使用包含可编辑 JTextArea 的 JPanel 渲染 JTree 叶

Question

我正在尝试渲染一个 JTree 叶以具有一个包含可编辑 JTextArea 的 JPanel，以便用户可以输入文本并能够在添加文本时向下滚动，

并且还使用包装器来限制文本的宽度，使其向下延伸以允许更多空间而不是左右滚动。

到目前为止，我已经实现了以下内容，但它看起来很奇怪，当我运行代码时，好像有两个叶子，默认一个和渲染上。任何类型的帮助都将受到高度赞赏。

我只想知道我想做的事情是否可以实现，如果不能，我可以在哪里修改。

我不想更改图标，只更改叶子。

import java.awt.Component;
import java.awt.event.ComponentEvent;
import java.awt.event.ComponentListener;
import java.awt.event.ItemEvent;
import java.util.EventObject;
import javax.swing.*;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.TreeCellEditor;
import javax.swing.tree.TreeCellRenderer;

/**
 *
 * @author Razaractor
 */
class LeafRenderer extends AbstractCellEditor implements
        TreeCellRenderer, TreeCellEditor {

    //Text area to be place on JPanel
    JTextArea text = new JTextArea();
    DefaultTreeCellRenderer nonLeafRenderer = new DefaultTreeCellRenderer();

    @Override
    public Object getCellEditorValue() {
        return text.getText();
    }

    @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) {
        //Default leaf
        Component render = nonLeafRenderer.getTreeCellRendererComponent(tree,
                value, selected, expanded, leaf, row, hasFocus);
        if (selected && leaf) {
            final JPanel panel = new JPanel();
            BoxLayout layout = new BoxLayout(panel, BoxLayout.X_AXIS);
            panel.setLayout(layout);
            text.setColumns(20);
            text.setLineWrap(true);
            text.setRows(5);
            text.setWrapStyleWord(true);
            text = new JTextArea(String.valueOf(value));
            text.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) {
                }
            });
            JScrollPane scroll = new JScrollPane(text);
            panel.add(scroll);
            render = panel;
            return panel;
        }
        return render;
    }

    @Override
    public Component getTreeCellEditorComponent(
            final JTree tree,
            final Object value,
            final boolean isSelected,
            final boolean expanded,
            final boolean leaf,
            final int row) {
        Component editor = nonLeafRenderer.getTreeCellRendererComponent(tree,
                value, true, expanded, leaf, row, true);
        final JPanel p = new JPanel();
        if (editor instanceof JPanel) {
            editor = (JPanel) editor;
        }
        return editor;
    }

    public void itemStateChanged(ItemEvent itemEvent) {
        if (stopCellEditing()) {
            fireEditingStopped();
        }
    }
}

Answer 1

我不知道您真正想要实现什么，但请尝试这些更改。

import java.awt.Component;
import java.awt.Dimension;
import java.awt.event.ComponentEvent;
import java.awt.event.ComponentListener;
import java.awt.event.ItemEvent;
import java.util.EventObject;
import javax.swing.*;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.TreeCellEditor;
import javax.swing.tree.TreeCellRenderer;

/**
 *
 * @author Razaractor
 */
class LeafRenderer extends AbstractCellEditor implements
        TreeCellRenderer, TreeCellEditor {

    //Text area to be place on JPanel
    JTextArea text = new JTextArea();
    DefaultTreeCellRenderer nonLeafRenderer = new DefaultTreeCellRenderer();

    @Override
    public Object getCellEditorValue() {
        return text.getText();
    }

    @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) {
        //Default leaf
        Component render = nonLeafRenderer.getTreeCellRendererComponent(tree,
                value, selected, expanded, leaf, row, hasFocus);
        if (selected && leaf) {
            final JPanel panel = new JPanel();
            BoxLayout layout = new BoxLayout(panel, BoxLayout.X_AXIS);
            panel.setLayout(layout);
            //Changed code
            //moved from
            text = new JTextArea(String.valueOf(value));
            text.setColumns(20);
            text.setLineWrap(true);
            text.setRows(5);
            text.setWrapStyleWord(true);
            //here. You were creating just ordinary JTextArea.
            text.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) {
                }
            });
            JScrollPane scroll = new JScrollPane(text);
            //changed Code
            //if you want to hide scrollbars uncomment one of these
            //scroll.getVerticalScrollBar().setPreferredSize(new Dimension(0, 0));
            //scroll.getHorizontalScrollBar().setPreferredSize(new Dimension(0, 0));
            panel.add(scroll);
            render = panel;
            return panel;
        }
        return render;
    }

    @Override
    public Component getTreeCellEditorComponent(
            final JTree tree,
            final Object value,
            final boolean isSelected,
            final boolean expanded,
            final boolean leaf,
            final int row) {
        Component editor = nonLeafRenderer.getTreeCellRendererComponent(tree,
                value, true, expanded, leaf, row, true);
        final JPanel p = new JPanel();
        if (editor instanceof JPanel) {
            editor = (JPanel) editor;
        }
        return editor;
    }

    public void itemStateChanged(ItemEvent itemEvent) {
        if (stopCellEditing()) {
            fireEditingStopped();
        }
    }
}