e1011. using a popup to apply styles to a jtextpane.txt

这里面包含了一百多个JAVA源文件

This example implements a text pane that allows the user to display a popup of available styles. If the user selects a style in the popup, the characters in the selection are formatted with the attributes in the style. 
    JTextPane textPane = new JTextPane();
    
    // Makes text red
    Style style = textPane.addStyle("Red", null);
    StyleConstants.setForeground(style, Color.red);
    
    // Inherits from "Red"; makes text red and underlined
    style = textPane.addStyle("Red Underline", style);
    StyleConstants.setUnderline(style, true);
    
    // Makes text 24pts
    style = textPane.addStyle("24pts", null);
    StyleConstants.setFontSize(style, 24);
    
    // Makes text 12pts
    style = textPane.addStyle("12pts", null);
    StyleConstants.setFontSize(style, 12);
    
    // Makes text italicized
    style = textPane.addStyle("Italics", null);
    StyleConstants.setItalic(style, true);
    
    // Makes text bold
    style = textPane.addStyle("Bold", null);
    StyleConstants.setBold(style, true);
    
    JTextPane c = textPane;
    // Construct a sorted list of style names
    DefaultStyledDocument doc = (DefaultStyledDocument)textPane.getDocument();
    java.util.List l = new ArrayList();
    Enumeration enum = doc.getStyleNames();
    while (enum.hasMoreElements()) {
        l.add(enum.nextElement());
    }
    Collections.sort(l);
    
    // First sub menu applies character attributes
    final JPopupMenu menu = new JPopupMenu();
    JMenu submenu = new JMenu("Character");
    for (int i=0; i<l.size(); i++) {
        submenu.add(new JMenuItem(new DoStyleAction((String)l.get(i), CHARACTER)));
    }
    menu.add(submenu);
    
    // Second sub menu applies paragraph attributes
    submenu = new JMenu("Paragraph");
    for (int i=0; i<l.size(); i++) {
        submenu.add(new JMenuItem(new DoStyleAction((String)l.get(i), PARAGRAPH)));
    }
    menu.add(submenu);
    
    // Third submenu applies logical attributes
    submenu = new JMenu("Logical");
    for (int i=0; i<l.size(); i++) {
        submenu.add(new JMenuItem(new DoStyleAction((String)l.get(i), LOGICAL)));
    }
    menu.add(submenu);
    
    // Add a listener to display pop-up
    textPane.addMouseListener(new MouseAdapter() {
        public void mousePressed(MouseEvent evt) {
            if (evt.isPopupTrigger()) {
                menu.show(evt.getComponent(), evt.getX(), evt.getY());
            }
        }
        public void mouseReleased(MouseEvent evt) {
            if (evt.isPopupTrigger()) {
                menu.show(evt.getComponent(), evt.getX(), evt.getY());
            }
        }
    });
    
    static final int CHARACTER = 1;
    static final int PARAGRAPH = 2;
    static final int LOGICAL = 3;
    
    // Assumes the style name is the same as the action name.
    // The type specifies how the style should be applied.
    // The style is applied to the text within the selection.
    public static class DoStyleAction extends StyledEditorKit.StyledTextAction {
        int type;
        public DoStyleAction(String styleName, int type) {
            super(styleName);
            this.type = type;
        }
        public void actionPerformed(ActionEvent e) {
            JTextPane c = (JTextPane)getEditor(e);
            if (c != null) {
                String styleName = e.getActionCommand();
                StyledDocument doc = (StyledDocument)c.getDocument();
    
                switch (type) {
                case CHARACTER:
                    c.setCharacterAttributes(doc.getStyle(styleName), true);
                    break;
                case PARAGRAPH:
                    c.setParagraphAttributes(doc.getStyle(styleName), true);
                    break;
                case LOGICAL:
                    c.setLogicalStyle(doc.getStyle(styleName));
                    break;
                }
            }
        }
    }