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swing:jtree_demo_01

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swing:jtree_demo_01 [2015/05/18 02:44]
 swing:jtree_demo_01 [2015/05/18 03:44]
gthanos
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 +====== TreeDemo ======
  
 +Για την ορθή εκτέλεση του παρακάτω παραδείγματος θα χρειαστείτε και αυτά τα αρχεία html {{:swing:html.zip|}}.
 +
 +<code java TreeDemo.java>
 +package components;
 +/**
 + * This application that requires the following additional files:
 + *   TreeDemoHelp.html
 + *  arnold.html
 + *  bloch.html
 + *  chan.html
 + *  jls.html
 + *  swingtutorial.html
 + *  tutorial.html
 + *  tutorialcont.html
 + *  vm.html
 + */
 +import javax.swing.JEditorPane;
 +import javax.swing.JFrame;
 +import javax.swing.JPanel;
 +import javax.swing.JScrollPane;
 +import javax.swing.JSplitPane;
 +import javax.swing.UIManager;
 +
 +import javax.swing.JTree;
 +import javax.swing.tree.DefaultMutableTreeNode;
 +import javax.swing.tree.TreeSelectionModel;
 +import javax.swing.event.TreeSelectionEvent;
 +import javax.swing.event.TreeSelectionListener;
 +import javax.swing.event.*;
 +
 +import java.net.URL;
 +import java.io.IOException;
 +import java.awt.Dimension;
 +import java.awt.GridLayout;
 +
 +public class TreeDemo extends JPanel
 +            implements TreeSelectionListener {
 +  private JEditorPane htmlPane;
 +  private JTree tree;
 +  private URL helpURL;
 +  private static boolean DEBUG = false;
 +
 +  //Optionally play with line styles.  Possible values are
 +  //"Angled" (the default), "Horizontal", and "None".
 +  private static boolean playWithLineStyle = false;
 +  private static String lineStyle = "Horizontal";
 +  
 +  //Optionally set the look and feel.
 +  private static boolean useSystemLookAndFeel = false;
 +
 +  public TreeDemo() {
 +    super(new GridLayout(1,0));
 +
 +    //Create the nodes.
 +    DefaultMutableTreeNode top =
 +      new DefaultMutableTreeNode("The Java Series");
 +    createNodes(top);
 +
 +    //Create a tree that allows one selection at a time.
 +    tree = new JTree(top);
 +    tree.setEditable(true);
 +    tree.getSelectionModel().setSelectionMode
 +        (TreeSelectionModel.SINGLE_TREE_SELECTION);
 +
 +    //Listen for when the selection changes.
 +    tree.addTreeSelectionListener(this);
 +
 +    if (playWithLineStyle) {
 +      System.out.println("line style = " + lineStyle);
 +      tree.putClientProperty("JTree.lineStyle", lineStyle);
 +    }
 +
 +    //Create the scroll pane and add the tree to it. 
 +    JScrollPane treeView = new JScrollPane(tree);
 +
 +    //Create the HTML viewing pane.
 +    htmlPane = new JEditorPane();
 +    htmlPane.setEditable(false);
 +    initHelp();
 +    JScrollPane htmlView = new JScrollPane(htmlPane);
 +
 +    //Add the scroll panes to a split pane.
 +    JSplitPane splitPane = new JSplitPane(JSplitPane.VERTICAL_SPLIT);
 +    splitPane.setTopComponent(treeView);
 +    splitPane.setBottomComponent(htmlView);
 +
 +    Dimension minimumSize = new Dimension(100, 50);
 +    htmlView.setMinimumSize(minimumSize);
 +    treeView.setMinimumSize(minimumSize);
 +    splitPane.setDividerLocation(100); 
 +    splitPane.setPreferredSize(new Dimension(500, 300));
 +
 +    //Add the split pane to this panel.
 +    add(splitPane);
 +  }
 +
 +  /** Required by TreeSelectionListener interface. */
 +  public void valueChanged(TreeSelectionEvent e) {
 +    DefaultMutableTreeNode node = (DefaultMutableTreeNode)
 +               tree.getLastSelectedPathComponent();
 +
 +    if (node == null) return;
 +
 +    Object nodeInfo = node.getUserObject();
 +    if (node.isLeaf()) {
 +      BookInfo book = (BookInfo)nodeInfo;
 +      displayURL(book.bookURL);
 +      if (DEBUG) {
 +        System.out.print(book.bookURL + ":  \n  ");
 +      }
 +    } else {
 +      displayURL(helpURL); 
 +    }
 +    if (DEBUG) {
 +      System.out.println(nodeInfo.toString());
 +    }
 +  }
 +
 +  private class BookInfo {
 +    public String bookName;
 +    public URL bookURL;
 +
