defaulttreecellrenderer

defaulttreecellrenderer是Java Swing中的一个类，用于绘制树形结构中的节点。它是TreeCellRenderer接口的默认实现，可以通过设置JTree的setCellRenderer方法来使用它。它可以绘制节点的文本、图标、背景色等，并且可以根据节点的选中状态、展开状态等进行不同的绘制。

相关问题

treedemo实现复选框

要在TreeDemo中实现复选框，您需要进行以下步骤：

1. 首先，在TreeDemo中创建一个TreeCellRenderer类，用于渲染树节点。您可以继承DefaultTreeCellRenderer类并添加一个复选框来实现这一点。

2. 接下来，您需要重写TreeSelectionModel类的valueForPathChanged方法，以便当复选框的状态更改时更新树的状态。

3. 在TreeDemo的createNodes方法中，为每个节点添加一个TreeSelectionListener来监听复选框的状态更改。

4. 最后，在TreeDemo的main方法中创建一个JFrame并将树添加到该窗口中。

以下是一个简单的示例代码，演示如何在TreeDemo中实现复选框：

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.GridLayout;

import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.UIManager;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreeCellRenderer;
import javax.swing.tree.TreePath;
import javax.swing.tree.TreeSelectionModel;

public class TreeDemo extends JPanel implements TreeSelectionListener {
    private JTree tree;
    private DefaultTreeModel treeModel;

    public TreeDemo() {
        super(new GridLayout(1,0));

        DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root");
        treeModel = new DefaultTreeModel(root);

        tree = new JTree(treeModel);
        tree.getSelectionModel().setSelectionMode(TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTION);
        tree.setCellRenderer(new CheckBoxNodeRenderer());
        tree.setCellEditor(new CheckBoxNodeEditor(tree));
        tree.setEditable(true);

        JScrollPane scrollPane = new JScrollPane(tree);

        add(scrollPane);
    }

    public void valueChanged(TreeSelectionEvent e) {
        DefaultMutableTreeNode node = (DefaultMutableTreeNode)
                           tree.getLastSelectedPathComponent();

        if (node == null) return;

        Object nodeInfo = node.getUserObject();
    }

    private static void createAndShowGUI() {
        JFrame frame = new JFrame("TreeDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        TreeDemo newContentPane = new TreeDemo();
        newContentPane.setOpaque(true);
        frame.setContentPane(newContentPane);

        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}

class CheckBoxNodeRenderer implements TreeCellRenderer {
    private JCheckBox leafRenderer = new JCheckBox();

    private DefaultTreeCellRenderer nonLeafRenderer = new DefaultTreeCellRenderer();

    Color selectionBorderColor, selectionForeground, selectionBackground,
          textForeground, textBackground;

    protected JCheckBox getLeafRenderer() {
        return leafRenderer;
    }

    public CheckBoxNodeRenderer() {
        Font fontValue;
        fontValue = UIManager.getFont("Tree.font");
        if (fontValue != null) {
            leafRenderer.setFont(fontValue);
        }
        Boolean booleanValue = (Boolean) UIManager.get("Tree.drawsFocusBorderAroundIcon");
        leafRenderer.setFocusPainted((booleanValue != null) && (booleanValue.booleanValue()));

        selectionBorderColor = UIManager.getColor("Tree.selectionBorderColor");
        selectionForeground = UIManager.getColor("Tree.selectionForeground");
        selectionBackground = UIManager.getColor("Tree.selectionBackground");
        textForeground = UIManager.getColor("Tree.textForeground");
        textBackground = UIManager.getColor("Tree.textBackground");
    }

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

        Component returnValue;
        if (leaf) {

            String stringValue = tree.convertValueToText(value, selected,
                expanded, leaf, row, false);
            leafRenderer.setText(stringValue);
            leafRenderer.setSelected(false);

            leafRenderer.setEnabled(tree.isEnabled());

            if (selected) {
                leafRenderer.setForeground(selectionForeground);
                leafRenderer.setBackground(selectionBackground);
            } else {
                leafRenderer.setForeground(textForeground);
                leafRenderer.setBackground(textBackground);
            }

