Develop Reference

JAVA - How to change JTable row color after clicking on it?

I 'm a Java beginner.
I create an application with a JTable which is populated with a database.
In my database I have some 'news'. In my JTable I display titles of 'news' and when an user click on a row, it display a popup with the right contents of the news.
But I want to colorize the cell which are 'read' when the user clicked on it.
I use my own TableModel.
I hope I'm clear...
If I need to put some code, tell me what please...

public class JTableTest extends JFrame {
private JTable table;
private int col;
private int rowz;
/**
* Create the frame.
*/
public JTableTest() {
initComponents();
}
private void initComponents() {
/** any other components */
table = new JTable();//create the table
table.setDefaultRenderer(Object.class, new CustomModel());
table.addMouseListener(new CustomListener());
}
public class CustomListener extends MouseAdapter {
#Override
public void mouseClicked(MouseEvent arg0) {
super.mouseClicked(arg0);
//get the clicked cell's row and column
rowz = table.getSelectedRow();
col = table.getSelectedColumn();
// Repaints JTable
table.repaint();
}
}
public class CustomModel extends DefaultTableCellRenderer {
private static final long serialVersionUID = 1L;
#Override
public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
JLabel label = (JLabel) super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
Color c = Color.WHITE;//define the color you want
if (isSelected && row == rowz & column == col)
c = Color.GREEN;
label.setBackground(c);
return label;
}
}
}

Found this example of how to get the table cell on mouseClick: http://codeprogress.com/java/showSamples.php?index=52&key=JTableValueofSelectedCell
You can use this to get the selected row and column.
Then you need to create a custom TableCellRenderer, possibly as an inner class so that it can use the selected row and column data and set the background of the cell to your highlighted color

Compound JTree Node allowing events to pass through to objects underneath

I'm trying to create a JTree in which some nodes are compound objects containing a JLabel and a JButton. The Node is representing a server and port shown by the JLabel, the JButton will use the Desktop API to open the default browser and go to the URL.
I have read the following already and have followed them as closely as I can. The Node is displayed how I want it (mostly - I can deal with making it nicer later) but when I try to click on the button the JTree is responding to the events, not the button.
java swing: add custom graphical button to JTree item
http://www.java2s.com/Code/Java/Swing-JFC/TreeCellRenderer.htm
https://stackoverflow.com/a/3769158/1344282
I need to know how to allow the events to pass through the JTree so that they are handled by the object(s) underneath - the JButton or JLabel.
Here is my TreeCellEditor:
public class UrlValidationCellEditor extends DefaultTreeCellEditor
{
public UrlValidationCellEditor(JTree tree, DefaultTreeCellRenderer renderer)
{
super(tree, renderer);
}
#Override
public Component getTreeCellEditorComponent(JTree tree, Object value,
boolean isSelected, boolean expanded, boolean leaf, int row)
{
return renderer.getTreeCellRendererComponent(tree, value, true, expanded, leaf, row, true);
}
#Override
public boolean isCellEditable(EventObject anEvent)
{
return true; // Or make this conditional depending on the node
}
}
Here is the TreeCellRenderer:
public class UrlValidationRenderer extends DefaultTreeCellRenderer implements TreeCellRenderer
{
JLabel titleLabel;
UrlGoButton goButton;
JPanel renderer;
DefaultTreeCellRenderer defaultRenderer = new DefaultTreeCellRenderer();
public UrlValidationRenderer()
{
renderer = new JPanel(new GridLayout(1, 2));
titleLabel = new JLabel(" ");
titleLabel.setForeground(Color.blue);
renderer.add(titleLabel);
goButton = new UrlGoButton();
renderer.add(goButton);
renderer.setBorder(BorderFactory.createLineBorder(Color.black));
backgroundSelectionColor = defaultRenderer
.getBackgroundSelectionColor();
backgroundNonSelectionColor = defaultRenderer
.getBackgroundNonSelectionColor();
}
#Override
public Component getTreeCellRendererComponent(JTree tree, Object value,
boolean selected, boolean expanded, boolean leaf, int row,
boolean hasFocus)
{
Component returnValue = null;
if ((value != null) && (value instanceof DefaultMutableTreeNode))
{
Object userObject = ((DefaultMutableTreeNode) value)
.getUserObject();
if (userObject instanceof UrlValidation)
{
UrlValidation validationResult = (UrlValidation) userObject;
titleLabel.setText(validationResult.getServer()+":"+validationResult.getPort());
goButton.setUrl(validationResult.getUrl());
if (selected) {
renderer.setBackground(backgroundSelectionColor);
} else {
renderer.setBackground(backgroundNonSelectionColor);
}
renderer.setEnabled(tree.isEnabled());
returnValue = renderer;
}
}
if (returnValue == null)
{
returnValue = defaultRenderer.getTreeCellRendererComponent(tree,
value, selected, expanded, leaf, row, hasFocus);
}
return returnValue;
}
}
I would appreciate any insight or suggestions. Thanks!

