1. SD2054 Software Development

3. By the end of this lecture you should be able to: Advanced Graphics Programming create pull down menus create combo boxes create option dialogues create message dialogues create input dialogues create confirm dialogues.

4. import javax.swing.*;

5. Making choices pull-down menus combo boxes

6. Pull-down menus

12. JFrame

13. public class Flag extends JFrame implements ActionListener { }

14. Declare menu components as attributes of the Flag class

16. JMenuBar

17. private JMenuBar bar = new JMenuBar();

19. JMenu

20. private JMenu topStripeMenu = new JMenu("Top Colour");

22. private JMenu middleStripeMenu = new JMenu(“Middle Colour");

24. private JMenu bottomStripeMenu = new JMenu(“Bottom Colour");

26. JMenuItem

27. private JMenuItem blueStripe = new JMenuItem("Blue");

29. private JMenuItem redStripe = new JMenuItem(“Red");

30. Assemble menu components onto the screen in the Constructor

31. public Flag( ) { setVisible(true); }

32. First, add menu-items …..

33. … to menu

34. blueStripe

35. topStripeMenu blueStripe

36. topStripeMenu.add(blueStripe); topStripeMenu blueStripe

37. topStripeMenu redStripe

38. topStripeMenu redStripe topStripeMenu.add(redStripe);

39. Then, add menu …..

40. … to menu-bar

41. bar

42. topStripeMenu bar

43. topStripeMenu bar bar.add(topStripeMenu);

44. Finally, add menu-bar …..

45. …. to frame

46. bar

47. setJMenuBar(bar);

48. Processing menu choices…..

49. ..first, give each menu item a listener in the constructor.

50. blueStripe

51. blueStripe.addActionListener(this);

52. ..then write the code to process a menu item in the actionPerformed method.

53. blueStripe public void actionPerformed(ActionEvent e) { }

54. public void actionPerformed(ActionEvent e) { } if (e.getSource() == blueStripe) { // code to process menu choice here }

55. JPanel public void actionPerformed(ActionEvent e) { } if (e.getSource() == blueStripe) { // code to process menu choice here }

56. topPanel public void actionPerformed(ActionEvent e) { } if (e.getSource() == blueStripe) { // code to process menu choice here }

57. topPanel public void actionPerformed(ActionEvent e) { } if (e.getSource() == blueStripe) { topPanel.setBackground(Color.blue); }

58. public void actionPerformed(ActionEvent e) { } if (e.getSource() == blueStripe) { topPanel.setBackground(Color.blue); }

59. The JComboBox class

61. private String[ ] colours = {"Select colour","Red", "Blue", "Green"}; private JComboBox box = new JComboBox(colours);

62. box.addActionListener(this);

63. String item = box.getSelectedItem();

64. String item = box.getSelectedItem();

65. String item = (String) box.getSelectedItem();

67. if (item.equals("Red")) { getContentPane().setBackground(Color.red); }

68. if (item.equals("Red")) { getContentPane().setBackground(Color.red); }

69. box.setSelectedIndex(0);

70. box.setSelectedIndex(0);

71. The JOption Class creating option dialogues creating message dialogues creating input dialogues creating confirm dialogues.

72. The JOptionPane dialogue class

73. Option Dialogue

78. String[ ] choice = {"Enter a word", "Find the secret", "Quit"};

79. String[ ] choice = {"Enter a word", "Find the secret", "Quit"};

80. result = JOptionPane.showOptionDialog (null, "Choose an option", "Magic Words", JOptionPane.DEFAULT_OPTION, JOptionPane.PLAIN_MESSAGE, null, choice, "Enter a word");

81. result = JOptionPane.showOptionDialog (null, "Choose an option", "Magic Words", JOptionPane.DEFAULT_OPTION, JOptionPane.PLAIN_MESSAGE, null, choice, "Enter a word");

82. result = JOptionPane.showOptionDialog (null, "Choose an option", "Magic Words", JOptionPane.DEFAULT_OPTION, JOptionPane.PLAIN_MESSAGE, null, choice, "Enter a word"); indicates no parent frame

83. result = JOptionPane.showOptionDialog (null, "Choose an option", "Magic Words", JOptionPane.DEFAULT_OPTION, JOptionPane.PLAIN_MESSAGE, null, choice, "Enter a word"); Could use the this keyword if there is a parent frame.

