1. Advanced GUIs and Graphics
Java Programming: From Problem Analysis to Program Design, 3e Chapter 13
Advanced GUIs and Graphics

2. Chapter Objectives Learn about applets Explore the class Graphics
Learn about the class Font
Explore the class Color
Java Programming: From Problem Analysis to Program Design, 3e

3. Chapter Objectives (continued)
Learn to use additional Layout managers
Become familiar with more GUI components
Learn how to create menu-based programs
Explore how to handle key and mouse events
Java Programming: From Problem Analysis to Program Design, 3e

4. Inheritance Hierarchy of GUI Classes
Java Programming: From Problem Analysis to Program Design, 3e

5. Constructors and Methods of the class Component
Java Programming: From Problem Analysis to Program Design, 3e

6. Constructors and Methods of the class Component (continued)
Java Programming: From Problem Analysis to Program Design, 3e

7. Constructors and Methods of the class Component (continued)
Java Programming: From Problem Analysis to Program Design, 3e

8. Constructors and Methods of the class Component (continued)
Java Programming: From Problem Analysis to Program Design, 3e

9. Constructors and Methods of the class Container
Java Programming: From Problem Analysis to Program Design, 3e

10. Applets
Applet: a Java program that is embedded within a Web page and executed by a Web browser
Create an applet by extending the class JApplet
class JApplet contained in package javax.swing
Java Programming: From Problem Analysis to Program Design, 3e

11. Members of class JApplet
Java Programming: From Problem Analysis to Program Design, 3e

12. Members of class Japplet (continued)
Java Programming: From Problem Analysis to Program Design, 3e

13. Applets (continued) No main method
Methods init, start, and paint guaranteed to be invoked in sequence
To develop an applet
Override any/all of the methods above
Java Programming: From Problem Analysis to Program Design, 3e

14. Applet Methods init Method paint Method Initializes variables
Gets data from user
Places various GUI components
paint Method
Performs output
Java Programming: From Problem Analysis to Program Design, 3e

15. Skeleton of a Java Applet
import java.awt.Graphics;
import javax.swing.JApplet;
public class WelcomeApplet extends JApplet { }
Java Programming: From Problem Analysis to Program Design, 3e

16. Applet Displaying Welcome Message
//Welcome Applet
import java.awt.Graphics;
import javax.swing.JApplet;
public class WelcomeApplet extends JApplet {
public void paint(Graphics g)
super.paint(g); //Line 1
g.drawString("Welcome to Java Programming" ,
30, 30); //Line 2 }
Java Programming: From Problem Analysis to Program Design, 3e

17. HTML to Run Applet
Java Programming: From Problem Analysis to Program Design, 3e

18. class Font Shows text in different fonts Contained in package java.awt
Available fonts
Serif/SanSerif
Monospaced
Dialog/DialogInput
Arguments for constructor
String specifying the Font face name
int value specifying Font style
int value specifying Font size
Expressed in points (72 points = 1 inch)
Java Programming: From Problem Analysis to Program Design, 3e

19. Constructors and Methods of the class Font
Java Programming: From Problem Analysis to Program Design, 3e

20. Constructors and Methods of the class Font (continued)
Java Programming: From Problem Analysis to Program Design, 3e

21. Constructors and Methods of the class Font (continued)
Java Programming: From Problem Analysis to Program Design, 3e

22. class Color Shows text in different colors
Changes background color of component
Contained in package java.awt
Java Programming: From Problem Analysis to Program Design, 3e

23. Constructors of the class Color
Java Programming: From Problem Analysis to Program Design, 3e

24. Constructors of the class Color (continued)
Java Programming: From Problem Analysis to Program Design, 3e

25. Constants Defined in the class Color
Java Programming: From Problem Analysis to Program Design, 3e

26. Constants Defined in the class Color (continued)
Java Programming: From Problem Analysis to Program Design, 3e

27. Constants Defined in the class Color (continued)
Java Programming: From Problem Analysis to Program Design, 3e

28. class Graphics
Provides methods for drawing items such as lines, ovals, and rectangles on the screen
Contains methods to set the properties of graphic elements including clipping area, fonts, and colors
Contained in the package java.awt
Java Programming: From Problem Analysis to Program Design, 3e

29. Constructors and Methods of the class Graphics
Java Programming: From Problem Analysis to Program Design, 3e

30. Constructors and Methods of the class Graphics (continued)
Java Programming: From Problem Analysis to Program Design, 3e

31. Constructors and Methods of the class Graphics (continued)
Java Programming: From Problem Analysis to Program Design, 3e

32. Constructors and Methods of the class Graphics (continued)
Java Programming: From Problem Analysis to Program Design, 3e

33. Constructors and Methods of the class Graphics (continued)
Java Programming: From Problem Analysis to Program Design, 3e

34. Constructors and Methods of the class Graphics (continued)
Java Programming: From Problem Analysis to Program Design, 3e

35. Constructors and Methods of the class Graphics (continued)
Java Programming: From Problem Analysis to Program Design, 3e

36. Constructors and Methods of the class Graphics (continued)
Java Programming: From Problem Analysis to Program Design, 3e