The renderers do not work this way. They are used as rubber stamps, which means that there is really only one instance of renderer that is painted all over the place as the JList is painted. So it cannot handle mouse inputs, as the objects are not really there - they are just painted.
In order to pass mouse events to objects underneath, you need to implement a cell editor. Sometimes, the editor looks different than the renderer (String renderers are labels, editors are textfields, for example). Following this logic, the editor must be implemented using another instance of a component.
Now you are going to render buttons and use them for manipulating (ie. editing). The editor then must be another instance of JButton, distinctive from the renderer. Implementing button as renderer is easy, but the tricky part is to implement is as an editor. You need to extend AbstractCellEditor and implement TreeCellEditor and ActionListener. The button is then a field of the editor class. In the constructor of the editor class, you initialize the button and add this as a new action listener for the button. In the getTreeCellEditorComponent method, you just return the button. In the actionPerformed, you call whatever code you need to do on button press and then call stopCellEditing().
This way it works for me.
I made a SSCCE that demonstrates the usage on a String Tree
public class Start
{
public static class ButtonCellEditor extends AbstractCellEditor implements TreeCellEditor, ActionListener, MouseListener
{
private JButton button;
private JLabel label;
private JPanel panel;
private Object value;
public ButtonCellEditor(){
panel = new JPanel(new BorderLayout());
button = new JButton("Press me!");
button.addActionListener(this);
label = new JLabel();
label.addMouseListener(this);
panel.add(button, BorderLayout.EAST);
panel.add(label);
}
#Override public Object getCellEditorValue(){
return value.toString();
}
#Override public void actionPerformed(ActionEvent e){
String val = value.toString();
System.out.println("Pressed: " + val);
stopCellEditing();
}
#Override public Component getTreeCellEditorComponent(JTree tree, Object value, boolean isSelected, boolean expanded, boolean leaf, int row){
this.value = value;
label.setText(value.toString());
return panel;
}
#Override public void mouseClicked(MouseEvent e){
}
#Override public void mousePressed(MouseEvent e){
String val = value.toString();
System.out.println("Clicked: " + val);
stopCellEditing();
}
#Override public void mouseReleased(MouseEvent e){
}
#Override public void mouseEntered(MouseEvent e){
}
#Override public void mouseExited(MouseEvent e){
}
}
public static class ButtonCellRenderer extends JPanel implements TreeCellRenderer
{
JButton button;
JLabel label;
ButtonCellRenderer(){
super(new BorderLayout());
button = new JButton("Press me!");
label = new JLabel();
add(button, BorderLayout.EAST);
add(label);
}
#Override public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus){
label.setText(value.toString());
return this;
}
}
public static void main(String[] args){
JTree tree = new JTree();
tree.setEditable(true);
tree.setCellRenderer(new ButtonCellRenderer());
tree.setCellEditor(new ButtonCellEditor());
JFrame test = new JFrame();
test.add(new JScrollPane(tree));
test.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
test.setSize(500, 500);
test.setLocationRelativeTo(null);
test.setVisible(true);
}
}

the node should have 2 parts a label and a button. When the user clicks the label then some detailed information about the node should appear in a different part of the GUI. When the user clicks the button it should result in a browser window opening. ..
Don't do it that way. Instead, have just the label in the tree. Add the button to the same GUI that displays the 'detailed information about the node'.

