How to delete a row from jtable

Question

I want to change the action of the button to delete. I have this code:

package buttonexample;

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.*;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableModel;


public class ButtonExample {

public JTable table;

    public static void main(String[] args) {
    final ButtonExample example = new ButtonExample();
    javax.swing.SwingUtilities.invokeLater(new Runnable() {
        public void run() {
            example.createAndShowGUI();
        }
    });
}

private void createAndShowGUI() {
    JFrame frame = new JFrame("Button Example");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    table = new JTable(new JTableModel()); 
    JScrollPane scrollPane = new JScrollPane(table);
    table.setFillsViewportHeight(true); 

    TableCellRenderer buttonRenderer = new JTableButtonRenderer();
    //table.getColumn("Button1").setCellRenderer(buttonRenderer);
    table.getColumn("Button2").setCellRenderer(buttonRenderer);
    table.addMouseListener(new JTableButtonMouseListener(table));

    frame.getContentPane().add(scrollPane, BorderLayout.CENTER);
    frame.getContentPane().setPreferredSize(new Dimension(500, 200));
    frame.pack();
    frame.setVisible(true);
}

public static class JTableModel extends AbstractTableModel {
    private static final long serialVersionUID = 1L;
    private static final String[] COLUMN_NAMES = new String[] {"Id", "Stuff", "Asdfsdf", "Button2"};
    private static final Class[] COLUMN_TYPES = new Class[] {Integer.class, String.class, String.class,  JButton.class};

    @Override public int getColumnCount() {
        return COLUMN_NAMES.length;
    }

    @Override public int getRowCount() {
        return 4;
    }

    @Override public String getColumnName(int columnIndex) {
        return COLUMN_NAMES[columnIndex];
    }

    @Override public Class getColumnClass(int columnIndex) {
        return COLUMN_TYPES[columnIndex];
    }

    @Override public Object getValueAt(final int rowIndex, final int columnIndex) {

        switch (columnIndex) {
            case 0: return rowIndex;
            case 1: return "Text for "+rowIndex;
            case 2: return "Column for "+rowIndex;
            case 3: final JButton button = new JButton(COLUMN_NAMES[columnIndex]);
                    button.addActionListener(new ActionListener() {
            @Override
                        public void actionPerformed(ActionEvent arg0) {
                                                            // When this is clicked the whole row will be deleted.
                            JOptionPane.showMessageDialog(JOptionPane.getFrameForComponent(button), 
                                    "Button clicked for row "+rowIndex);
                        }
                    });
                    return button;
            default: return "Error";
        }
    }   
}

private static class JTableButtonRenderer implements TableCellRenderer {        
    @Override public Component getTableCellRendererComponent(JTable table, Object     value, boolean isSelected, boolean hasFocus, int row, int column) {
        JButton button = (JButton)value;
        if (isSelected) {
            button.setForeground(table.getSelectionForeground());
            button.setBackground(table.getSelectionBackground());
        } else {
            button.setForeground(table.getForeground());
            button.setBackground(UIManager.getColor("Button.background"));
        }
        return button;  
    }
}

private static class JTableButtonMouseListener extends MouseAdapter {
    private final JTable table;

    public JTableButtonMouseListener(JTable table) {
        this.table = table;
    }

    public void mouseClicked(MouseEvent e) {
        int column = table.getColumnModel().getColumnIndexAtX(e.getX());
        int row    = e.getY()/table.getRowHeight(); 

        if (row < table.getRowCount() && row >= 0 && column < table.getColumnCount() &&                    
column >= 0) {
            Object value = table.getValueAt(row, column);
            if (value instanceof JButton) {
                ((JButton)value).doClick();
            }
        }
    }
}
}

But the (DefaultTableModel)someTable.getModel(); model.removeRow(row); I can't make it work because the table model does not have any name and I don't know what to name it. I have tried initializing a table model and I get error saying non-static variable model cannot be reference to a static context. Is there a way to delete the row in a static context?

