在JTree节点中动态调整JTextField的大小

Question

我正在使用带有一些JLabel和JTextField的JPanel作为JTree中的编辑器和渲染器.

用户可以单击任何JTextField并修改文本.一切正常.

我所缺少的是如何在用户输入时动态调整(增长)JTextField.

下面是一个说明问题的小样本程序.单击即"颜色"并输入一些其他字符.JTextField保持其大小,这是预期的,但我希望它增长和缩小以适应文本.

我尝试了不同的布局管理器,计算JTextField和JPanel的preferredSize,调用invalidate()以及JPanel和Tree等,但没有成功.

有任何想法吗？

import java.awt.Component;
import java.util.EventObject;

import javax.swing.AbstractCellEditor;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTree;
import javax.swing.tree.TreeCellEditor;
import javax.swing.tree.TreeCellRenderer;

public class Tree {

    public static void main(final String[] args) {
        new Tree().grow();
    }

    private void grow() {
        final JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        final JTree tree = new JTree();
        tree.setEditable(true);
        tree.setCellRenderer(new SomeTreeCellRenderer());
        tree.setCellEditor(new SomeTreeCellRenderer());

        frame.add(new JScrollPane(tree));

        frame.pack();
        frame.setSize(400, 300);
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    private class SomeTreeCellRenderer extends AbstractCellEditor implements 
            TreeCellRenderer, TreeCellEditor {

        @Override
        public Object getCellEditorValue() {
            return null;
        }

        @Override
        public boolean isCellEditable(final EventObject event) {
            return true;
        }

        @Override
        public Component getTreeCellRendererComponent(
                final JTree tree, final Object value, final boolean selected, final boolean expanded, 
                final boolean leaf, final int row, final boolean hasFocus) {

            final JPanel panel = new JPanel();
            final BoxLayout layout = new BoxLayout(panel, BoxLayout.X_AXIS);
            panel.setLayout(layout);

            panel.add(new JLabel("Some text: "));
            panel.add(new JTextArea(String.valueOf(value)));

            return panel;
        }

        @Override
        public Component getTreeCellEditorComponent(
                final JTree tree, final Object value, final boolean isSelected,
                final boolean expanded, final boolean leaf, final int row) {

            return getTreeCellRendererComponent(tree, value, isSelected, expanded, leaf, row, false);
        }

    }

}

Answer 1

发生的情况是，拥有您的容器panel没有分配给它的布局管理器 - 因此panel当文本区域调整大小时，它不会调整大小。解决此问题的一个简单方法是在文本区域调整大小时设置面板的大小。因此，不要直接这样做：

        panel.add(new JTextArea(String.valueOf(value)));

你可以这样做：

        JTextArea ta = new JTextArea(String.valueOf(value));
        ta.addComponentListener(new ComponentListener() {

            @Override
            public void componentResized(ComponentEvent e) {
                panel.setSize(panel.getPreferredSize());
            }

            @Override
            public void componentShown(ComponentEvent e) {}

            @Override
            public void componentMoved(ComponentEvent e) {}

            @Override
            public void componentHidden(ComponentEvent e) {}
        });

        panel.add(ta);