How do I make a list with checkboxes in Java Swing?

Question

What would be the best way to have a list of items with a checkbox each in Java Swing?

I.e. a JList with items that have some text and a checkbox each?

Grandchild

You can use the Japura API. There is a List component with checkboxes http://www.japura.org/checklist.html – Azygous

That Japura API link is now broken. – Adactylous

Answer 1

Create a custom ListCellRenderer and asign it to the JList.

This custom ListCellRenderer must return a JCheckbox in the implementantion of getListCellRendererComponent(...) method.

But this JCheckbox will not be editable, is a simple paint in the screen is up to you to choose when this JCheckbox must be 'ticked' or not,

For example, show it ticked when the row is selected (parameter isSelected), but this way the check status will no be mantained if the selection changes. Its better to show it checked consulting the data below the ListModel, but then is up to you to implement the method who changes the check status of the data, and notify the change to the JList to be repainted.

I Will post sample code later if you need it

ListCellRenderer

Cookson

Answer 2

A wonderful answer is this CheckBoxList. It implements Telcontar's answer (though 3 years before :)... I'm using it in Java 1.6 with no problems. I've also added an addCheckbox method like this (surely could be shorter, haven't used Java in a while):

public void addCheckbox(JCheckBox checkBox) {
    ListModel currentList = this.getModel();
    JCheckBox[] newList = new JCheckBox[currentList.getSize() + 1];
    for (int i = 0; i < currentList.getSize(); i++) {
        newList[i] = (JCheckBox) currentList.getElementAt(i);
    }
    newList[newList.length - 1] = checkBox;
    setListData(newList);
}

I tried out the demo for the Jidesoft stuff, playing with the CheckBoxList I encountered some problems (behaviors that didn't work). I'll modify this answer if I find problems with the CheckBoxList I linked to.

Kauppi

I needed to add checkbox.setOpaque(true); for the background to paint (using GTK+ L&F). – Branham

And how does one add listeners to each checkbox? – Inanimate

I'm using this with no problems. The OTHER thing I mentioned had problems. – Kauppi

how can you get all selected rows? – Cosper

@HiradRoshandel make a method that goes through all the rows and returns those that are selected. See docs.oracle.com/javase/7/docs/api/javax/swing/… – Kauppi

Answer 3

Just implement a ListCellRenderer

public class CheckboxListCellRenderer extends JCheckBox implements ListCellRenderer {

    public Component getListCellRendererComponent(JList list, Object value, int index, 
            boolean isSelected, boolean cellHasFocus) {

        setComponentOrientation(list.getComponentOrientation());
        setFont(list.getFont());
        setBackground(list.getBackground());
        setForeground(list.getForeground());
        setSelected(isSelected);
        setEnabled(list.isEnabled());

        setText(value == null ? "" : value.toString());  

        return this;
    }
}

and set the renderer

JList list = new JList();
list.setCellRenderer(new CheckboxListCellRenderer());

this will result in

Details at Custom swing component renderers.

PS: If you want radio elements just replace extends JCheckbox with extends JRadioButton.

Swetiana

I can only select multiple checkboxes using the ctrl. Is this expected? I would like to freely select as many as I want like normal checkboxes. Thanks. – Gyrostabilizer

Answer 4

I'd probably be looking to use a JTable rather than a JList and since the default rendering of a checkbox is rather ugly, I'd probably be looking to drop in a custom TableModel, CellRenderer and CellEditor to represent a boolean value. Of course, I would imagine this has been done a bajillion times already. Sun has good examples.

Twelve

Answer 5

Better solution for Java 7 and newer

I stumbled upon this question and realized that some of the answers are pretty old and outdated. Nowadays, JList is generic and thus there are better solutions.