37. Differences Between Applets and GUI Applications
Derived from JApplet
No main method
Uses init method
Displayed by HTML
Sets title in HTML
Size set in HTML
Applet closes when HTML doc closes
GUI applications
class extends JFrame
Invokes main method
Uses constructors
Uses method setVisible
Uses setTitle method
Uses method setSize
Closes with Exit button
Java Programming: From Problem Analysis to Program Design, 3e

38. Converting a GUI Application to an Applet
Change JFrame to JApplet
Change constructor to method init
Remove method calls such as setVisible, setTitle, setSize
Remove the method main
If applicable, remove Exit button/all code associated with it (e.g. action listener)
Java Programming: From Problem Analysis to Program Design, 3e

39. Additional GUI Components
JTextArea
JCheckBox
JRadioButton
JComboBox
JList
Java Programming: From Problem Analysis to Program Design, 3e

40. JTextArea Can collect multiple lines of input from user
Can display multiple lines of output
Pressing Enter key separates lines of text
Each line ends with newline character ‘\n’
Derived from class JTextComponent
Java Programming: From Problem Analysis to Program Design, 3e

41. JTextArea (continued)
Java Programming: From Problem Analysis to Program Design, 3e

42. Methods Inherited by class JTextArea from Parent class JTextComponent
Java Programming: From Problem Analysis to Program Design, 3e

43. JTextArea Example
Java Programming: From Problem Analysis to Program Design, 3e

44. JCheckBox User selects from predefined values
Example of a toggle button
Clicking JCheckBox generates item event
Use interface ItemListener and its abstract method itemStateChanged to handle event
Java Programming: From Problem Analysis to Program Design, 3e

45. Constructors and Methods of class JCheckBox
Java Programming: From Problem Analysis to Program Design, 3e

46. Constructors and Methods of class JCheckBox (continued)
Java Programming: From Problem Analysis to Program Design, 3e

47. Constructors and Methods of class JCheckBox (continued)
Java Programming: From Problem Analysis to Program Design, 3e

48. Constructors and Methods of class JCheckBox (continued)
Java Programming: From Problem Analysis to Program Design, 3e

49. JRadioButton Created same way as check boxes
Placed in content pane of applet
Forces user to select only one radio button at a time
You create a button group to group radio buttons
Generates an ItemEvent
interface ItemListener and method itemStateChanged used to handle events
Java Programming: From Problem Analysis to Program Design, 3e

50. JRadioButton (continued)
Java Programming: From Problem Analysis to Program Design, 3e

51. JRadioButton (continued)
Java Programming: From Problem Analysis to Program Design, 3e

52. JRadioButton (continued)
Java Programming: From Problem Analysis to Program Design, 3e

53. JRadioButton (continued)
Java Programming: From Problem Analysis to Program Design, 3e

54. JComboBox Commonly known as a drop-down list
Used to select an item from a list of possibilities
Generates an ItemEvent
Event monitored by ItemListener
ItemListener invokes method itemStateChanged
Java Programming: From Problem Analysis to Program Design, 3e

55. Constructors of class JComboBox
Java Programming: From Problem Analysis to Program Design, 3e

56. Applet with JCheckBox, JComboBox, and JRadioButton
Java Programming: From Problem Analysis to Program Design, 3e

57. Constructors of class JList
Java Programming: From Problem Analysis to Program Design, 3e

58. Constructors of class Jlist (continued)
Java Programming: From Problem Analysis to Program Design, 3e

59. Constructors of class Jlist (continued)
Java Programming: From Problem Analysis to Program Design, 3e

60. Layout Managers FlowLayout GridLayout Default layout manager
Places components from left to right, center by default, until no more items can be placed
Can align each line left, center, or right
Default alignment: LEFT
GridLayout
Similar to FlowLayout
All rows (columns) have same number of components
All components have the same size
Java Programming: From Problem Analysis to Program Design, 3e

61. Layout Managers (continued)
BorderLayout
Items placed into one of 5 specific regions
NORTH/SOUTH
EAST/WEST
CENTER
NORTH and SOUTH components extend horizontally (completely span one edge to the other)
EAST and WEST components extend vertically between components in NORTH and SOUTH regions
CENTER component expands to occupy any unused regions
Java Programming: From Problem Analysis to Program Design, 3e

62. Menus
Allow for various functions without cluttering GUI with too many components
Can be attached to objects such as JFrame and JApplet (setJMenuBar method)
To set a menu bar
private JMenuBar menuMB =
new JMenuBar();
setJMenuBar(menuMB);
Add menus to menu bar; add menu items to menu
Order of menus added = Order of appearance
Java Programming: From Problem Analysis to Program Design, 3e

63. Key and Mouse Events
Java Programming: From Problem Analysis to Program Design, 3e

64. Chapter Summary Creating Applets class Font class Graphics class Color
Differences between Applet and GUI application
Converting GUI application to Applet
Java Programming: From Problem Analysis to Program Design, 3e

65. Chapter Summary (continued)
GUI components
JTextArea
JCheckBox
JRadioButton
Layout managers
Menus
Key and mouse events
Java Programming: From Problem Analysis to Program Design, 3e