 +    public BookInfo(String book, String filename) {
 +      bookName = book;
 +      bookURL = getClass().getResource("html/"+filename);
 +      if (bookURL == null) {
 +        System.err.println("Couldn't find file: "
 +                   + filename);
 +      }
 +    }
 +
 +    public String toString() {
 +      return bookName;
 +    }
 +  }
 +
 +  private void initHelp() {
 +    String s = "TreeDemoHelp.html";
 +    helpURL = getClass().getResource(s);
 +    if (helpURL == null) {
 +      System.err.println("Couldn't open help file: " + s);
 +    } else if (DEBUG) {
 +      System.out.println("Help URL is " + helpURL);
 +    }
 +
 +    displayURL(helpURL);
 +  }
 +
 +  private void displayURL(URL url) {
 +    try {
 +      if (url != null) {
 +        htmlPane.setPage(url);
 +      } else { //null url
 + htmlPane.setText("File Not Found");
 +        if (DEBUG) {
 +          System.out.println("Attempted to display a null URL.");
 +        }
 +      }
 +    } catch (IOException e) {
 +      System.err.println("Attempted to read a bad URL: " + url);
 +    }
 +  }
 +
 +  private void createNodes(DefaultMutableTreeNode top) {
 +    DefaultMutableTreeNode category = null;
 +    DefaultMutableTreeNode book = null;
 +
 +    category = new DefaultMutableTreeNode("Books for Java Programmers");
 +    top.add(category);
 +
 +    //original Tutorial
 +    book = new DefaultMutableTreeNode(new BookInfo
 +      ("The Java Tutorial: A Short Course on the Basics",
 +      "tutorial.html"));
 +    category.add(book);
 +
 +    //Tutorial Continued
 +    book = new DefaultMutableTreeNode(new BookInfo
 +      ("The Java Tutorial Continued: The Rest of the JDK",
 +      "tutorialcont.html"));
 +    category.add(book);
 +
 +    //JFC Swing Tutorial
 +    book = new DefaultMutableTreeNode(new BookInfo
 +      ("The JFC Swing Tutorial: A Guide to Constructing GUIs",
 +      "swingtutorial.html"));
 +    category.add(book);
 +
 +    //Bloch
 +    book = new DefaultMutableTreeNode(new BookInfo
 +      ("Effective Java Programming Language Guide",
 +    "bloch.html"));
 +    category.add(book);
 +
 +    //Arnold/Gosling
 +    book = new DefaultMutableTreeNode(new BookInfo
 +      ("The Java Programming Language", "arnold.html"));
 +    category.add(book);
 +
 +    //Chan
 +    book = new DefaultMutableTreeNode(new BookInfo
 +      ("The Java Developers Almanac",
 +       "chan.html"));
 +    category.add(book);
 +
 +    category = new DefaultMutableTreeNode("Books for Java Implementers");
 +    top.add(category);
 +
 +    //VM
 +    book = new DefaultMutableTreeNode(new BookInfo
 +      ("The Java Virtual Machine Specification",
 +       "vm.html"));
 +    category.add(book);
 +
 +    //Language Spec
 +    book = new DefaultMutableTreeNode(new BookInfo
 +      ("The Java Language Specification",
 +       "jls.html"));
 +    category.add(book);
 +  }
 +    
 +  /**
 +   * Create the GUI and show it.  For thread safety,
 +   * this method should be invoked from the
 +   * event dispatch thread.
 +   */
 +  private static void createAndShowGUI() {
 +    if (useSystemLookAndFeel) {
 +      try {
 +        UIManager.setLookAndFeel(
 +          UIManager.getSystemLookAndFeelClassName());
 +      } catch (Exception e) {
 +        System.err.println("Couldn't use system look and feel.");
 +      }
 +    }
 +
 +    //Create and set up the window.
 +    JFrame frame = new JFrame("TreeDemo");
 +    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 +
 +    //Add content to the window.
 +    frame.add(new TreeDemo());
 +
 +    //Display the window.
 +    frame.pack();
 +    frame.setVisible(true);
 +  }
 +
 +  public static void main(String[] args) {
 +    //Schedule a job for the event dispatch thread:
 +    //creating and showing this application's GUI.
 +    javax.swing.SwingUtilities.invokeLater(new Runnable() {
 +      public void run() {
 +        createAndShowGUI();
 +      }
 +    });
 +  }
 +}
 +</code>
swing/jtree_demo_01.txt · Last modified: 2015/05/18 02:44 (external edit)

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