My solution of the generic JCheckBoxList:

import java.awt.Component;

import javax.swing.*;
import javax.swing.border.*;

import java.awt.event.*;

@SuppressWarnings("serial")
public class JCheckBoxList extends JList<JCheckBox> {
  protected static Border noFocusBorder = new EmptyBorder(1, 1, 1, 1);

  public JCheckBoxList() {
    setCellRenderer(new CellRenderer());
    setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
    addMouseListener(new MouseAdapter() {
      @Override
      public void mousePressed(MouseEvent e) {
        int index = locationToIndex(e.getPoint());
        if (index != -1) {
          JCheckBox checkbox = getModel().getElementAt(index);
          checkbox.setSelected(!checkbox.isSelected());
          repaint();
        }
      }
    });
  }

  public JCheckBoxList(ListModel<JCheckBox> model){
    this();
    setModel(model);
  }

  protected class CellRenderer implements ListCellRenderer<JCheckBox> {
    public Component getListCellRendererComponent(
        JList<? extends JCheckBox> list, JCheckBox value, int index,
        boolean isSelected, boolean cellHasFocus) {
      JCheckBox checkbox = value;

      // drawing checkbox, change the appearance here
      checkbox.setBackground(isSelected ? getSelectionBackground()
          : getBackground());
      checkbox.setForeground(isSelected ? getSelectionForeground()
          : getForeground());
      checkbox.setEnabled(isEnabled());
      checkbox.setFont(getFont());
      checkbox.setFocusPainted(false);
      checkbox.setBorderPainted(true);
      checkbox.setBorder(isSelected ? UIManager
          .getBorder("List.focusCellHighlightBorder") : noFocusBorder);
      return checkbox;
    }
  }
}

For dynamically adding JCheckBox lists you need to create your own ListModel or add the DefaultListModel.

DefaultListModel<JCheckBox> model = new DefaultListModel<JCheckBox>();
JCheckBoxList checkBoxList = new JCheckBoxList(model);

The DefaultListModel are generic and thus you can use methods specified by JAVA 7 API here like this:

model.addElement(new JCheckBox("Checkbox1"));
model.addElement(new JCheckBox("Checkbox2"));
model.addElement(new JCheckBox("Checkbox3"));

Phillis

May i ask you how to get a list of the checked elements in the my Jcheckboxlist? PS: (i changed ListSelectionModel.SINGLE_SELECTION to ListSelectionModel.MULTIPLE_INTERVAL_SELECTION) – Unfolded

I've been trying to make this work in NetBeans but can't get it to show up on the screen when I run it. Can someone post a code snippet showing how to add the CheckBoxList to a JPanel? – Marquetry

Figured it out. I had not set the size of the CheckBoxList: 'CheckBoxListYetAnother checkBoxListYetAnother = new CheckBoxListYetAnother(model); checkBoxListYetAnother.setSize(new Dimension(500, 200)); rtPanel.add(checkBoxListYetAnother);' – Marquetry

I think having model full of checkboxes is fine untin you do not need to manage large amout of them. For this reason is the correct approach using just renderer and keep model without them – Bonnard

Indeed a model should contain only data, not UI components (Basically echoing what @JanPešta is saying). – Knockwurst

Answer 6

I recommend you use a JPanel with a GridLayout of 1 column. Add the checkBoxes to the JPanel, and set the JPanel as the data source of a JScrollPane. And to get the selected CheckBoxes, just call the getComponents() of the JPanel to get the CheckBoxes.

Verst

Answer 7

I don't like the solutions that put a Checkbox into the model. The model should only contain data not display elements.

I found this http://www.java2s.com/Tutorials/Java/Swing_How_to/JList/Create_JList_of_CheckBox.htm

which I optimized a bit. The ACTIVE flag represents the Checkbox, the SELECTED flag shows what entry the cursor sits on.

my version requires a renderer

import java.awt.Component;

import javax.swing.JCheckBox;
import javax.swing.JList;
import javax.swing.ListCellRenderer;

class CheckListRenderer extends JCheckBox implements ListCellRenderer<Entity> {

    @Override
    public Component getListCellRendererComponent(JList<? extends Entity> list, 
        Entity value, int index, boolean isSelected, boolean cellHasFocus) {

            setEnabled(list.isEnabled());
            setSelected(value.isActive()); // sets the checkbox
            setFont(list.getFont());
        if (isSelected) { // highlights the currently selected entry
            setBackground(list.getSelectionBackground());
            setForeground(list.getSelectionForeground());
        } else {
            setBackground(list.getBackground());
            setForeground(list.getForeground());
        }
        setText(value.toString()+" - A" + value.isActive()+" - F"+cellHasFocus+" - S"+isSelected );
        return this;
    }