84. result = JOptionPane.showOptionDialog (null, "Choose an option", "Magic Words", JOptionPane.DEFAULT_OPTION, JOptionPane.PLAIN_MESSAGE, null, choice, "Enter a word");

85. result = JOptionPane.showOptionDialog (null, "Choose an option", "Magic Words", JOptionPane.DEFAULT_OPTION, JOptionPane.PLAIN_MESSAGE, null, choice, "Enter a word");

86. result = JOptionPane.showOptionDialog (null, "Choose an option", "Magic Words", JOptionPane.DEFAULT_OPTION, JOptionPane.PLAIN_MESSAGE, null, choice, "Enter a word");

87. result = JOptionPane.showOptionDialog (null, "Choose an option", "Magic Words", JOptionPane.DEFAULT_OPTION, JOptionPane.PLAIN_MESSAGE, null, choice, "Enter a word");

88. result = JOptionPane.showOptionDialog (null, "Choose an option", "Magic Words", JOptionPane.DEFAULT_OPTION, JOptionPane.PLAIN_MESSAGE, null, choice, "Enter a word");

89. result = JOptionPane.showOptionDialog (null, "Choose an option", "Magic Words", JOptionPane.DEFAULT_OPTION, JOptionPane.PLAIN_MESSAGE, null, choice, "Enter a word"); or an icon of your choice

90. result = JOptionPane.showOptionDialog (null, "Choose an option", "Magic Words", JOptionPane.DEFAULT_OPTION, JOptionPane.PLAIN_MESSAGE, null, choice, "Enter a word");

91. result = JOptionPane.showOptionDialog (null, "Choose an option", "Magic Words", JOptionPane.DEFAULT_OPTION, JOptionPane.PLAIN_MESSAGE, null, choice, "Enter a word");

92. result = JOptionPane.showOptionDialog (null, "Choose an option", "Magic Words", JOptionPane.DEFAULT_OPTION, JOptionPane.PLAIN_MESSAGE, null, choice, "Enter a word");

93. result = JOptionPane.showOptionDialog (null, "Choose an option", "Magic Words", JOptionPane.DEFAULT_OPTION, JOptionPane.PLAIN_MESSAGE, null, choice, "Enter a word"); 0 = button 1 1 = button 2 2 = button 3

94. The JOptionPane dialogue class

95. Input Dialogue

97. word = JOptionPane.showInputDialog (null, "Enter a word", null, JOptionPane.PLAIN_MESSAGE);

98. word = JOptionPane.showInputDialog (null, "Enter a word", null, JOptionPane.PLAIN_MESSAGE);

99. word = JOptionPane.showInputDialog (null, "Enter a word", null, JOptionPane.PLAIN_MESSAGE);

100. word = JOptionPane.showInputDialog (null, "Enter a word", null, JOptionPane.PLAIN_MESSAGE);

101. word = JOptionPane.showInputDialog (null, "Enter a word", null, JOptionPane.PLAIN_MESSAGE);

102. word = JOptionPane.showInputDialog (null, "Enter a word", null, JOptionPane.PLAIN_MESSAGE);

103. The JOptionPane dialogue class

104. Message Dialogue

106. JOptionPane.showMessageDialog (null, “You did not enter a magic word”, null, JOptionPane.INFORMATION_MESSAGE);

107. JOptionPane.showMessageDialog (null, “You did not enter a magic word”, null, JOptionPane.INFORMATION_MESSAGE);

108. JOptionPane.showMessageDialog (null, “You did not enter a magic word”, null, JOptionPane.INFORMATION_MESSAGE);

109. JOptionPane.showMessageDialog (null, “You did not enter a word”, null, JOptionPane.INFORMATION_MESSAGE);

110. JOptionPane.showMessageDialog (null, “You did not enter a word”, null, JOptionPane.INFORMATION_MESSAGE);

111. JOptionPane.showMessageDialog (null, “You did not enter a word”, null, JOptionPane.ERROR_MESSAGE);

112. The JOptionPane dialogue class

113. Confirm Dialogue

114. answer = JOptionPane.showConfirmDialog (null, "Are you sure you want to know the secret?", null, JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE);

115. answer = JOptionPane.showConfirmDialog (null, "Are you sure you want to know the secret?", null, JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE);

116. answer = JOptionPane.showConfirmDialog (null, "Are you sure you want to know the secret?", null, JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE);

117. answer = JOptionPane.showConfirmDialog (null, "Are you sure you want to know the secret?", null, JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE);

118. answer = JOptionPane.showConfirmDialog (null, "Are you sure you want to know the secret?", null, JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE);

119. if(answer == JOptionPane.YES_OPTION) { // process choice here }