在Java中右键单击Swing中的节点来添加JPopup菜单

Question

在图形用户界面中，我在JPanel的左侧显示了一个JTree。现在，对于每个Node(leaf)，在鼠标右键单击时，我想显示JPopup菜单，要求在右JPanel中显示有关Node的统计信息。

由于我是swing的新手，有人可以帮助我编写代码吗？提前谢谢。

你好，图沙尔·多迪亚。

Answer 1

使用JTree的方法

public TreePath getPathForLocation(int x, int y)

然后是TreePath

public Object getLastPathComponent()

这将从用户右键单击的位置返回所需的节点。

Answer 2

似乎引起了一些困惑(把我自己搞糊涂了;-) -这里有一段代码片段，用于对componentPopup进行与目标位置相关的配置

    JPopupMenu popup = new JPopupMenu();
    final Action action = new AbstractAction("empty") {

        @Override
        public void actionPerformed(ActionEvent e) {
            // TODO Auto-generated method stub
        }
    };
    popup.add(action); 
    JTree tree = new JTree() {

        /** 
         * @inherited <p>
         */
        @Override
        public Point getPopupLocation(MouseEvent e) {
            if (e != null) {
               TreePath path = getClosestPathForLocation(e.getX(), e.getY());
               action.putValue(Action.NAME, String.valueOf(path.getLastPathComponent()));
               return e.getPoint();
            }
            action.putValue(Action.NAME, "no mouse"); 
            return null;
        }

    };
    tree.setComponentPopupMenu(popup);

Answer 3

我采用了@kleopatra解决方案，并对其进行了轻微更改。也许这不是最好的方法，但对我来说很有效。

JTree tree = new JTree() {
    private static final long serialVersionUID = 1L;
    @Override public Point getPopupLocation(MouseEvent e) {
        if (e == null) return new Point(0,0);
        TreePath path = getClosestPathForLocation(e.getX(), e.getY());
        Object selected = path != null ? path.getLastPathComponent() : null;
        setComponentPopupMenu(getMenuForTreeNode(getComponentPopupMenu(), selected));
        setSelectionPath(path);
        return e.getPoint();
    }
};



public JPopupMenu getMenuForTreeNode(JPopupMenu menu, Object treeNode) {
    if (menu == null) menu = new JPopupMenu("Menu:");
    menu.removeAll();
    if (treeNode instanceof MyTreeItem) {
        menu.add(new JMenuItem("This is my tree item: " + treeNode.toString()));
    }
    return menu;
}