Avoid focus on non-editable cells in a JTable

CustomSelectTable.java

package lu.statec.gui.blaise;

import java.awt.event.KeyEvent;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JComponent;
import javax.swing.KeyStroke;
import javax.swing.table.TableModel;
import org.jdesktop.swingx.JXTable;

/**
 * This table overrides the selection behavior. If the selection happens to land
 * on a non-editable cell, the selection is forwarded to the next editable cell.
 *
 * Additionally, the "Enter"/"Return" key is rebound, so it selects the next
 * cell instead of next row.
 *
 * NOTE:
 *    It extends JXTable from swingx. This is for convenience only. If you don't
 *    have or want to use swingx, you can simply replace it with a simple JTable
 *    in the class definition.
 *
 * Original idea by Joe Knapka can be found at:
 *    http://www.javakb.com/Uwe/Forum.aspx/java-gui/3796/Cell-focus-in-JTable-avoid-focus-on-non-editable-cells
 *
 * @author Michel Albert
 */
public class QuickEditTable extends JXTable {

    public static enum DIR {
        Up, Down, Left, Right
    }

    /**
     * The logger
     */
    private static final Logger LOG = Logger.getLogger(QuickEditTable.class.getCanonicalName());

    /**
     * Standard constructor
     */
    public QuickEditTable() {
        init();
    }

    /**
     * Default constructor, initialising the table with a TableModel
     *
     * @param tableModel
     */
    public QuickEditTable(TableModel tableModel) {
        super(tableModel);
        init();
    }

    /**
     * Initialisations common to all constructors.
     */
    private void init() {
        // When pressing enter, move to the next cell instead of the next row.
        getInputMap(JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT)
                .put(KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0), "selectNextColumnCell");

    }

    @Override
    public void changeSelection(int row, int col, boolean toggle, boolean expand) {
        // This method is called when the user tries to move to a different cell.
        // If the cell they're trying to move to is not editable, we look for
        // the next cell in the proper direction that is editable.
        
        // initialise the new (future) selection to the indices as specified in
        // the method call.
        // if everything is "normal" we can just use these values. All special
        // cases will overwrite the value contained herein. Eventually, these
        // variables are returned.
        int targetViewRow = row;
        int targetViewCol = col;

        int targetModelRow = convertRowIndexToModel(targetViewRow);
        int targetModelCol = convertColumnIndexToModel(targetViewCol);

        if (LOG.isLoggable(Level.FINE)){
            LOG.fine(String.format("Attempting to change the table selection "
                    + "to row %d, col %d, using toggle=%b and expand=%b",
                    targetViewRow, targetViewCol, toggle, expand));
            LOG.fine(String.format(" --> this maps to model row %d and col %d",
                    targetModelRow, targetModelCol));
        }

        if (!getModel().isCellEditable(targetModelRow, targetModelCol)) {
            if (LOG.isLoggable(Level.FINE)){
                LOG.fine(String.format("Cell %d,%d (%d,%d) is not editable!",
                        targetViewRow, targetViewCol, targetModelRow, targetModelCol));
            }

            // Find the row and column we're coming from.
            int oldViewRow = getEditingRow();
            int oldViewCol = getEditingColumn();
            if (oldViewRow == -1) {
                oldViewRow = getSelectedRow();
            }
            if (oldViewCol == -1) {
                oldViewCol = getSelectedColumn();
            }

            if (LOG.isLoggable(Level.FINE)) {
                LOG.fine(String.format("We came from cell %d,%d",
                        oldViewRow, oldViewCol));
            }

            DIR direction;
            if (oldViewCol == targetViewCol && oldViewRow < targetViewRow) {
                direction = DIR.Down;
            } else if (oldViewCol == targetViewCol && oldViewRow >= targetViewRow) {
                direction = DIR.Up;
            } else if (oldViewCol == targetViewCol && oldViewRow == targetViewRow) {
                direction = DIR.Left;
            } else {
                // defaulting to right
                direction = DIR.Right;
            }

            LOG.fine(String.format("Moving %s", direction));

            // determine next cell position
            while (!getModel().isCellEditable(targetModelRow, targetModelCol)) {
                LOG.fine(String.format("Model-Cell %d,%d is still not editable",
                        targetModelRow, targetModelCol));
                switch (direction) {
                    case Up:
                        targetViewRow -= 1;
                        if (targetViewRow < 0) {
                            targetViewRow = getRowCount() - 1;
                        }
                        break;
                    case Down:
                        targetViewRow += 1;
                        if (targetViewRow > getRowCount() - 1) {
                            targetViewRow = 0;
                        }
                        break;
                    case Left:
                        targetViewCol -= 1;
                        if (targetViewCol < 0) {
                            targetViewCol = getRowCount() - 1;
                            targetViewRow -= 1;
                            if (targetViewRow < 0) {
                                targetViewRow = getRowCount() - 1;
                            }
                        }
                        break;
                    case Right:
                        targetViewCol += 1;
                        if (targetViewCol > getColumnCount() - 1) {
                            targetViewCol = 0;
                            targetViewRow += 1;
                            if (targetViewRow > getRowCount() - 1) {
                                targetViewRow = 0;
                            }
                        }
                        break;
                }
                targetModelRow = convertRowIndexToModel(targetViewRow);
                targetModelCol = convertColumnIndexToModel(targetViewCol);
            }
            LOG.fine(String.format("Trying to move selection to %d,%d instead!",
                    targetViewRow, targetViewCol));

        }

        super.changeSelection(targetViewRow, targetViewCol, toggle, expand);
    }

}

This class was first written by Joe Knapka. With his permission, I decided to put it here, to allow easy fixes and edits.

Joe's original post: http://www.javakb.com/Uwe/Forum.aspx/java-gui/3796/Cell-focus-in-JTable-avoid-focus-on-non-editable-cells

My current version uses offsets to ensure model indices. I should replace this with properly mapped indices. I am currently working on this.

I just finished the modifications concerning the row/column indices. They are now properly mapped to the underlying model. Along the lines, I added a standard logger and some logging messages.

Rewrote the selection logic slightly. My previous modification had a flawed logic concerning the model <-> view conversion of column indices. This implementation seems to work correctly. At the same time, I inlined the two separate methods into one block.

Hello, it's a great pleasure to say hello, I do not speak or write in English and I apologize if it does not read well since I use Google translation, I'm a Java beginner and I do not know how to start this class to use a JFrame, I have a project at the university and they ask me to do what they implemented in this class. I do not know if you could help me use your class from a jframe that has a table to evaluate the cells when they have the focus, thanks in advance.
I use the Netbeans IDE and the table is created graphically, not by code, my question is how do I apply its class to the table that I create graphically. So I have tried but it does not work for me:

Object [] col = {"Sku", "Descripcon", "Measure", "Quantity", "Price", "SubTotal"};

// this table is the one I have created from the graphic environment and here I assign it to its class but it does not work
table = new CustomSelectTable (model);

I do not know how it would be the correct way to implement your class to the JTable that you create.

And modelÑ
DefaultTableModel model = new DefaultTableModel(null,col);