javax.swing.JComboBox#isPopupVisible ( )源码实例Demo

@SuppressWarnings("unchecked")
private JPanel createInputPanel()
{
    JPanel outerPanel = new JPanel(new BorderLayout());
    JPanel innerPanel = new JPanel(new BorderLayout());
    m_comboBox = new JComboBox(getHistory().toArray());
    StringBuilder prototype = new StringBuilder(70);
    for (int i = 0; i < 40; ++i)
        prototype.append('-');
    m_comboBox.setPrototypeDisplayValue(prototype.toString());
    m_comboBox.setEditable(true);
    ComboBoxEditor editor = m_comboBox.getEditor();
    m_comboBox.addActionListener(this);
    m_textField = (JTextField)editor.getEditorComponent();
    m_textField.selectAll();
    KeyListener keyListener = new KeyAdapter()
        {
            public void keyPressed(KeyEvent e)
            {
                int c = e.getKeyCode();
                if (c == KeyEvent.VK_ESCAPE
                    && ! m_comboBox.isPopupVisible())
                    dispose();
            }
        };
    m_textField.addKeyListener(keyListener);
    GuiUtil.setMonospacedFont(m_comboBox);
    innerPanel.add(m_comboBox, BorderLayout.CENTER);
    outerPanel.add(innerPanel, BorderLayout.NORTH);
    return outerPanel;
}
 

@Override
public boolean accept(Object sender) {
    ACTION_ACCEPTED_CALLS++;
    if (sender instanceof JComboBox) {
        JComboBox c = (JComboBox) sender;
        return !c.isPopupVisible();
    }
    return false;
}
 

/**
 * Test fails if it throws any exception.
 *
 * @throws Exception
 */
private void init() throws Exception {

    if (!System.getProperty("os.name").startsWith("Windows")) {
        System.out.println("This is Windows only test.");
        return;
    }

    final Frame frame = new Frame("AWT Frame");
    frame.pack();
    frame.setSize(200, 200);
    FramePeer frame_peer = AWTAccessor.getComponentAccessor()
                                .getPeer(frame);
    Class comp_peer_class
            = Class.forName("sun.awt.windows.WComponentPeer");
    Field hwnd_field = comp_peer_class.getDeclaredField("hwnd");
    hwnd_field.setAccessible(true);
    long hwnd = hwnd_field.getLong(frame_peer);

    Class clazz = Class.forName("sun.awt.windows.WEmbeddedFrame");
    Constructor constructor
            = clazz.getConstructor(new Class[]{long.class});
    final Frame embedded_frame
            = (Frame) constructor.newInstance(new Object[]{
                new Long(hwnd)});;
    final JComboBox<String> combo = new JComboBox<>(new String[]{
        "Item 1", "Item 2"
    });
    combo.setSelectedIndex(1);
    final Panel p = new Panel();
    p.setLayout(new BorderLayout());
    embedded_frame.add(p, BorderLayout.CENTER);
    embedded_frame.validate();
    p.add(combo);
    p.validate();
    frame.setVisible(true);
    Robot robot = new Robot();
    robot.delay(2000);
    Rectangle clos = new Rectangle(
            combo.getLocationOnScreen(), combo.getSize());
    robot.mouseMove(clos.x + clos.width / 2, clos.y + clos.height / 2);
    robot.mousePress(InputEvent.BUTTON1_MASK);
    robot.mouseRelease(InputEvent.BUTTON1_MASK);
    robot.delay(1000);
    if (!combo.isPopupVisible()) {
        throw new RuntimeException("Combobox popup is not visible!");
    }
    robot.mouseMove(clos.x + clos.width / 2, clos.y + clos.height + 3);
    robot.mousePress(InputEvent.BUTTON1_MASK);
    robot.mouseRelease(InputEvent.BUTTON1_MASK);
    robot.delay(1000);
    if (combo.getSelectedIndex() != 0) {
        throw new RuntimeException("Combobox selection has not changed!");
    }
    embedded_frame.remove(p);
    embedded_frame.dispose();
    frame.dispose();

}
 

/**
 * Enables automatic completion for the given JComboBox. The automatic
 * completion will be strict (only items from the combo box can be selected)
 * if the combo box is not editable.
 * @param comboBox a combo box
 * @param stringConverter the converter used to transform items to strings
 */
public static void decorate(final JComboBox comboBox, final ObjectToStringConverter stringConverter) {
    boolean strictMatching = !comboBox.isEditable();
    // has to be editable
    comboBox.setEditable(true);
    // fix the popup location
    AquaLnFPopupLocationFix.install(comboBox);

    // configure the text component=editor component
    JTextComponent editorComponent = (JTextComponent) comboBox.getEditor().getEditorComponent();
    final AbstractAutoCompleteAdaptor adaptor = new ComboBoxAdaptor(comboBox);
    final AutoCompleteDocument document = new AutoCompleteDocument(adaptor, strictMatching, stringConverter);
    decorate(editorComponent, document, adaptor);
    
    // show the popup list when the user presses a key
    final KeyListener keyListener = new KeyAdapter() {
        public void keyPressed(KeyEvent keyEvent) {
            // don't popup on action keys (cursor movements, etc...)
            if (keyEvent.isActionKey()) return;
            // don't popup if the combobox isn't visible anyway
            if (comboBox.isDisplayable() && !comboBox.isPopupVisible()) {
                int keyCode = keyEvent.getKeyCode();
                // don't popup when the user hits shift,ctrl or alt
                if (keyCode==keyEvent.VK_SHIFT || keyCode==keyEvent.VK_CONTROL || keyCode==keyEvent.VK_ALT) return;
                // don't popup when the user hits escape (see issue #311)
                if (keyCode==keyEvent.VK_ESCAPE) return;
                comboBox.setPopupVisible(true);
            }
        }
    };
    editorComponent.addKeyListener(keyListener);
    
    if (stringConverter!=ObjectToStringConverter.DEFAULT_IMPLEMENTATION) {
        comboBox.setEditor(new AutoCompleteComboBoxEditor(comboBox.getEditor(), stringConverter));
    }
    
    // Changing the l&f can change the combobox' editor which in turn
    // would not be autocompletion-enabled. The new editor needs to be set-up.
    comboBox.addPropertyChangeListener("editor", new PropertyChangeListener() {
        public void propertyChange(PropertyChangeEvent e) {
          	ComboBoxEditor editor = (ComboBoxEditor) e.getNewValue();
          	if (editor!=null && editor.getEditorComponent()!=null) {
                if (!(editor instanceof AutoCompleteComboBoxEditor) 
                    && stringConverter!=ObjectToStringConverter.DEFAULT_IMPLEMENTATION) {
                    comboBox.setEditor(new AutoCompleteComboBoxEditor(editor, stringConverter));
                    // Don't do the decorate step here because calling setEditor will trigger
                    // the propertychange listener a second time, which will do the decorate
                    // and addKeyListener step.
                } else {
                    decorate((JTextComponent) editor.getEditorComponent(), document, adaptor);
                    editor.getEditorComponent().addKeyListener(keyListener);
                }
          	}
        }
    });
}