Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.awt.Component;
import java.awt.Dimension;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseEvent;
import java.util.EventObject;

import javax.swing.DefaultCellEditor;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.TreeCellRenderer;
import javax.swing.tree.TreePath;

public class Main {
    public static void main(String[] args) {
        String[] m = { "A", "B", "C" };
        DefaultMutableTreeNode root = new DefaultMutableTreeNode(new Node("Values"));
        root.add(new DefaultMutableTreeNode(new Node("Value 1", m)));
        root.add(new DefaultMutableTreeNode(new Node("Value 2", m)));
        DefaultMutableTreeNode leaf = new DefaultMutableTreeNode(new Node("Value 3", m));
        root.add(leaf);
        leaf.add(new DefaultMutableTreeNode(new Node("Value 3A", m)));
        leaf.add(new DefaultMutableTreeNode(new Node("Value 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);

        JFrame f = new JFrame();
        f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        f.getContentPane().add(new JScrollPane(tree));
        f.setSize(320, 240);
        f.setVisible(true);
    }
}

class Node {
    String name;
    String[] Values;
    int myIndex;

    public Node(String name, String... Values) {
        this.name = name;
        this.Values = Values;
    }

    public String toString() {
        return name;
    }

    public int getMyIndex() {
        return myIndex;
    }

    public void setIndex(int selectedValueIndex) {
        this.myIndex = selectedValueIndex;
    }

    public String[] getValues() {
        return Values;
    }
}

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

    public RendererDispatcher(JComboBox<String> comboBox) {
        super(comboBox);
        this.comboBox = comboBox;
        panel.setOpaque(false);
        panel.add(ValueName);
        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(ValueName.getText(), node.getValues());
        n.setIndex(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;
        }
        JTree tree = (JTree) source;
        MouseEvent mouseEvent = (MouseEvent) event;
        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())) {
            Point pt = SwingUtilities.convertPoint(tree, mouseEvent.getPoint(), panel);
            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;
        }
        ValueName.setText(node.toString());
        DefaultComboBoxModel<String> model = (DefaultComboBoxModel<String>) comboBox.getModel();
        model.removeAllElements();
        if (node.getValues().length > 0) {
            panel.add(comboBox);
            for (String s : node.getValues()) {
                model.addElement(s);
            }
            comboBox.setSelectedIndex(node.getMyIndex());
        } else {
            panel.remove(comboBox);
        }
    }
}