Javaルックアンドフィールウィンドウのサイズ変更と動作しない

Question

ルックアンドフィールに関する問題が発生しています。私はルック・アンド・フィールを変えるサブメニューを持っていますが、何もしません。窓バーのサイズを変更するだけです。

1）私は私のコードを持っている問題は、私は外観を変更し、テキスト領域が何らかの理由でサイズを変更すると感じた場合でも、UI

2）の更新にもかかわらず、見て、動作しない感じです。

import javax.swing.*; 
import java.awt.*; 
import java.awt.event.*; 

public class NoteTaker extends JFrame 
{ 
    // Constants for set up of the note taking area 
    public static final int WIDTH = 600; 
    public static final int HEIGHT = 300; 
    public static final int LINES = 13; 
    public static final int CHAR_PER_LINE = 45; 

    // Objects in GUI 
    private JTextArea theText; // Text area to take notes 
    private JMenuBar mBar;  // Horizontal menu bar 
    private JPanel textPanel; // Scrolling text area panel 
    private JMenu notesMenu; // Vertical menu for notes 

    // THESE ITEMS ARE NOT YET USED 
    // YOU WILL BE CREATING THEM IN THIS LAB 
    private JMenu viewMenu; // Vertical menu for views 
    private JMenu lafMenu; // Vertical menu look and feel 
    private JMenu sbMenu; // Vertical menu for scroll bar 
    private JScrollPane scrolledText; // Scroll bars 

    // Default notes 
    private String note1 = "No Note 1."; 
    private String note2 = "No Note 2."; 

    /** 
     Constructor 
    */ 

    public NoteTaker() 
    { 
     // Create a closeable JFrame with a specific size 
     super("Note Taker"); 
     setSize(WIDTH, HEIGHT); 
     setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE); 

     // Get contentPane and set layout of the window 
     Container contentPane = getContentPane(); 
     contentPane.setLayout(new BorderLayout()); 

     // Creates the vertical menus 
     createNotes(); 
     createViews(); 

     // Creates horizontal menu bar and 
     // adds vertical menus to it 
     mBar = new JMenuBar(); 
     mBar.add(notesMenu); 
     mBar.add(viewMenu); 
     // ADD THE viewMenu TO THE MENU BAR HERE 
     setJMenuBar(mBar); 

     // Creates a panel to take notes on 
     textPanel = new JPanel(); 
     textPanel.setBackground(Color.blue); 
     theText = new JTextArea(LINES, CHAR_PER_LINE); 
     theText.setBackground(Color.white); 

     // CREATE A JScrollPane OBJECT HERE CALLED 
     // scrolledText AND PASS IN theText, THEN 
     scrolledText = new JScrollPane(theText); 
     // CHANGE THE LINE BELOW BY PASSING IN scrolledText 
     textPanel.add(scrolledText); 
     contentPane.add(textPanel, BorderLayout.CENTER); 
    } 

    /** 
     Creates vertical menu associated with Notes 
     menu item on menu bar. 
    */ 

    public void createNotes() 
    { 
     notesMenu = new JMenu("Notes"); 
     JMenuItem item; 

     item = new JMenuItem("Save Note 1"); 
     item.addActionListener(new MenuListener()); 
     notesMenu.add(item); 

     item = new JMenuItem("Save Note 2"); 
     item.addActionListener(new MenuListener()); 
     notesMenu.add(item); 

     item = new JMenuItem("Open Note 1"); 
     item.addActionListener(new MenuListener()); 
     notesMenu.add(item); 

     item = new JMenuItem("Open Note 2"); 
     item.addActionListener(new MenuListener()); 
     notesMenu.add(item); 

     item = new JMenuItem("Clear"); 
     item.addActionListener(new MenuListener()); 
     notesMenu.add(item); 

     item = new JMenuItem("Exit"); 
     item.addActionListener(new MenuListener()); 
     notesMenu.add(item); 
    } 

    /** 
     Creates vertical menu associated with Views 
     menu item on the menu bar. 
    */ 

    public void createViews() 
    { 
     viewMenu = new JMenu("Views"); // Creates Menu Item called Views on horizontal Menu Bar 

     createLookAndFeel(); //Creates submenu Look And Feel 
     lafMenu.addActionListener(new MenuListener()); 

     createScrollBars(); //Creates submenu Scroll Bars 
     sbMenu.addActionListener(new MenuListener()); 
    } 

    /** 
     Creates the look and feel Sub menu. 
    */ 

    public void createLookAndFeel() 
    { 
     lafMenu = new JMenu("Look and Feel"); //Creates Menu Item called Look and Feel 
     viewMenu.add(lafMenu); 

     //Adds Menu item metal 
     JMenuItem itemMetal; 
     itemMetal = new JMenuItem("Metal"); 
     itemMetal.addActionListener(new MenuListener()); 
     lafMenu.add(itemMetal); 

