JTree选择问题

Question

我有一个JTree，其节点由JLabel和JComboBox组成。我想要的是，当单击时，选定的JComboBox会展开，但似乎第一次单击是JTree本身（？）占用的，因此我必须单击两次。

这是我的代码：

import java.awt.*;
import java.awt.event.*;
import java.util.*;

import javax.swing.*;
import javax.swing.UIManager.LookAndFeelInfo;
import javax.swing.plaf.ColorUIResource;
import javax.swing.tree.*;

public class JComboBoxJTree extends JPanel {

    final JTree entitiesTree;

    public JComboBoxJTree() {

        entitiesTree = createTree();
        JScrollPane entitiesTreeScrollPane = new JScrollPane(entitiesTree);

        this.setLayout(new GridBagLayout());

        GridBagConstraints c = new GridBagConstraints();

        c.gridx = 0;
        c.gridy = 1;
        c.weightx = 1.0;
        c.weighty = 1.0;
        c.fill = GridBagConstraints.BOTH;
        c.insets = new Insets(0, 5, 0, 5);

        this.add(entitiesTreeScrollPane, c);

        entitiesTree.setBackground(Color.black);
        entitiesTreeScrollPane.setBackground(Color.black);
        this.setBackground(Color.black);

    }

    public static void main(String[] args) {
        try {
            for (LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {

                    UIManager.setLookAndFeel(info.getClassName());

                    UIManager.getLookAndFeelDefaults().put("Button.background",
                            Color.BLACK);

                    UIManager.getLookAndFeelDefaults().put(
                            "TextField.background", Color.BLACK);

                    UIManager.getLookAndFeelDefaults().put(
                            "ComboBox.background", Color.BLACK);

                    UIManager.getLookAndFeelDefaults().put(
                            "TextField.foreground", Color.WHITE);

                    UIManager.getLookAndFeelDefaults().put("List.foreground",
                            Color.WHITE);
                    UIManager.getLookAndFeelDefaults().put("List.background",
                            Color.BLACK);

                    UIManager.put("textForeground", Color.white);

                    UIManager.put("info", new ColorUIResource(Color.BLACK));

                    UIManager.put("ScrollPane.background", Color.black);

                    break;
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        JComboBoxJTree dialog = new JComboBoxJTree();

        JDialog jd = new JDialog();
        jd.add(dialog);
        jd.pack();
        jd.setVisible(true);
    }

    private static JTree createTree() {
        DefaultMutableTreeNode root = new DefaultMutableTreeNode(new Node(
                "Plugins"));
        root.add(new DefaultMutableTreeNode(new Node("Plugin 1", "Running",
                "Paused", "Stopped")));
        root.add(new DefaultMutableTreeNode(new Node("Plugin 2", "Running",
                "Paused", "Stopped")));
        DefaultMutableTreeNode leaf = new DefaultMutableTreeNode(new Node(
                "Plugin 3", "Running", "Paused", "Stopped"));

        root.add(leaf);

        leaf.add(new DefaultMutableTreeNode(new Node("Plugin 3A", "Running",
                "Paused", "Stopped")));
        leaf.add(new DefaultMutableTreeNode(new Node("Plugin 3B", "Running",
                "Paused", "Stopped")));

        JTree tree = new JTree(root);

        RendererDispatcher rendererDispatcher = new RendererDispatcher(tree);
        RendererDispatcher editorDispatcher = new RendererDispatcher(tree);
        tree.setCellRenderer(rendererDispatcher);
        tree.setCellEditor(editorDispatcher);

        tree.setEditable(true);
        return tree;
    }
}

class Node {

    final String name;
    final String[] plugins;
    boolean selected;
    int selectedPluginIndex;

    public Node(String name, String... plugins) {
        this.name = name;
        this.selected = false;
        this.plugins = plugins;
        if (plugins == null) {
            this.selectedPluginIndex = -1;
        } else {
            this.selectedPluginIndex = 0;
        }
    }

    public boolean isSelected() {
        return selected;
    }

    public void setSelected(boolean selected) {
        this.selected = selected;
    }

    public String toString() {
        return name;
    }

    public int getSelectedPluginIndex() {
        return selectedPluginIndex;
    }

    public void setSelectedPluginIndex(int selectedPluginIndex) {
        this.selectedPluginIndex = selectedPluginIndex;
    }

    public String[] getPlugins() {
        return plugins;
    }
}

class RendererDispatcher extends AbstractCellEditor implements
        TreeCellRenderer, TreeCellEditor {

    final static Color selectionForeground = UIManager
            .getColor("Tree.selectionForeground");
    final static Color selectionBackground = UIManager
            .getColor("Tree.selectionBackground");
    final static Color textForeground = UIManager
            .getColor("Tree.textForeground");
    final static Color textBackground = UIManager
            .getColor("Tree.textBackground");
    final JTree tree;
    final DefaultComboBoxModel comboBoxModel = new DefaultComboBoxModel();
    final JPanel panel = new JPanel();
    JLabel pluginName = new JLabel();
    final JComboBox comboBox = new JComboBox(comboBoxModel);
    final JComponent components[] = { panel, pluginName, comboBox };

