Java Handout For Java Lab 4: JTree Help | CS 402, Study notes of Computer Science

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Java Handout For Java Lab

JTree Help

How to Use JTree

• Step 1: Create tree nodes DefaultMutableTreeNode nba = new DefaultMutableTreeNode("National BasketBall Association"); DefaultMutableTreeNode westConf = new DefaultMutableTreeNode("Western Conference");
• Step 2: Group the nodes (parent add children ) nba.add(westConf);
• Step 3: Construct the tree JTree tree = new JTree(nba);

JMenuBar

javax.swing.JmenuBar public class JMenuBar extends JComponent

Ex. JMenuBar menuBar = new JMenuBar(); setJMenuBar(menuBar);

JMenu

javax.swing.JMenu public class JMenu extends JMenuItem

Ex. JMenu fileMenu = new JMenu("File"); menuBar.add(fileMenu);

JPanel

javax.swing.Jpanel public class JPanel extends JComponent

Ex. JPanel textPanel = new JPanel(); getContentPane().add(textPanel, BorderLayout.SOUTH);

JTextField

javax.swing.JtextField public class JTextField extends JTextComponent

Ex. JTextField textField = new JTextField(40); textField.setText( "TEXT FIELD " );

JTree

javax.swing.Jtree public class JTree extends Jcomponent void addTreeSelectionListener(TreeSelectionListener tsl) // Adds a listener for TreeSelection events.

Ex. JTree tree = new JTree( root ); // DefaultMutableTreeNode root tree.addTreeSelectionListener (new MyTreeSelectionListener());

TreeSelectionListener

javax.swing.event public interface TreeSelectionListener extends EventListener

Ex. class MyTreeSelectionListener implements TreeSelectionListener { public void valueChanged (TreeSelectionEvent e) { TreePath path = e.getPath(); … if (path.getPathCount() > 3) textField.setText( path.getLastPathComponent() + " Wins = " + s1 + "; Losses = " + s2); else textField.setText( " " ); } // end of valueChanged } // end of MyTreeSelectionListener

JScrollPane

javax.swing.JScrollPane public class JScrollPane extends JComponent Ex. JPanel treePanel = new JPanel(); JTree tree = new JTree( root ); JScrollPane sp = new JScrollPane(tree); treePanel.add(sp, BorderLayout.CENTER);

NBA JTree