Scrollable Cells in JTable

I have a Jtable in which I have to show some big data. I cann't increase the size of the Cells So I need to add a scrollbar in each cell of the table through which I can scroll the text of cells.
I have tried to add a Custom Cell Renderer
private class ExtendedTableCellEditor extends AbstractCellEditor implements TableCellEditor
{
JLabel area = new JLabel();
String text;
public Component getTableCellEditorComponent(JTable table, Object value, boolean isSelected, int rowIndex, int vColIndex)
{
area.setText(text);
return new JScrollPane(area);
}
public Object getCellEditorValue()
{
return text;
}
}
Now I am able to see the Scroll bar on the cells but not able to click and scroll them.
Any suggestions to this issue will be great.
Thanks in Advance.

Adding a JScrollPaneand placing the JLabel in the JScrollPane solved the issue. So I would like to share it with you all.
private class ExtendedTableCellEditor extends AbstractCellEditor implements TableCellEditor
{
JLabel _component = new JLabel();
JScrollPane _pane = new JScrollPane(_component, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
/**
* Returns the cell editor component.
*
*/
public Component getTableCellEditorComponent(JTable table, Object value, boolean isSelected, int rowIndex, int vColIndex)
{
if (value == null) return null;
_component.setText(value != null ? value.toString() : "");
_component.setToolTipText(value != null ? value.toString() : "");
_component.setOpaque(true);
_component.setBackground((isSelected) ? Color.BLUE_DARK : Color.WHITE);
_component.setForeground((isSelected) ? Color.WHITE : Color.BLACK);
_pane.setHorizontalScrollBar(_pane.createHorizontalScrollBar());
_pane.setVerticalScrollBar(_pane.createVerticalScrollBar());
_pane.setBorder(new EmptyBorder(0,0,0,0));
_pane.setToolTipText(value != null ? value.toString() : "");
return _pane;
}
public Object getCellEditorValue()
{
return _component.getText();
}
}

How to Insert Image into JTable Cell

Can someone point me in the right direction on how to add an image into Java Table cell.

JTable already provides a default renderer for icons. You just need to tell the table what data is stored in a given column so it can choose the appropriate renderer. This is done by overriding the getColumnClass(...) method:
import java.awt.*;
import javax.swing.*;
import javax.swing.table.*;
public class TableIcon extends JPanel
{
public TableIcon()
{
Icon aboutIcon = new ImageIcon("about16.gif");
Icon addIcon = new ImageIcon("add16.gif");
Icon copyIcon = new ImageIcon("copy16.gif");
String[] columnNames = {"Picture", "Description"};
Object[][] data =
{
{aboutIcon, "About"},
{addIcon, "Add"},
{copyIcon, "Copy"},
};
DefaultTableModel model = new DefaultTableModel(data, columnNames)
{
// Returning the Class of each column will allow different
// renderers to be used based on Class
public Class getColumnClass(int column)
{
return getValueAt(0, column).getClass();
}
};
JTable table = new JTable( model );
table.setPreferredScrollableViewportSize(table.getPreferredSize());
JScrollPane scrollPane = new JScrollPane( table );
add( scrollPane );
}
private static void createAndShowGUI()
{
JFrame frame = new JFrame("Table Icon");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TableIcon());
frame.setLocationByPlatform( true );
frame.pack();
frame.setVisible( true );
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowGUI();
}
});
}
}

Either create the imageicon up front:
ImageIcon icon = new ImageIcon("image.gif");
table.setValueAt(icon, row, column);
Or you can try overriding the renderer for your icon field:
static class IconRenderer extends DefaultTableCellRenderer {
public IconRenderer() { super(); }
public void setValue(Object value) {
if (value == null) {
setText("");
}
else
{
setIcon(value);
}
}

1- add label to jtable ( create class for this)
class LabelRendar implements TableCellRenderer{
#Override
public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
// throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
return (Component)value;
}
}
2- code jButton to add image
DefaultTableModel m = (DefaultTableModel) jTable1.getModel();
jTable1.getColumn("image").setCellRenderer(new LabelRendar()); // call class
JLabel lebl=new JLabel("hello");
lebl.setIcon(new javax.swing.ImageIcon(getClass().getResource("/main/bslogo120.png"))); // NOI18N
m.addRow(new Object[]{"", "","",lebl});

