I'm new to GUI design and I'm trying to plan this out before I go too far the wrong way, any help would be nice. I'm trying to display a JTable with rows of Employee, which itself has datatypes of String and ArrayList<Cert>. Cert contains a String.
I'd like to have the table present the data for editing, but for a few of the columns I'd like to implement a JComboBox for selection of a String from a set of valid strings, as well as color each option differently (different background colors in the JComboBox).
Also, the ArrayList<Cert> currently displays in a cell as [xxx, xxx, ...] where XXX is the return from the toString() function for each item in the ArrayList. I think I'd like to display that ArrayList<Cert> as a read-only JComboBox, but I'm not as concerned with this item.
I'm questioning how many classes I need to create to make this happen. I already have a custom model for the JTable extending AbstractTableModel. Do I need to write an extension of JComboBox or do I just need to extend the appropriate renderer for a JComboBox as a cell and do the magic there, then assign that custom renderer to the cell renderer for the String cell?
Here's what I have so far, lightly abridged:
public class EmployeeTableModel extends AbstractTableModel {
...
private ArrayList<Employee> myDataObjects = new ArrayList<Employee>();
...
@Override
public Object getValueAt(int row, int column) {
Employee emp = myDataObjects.get(row);
switch (column) {
case 0:
return emp.getName();
case 1:
return emp.getShift();
case 2:
return emp.getCertifications();
default:
return "";
}
}
}
Employees:
public class Employee {
private String name;
private String shift;
private ArrayList<Cert> certs;
...
public String getName() {
return name;
}
public String getShift() {
return shift;
}
public ArrayList<Cert> getCerts() {
return certs;
}
...
}
And the initializations:
EmployeeTableModel etm = new EmployeeTableModel();
JTable employeeTable = new JTable();
employeeTable.setModel( etm );
you can to start with, simplest code as is possible, maybe depends if you want to see JComboBox as Renderer too by @aterai
import java.awt.BorderLayout;
import javax.swing.DefaultCellEditor;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableColumn;
import java.awt.Component;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JList;
import javax.swing.plaf.basic.BasicComboBoxRenderer;
public class TableRenderDemo extends JPanel {
private static final long serialVersionUID = 1L;
public TableRenderDemo() {
super(new BorderLayout(5, 5));
final JTable table = new JTable(new MyTableModel());
table.setPreferredScrollableViewportSize(table.getPreferredSize());
table.setFillsViewportHeight(true);
table.setRowHeight(20);
JScrollPane scrollPane = new JScrollPane(table);
initColumnSizes(table);
setUpSportColumn(table, table.getColumnModel().getColumn(2));
add(scrollPane, BorderLayout.CENTER);
JButton resetButton = new JButton("Reset to default");
resetButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
for (int i = 0; i < table.getRowCount(); i++) {
table.getModel().setValueAt("None of the above", i, 2);
}
}
});
add(resetButton, BorderLayout.SOUTH);
}
private void initColumnSizes(JTable table) {
MyTableModel model = (MyTableModel) table.getModel();
TableColumn column = null;
Component comp = null;
int headerWidth = 0;
int cellWidth = 0;
Object[] longValues = model.longValues;
TableCellRenderer headerRenderer = table.getTableHeader().getDefaultRenderer();
for (int i = 0; i < 5; i++) {
column = table.getColumnModel().getColumn(i);
comp = headerRenderer.getTableCellRendererComponent(null, column.getHeaderValue(), false, false, 0, 0);
headerWidth = comp.getPreferredSize().width;
comp = table.getDefaultRenderer(model.getColumnClass(i)).getTableCellRendererComponent(table, longValues[i], false, false, 0, i);
cellWidth = comp.getPreferredSize().width;
column.setPreferredWidth(Math.max(headerWidth, cellWidth));
}
}
private void setUpSportColumn(JTable table, TableColumn sportColumn) {
ArrayList<String> listSomeString = new ArrayList<String>();
listSomeString.add("Snowboarding");
listSomeString.add("Rowing");
listSomeString.add("Knitting");
listSomeString.add("Speed reading");
listSomeString.add("Pool");
listSomeString.add("None of the above");
JComboBox comboBox = new JComboBox();
comboBox.addItem(new Item(1, "-"));
comboBox.addItem(new Item(2, "Snowboarding"));
comboBox.addItem(new Item(3, "Rowing"));
comboBox.addItem(new Item(4, "Knitting"));
comboBox.addItem(new Item(5, "Speed reading"));
comboBox.addItem(new Item(6, "Pool"));
comboBox.addItem(new Item(7, "None of the above"));
comboBox.setMaximumRowCount(3);
comboBox.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
JComboBox comboBox = (JComboBox) e.getSource();
Item item = (Item) comboBox.getSelectedItem();
System.out.println(item.getId() + " : " + item.getDescription());
}
});
comboBox.setRenderer(new ItemRenderer());
sportColumn.setCellEditor(new DefaultCellEditor(comboBox));
DefaultTableCellRenderer renderer = new DefaultTableCellRenderer();
renderer.setToolTipText("Click for combo box");
sportColumn.setCellRenderer(renderer);
}
class ItemRenderer extends BasicComboBoxRenderer {
@Override
public Component getListCellRendererComponent(JList list, Object value,
int index, boolean isSelected, boolean cellHasFocus) {
super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
if (value != null) {
Item item = (Item) value;
setText(item.getDescription().toUpperCase());
}
if (index == -1) {
Item item = (Item) value;
setText("" + item.getId());
}
return this;
}
}
class Item {
private int id;
private String description;
public Item(int id, String description) {
this.id = id;
this.description = description;
}
public int getId() {
return id;
}
public String getDescription() {
return description;
}
@Override
public String toString() {
return description;
}
}
class MyTableModel extends AbstractTableModel {
private static final long serialVersionUID = 1L;
private String[] columnNames = {"First Name", "Last Name", "Sport", "# of Years", "Vegetarian"};
private Object[][] data = {{"Kathy", "Smith", "Snowboarding", new Integer(5), false},
{"John", "Doe", "Rowing", new Integer(3), true}, {"Sue", "Black", "Knitting", new Integer(2), false},
{"Jane", "White", "Speed reading", new Integer(20), true}, {"Joe", "Brown", "Pool", new Integer(10), false}};
public final Object[] longValues = {"Jane", "Kathy", "None of the above", new Integer(20), Boolean.TRUE};
@Override
public int getColumnCount() {
return columnNames.length;
}
@Override
public int getRowCount() {
return data.length;
}
@Override
public String getColumnName(int col) {
return columnNames[col];
}
@Override
public Object getValueAt(int row, int col) {
return data[row][col];
}
@Override
public Class<?> getColumnClass(int c) {
return getValueAt(0, c).getClass();
}
@Override
public boolean isCellEditable(int row, int col) {
if (col < 2) {
return false;
} else {
return true;
}
}
@Override
public void setValueAt(Object value, int row, int col) {
data[row][col] = value;
fireTableCellUpdated(row, col);
System.out.println("New value of data: " + getValueAt(row, col));
}
}
private static void createAndShowGUI() {
JFrame frame = new JFrame("TableRenderDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
TableRenderDemo newContentPane = new TableRenderDemo();
frame.setContentPane(newContentPane);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
createAndShowGUI();
}
});
}
}