添加筛选列表框的历史记录，筛选列表框历史记录,class Filter

添加筛选列表框的历史记录，筛选列表框历史记录,class Filter

class FilterField extends JComponent    implements DocumentListener, ActionListener {    LinkedList prevSearches;    JTextField textField;    JButton prevSearchButton;    JPopupMenu prevSearchMenu;    public FilterField (int width) {        super();        setLayout(new BorderLayout());        textField = new JTextField (width);        textField.getDocument().addDocumentListener (this);        textField.addActionListener (this); prevSearchButton =             new JButton (new ImageIcon ("mag-glass.png"));        prevSearchButton.setBorder(null);        prevSearchButton.addMouseListener (new MouseAdapter() {                public void mousePressed (MouseEvent me) {                               popMenu (me.getX(), me.getY());                 }             });        add (prevSearchButton, BorderLayout.WEST);        add (textField, BorderLayout.CENTER);        prevSearches = new LinkedList ();  }  public void popMenu (int x, int y) {      prevSearchMenu = new JPopupMenu();      Iterator it = prevSearches.iterator();      while (it.hasNext())          prevSearchMenu.add (                            new PrevSearchAction(it.next().toString()));      prevSearchMenu.show (prevSearchButton, x, y);  }  public void actionPerformed (ActionEvent e) {      // called on return/enter, adds term to prevSearches      if (e.getSource() == textField) {          prevSearches.addFirst (textField.getText());          if (prevSearches.size() > 10)              prevSearches.removeLast();      }  }  public void changedUpdate (DocumentEvent e) {         ((FilterModel)getModel()).refilter();  }  public void insertUpdate (DocumentEvent e) {         ((FilterModel)getModel()).refilter();  }  public void removeUpdate (DocumentEvent e) {         ((FilterModel)getModel()).refilter();  }}     class PrevSearchAction extends AbstractAction {         String term;         public PrevSearchAction (String s) {             term = s;             putValue (Action.NAME, term);         }         public String toString() { return term; }         public void actionPerformed (ActionEvent e) {             getFilterField().textField.setText (term);         }      }//该片段来自于http://byrx.net