I created my own class that implements TableCellRenderer. I can extend this class from JLabel, but I have preferred to keep it independent and used JLabel 'label' as a class component.
public class GLabel implements TableCellRenderer{
//The JLabel that is used to display image
private final JLabel label = new JLabel();
/**
*
* #param text
* #param image
*/
public GLabel(String text, ImageIcon image) {
label.setText(text);
label.setIcon(image);
}
public GLabel(){}
public JLabel getLabel() {
return label;
}
/**
*
* #param table the JTable that is asking the renderer to draw; can be null
* #param value the value of the cell to be rendered.
* It is up to the specific renderer to interpret and draw the value.
* For example, if value is the string "true", it could be rendered as a string or it could be rendered as a check box that is checked.
* null is a valid value
* #param isSelected true if the cell is to be rendered with the selection highlighted; otherwise false
* #param hasFocus if true, render cell appropriately. For example, put a special border on the cell, if the cell can be edited, render in the color used to indicate editing
* #param row the row index of the cell being drawn. When drawing the header, the value of row is -1
* #param column the column index of the cell being drawn
* #return
*/
#Override
public Component getTableCellRendererComponent(JTable table,
Object value,
boolean isSelected,
boolean hasFocus,
int row,
int column) {
GLabel gLabel = (GLabel)value;
return (Component) gLabel.getLabel();
}
}
I created a new DefaultTableModel object. I overrides getColumnClass() method to pass appropriate Class at runtime.
private final DefaultTableModel tblmodel = new DefaultTableModel() {
/**
* This method is called by table cell renderer.
* The method returns class of the cell data. This helps the renderer to display icons and
* other graphics in the table.
*/
#Override
public Class getColumnClass(int column)
{
for(int i = 0; i < tblmodel.getRowCount(); i++)
{
//The first valid value of a cell of given column is retrieved.
if(getValueAt(i,column) != null)
{
return getValueAt(i, column).getClass();
}
}
//if no valid value is found, default renderer is returned.
return super.getColumnClass(column);
}
};
I created JTable object using DefaultTableModel I created.
JTable jtable = new JTable(tblmodel);
I set default renderer for GLabel class
jtable.setDefaultRenderer(GLabel.class, new GLabel());
I created new GLabel object.
GLabel glabel = new GLabel("testing", new ImageIcon("c://imagepath"));
Finally, I used addRow(Object[] rowData) method of TableModel to add GLabel to the JTable.

Issues with add JButton in the table

I am adding Jbutton to a table by extendibg AbstractCellEditor class. But on click of button the text doesnt change from "Start" to "Stop" .here is the class i implemented
public class ButtonEditor1 extends AbstractCellEditor implements
TableCellEditor,ActionListener,TableCellRenderer{
JButton btnSTART = new JButton("START");
private JTable table ;
public ButtonEditor1(JTable table){
this.table = table;
btnSTART.addActionListener(this);
}
public Component getTableCellEditorComponent(JTable table, Object value,
boolean isSelected, int row, int column) {
return btnSTART;
}
public Object getCellEditorValue() {
// TODO Auto-generated method stub
return btnSTART;
}
public void actionPerformed(ActionEvent e) {
int row = table.getSelectedRow();
if(btnSTART.getText().equals("START")){
if(row != -1){
btnSTART.setText("STOP");
}
}else if(btnSTART.getText().equals("STOP")){
if(row != -1){
btnSTART.setText("START");
}
}
fireEditingStopped();
}
public Component getTableCellRendererComponent(JTable table, Object value,
boolean isSelected, boolean hasFocus, int row, int column) {
return btnSTART;
}
}
what i am doing wrong .. I have a Model class which takes the column as JButton and have overriden the method setValueAt and getValueAt.

A JTable uses renderers to display data. Once you click on the cell using the button as an editor, the button editor is invoked for a split second, then the cell is placed back in rendering mode. So if you want to change the text you change the value in the model.