简单快速的JTree Cell Editor

Question

我有一个带有自定义TreeModel和自定义TreeRenderer的JTree.树模型包含一堆不同类型的对象.其中一种类型的显示方式与其他类型不同:显示的文本是对象的两个字段的串联.当我编辑单元格时,我想用编辑的文本更新其中一个字段.到目前为止,我的工作得很好.

我的问题:当编辑时显示的文本是2个字段的完整连接值时,即使您实际上只是编辑其中一个字段,这也很令人困惑.所以我想只显示用户开始编辑时正在编辑的一个字段的内容.

我尝试使用自定义CellEditor来做这件事,我看到它应该工作的方式,这种方法在我的情况下似乎有点过分.我只是想在很多情况下改变显示的文本,所以我自然而然地希望实现它,而不是整个CellEditor来完成我的Tree的整个内容.

是否有更快速,更简单的方法,或者我必须使用自定义编辑器？

谢谢

Answer 1

没有办法绕过自定义编辑器,它是最简单的解决方案:-)此外,您需要在数据领域中有一些方法可以适当地解释编辑值并自我更新,自定义节点.

Fi(稍后会评论,我这台机器上的蹩脚firefox正在把我推到墙上)

/**
 * Basic code stolen from @trashgod at
* @see http://stackoverflow.com/a/11113648/230513
*/
public class TreeEditDemo extends JPanel {

    private JTree tree;
    private DefaultMutableTreeNode root;
    private DefaultTreeCellEditor editor;

    public TreeEditDemo() {
        super.setLayout(new GridLayout());
        root = new DefaultMutableTreeNode("Nodes");
        root.add(new MyResourceNode(new Resource("one", "first")));
        root.add(new MyResourceNode(new Resource("two", "first")));
        tree = new JTree(root);
        tree.setEditable(true);
        editor = new MyTreeCellEditor(tree,
            (DefaultTreeCellRenderer) tree.getCellRenderer());
        tree.setCellEditor(editor);
        this.add(new JScrollPane(tree));
    }

    private static class MyTreeCellEditor extends DefaultTreeCellEditor {

        public MyTreeCellEditor(JTree tree, DefaultTreeCellRenderer renderer) {
            super(tree, renderer);
        }

        @Override
        public Component getTreeCellEditorComponent(JTree tree, Object value,
                boolean isSelected, boolean expanded, boolean leaf, int row) {
            if (value instanceof MyResourceNode) {
                value = ((MyResourceNode) value).getName();
            }
            return super.getTreeCellEditorComponent(tree, value, isSelected, expanded,
                    leaf, row);
        }

        @Override
        public boolean isCellEditable(EventObject e) {
            return super.isCellEditable(e)
                && ((TreeNode) lastPath.getLastPathComponent()).isLeaf();
        }
    }

    public static class MyResourceNode extends DefaultMutableTreeNode {

        /**
         * @param resource
         */
        public MyResourceNode(Resource resource) {
            super(resource);
        }

        @Override
        public void setUserObject(Object userObject) {
            if (userObject instanceof String) {
                setName((String) userObject);
            } else if (userObject instanceof Resource) {
                super.setUserObject(userObject);
            }    
        }

        public void setName(String name) {
            if (getUserObject() != null) {
                getUserObject().setName(name);
            }
        }

        public String getName() {
            if (getUserObject() != null) {
                return getUserObject().getName();
            }
            return null;
        }

        @Override
        public Resource getUserObject() {
            return (Resource) super.getUserObject();
        }


    }
    private static class Resource {

        String name;
        private String category;

        public Resource(String name, String category) {
            this.name = name;
            this.category = category;
        }

        public void setName(String name) {
            this.name = name;
        }

        public String getName() {
            return name;
        }
        @Override
        public String toString() {
            // BEWARE: don't do this in production code!
            return name + " (" + category + ")";
        }
    }

    private void display() {
        JFrame f = new JFrame("TreeEditorDemo");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(this);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                new TreeEditDemo().display();
            }
        });
    }
}