TreeRolloverController.java 文件源码

@Override
protected RolloverRenderer getRolloverRenderer(Point location, boolean prepare) {
    TreeCellRenderer renderer = component.getCellRenderer();
    RolloverRenderer rollover = renderer instanceof RolloverRenderer 
        ? (RolloverRenderer) renderer : null;
    if ((rollover != null) && !rollover.isEnabled()) {
        rollover = null;
    }
    if ((rollover != null) && prepare) {
        TreePath path = component.getPathForRow(location.y);
        Object element = path != null ? path.getLastPathComponent() : null;
        renderer.getTreeCellRendererComponent(component, element, false, 
                false, false, 
                location.y, false);
    }
    return rollover;
}