为JTable中的不同单元格添加不同的JComboBoxes

Question

Say I have an object representing a Person. Each person has a name, and a list of hobbies.

Now, I want to create a table with 2 columns for the list of persons that I have. The first column will show the name of the person, and the second will show the list of hobbies in a combo box.

The thing is, I iterate over my list of persons in order to populate the table. So I don't have a way to know at the beginning "row 1 will have combo box X, row 2 will have combo box Y and so on". I will only know these things at runtime.

Got any ideas?

Answer 1

Cell editing is provided by a CellEditor . This basically means that each column will have the same cell editor. There are ways around this, but lets keep it simple.

Assuming that the list of hobbies is finite, and the list is the same for all people, it would be a simple matter to create a JComboBox based CellEditor and apply it to the table

Start by taking a look at Concepts: Editors and Renderers and Using Other Editors

import java.awt.EventQueue;
import java.util.ArrayList;
import java.util.List;
import javax.swing.ComboBoxModel;
import javax.swing.DefaultCellEditor;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.table.AbstractTableModel;

public class Hobbies {

    public static void main(String[] args) {
        new Hobbies();
    }

    public Hobbies() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                List<Person> people = new ArrayList<>(25);
                people.add(new Person("Mellisa"));
                people.add(new Person("Annabell"));
                people.add(new Person("Margarita"));
                people.add(new Person("Steve"));
                people.add(new Person("Christel"));

                DefaultCellEditor editor = new DefaultCellEditor(new JComboBox(createHobbiesComboBoxModel()));

                PersonTableModel model = new PersonTableModel(people);
                JTable table = new JTable(model);
                table.getColumnModel().getColumn(1).setCellEditor(editor);

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new JScrollPane(table));
                frame.pack();
                frame.setLocationByPlatform(true);
                frame.setVisible(true);
            }
        });
    }

    public ComboBoxModel createHobbiesComboBoxModel() {
        String[] hobbies = {"3D Printing",
            "A vintage scrapbook",
            "Amateur radio[1]",
            "Baton twirling",
            "Cleaning",
            "Computer programming",
            "Cooking",
            "Coloring",
            "Cosplaying",
            "Creative writing",
            "Crocheting",
            "Cryptography",
            "Dance",
            "Digital arts",
            "Drama",
            "Drawing",
            "Drinking Coffee",
            "Eating",
            "Electronics",
            "Embroidery",
            "Foreign language learning",
            "Gaming (tabletop games and role-playing games)",
            "Gambling",
            "Genealogy",
            "Homebrewing"};
        return new DefaultComboBoxModel(hobbies);
    }

    public class PersonTableModel extends AbstractTableModel {

        private List<Person> people;

        public PersonTableModel(List<Person> person) {
            people = new ArrayList<>(person);
        }

        @Override
        public int getRowCount() {
            return people.size();
        }

        @Override
        public int getColumnCount() {
            return 2;
        }

        @Override
        public boolean isCellEditable(int rowIndex, int columnIndex) {
            return columnIndex == 1;
        }

        @Override
        public String getColumnName(int columnIndex) {
            String value = null;
            switch (columnIndex) {
                case 0:
                    value = "Name";
                    break;
                case 1:
                    value = "Hobby";
                    break;
            }
            return value;
        }

        @Override
        public void setValueAt(Object aValue, int rowIndex, int columnIndex) {
            if (columnIndex == 1) {
                Person person = people.get(rowIndex);
                person.setHobby(aValue == null ? null : aValue.toString());
                fireTableCellUpdated(rowIndex, columnIndex);
            }
        }

        @Override
        public Object getValueAt(int rowIndex, int columnIndex) {
            Object value = null;
            Person person = people.get(rowIndex);
            switch (columnIndex) {
                case 0:
                    value = person.getName();
                    break;
                case 1:
                    value = person.getHobby();
                    break;
            }
            return value;
        }

    }

    public class Person {

        private String name;
        private String hobby;

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

        public void setHobby(String hobby) {
            this.hobby = hobby;
        }

        public String getName() {
            return name;
        }

        public String getHobby() {
            return hobby;
        }

    }

}