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javaswinguser-interfacejtreejcheckbox

Checkbox JTree with selectable nodes

I'm using this example code here to create a JTree where all the leafs have a checkbox. The issue I'm running into is I also need to be able to select node objects without it necessarily ticking the check box. In my use case, ticking the checkbox will make something visible or hidden, but selecting the node will allow the object to be edited in a separate portion of the UI. What is the best way to go about this, is it possible to detect when the 'box' portion of the checkbox is clicked on and otherwise the node get selected?

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Font;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.MouseEvent;
import java.util.EventObject;
import java.util.Vector;
import javax.swing.AbstractCellEditor;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.UIManager;
import javax.swing.event.ChangeEvent;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.TreeCellEditor;
import javax.swing.tree.TreeCellRenderer;
import javax.swing.tree.TreePath;

public class CheckBoxNodeTreeSample {
    public static void main(String args[]) {
            JFrame frame = new JFrame("CheckBox Tree");

            CheckBoxNode accessibilityOptions[] = {
                            new CheckBoxNode(
                                            "Move system caret with focus/selection changes", false),
                            new CheckBoxNode("Always expand alt text for images", true) };
            CheckBoxNode browsingOptions[] = {
                            new CheckBoxNode("Notify when downloads complete", true),
                            new CheckBoxNode("Disable script debugging", true),
                            new CheckBoxNode("Use AutoComplete", true),
                            new CheckBoxNode("Browse in a new process", false) };
            Vector accessVector = new NamedVector("Accessibility",
                            accessibilityOptions);
            Vector browseVector = new NamedVector("Browsing", browsingOptions);
            Object rootNodes[] = { accessVector, browseVector };
            Vector rootVector = new NamedVector("Root", rootNodes);
            JTree tree = new JTree(rootVector);

            CheckBoxNodeRenderer renderer = new CheckBoxNodeRenderer();
            tree.setCellRenderer(renderer);

            tree.setCellEditor(new CheckBoxNodeEditor(tree));
            tree.setEditable(true);

            JScrollPane scrollPane = new JScrollPane(tree);
            frame.getContentPane().add(scrollPane, BorderLayout.CENTER);
            frame.setSize(300, 150);
            frame.setVisible(true);
    }
}

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 AbstractCellEditor implements TreeCellEditor {

    CheckBoxNodeRenderer renderer = new CheckBoxNodeRenderer();

    ChangeEvent changeEvent = null;

    JTree tree;

    public CheckBoxNodeEditor(JTree tree) {
            this.tree = tree;
    }

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

    public boolean isCellEditable(EventObject event) {
            boolean returnValue = false;
            if (event instanceof MouseEvent) {
                    MouseEvent mouseEvent = (MouseEvent) event;
                    TreePath path = tree.getPathForLocation(mouseEvent.getX(),
                                    mouseEvent.getY());
                    if (path != null) {
                            Object node = path.getLastPathComponent();
                            if ((node != null) && (node instanceof DefaultMutableTreeNode)) {
                                    DefaultMutableTreeNode treeNode = (DefaultMutableTreeNode) node;
                                    Object userObject = treeNode.getUserObject();
                                    returnValue = ((treeNode.isLeaf()) && (userObject instanceof CheckBoxNode));
                            }
                    }
            }
            return returnValue;
    }

    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;
    }
}

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 + "]";
    }
}

class NamedVector extends Vector {
    String name;

    public NamedVector(String name) {
            this.name = name;
    }

    public NamedVector(String name, Object elements[]) {
            this.name = name;
            for (int i = 0, n = elements.length; i < n; i++) {
                    add(elements[i]);
            }
    }

    public String toString() {
            return "[" + name + "]";
    }
}

The other bug I'm seeing is when the 'folder' has sub-elements, the indicator to the left of the folder properly shows the the folder is open:

Folder With Sub-Elements (Closed)Folder With Sub-Elements (Open)

But if the 'folder' is empty, that indicator appears initially, but when you open it it disappears. I would assume this should not appear initially if the folder is empty.

Folder Without Sub-Elements (Closed)Folder Without Sub-Elements (Closed)

Solution

  • I was able to get this working with @MadProgrammer suggestion to decouple the Checkbox and text, as well as removed the tree reference in CheckBoxNodeEditor, the updated code is below:

    import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Font;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.MouseEvent;
import java.util.EventObject;
import java.util.Vector;

import javax.swing.AbstractCellEditor;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.UIManager;
import javax.swing.border.EmptyBorder;
import javax.swing.event.ChangeEvent;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.TreeCellEditor;
import javax.swing.tree.TreeCellRenderer;
import javax.swing.tree.TreePath;

public class CheckBoxNodeTreeSample 
{
    
    private JTree tree;

    public static void main(String... s)
    {
        new CheckBoxNodeTreeSample();
    }

    public CheckBoxNodeTreeSample() 
    {
        JFrame frame = new JFrame("CheckBox Tree");
    