     //Adds Menu item Motif 
     JMenuItem itemMotif; 
     itemMotif = new JMenuItem("Motif"); 
     itemMotif.addActionListener(new MenuListener()); 
     lafMenu.add(itemMotif); 

     //Adds Menu item Windows 
     JMenuItem itemWindows; 
     itemWindows = new JMenuItem("Windows"); 
     itemWindows.addActionListener(new MenuListener()); 
     lafMenu.add(itemWindows); 
    } 

    /** 
     Creates the scroll bars submenu. 
    */ 

    public void createScrollBars() 
    { 
     sbMenu = new JMenu("Scroll Bars"); 
     viewMenu.add(sbMenu); 

     //Adds MenuItem called Never 
     JMenuItem itemNever; 
     itemNever = new JMenuItem("Never"); 
     itemNever.addActionListener(new MenuListener()); 
     sbMenu.add(itemNever); 

     //Adds Menu item Always 
     JMenuItem itemAlways; 
     itemAlways = new JMenuItem("Always"); 
     itemAlways.addActionListener(new MenuListener()); 
     sbMenu.add(itemAlways); 

     //Adds Menu item As Needed 
     JMenuItem itemAsNeeded; 
     itemAsNeeded = new JMenuItem("As Needed"); 
     itemAsNeeded.addActionListener(new MenuListener()); 
     sbMenu.add(itemAsNeeded); 
    } 

    /** 
     Private inner class that handles the Menu object's 
     action events. 
    */ 

    private class MenuListener implements ActionListener 
    { 

     public void actionPerformed(ActionEvent e) 
     { 
     String actionCommand = e.getActionCommand(); 
     if (actionCommand.equals("Save Note 1")) 
      note1 = theText.getText(); 
     else if (actionCommand.equals("Save Note 2")) 
      note2 = theText.getText(); 
     else if (actionCommand.equals("Clear")) 
      theText.setText(""); 
     else if (actionCommand.equals("Open Note 1")) 
      theText.setText(note1); 
     else if (actionCommand.equals("Open Note 2")) 
      theText.setText(note2); 
     else if (actionCommand.equals("Exit")) 
      System.exit(0); 
     // ADD 6 BRANCHES TO THE ELSE-IF STRUCTURE 
     // TO ALLOW ACTION TO BE PERFORMED FOR EACH 
     // MENU ITEM YOU HAVE CREATED 
     else if (actionCommand.equals("Metal")) { 
      try { 
       UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel"); 
       SwingUtilities.updateComponentTreeUI(getContentPane()); 
      } catch (Exception e1) { 
       JOptionPane.showMessageDialog(null, "Error for Look and Feel"); 
       System.exit(0); 
      } 
     } else if (actionCommand.equals("Motif")) { 
      try { 
       UIManager.setLookAndFeel("com.sun.java.swing.plaf.motif.MotifLookAndFeel"); 
       SwingUtilities.updateComponentTreeUI(getContentPane()); 
      } catch (Exception e1) { 
       JOptionPane.showMessageDialog(null, "Error setting the look and feel."); 
       System.exit(0); 
      } 
     } else if (actionCommand.equals("Windows")) { 
      try { 
       UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel"); 
       SwingUtilities.updateComponentTreeUI(getContentPane()); 
      } catch (Exception e1) { 
       JOptionPane.showMessageDialog(null, "Error setting the look and feel."); 
       System.exit(0); 
      } 
     } else if (actionCommand.equals("Never")) { 
      scrolledText.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER); 
      SwingUtilities.updateComponentTreeUI(getContentPane()); 
      scrolledText.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_NEVER); 
      SwingUtilities.updateComponentTreeUI(getContentPane()); 
     } else if (actionCommand.equals("Always")) { 
      scrolledText.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS); 
      SwingUtilities.updateComponentTreeUI(getContentPane()); 
      scrolledText.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS); 
      SwingUtilities.updateComponentTreeUI(getContentPane()); 
     } else if (actionCommand.equals("As Needed")) { 
      scrolledText.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED); 
      SwingUtilities.updateComponentTreeUI(getContentPane()); 
      scrolledText.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED); 
      SwingUtilities.updateComponentTreeUI(getContentPane()); 
     } 
     else { 
      theText.setText("Error in memo interface"); 
     } 
    } 
} 

    /** 
     The main method creates an instance of the 
     NoteTaker class which causes it to display 
     its window. 
    */ 

    public static void main(String[] args) 
    { 
     NoteTaker gui = new NoteTaker(); 
     gui.setVisible(true); 
    } 
} 

Answer 1

問題は、コンポーネントツリーのUIを更新しているときに、メニューがある部分を更新していないことです。つまり、メニューバーとそのサブコンポーネントdo notがコンテンツペインにあります。これは、フレームを更新するツリーのルートとして単に使用することで修正できます。だから、問題を修正する必要があり

SwingUtilities.updateComponentTreeUI(NoteTaker.this); 

に

SwingUtilities.updateComponentTreeUI(getContentPane()); 

を変更します。