JTabbedPane
A JTabbedPane arranges GUI components into layers in which only one layer is visible at a time. Users access each layer via a tabsimilar to folders in a file cabinet. When the user clicks a tab, the appropriate layer is displayed. The tabs appear at the top by default but also can be positioned at the left, right or bottom of the JTabbedPane. Any component can be placed on a tab. If the component is a container, such as a panel, it can use any layout manager to lay out several components on the tab. Class JTabbedPane is a subclass of JComponent. The application in Fig. 22.13 and Fig. 22.14 creates one tabbed pane with three tabs. Each tab displays one of the JPanelspanel1, panel2 or panel3.
Figure 22.13. JTabbedPane used to organize GUI components.
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1 // Fig. 22.13: JTabbedPaneFrame.java 2 // Demonstrating JTabbedPane. 3 import java.awt.BorderLayout; 4 import java.awt.Color; 5 import javax.swing.JFrame; 6 import javax.swing.JTabbedPane; 7 import javax.swing.JLabel; 8 import javax.swing.JPanel; 9 import javax.swing.JButton; 10 import javax.swing.SwingConstants; 11 12 public class JTabbedPaneFrame extends JFrame 13 { 14 // set up GUI 15 public JTabbedPaneFrame() 16 { 17 super( "JTabbedPane Demo " ); 18 19 JTabbedPane tabbedPane = new JTabbedPane(); // create JTabbedPane 20 21 // set up pane11 and add it to JTabbedPane 22 JLabel label1 = new JLabel( "panel one", SwingConstants.CENTER ); 23 JPanel panel1 = new JPanel(); // create first panel 24 panel1.add( label1 ); // add label to panel 25 tabbedPane.addTab( "Tab One", null, panel1, "First Panel" ); 26 27 // set up panel2 and add it to JTabbedPane 28 JLabel label2 = new JLabel( "panel two", SwingConstants.CENTER ); 29 JPanel panel2 = new JPanel(); // create second panel 30 panel2.setBackground( Color.YELLOW ); // set background to yellow 31 panel2.add( label2 ); // add label to panel 32 tabbedPane.addTab( "Tab Two", null, panel2, "Second Panel" ); 33 34 // set up panel3 and add it to JTabbedPane 35 JLabel label3 = new JLabel( "panel three" ); 36 JPanel panel3 = new JPanel(); // create third panel 37 panel3.setLayout( new BorderLayout() ); // use borderlayout 38 panel3.add( new JButton( "North" ), BorderLayout.NORTH ); 39 panel3.add( new JButton( "West" ), BorderLayout.WEST ); 40 panel3.add( new JButton( "East" ), BorderLayout.EAST ); 41 panel3.add( new JButton( "South" ), BorderLayout.SOUTH ); 42 panel3.add( label3, BorderLayout.CENTER ); 43 tabbedPane.addTab( "Tab Three", null, panel3, "Third Panel" ); 44 45 add( tabbedPane ); // add JTabbedPane to frame 46 } // end JTabbedPaneFrame constructor 47 } // end class JTabbedPaneFrame |
Figure 22.14. Test class for JTabbedPaneFrame.
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1 // Fig. 22.14: JTabbedPaneDemo.java 2 // Demonstrating JTabbedPane. 3 import javax.swing.JFrame; 4 5 public class JTabbedPaneDemo 6 { 7 public static void main( String args[] ) 8 { 9 JTabbedPaneFrame tabbedPaneFrame = new JTabbedPaneFrame(); 10 tabbedPaneFrame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); 11 tabbedPaneFrame.setSize( 250, 200 ); // set frame size 12 tabbedPaneFrame.setVisible( true ); // display frame 13 } // end main 14 } // end class JTabbedPaneDemo
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The constructor (lines 1546) builds the GUI. Line 19 creates an empty JTabbedPane with default settingsthat is, tabs across the top. If the tabs do not fit on one line, they will wrap to form additional lines of tabs. Next the constructor creates the JPanels panel1, panel2 and panel3 and their GUI components. As we set up each panel, we add it to tabbedPane, using JTabbedPane method addTab with four arguments. The first argument is a string that specifies the title of the tab. The second argument is an Icon reference that specifies an icon to display on the tab. If the Icon is a null reference, no image is displayed. The third argument is a Component reference that represents the GUI component to display when the user clicks the tab. The last argument is a string that specifies the tool tip for the tab. For example, line 25 adds JPanel panel1 to tabbedPane with title "Tab One" and the tool tip "First Panel". JPanels panel2 and panel3 are added to tabbedPane at lines 32 and 43. To view a tab, click it with the mouse or use the arrow keys to cycle through the tab=.