            if ((value != null) && (value instanceof DefaultMutableTreeNode)) {
                Object userObject = ((DefaultMutableTreeNode) value).getUserObject();
                if (userObject instanceof CheckBoxNode) {
                    CheckBoxNode node = (CheckBoxNode) userObject;
                    leafRenderer.setText(node.getText());
                    leafRenderer.setSelected(node.isSelected());
                }
            }
            returnValue = leafRenderer;
        } else {
            returnValue = nonLeafRenderer.getTreeCellRendererComponent(tree,
                value, selected, expanded, leaf, row, hasFocus);
        }
        return returnValue;
    }
}

class CheckBoxNodeEditor extends DefaultTreeCellEditor {
    CheckBoxNodeRenderer renderer = new CheckBoxNodeRenderer();

    public CheckBoxNodeEditor(JTree tree) {
        super(tree);
    }

    public Component getTreeCellEditorComponent(JTree tree, Object value,
        boolean selected, boolean expanded, boolean leaf, int row) {

        Component editor = renderer.getTreeCellRendererComponent(tree, value,
            true, expanded, leaf, row, true);

        // editor always selected / focused
        ItemListener itemListener = new ItemListener() {
            public void itemStateChanged(ItemEvent itemEvent) {
                if (stopCellEditing()) {
                    fireEditingStopped();
                }
            }
        };
        if (editor instanceof JCheckBox) {
            ((JCheckBox) editor).addItemListener(itemListener);
        }
        return editor;
    }

    public Object getCellEditorValue() {
        JCheckBox checkbox = renderer.getLeafRenderer();
        CheckBoxNode checkBoxNode = new CheckBoxNode(checkbox.getText(),
            checkbox.isSelected());
        return checkBoxNode;
    }
}

class CheckBoxNode {
    String text;

    boolean selected;

    public CheckBoxNode(String text, boolean selected) {
        this.text = text;
        this.selected = selected;
    }

    public boolean isSelected() {
        return selected;
    }

    public void setSelected(boolean newValue) {
        selected = newValue;
    }

    public String getText() {
        return text;
    }

    public void setText(String newValue) {
        text = newValue;
    }

    public String toString() {
        return getClass().getName() + "[" + text + "/" + selected + "]";
    }
}

请注意，上面的示例代码可能需要根据您的具体要求进行修改。

JXTreeTable例子

JXTreeTable 是 SwingX 扩展库提供的一个 JTable 的子类，它可以以树状结构展示表格数据。以下是一个简单的 JXTreeTable 的例子：

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import org.jdesktop.swingx.JXTreeTable;

public class JXTreeTableExample {
    public static void main(String[] args) {
        // 构造树状数据模型
        DefaultMutableTreeNode rootNode = new DefaultMutableTreeNode("根节点");
        DefaultMutableTreeNode node1 = new DefaultMutableTreeNode("节点1");
        DefaultMutableTreeNode node2 = new DefaultMutableTreeNode("节点2");
        rootNode.add(node1);
        rootNode.add(node2);
        DefaultTreeModel treeModel = new DefaultTreeModel(rootNode);
        
        // 构造表格数据模型
        Object[][] data = {{"A", "B", "C"}, {"1", "2", "3"}};
        String[] columnNames = {"列1", "列2", "列3"};
        JTable table = new JTable(data, columnNames);
        
        // 构造 JXTreeTable
        JXTreeTable treeTable = new JXTreeTable(treeModel, table.getColumnModel());
        treeTable.setRootVisible(false); // 隐藏根节点
        treeTable.setShowGrid(false); // 隐藏网格线
        treeTable.setColumnControlVisible(true); // 显示列控制器
        treeTable.setHorizontalScrollEnabled(true); // 允许水平滚动
        treeTable.setTreeCellRenderer(new DefaultTreeCellRenderer()); // 设置树节点渲染器
        
        // 将 JXTreeTable 放入 JFrame 中
        JFrame frame = new JFrame("JXTreeTable Example");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(new JScrollPane(treeTable));
        frame.pack();
        frame.setVisible(true);
    }
}

该例子中，我们构造了一个包含两个节点的树状数据模型，和一个简单的表格数据模型。然后，我们通过传入这两个模型来构造一个 JXTreeTable。最后，我们将 JXTreeTable 放入 JFrame 中展示出来。运行该例子，可以看到一个包含树状结构的表格。