}

and an entity that got the active field:

public class Entity {

    private boolean active = true;

    public boolean isActive() {
        return active;
    }

    public void setActive(boolean isActive) {
        this.active = isActive;
    }

}

Now you only have to add this to your JList:

list = new JList<Entity>();
list.setModel(new DefaultListModel<Entity>());
list.setCellRenderer(new CheckListRenderer());
list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
list.addMouseListener(new MouseAdapter() {
    @Override
    public void mouseClicked(MouseEvent event) {
        if (event.getX() < 20) { 
            // Quick and dirty: only change the tick if clicked into the leftmost pixels
            @SuppressWarnings("unchecked")
            JList<Entity> list = ((JList<Entity>) event.getSource());
            int index = list.locationToIndex(event.getPoint());// Get index of item clicked
            if (index >= 0) {
                Entity item = (Entity) list.getModel().getElementAt(index);
                item.setActive(!item.isActive()); // Toggle selected state
                list.repaint(list.getCellBounds(index, index));// Repaint cell
            }
        }
    }
});

Adulterous

Answer 8

Odds are good w/ Java that someone has already implemented the widget or utility you need. Part of the benefits of a large OSS community. No need to reinvent the wheel unless you really want to do it yourself. In this case it would be a good learning exercise in CellRenderers and Editors.

My project has had great success with JIDE. The component you want, a Check Box List, is in the JIDE Common Layer (which is OSS and hosted on java.net). The commercial stuff is good too, but you don't need it.

http://www.jidesoft.com/products/oss.htm https://jide-oss.dev.java.net/

Hungary

Answer 9

All of the aggregate components in Swing--that is, components made up other components, such as JTable, JTree, or JComboBox--can be highly customized. For example, a JTable component normally displays a grid of JLabel components, but it can also display JButtons, JTextFields, or even other JTables. Getting these aggregate components to display non-default objects is the easy part, however. Making them respond properly to keyboard and mouse events is a much harder task, due to Swing's separation of components into "renderers" and "editors." This separation was (in my opinion) a poor design choice and only serves to complicate matters when trying to extend Swing components.

To see what I mean, try enhancing Swing's JList component so that it displays checkboxes instead of labels. According to Swing philosophy, this task requires implementing two interfaces: ListCellRenderer (for drawing the checkboxes) and CellEditor (for handling keyboard and mouse events on the checkboxes). Implementing the ListCellRenderer interface is easy enough, but the CellEditor interface can be rather clumsy and hard to understand. In this particular case, I would suggest forgetting CellEditor entirely and to handle input events directly, as shown in the following code.

import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
import java.awt.event.*;

public class CheckBoxList extends JList
{
   protected static Border noFocusBorder = new EmptyBorder(1, 1, 1, 1);

   public CheckBoxList()
   {
      setCellRenderer(new CellRenderer());

      addMouseListener(new MouseAdapter()
         {
            public void mousePressed(MouseEvent e)
            {
               int index = locationToIndex(e.getPoint());

               if (index != -1) {
                  JCheckBox checkbox = (JCheckBox)
                              getModel().getElementAt(index);
                  checkbox.setSelected(
                                     !checkbox.isSelected());
                  repaint();
               }
            }
         }
      );

      setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
   }

   protected class CellRenderer implements ListCellRenderer
   {
      public Component getListCellRendererComponent(
                    JList list, Object value, int index,
                    boolean isSelected, boolean cellHasFocus)
      {
         JCheckBox checkbox = (JCheckBox) value;
         checkbox.setBackground(isSelected ?
                 getSelectionBackground() : getBackground());
         checkbox.setForeground(isSelected ?
                 getSelectionForeground() : getForeground());
         checkbox.setEnabled(isEnabled());
         checkbox.setFont(getFont());
         checkbox.setFocusPainted(false);
         checkbox.setBorderPainted(true);
         checkbox.setBorder(isSelected ?
          UIManager.getBorder(
           "List.focusCellHighlightBorder") : noFocusBorder);
         return checkbox;
      }
   }
}

Here, I intercept mouse clicks from the listbox and simulate a click on the appropriate checkbox. The result is a "CheckBoxList" component that is both simpler and smaller than an equivalent component using the CellEditor interface. To use the class, simply instantiate it, then pass it an array of JCheckBox objects (or subclasses of JCheckBox objects) by calling setListData. Note that the checkboxes in this component will not respond to keypresses (i.e. the spacebar), but you could always add your own key listener if needed.