    public RendererDispatcher(JTree tree) {
        this.tree = tree;
        Font font = UIManager.getFont("Tree.font");

        panel.add(pluginName);
        setForeground(Color.white);
        setBackground(Color.BLACK);

        if (font != null) {
            this.setFont(font);
        }
    }

    public Component getTreeCellRendererComponent(JTree tree, Object value,
            boolean selected, boolean expanded, boolean leaf, int row,
            boolean hasFocus) {
        final Node node = extractNode(value);

        this.setContents(node);

        this.setEnabled(tree.isEnabled());

        this.setForeground(Color.white);
        this.setBackground(Color.BLACK);

        return this.getComponent();
    }

    public Component getTreeCellEditorComponent(JTree tree, Object value,
            boolean selected, boolean expanded, boolean leaf, int row) {
        return getTreeCellRendererComponent(tree, value, true, expanded, leaf,
                row, true);
    }

    public Object getCellEditorValue() {
        return this.getContents();
    }

    public boolean isCellEditable(final EventObject event) {
        if (!(event instanceof MouseEvent)) {
            return false;
        }

        final MouseEvent mouseEvent = (MouseEvent) event;
        final TreePath path = tree.getPathForLocation(mouseEvent.getX(),
                mouseEvent.getY());
        if (path == null) {
            return false;
        }

        Object node = path.getLastPathComponent();
        if (node == null || (!(node instanceof DefaultMutableTreeNode))) {
            return false;
        }

        DefaultMutableTreeNode treeNode = (DefaultMutableTreeNode) node;
        Object userObject = treeNode.getUserObject();

        return (userObject instanceof Node);
    }

    private static Node extractNode(Object value) {
        if ((value != null) && (value instanceof DefaultMutableTreeNode)) {
            DefaultMutableTreeNode node = (DefaultMutableTreeNode) value;
            Object userObject = node.getUserObject();
            if ((userObject != null) && (userObject instanceof Node)) {
                return (Node) userObject;
            }
        }

        return null;
    }

    public void setForeground(final Color foreground) {
        for (int i = 0; i < components.length; i++) {
            components[i].setForeground(foreground);
        }
    }

    public void setBackground(final Color background) {
        for (int i = 0; i < components.length; i++) {
            components[i].setBackground(background);
        }
    }

    public void setFont(final Font font) {
        for (int i = 0; i < components.length; i++) {
            components[i].setFont(font);
        }
    }

    public void setEnabled(final boolean enabled) {
        for (int i = 0; i < components.length; i++) {
            components[i].setEnabled(enabled);
        }
    }

    public void setContents(Node node) {
        // checkBox.setText(node.toString());
        pluginName.setText(node.toString());

        comboBoxModel.removeAllElements();
        if (node.getPlugins().length > 0) {
            panel.add(comboBox);
            for (int i = 0; i < node.getPlugins().length; i++) {
                comboBoxModel.addElement(node.getPlugins()[i]);
            }
        } else {
            panel.remove(comboBox);
        }
    }

    public Object getContents() {
        String title = pluginName.getText();
        String[] plugins = new String[comboBoxModel.getSize()];
        for (int i = 0; i < comboBoxModel.getSize(); i++) {
            plugins[i] = comboBoxModel.getElementAt(i).toString();
        }
        Node node = new Node(title, plugins);
        node.setSelectedPluginIndex(comboBoxModel.getIndexOf(comboBoxModel
                .getSelectedItem()));
        return node;
    }

    public Component getComponent() {
        return panel;
    }
}

Answer 1

• 这是一个简短的示例：
• 这对我有用Java 1.8.0：Bug ID：JDK-8023474第一次按下鼠标并没有开始在JTree中进行编辑

    import java.awt.*;
    import java.awt.event.*;
    import java.util.*;
    import javax.swing.*;
    import javax.swing.tree.*;

    public class JComboBoxJTree2 {
      public JComponent makeUI() {
        String[] m = {"Running", "Paused", "Stopped"};
        DefaultMutableTreeNode root = new DefaultMutableTreeNode(new Node("Plugins"));
        root.add(new DefaultMutableTreeNode(new Node("Plugin 1", m)));
        root.add(new DefaultMutableTreeNode(new Node("Plugin 2", m)));
        DefaultMutableTreeNode leaf = new DefaultMutableTreeNode(new Node("Plugin 3", m));
        root.add(leaf);
        leaf.add(new DefaultMutableTreeNode(new Node("Plugin 3A", m)));
        leaf.add(new DefaultMutableTreeNode(new Node("Plugin 3B", m)));