        CheckBoxNode accessibilityOptions[] = {
                    new CheckBoxNode(
                                    "Move system caret with focus/selection changes", false),
                    new CheckBoxNode("Always expand alt text for images", true) };
        CheckBoxNode browsingOptions[] = {
                    new CheckBoxNode("Notify when downloads complete", true),
                    new CheckBoxNode("Disable script debugging", true),
                    new CheckBoxNode("Use AutoComplete", true),
                    new CheckBoxNode("Browse in a new process", false) };
        Vector accessVector = new NamedVector("Accessibility",
                    accessibilityOptions);
        Vector browseVector = new NamedVector("Browsing", browsingOptions);
        Object rootNodes[] = { accessVector, browseVector };
        Vector rootVector = new NamedVector("Root", rootNodes);
        tree = new JTree(rootVector);
   
    
        CheckBoxNodeRenderer renderer = new CheckBoxNodeRenderer();
        tree.setCellRenderer(renderer);
        tree.setCellEditor(new CheckBoxNodeEditor());
        tree.setEditable(true);

        JScrollPane scrollPane = new JScrollPane(tree);
        frame.getContentPane().add(scrollPane, BorderLayout.CENTER);
        frame.setSize(360, 260);
        frame.setVisible(true);
    }
}

class CheckBoxPanel extends JPanel
{
    public JCheckBox checkBox;
    public JLabel label;

    public CheckBoxPanel() 
    { 
        super();
    
        checkBox = new JCheckBox();
        label = new JLabel();
    
        checkBox.setBorder(new EmptyBorder(0, 0, 0, 0));

        add(checkBox);
        add(label);
    }
}

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

    private DefaultTreeCellRenderer nonLeafRenderer = new DefaultTreeCellRenderer();

    Color selectionBorderColor, selectionForeground, selectionBackground,
                    textForeground, textBackground;

    protected CheckBoxPanel getLeafRenderer() 
    {
            return leafRenderer;
    }

    public CheckBoxNodeRenderer() {
            Font fontValue;
            fontValue = UIManager.getFont("Tree.font");
            if (fontValue != null) {
                    leafRenderer.checkBox.setFont(fontValue);
                    leafRenderer.label.setFont(fontValue);
            }
            Boolean booleanValue = (Boolean) UIManager
                            .get("Tree.drawsFocusBorderAroundIcon");
            leafRenderer.checkBox.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.checkBox.setSelected(false);
                    leafRenderer.label.setText(stringValue);

                    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.checkBox.setSelected(node.isSelected());
                                    leafRenderer.label.setText(node.getText());
                            }
                    }
                    returnValue = leafRenderer;
            } else {
                    returnValue = nonLeafRenderer.getTreeCellRendererComponent(tree,
                                    value, selected, expanded, leaf, row, hasFocus);
            }
            return returnValue;
    }
}

class CheckBoxNodeEditor extends AbstractCellEditor implements TreeCellEditor {

    CheckBoxNodeRenderer renderer = new CheckBoxNodeRenderer();

    ChangeEvent changeEvent = null;

    public Object getCellEditorValue() {
            CheckBoxPanel checkBoxPanel = renderer.getLeafRenderer();
            CheckBoxNode checkBoxNode = new CheckBoxNode(checkBoxPanel.label.getText(),
                    checkBoxPanel.checkBox.isSelected());
            return checkBoxNode;
    }

    public boolean isCellEditable(EventObject event) {
            boolean returnValue = false;
            if (event instanceof MouseEvent) {
                    MouseEvent mouseEvent = (MouseEvent) event;
                    JTree tree = (JTree)event.getSource();

                    TreePath path = tree.getPathForLocation(mouseEvent.getX(),
                                    mouseEvent.getY());
                    if (path != null) {
                            Object node = path.getLastPathComponent();
                            if ((node != null) && (node instanceof DefaultMutableTreeNode)) {
                                    DefaultMutableTreeNode treeNode = (DefaultMutableTreeNode) node;
                                    Object userObject = treeNode.getUserObject();
                                    returnValue = ((treeNode.isLeaf()) && (userObject instanceof CheckBoxNode));
                            }
                    }
            }
            return returnValue;
    }

    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 CheckBoxPanel) 
            {
                ((CheckBoxPanel) editor).checkBox.addItemListener(itemListener);
            }

            return editor;
    }
}

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 + "]";
    }
}

class NamedVector extends Vector 
{
    String name;

    public NamedVector(String name) {
            this.name = name;
    }

    public NamedVector(String name, Object elements[]) {
            this.name = name;
            for (int i = 0, n = elements.length; i < n; i++) {
                    add(elements[i]);
            }
    }

    public String toString() {
            return "[" + name + "]";
    }
}