Understanding Abstract Classes and Interfaces - Java Programming: Comprehensive Concepts and Techniques - page 649

57 // Define components for panel 3

58 JLabel label3 = new JLabel ( "User name: " +user.getName ()) ;

59 jbtLogout = new JButton ( "Log out" ) ;

60
61 JPanel p3= new JPanel () ;

62 p3.setLayout ( new GridLayout ( 1,2 )) ;

63 p3.add ( label3 ) ;

64 p3.add ( jbtLogout ) ;

65 p3.setBorder ( new TitledBorder ( "Current user" )) ;

66
67

// Use nested panels for positioning

68 JPanel p4= new JPanel () ;

69 p4.setLayout ( new GridLayout ( 3,1,10,5 )) ; // rows, cols, hgap, vgap

70 p4.add ( p1 ) ;

71 p4.add ( p2 ) ;

72 p4.add ( p3 ) ;

73
74 JPanel p5 = new JPanel ( new BorderLayout ( 10,10 )) ;

75 p5.add ( p4, BorderLayout .WEST ) ;

76 JPanel p6 = new JPanel ( new BorderLayout ( 10,10 )) ;

77 p6.add ( p5, BorderLayout .EAST ) ;

78
79 setContentPane ( p6 ) ;

80
81 // Register listeners

82 addWindowListener ( this ) ;

83 jbtAddStock.addActionListener ( this ) ;

84 jbtLogout.addActionListener ( this ) ;

85 jcbStockList.addActionListener ( this ) ;

86
87

// Prepare for display

88 pack () ;

89 if ( width < getWidth ()) // prevent setting width too small

90 width = getWidth () ;

91 if ( height < getHeight ()) // prevent setting height too small

92 height = getHeight () ;

93 centerOnScreen ( width, height ) ;

94 jtfStockSymbol.setText ( "" ) ;

95 jtfStockSymbol.requestFocus () ;

96 }

97
98 public void centerOnScreen ( int width, int height )

99 {

100 int top, left, x, y;

101
102

// Get the screen dimension

103 Dimension screenSize = Toolkit .getDefaultToolkit () .getScreenSize () ;

104
105 // Determine the location for the top left corner of the frame

106 x = ( screenSize.width - width ) /2;

107 y = ( screenSize.height - height ) /2;

108 left = ( x<0 ) ?0:x;

109 top = ( y<0 ) ?0:y;

110
111

this .setBounds ( left, top, width, height ) ;

112 }

113
114

public boolean stockInList ( String stock )

115 {

116 boolean inList = false ;

117 int numItems;

118
119

numItems = jcbStockList.getItemCount () ;

120
121

stock.trim () ; // remove any leading, trailing white space

122

FIGURE 10-41

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