MadProgrammer · Accepted Answer

The example by camickr is probably a more reusable solution, but for the sake of education...

Rendering of cells is the domain of the view
Model's should never contain components, especially if you're thinking about rendering them to the screen, this is simply the wrong approach to take...
You need to set up a TableCellEditor which will act as the means by which you can retrieve notification of the edit actions (mouse click or keypress)

This is a basic example, for simplicity, I've used a DefaultTableModel as it has a nice removeRow method, but conceivably, you could use any TableModel, so long as you provided the means to remove a row and modified by the editor to support it...

enter image description here

import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.EventObject;
import javax.swing.AbstractCellEditor;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.UIManager;
import javax.swing.event.CellEditorListener;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableCellEditor;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableModel;

public class ButtonExample {

    public JTable table;

    public static void main(String[] args) {
        final ButtonExample example = new ButtonExample();
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                example.createAndShowGUI();
            }
        });
    }

    private void createAndShowGUI() {
        JFrame frame = new JFrame("Button Example");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        table = new JTable(new ExampleTableModel());
        JScrollPane scrollPane = new JScrollPane(table);
        table.setFillsViewportHeight(true);

        table.getColumn("action").setCellRenderer(new ButtonCellRenderer());
        table.getColumn("action").setCellEditor(new ButtonCellEditor());

        frame.getContentPane().add(scrollPane, BorderLayout.CENTER);
        frame.pack();
        frame.setVisible(true);
    }

    public static class ExampleTableModel extends DefaultTableModel {

        public ExampleTableModel() {
            super(new Object[]{"id", "stuff", "blah", "action"}, 0);
            for (int index = 0; index < 10; index++) {
                addRow(new Object[]{index, "Text for " + index, "Na na", index});
            }
        }

        @Override
        public boolean isCellEditable(int rowIndex, int columnIndex) {
            return columnIndex == 3;
        }

    }

    public static class ButtonCellRenderer extends JButton implements TableCellRenderer {

        @Override
        public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
            if (value != null) {
                setText("Delete row " + value.toString());
            } else {
                setText("Delete Me");
            }
            if (isSelected) {
                setForeground(table.getSelectionForeground());
                setBackground(table.getSelectionBackground());
            } else {
                setForeground(table.getForeground());
                setBackground(UIManager.getColor("Button.background"));
            }
            return this;
        }
    }

    public static class ButtonCellEditor extends AbstractCellEditor implements TableCellEditor {

        private JButton editor;
        private Object value;
        private int row;
        private JTable table;

        public ButtonCellEditor() {
            editor = new JButton();
            editor.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    if (table != null) {
                        fireEditingStopped();
                        TableModel model = table.getModel();
                        if (model instanceof DefaultTableModel) {
                            ((DefaultTableModel) model).removeRow(row);
                        }
                    }
                }
            });
        }

        @Override
        public boolean isCellEditable(EventObject e) {
            return true;
        }

        @Override
        public Object getCellEditorValue() {
            return value;
        }

        @Override
        public Component getTableCellEditorComponent(JTable table, Object value, boolean isSelected, int row, int column) {
            this.table = table;
            this.row = row;
            this.value = value;
            if (value != null) {
                editor.setText("Delete row " + value.toString());
            } else {
                editor.setText("Delete Me");
            }
            if (isSelected) {
                editor.setForeground(table.getSelectionForeground());
                editor.setBackground(table.getSelectionBackground());
            } else {
                editor.setForeground(table.getForeground());
                editor.setBackground(UIManager.getColor("Button.background"));
            }
            return editor;
        }
    }

}

Take a closer look at How to Use Tables for more details

This is just a personal preference, but I prefer to use a toolbar or menu item and key bindings to provide this support. Buttons in a table just seem so...dated - IMHO

How to delete a row from jtable

Answers (1)

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