JToolTip on JTable - Not showing

Question

I am trying to implement a JToolTip on a JTable, however I have run into some issues. I Found the oracle example of how to do it on the following link:

http://docs.oracle.com/javase/tutorial/uiswing/examples/components/TableToolTipsDemoProject/src/components/TableToolTipsDemo.java

public class test extends JPanel {
    private boolean DEBUG = false;
    protected String[] columnToolTips = {null,
                                         null,
                                         "The person's favorite sport to participate in",
                                         "The number of years the person has played the sport",
                                         "If checked, the person eats no meat"};

    public test() {
        super(new GridLayout(1,0));

        JTable table = new JTable(new MyTableModel()) {

            //Implement table cell tool tips.
            public String getToolTipText(MouseEvent e) {
                String tip = null;
                java.awt.Point p = e.getPoint();
                int rowIndex = rowAtPoint(p);
                int colIndex = columnAtPoint(p);
                int realColumnIndex = convertColumnIndexToModel(colIndex);

                if (realColumnIndex == 2) { //Sport column
                    tip = "This person's favorite sport to "
                           + "participate in is: "
                           + getValueAt(rowIndex, colIndex);
                } else if (realColumnIndex == 4) { //Veggie column
                    TableModel model = getModel();
                    String firstName = (String)model.getValueAt(rowIndex,0);
                    String lastName = (String)model.getValueAt(rowIndex,1);
                    Boolean veggie = (Boolean)model.getValueAt(rowIndex,4);
                    if (Boolean.TRUE.equals(veggie)) {
                        tip = firstName + " " + lastName
                              + " is a vegetarian";
                    } else {
                        tip = firstName + " " + lastName
                              + " is not a vegetarian";
                    }
                } else { 
                    //You can omit this part if you know you don't 
                    //have any renderers that supply their own tool 
                    //tips.
                    tip = super.getToolTipText(e);
                }
                return tip;
            }

            //Implement table header tool tips. 
            protected JTableHeader createDefaultTableHeader() {
                return new JTableHeader(columnModel) {
                    public String getToolTipText(MouseEvent e) {
                        String tip = null;
                        java.awt.Point p = e.getPoint();
                        int index = columnModel.getColumnIndexAtX(p.x);
                        int realIndex = columnModel.getColumn(index).getModelIndex();
                        return columnToolTips[realIndex];
                    }
                };
            }
        };

        table.setPreferredScrollableViewportSize(new Dimension(500, 70));
        table.setFillsViewportHeight(true);

        //Create the scroll pane and add the table to it.
        JScrollPane scrollPane = new JScrollPane(table);

        //Add the scroll pane to this panel.
        add(scrollPane);
    }

    class MyTableModel extends AbstractTableModel {
        private String[] columnNames = {"First Name",
                                        "Last Name",
                                        "Sport",
                                        "# of Years",
                                        "Vegetarian"};
        private Object[][] data = {
        {"Kathy", "Smith",
         "Snowboarding", new Integer(5), new Boolean(false)},
        {"John", "Doe",
         "Rowing", new Integer(3), new Boolean(true)},
        {"Sue", "Black",
         "Knitting", new Integer(2), new Boolean(false)},
        {"Jane", "White",
         "Speed reading", new Integer(20), new Boolean(true)},
        {"Joe", "Brown",
         "Pool", new Integer(10), new Boolean(false)}
        };

        public int getColumnCount() {
            return columnNames.length;
        }

        public int getRowCount() {
            return data.length;
        }

        public String getColumnName(int col) {
            return columnNames[col];
        }

        public Object getValueAt(int row, int col) {
            return data[row][col];
        }

        /*
         * JTable uses this method to determine the default renderer/
         * editor for each cell.  If we didn't implement this method,
         * then the last column would contain text ("true"/"false"),
         * rather than a check box.
         */
        public Class getColumnClass(int c) {
            return getValueAt(0, c).getClass();
        }

        /*
         * Don't need to implement this method unless your table's
         * editable.
         */
        public boolean isCellEditable(int row, int col) {
            //Note that the data/cell address is constant,
            //no matter where the cell appears onscreen.
            if (col < 2) {
                return false;
            } else {
                return true;
            }
        }

        /*
         * Don't need to implement this method unless your table's
         * data can change.
         */
        public void setValueAt(Object value, int row, int col) {
            if (DEBUG) {
                System.out.println("Setting value at " + row + "," + col
                                   + " to " + value
                                   + " (an instance of "
                                   + value.getClass() + ")");
            }

            data[row][col] = value;
            fireTableCellUpdated(row, col);

            if (DEBUG) {
                System.out.println("New value of data:");
                printDebugData();
            }
        }

        private void printDebugData() {
            int numRows = getRowCount();
            int numCols = getColumnCount();

            for (int i=0; i < numRows; i++) {
                System.out.print("    row " + i + ":");
                for (int j=0; j < numCols; j++) {
                    System.out.print("  " + data[i][j]);
                }
                System.out.println();
            }
            System.out.println("--------------------------");
        }
    }

    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void createAndShowGUI() {
        //Create and set up the window.
        JFrame frame = new JFrame("TableToolTipsDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Create and set up the content pane.
        JComponent newContentPane = new test();
        newContentPane.setOpaque(true); //content panes must be opaque
        frame.setContentPane(newContentPane);

        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}

However, when I compile this and run it, no tool tips are shown?

Any help as to why would be great,

Thanks.

pratikch · Accepted Answer

as per your code snippet getToolTipText() method is returning the tooltips for selective columns only namely(2,4) and for headers you have an array columnToolTips where values for only 3,4,5 columns is specified.

So, In nutshell your code is working just fine. Please make the appropriate changes and you will be good to go.

JToolTip on JTable - Not showing

Answers (2)

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