Handler.java 文件源码

/**
 * Strips off the UI's mouse listeners attached to the associated toolbar
 * and replaces them with this handler's listeners.
 */
private void installListeners() {
    if (!ourVersionIsCompatible)
        return;

    ourToolBar.removePropertyChangeListener("UI", ourUIListener);

    // Uninstall the current ui, collect the remaining listeners
    // on the toolbar, and reinstall the ui...
    final ComponentUI ui = ourToolBar.getUI();
    ui.uninstallUI(ourToolBar);
    final java.util.List mList = Arrays.asList(ourToolBar
            .getListeners(MouseListener.class));

    final java.util.List mmList = Arrays.asList(ourToolBar
            .getListeners(MouseMotionListener.class));
    ui.installUI(ourToolBar);

    // ...then remove the listeners that were added by the ui...
    final MouseListener[] ml = ourToolBar
            .getListeners(MouseListener.class);
    final MouseMotionListener[] mml = ourToolBar
            .getListeners(MouseMotionListener.class);

    for (int i = 0; i < ml.length; i++) {
        if (!mList.contains(ml[i]))
            ourToolBar.removeMouseListener(ml[i]);
    }

    for (int i = 0; i < mml.length; i++) {
        if (!mmList.contains(mml[i]))
            ourToolBar.removeMouseMotionListener(mml[i]);
    }

    // ...and add our listeners to the toolbar.
    ourToolBar.addMouseListener(ourDragListener);
    ourToolBar.addMouseMotionListener(ourDragListener);
    ourToolBar.addPropertyChangeListener("UI", ourUIListener);
}