Swing Interfaces with Sorting and Searching - Java Programming: Comprehensive Concepts and Techniques - page 453

Naming Menu Components
Use the prefix, mnu, in the variable name for menu components.
Follow the prefix with the Menu's location and a keyword. For
example, the Copy command on the Edit menu might be named
mnuEditCopy.

Creating the Content Pane
You learned earlier that a content pane is a special-purpose container similar to
a Panel. Content panes hold individual components and are added to and,
therefore, contained by the JFrame. Many programmers and developers write a
method to create the content pane to prevent its components from being con-
fused with another part of the program.

Coding the createContentPane() Method

The createContentPane() method accepts no arguments, but it returns a
Container object. Container is the superclass for all containers in the API. Inside
the Classics on DVD program content pane, there will be a JPanel in the north
with a JComboBox and JLabel, and a JPanel in the center with a JTextPane and
JScrollPane.
Figure 7-19 displays the code for the createContentPane() method.

94 //create the content pane

95 public Container createContentPane ()

96 {

97 //populate the JComboBox

98 fieldCombo.addItem ( "Title" ) ;

99 fieldCombo.addItem ( "Studio" ) ;

100 fieldCombo.addItem ( "Year" ) ;

101 fieldCombo.addActionListener ( this ) ;

102 fieldCombo.setToolTipText ( "Click the drop-down arrow to display sort fields." ) ;

103
104 //construct and populate the north panel

105 JPanel northPanel = new JPanel () ;

106 northPanel.setLayout ( new FlowLayout ()) ;

107 northPanel.add ( sortPrompt ) ;

108 northPanel.add ( fieldCombo ) ;

109
110 //create the JTextPane and center panel

111 JPanel centerPanel = new JPanel () ;

112 setTabsAndStyles ( textPane ) ;

113 textPane = addTextToTextPane () ;

114 JScrollPane scrollPane = new JScrollPane ( textPane ) ;

115 scrollPane.setVerticalScrollBarPolicy ( JScrollPane.VERTICAL_SCROLLBAR_ALWAYS ) ;

116 scrollPane.setPreferredSize ( new Dimension ( 500, 200 )) ;

117 centerPanel.add ( scrollPane ) ;

118
119 //create Container and set attributes

120 Container c = getContentPane () ;

121 c.setLayout ( new BorderLayout ( 10,10 )) ;

122 c.add ( northPanel, BorderLayout .NORTH ) ;

123 c.add ( centerPanel, BorderLayout .CENTER ) ;

124
125 return c;

126 }

127

FIGURE 7-19