Source: DevX.com

Bernardobernarr

Answer 10

this is yet another example of making list with checkboxes

class JCheckList<T> extends JList<T> {

    protected static Border noFocusBorder = new EmptyBorder(1, 1, 1, 1);

    public void setSelected(int index) {
        if (index != -1) {
            JCheckBox checkbox = (JCheckBox) getModel().getElementAt(index);
            checkbox.setSelected(
                    !checkbox.isSelected());
            repaint();
        }
    }

    protected static class CellListener
            extends DefaultListModel
            implements ListDataListener {

        ListModel ls;

        public CellListener(ListModel ls) {
            ls.addListDataListener(this);
            int i = ls.getSize();
            for (int v = 0; v < i; v++) {
                var r = new JCheckBox();
                r.setText(ls.getElementAt(v).toString());
                this.addElement(r);
            }
            this.ls = ls;
        }

        @Override
        public void intervalAdded(ListDataEvent e) {
            int begin = e.getIndex0();
            int end = e.getIndex1();
            for (; begin <= end; begin++) {
                var r = new JCheckBox();
                r.setText(ls.getElementAt(begin).toString());
                this.add(begin, r);
            }
        }

        @Override
        public void intervalRemoved(ListDataEvent e) {
            int begin = e.getIndex0();
            int end = e.getIndex1();
            for (; begin <= end; end--) {
                this.remove(begin);
            }
        }

        @Override
        public void contentsChanged(ListDataEvent e) {

        }
    }

    public JCheckList() {
        setCellRenderer(new CellRenderer());

        addMouseListener(new MouseAdapter() {
            public void mousePressed(MouseEvent e) {
                int index = locationToIndex(e.getPoint());

                setSelected(index);
            }
        }
        );


    addKeyListener(new KeyListener(){
        @Override
        public void keyTyped(KeyEvent e) {
            
        }

        @Override
        public void keyPressed(KeyEvent e) {
            if (e.getKeyCode() == KeyEvent.VK_SPACE){
                
            int index = JCheckList.this.getSelectedIndex();

            setSelected(index);
            }
        }

        @Override
        public void keyReleased(KeyEvent e) {
            
        }
            
    });

        setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
    }

    @Override
    public void setModel(ListModel<T> d) {
        var r = new CellListener(d);
        d.addListDataListener(r);
        super.setModel(r);
    }

    protected class CellRenderer implements ListCellRenderer {

        public Component getListCellRendererComponent(
                JList list, Object value, int index,
                boolean isSelected, boolean cellHasFocus) {
            JCheckBox checkbox = (JCheckBox) value;
            checkbox.setBackground(isSelected
                    ? getSelectionBackground() : getBackground());
            checkbox.setForeground(isSelected
                    ? getSelectionForeground() : getForeground());
            checkbox.setEnabled(isEnabled());
            checkbox.setFont(getFont());
            checkbox.setFocusPainted(false);
            checkbox.setBorderPainted(true);
            checkbox.setBorder(isSelected
                    ? UIManager.getBorder(
                            "List.focusCellHighlightBorder") : noFocusBorder);
            return checkbox;
        }
    }
}

Villager

Answer 11

Here is just a little addition to the JCheckBoxList by Rawa. This will add the ability to select using space bar. If multiple items are selected, all will be set to inverted value of the first item.

        addKeyListener(new KeyAdapter() {
        @Override
        public void keyPressed(KeyEvent e) {
            int index = getSelectedIndex();
            if (index != -1 && e.getKeyCode() == KeyEvent.VK_SPACE) {
                boolean newVal = !((JCheckBox) (getModel()
                        .getElementAt(index))).isSelected();
                for (int i : getSelectedIndices()) {
                    JCheckBox checkbox = (JCheckBox) getModel()
                            .getElementAt(i);
                    checkbox.setSelected(newVal);
                    repaint();
                }
            }
        }
        });

Grilse