        JTree tree = new JTree(root);
        RendererDispatcher rendererDispatcher = new RendererDispatcher(new JComboBox<String>());
        RendererDispatcher editorDispatcher = new RendererDispatcher(new JComboBox<String>());
        tree.setCellRenderer(rendererDispatcher);
        tree.setCellEditor(editorDispatcher);
        tree.setEditable(true);

        return new JScrollPane(tree);
      }
      public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
          @Override public void run() {
            createAndShowGUI();
          }
        });
      }
      public static void createAndShowGUI() {
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        f.getContentPane().add(new JComboBoxJTree2().makeUI());
        f.setSize(320, 240);
        f.setLocationRelativeTo(null);
        f.setVisible(true);
      }
    }

    class Node {
      private final String name;
      private final String[] plugins;
      private int selectedPluginIndex;
      public Node(String name, String... plugins) {
        this.name = name;
        this.plugins = plugins;
      }
      public String toString() {
        return name;
      }
      public int getSelectedPluginIndex() {
        return selectedPluginIndex;
      }
      public void setSelectedPluginIndex(int selectedPluginIndex) {
        this.selectedPluginIndex = selectedPluginIndex;
      }
      public String[] getPlugins() {
        return plugins;
      }
    }

    class RendererDispatcher extends DefaultCellEditor implements TreeCellRenderer {
      private final JPanel panel = new JPanel();
      private final JLabel pluginName = new JLabel();
      private final JComboBox<String> comboBox;
      private Node node;

      public RendererDispatcher(JComboBox<String> comboBox) {
        super(comboBox);
        this.comboBox = comboBox;
        panel.setOpaque(false);
        panel.add(pluginName);
        panel.add(comboBox);
      }
      @Override public Component getTreeCellRendererComponent(
          JTree tree, Object value, boolean selected, boolean expanded,
          boolean leaf, int row, boolean hasFocus) {
        Node node = extractNode(value);
        setContents(node);
        return panel;
      }
      @Override public Component getTreeCellEditorComponent(
          JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row) {
        Node node = extractNode(value);
        setContents(node);
        this.node = node;
        return panel;
      }
      @Override public Object getCellEditorValue() {
        Object o = super.getCellEditorValue();
        DefaultComboBoxModel<String> m = (DefaultComboBoxModel<String>) comboBox.getModel();
        Node n = new Node(pluginName.getText(), node.getPlugins());
        n.setSelectedPluginIndex(m.getIndexOf(o));
        return n;
      }
      @Override public boolean isCellEditable(final EventObject event) {
        Object source = event.getSource();
        if (!(source instanceof JTree) || !(event instanceof MouseEvent)) {
          return false;
        }
        final JTree tree = (JTree) source;
        final MouseEvent mouseEvent = (MouseEvent) event;
        final TreePath path = tree.getPathForLocation(mouseEvent.getX(), mouseEvent.getY());
        if (path == null) {
          return false;
        }
        Object node = path.getLastPathComponent();
        if (node == null || !(node instanceof DefaultMutableTreeNode)) {
          return false;
        }

        Rectangle r = tree.getPathBounds(path);
        if (r == null) {
          return false;
        }
        Dimension d = panel.getPreferredSize();
        r.setSize(new Dimension(d.width, r.height));
        if (r.contains(mouseEvent.getX(), mouseEvent.getY())) {
          EventQueue.invokeLater(new Runnable() {
            @Override public void run() {
              Point pt = SwingUtilities.convertPoint(tree, mouseEvent.getPoint(), panel);
              //System.out.println(pt);
              Object o = SwingUtilities.getDeepestComponentAt(panel, pt.x, pt.y);
              if (o instanceof JComboBox) {
                comboBox.showPopup();
              } else if (o instanceof Component) {
                Object oo = SwingUtilities.getAncestorOfClass(JComboBox.class, (Component) o);
                if (oo instanceof JComboBox) {
                  comboBox.showPopup();
                }
              }
            }
          });
          return true;
        }
        return delegate.isCellEditable(event);
      }
      private static Node extractNode(Object value) {
        if (value instanceof DefaultMutableTreeNode) {
          DefaultMutableTreeNode node = (DefaultMutableTreeNode) value;
          Object userObject = node.getUserObject();
          if (userObject instanceof Node) {
            return (Node) userObject;
          }
        }
        return null;
      }
      private void setContents(Node node) {
        if (node == null) {
          return;
        }
        pluginName.setText(node.toString());
        DefaultComboBoxModel<String> model = (DefaultComboBoxModel<String>) comboBox.getModel();
        model.removeAllElements();
        if (node.getPlugins().length > 0) {
          panel.add(comboBox);
          for (String s : node.getPlugins()) {
            model.addElement(s);
          }
          comboBox.setSelectedIndex(node.getSelectedPluginIndex());
        } else {
          panel.remove(comboBox);
        }
      }
    }