JTree select node by clicking anywhere on the row

Question

I have code taken from here that would allow selection of a JTree Row by clicking anywhere on the row. it works fine in single row selection mode. However, I am not sure how to modify it in order to handle multiple row selections. how do I distinguish the case when user is make a multiple selection(eg. by holding down the shift or control button while making a left mouse click on a row)?

import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;

import javax.swing.JFrame;
import javax.swing.JTree;
import javax.swing.SwingUtilities;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.TreeNode;


@SuppressWarnings("serial")
public class NavTree extends JTree {

    private boolean                 fWholeRowSelectionEnabled;
    private MouseListener           fRowSelectionListener;
    final NavTree                   fThis;

    public NavTree(TreeNode rootNode) {
        super(rootNode);
        fThis = this;
        init();
    }
    public NavTree() {
        fThis = this;
        init();
    }

    private void init() {
        //setCellRenderer(new NavTreeCellRenderer());
        fRowSelectionListener = new MouseAdapter() {

            public void mousePressed(MouseEvent e) {
                if (SwingUtilities.isLeftMouseButton(e)) {
                    int closestRow = fThis.getClosestRowForLocation(
                            e.getX(), e.getY());
                    Rectangle closestRowBounds = fThis.getRowBounds(closestRow);
                    if(e.getY() >= closestRowBounds.getY() && 
                            e.getY() < closestRowBounds.getY() + 
                            closestRowBounds.getHeight()) {
                        if(e.getX() > closestRowBounds.getX() && 
                                closestRow < fThis.getRowCount()){

                                                    fThis.setSelectionRow(closestRow);
                                                }

                    } else
                        fThis.setSelectionRow(-1);
                }
            }

        };
        setWholeRowSelectionEnabled(true);
    }

    public void setWholeRowSelectionEnabled(boolean wholeRowSelectionEnabled) {
        fWholeRowSelectionEnabled = wholeRowSelectionEnabled;
        if (fWholeRowSelectionEnabled)
            addMouseListener(fRowSelectionListener);
        else
            removeMouseListener(fRowSelectionListener);
    }

    public boolean isWholeRowSelectionEnabled() {
        return fWholeRowSelectionEnabled;
    }

    public static void main(String[] args) {
        JFrame frame = new JFrame();
        DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root");
        root.add(new DefaultMutableTreeNode("Child 1"));
        root.add(new DefaultMutableTreeNode("Child 2"));
        root.add(new DefaultMutableTreeNode("Child 3"));
        NavTree tree = new NavTree(root);
        frame.add(tree);
        frame.setSize(200, 300);
        frame.setVisible(true);
    }
}

score 3 · Accepted Answer · answered Jun 06 '12 at 06:00

3

Use the modifier key information of the MouseEvent. See MouseEvent#getModifiersEx for more information

answered Jun 06 '12 at 06:00

Robin

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thanks, but it's a little bit platform dependent, is there a better way? – user881480 Jun 06 '12 at 07:23
2

It's only platform dependent in the sense that it requires a platform with a keyboard... – Tharwen Jun 06 '12 at 07:37

score 1 · Answer 2 · edited May 23 '17 at 12:32

PS: the listener registration contains a bug

public void setWholeRowSelectionEnabled(boolean wholeRowSelectionEnabled) {
    fWholeRowSelectionEnabled = wholeRowSelectionEnabled;
    if (fWholeRowSelectionEnabled)
        addMouseListener(fRowSelectionListener);
    else
        removeMouseListener(fRowSelectionListener);
}

Setting the property wholeRowSelectionEnabled to true should register the listener only one time. Your code would add the listener again and again if the property is set to true multiple times. What I mean is that the property setter should be idempotent.

A quickfix could be to remove it first and add it if enabled

public void setWholeRowSelectionEnabled(boolean wholeRowSelectionEnabled) {
    removeMouseListener(fRowSelectionListener);
    fWholeRowSelectionEnabled = wholeRowSelectionEnabled;
    if (fWholeRowSelectionEnabled)
        addMouseListener(fRowSelectionListener);
}

JTree select node by clicking anywhere on the row

2 Answers2