButtons.add(radBlue)
• theButtons.add(radBlack)
• colorGroup.add(radRed)
• colorGroup.add(radGreen)
• colorGroup.add(radBlue)
• colorGroup.add(radBlack)
• add(theButtons, BorderLayout.SOUTH)
• board.setPreferredSize(new Dimension(400,
  400))

38
Virtual Whiteboard (3 of 3)

• public void mouseDragged(MouseEvent e)
• int x e.getX(), y e.getY()
• Graphics g board.getGraphics()
• if (radRed.isSelected())
• g.setColor(Color.RED)
• else if (radGreen.isSelected())
• g.setColor(Color.GREEN)
• else if (radBlue.isSelected())
• g.setColor(Color.BLUE)
• else if (radBlack.isSelected())
• g.setColor(Color.BLACK)
• g.fillOval(x,y,5,5)
• g.dispose()
• waitAWhile(5)
• // end of mouseDragged method
• public void mouseMoved(MouseEvent e)
• // end of Whiteboard class

39
To the Computers...(may take 20 minutes)

• Try the Whiteboard program
• Drag from course folder to desktop
• Add an Erase button
• see ColorfulDots for how to implement it if you
  need help
• Convert the RadioButtons in Restaurant to
  JComboBox
• Will need to replace 4 textFields with one for
  price based on which Main Course was selected
• Can use cboEntrees.getSelectedItem() for index to
  use in array of prices

40
Java BREAK