Update
Forget to mention. The reason you’re having problems with the coloring of your combobox is because the color you are seeing is the selection color. The color is defined within the look and feel defaults, there is no way to change these colors for a single component without writing your own look and feel delegate, which I, personally wouldn’t
This is an example of providing highlighting to invalid fields using JXLayer (now JLayer, but I’ve not had the time to convert it), while this example does use the InputVerifer API, there is no reason it has to, it’s just used for part of the example. It would be quite easy to do post validation highlighting as well, the focus is on the highlighting functionality – not the method of validation ;).
This is based on the idea presented by Kirill Grouchnikov on his Pushing Pixels blog, Validation overlays using JXLayer
This is a prototype of an idea I did some time ago, the code still needs some tweaking to improve performance, but is otherwise quite functional…I’d prefer better in built support for real time validation…but that’s just me 😉
Main test class…
import com.jhlabs.image.GaussianFilter;
import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsEnvironment;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.Point;
import java.awt.Transparency;
import java.awt.image.BufferedImage;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.List;
import javax.swing.InputVerifier;
import javax.swing.JComboBox;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.event.EventListenerList;
import org.jdesktop.jxlayer.JXLayer;
import org.jdesktop.jxlayer.plaf.AbstractLayerUI;
public class FormValidationExample {
public static void main(String[] args) {
new FormValidationExample();
}
public FormValidationExample() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JXLayer<JPanel> layer;
private javax.swing.JComboBox cboOne;
private javax.swing.JTextField txtOne;
private javax.swing.JTextField txtTwo;
private DefaultValidationHighlightModel validationModel;
private boolean ignoreValidationRequest;
public TestPane() {
setLayout(new BorderLayout());
JPanel content = new JPanel(new GridBagLayout());
ValidationUI ui = new ValidationUI();
validationModel = new DefaultValidationHighlightModel(ui);
layer = new JXLayer<>(content, ui);
add(layer);
cboOne = new javax.swing.JComboBox();
cboOne.setInputVerifier(new AbstractValidationInputVerifier(validationModel) {
@Override
public boolean verify(JComponent input) {
boolean valid = false;
JComboBox cb = (JComboBox) input;
String textOfOne = txtOne.getText();
String textOfTwo = txtTwo.getText();
if (cb.getSelectedIndex() == 2) {
valid = true;
} else if (cb.getSelectedIndex() == 0
&& "123".equals(textOfOne)
&& "456".equals(textOfTwo)) {
valid = true;
} else if (cb.getSelectedIndex() == 1
&& "456".equals(textOfOne)
&& "789".equals(textOfTwo)) {
valid = true;
}
return valid;
}
});
txtOne = new javax.swing.JTextField("123", 10);
txtOne.setInputVerifier(new AbstractValidationInputVerifier(validationModel) {
@Override
public boolean verify(JComponent input) {
JTextField field = (JTextField) input;
String text = field.getText();
return "123".equals(text) || "456".equals(text);
}
});
txtTwo = new javax.swing.JTextField("123", 10);
txtTwo.setInputVerifier(new AbstractValidationInputVerifier(validationModel) {
@Override
public boolean verify(JComponent input) {
JTextField field = (JTextField) input;
String text = field.getText();
return "456".equals(text) || "789".equals(text);
}
});
cboOne.setModel(new javax.swing.DefaultComboBoxModel(new String[]{"Only works with 123, 456", "Only works with 456, 789", "Works with everybody"}));
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
gbc.fill = GridBagConstraints.HORIZONTAL;
gbc.insets = new Insets(4, 4, 4, 4);
content.add(cboOne, gbc);
content.add(txtOne, gbc);
content.add(txtTwo, gbc);
validateFields();
}
protected void validateFields() {
if (!ignoreValidationRequest) {
ignoreValidationRequest = true;
try {
cboOne.getInputVerifier().shouldYieldFocus(cboOne);
txtOne.getInputVerifier().shouldYieldFocus(txtOne);
txtTwo.getInputVerifier().shouldYieldFocus(txtTwo);
} finally {
ignoreValidationRequest = false;
}
}
}
public abstract class AbstractValidationInputVerifier extends InputVerifier {
private IValidationHighlightModel model;
public AbstractValidationInputVerifier(IValidationHighlightModel model) {
this.model = model;
}
public IValidationHighlightModel getModel() {
return model;
}
@Override
public boolean shouldYieldFocus(JComponent input) {
if (verify(input)) {
getModel().removeInvalidField(input);
} else {
getModel().addInvalidField(input);
}
validateFields();
return true;
}
}
}
}
JXLayer related, highlight UI layers…
public class ValidationUI extends HighlightComponentUI {
public ValidationUI() {
super(Color.RED);
}
}
public class HighlightComponentUI extends AbstractLayerUI<JPanel> {
private List<WeakReference<Component>> lstHighlights;
private Color highlightColor;
public HighlightComponentUI(Color highlight) {
highlightColor = highlight;
lstHighlights = new ArrayList<WeakReference<Component>>(25);
}
protected void cleanReferences() {
if (lstHighlights.size() > 0) {
List<WeakReference<Component>> removed = new ArrayList<WeakReference<Component>>(lstHighlights.size());
for (WeakReference<Component> wr : lstHighlights) {
Component weak = wr.get();
if (weak == null) {
removed.add(wr);
}
}
lstHighlights.removeAll(removed);
setDirty(true);
}
}
protected boolean contains(Component comp) {
boolean contains = false;
cleanReferences();
for (WeakReference<Component> wr : lstHighlights) {
Component weak = wr.get();
if (weak.equals(comp)) {
contains = true;
break;
}
}
return contains;
}
protected void clearHighlights() {
lstHighlights.clear();
setDirty(true);
}
protected void addHighlight(Component comp) {
if (comp != null) {
if (!contains(comp)) {
lstHighlights.add(new WeakReference<Component>(comp));
setDirty(true);
}
}
}
public Component[] getHighlightedComponents() {
List<Component> comps = new ArrayList<>(lstHighlights.size());
for (WeakReference<Component> wr : lstHighlights) {
Component comp = wr.get();
if (comp != null) {
comps.add(comp);
}
}
return comps.toArray(new Component[comps.size()]);
}
protected void removeHighlight(Component comp) {
cleanReferences();
WeakReference<Component> toRemove = null;
for (WeakReference<Component> wr : lstHighlights) {
Component weak = wr.get();
if (weak.equals(comp)) {
toRemove = wr;
break;
}
}
if (toRemove != null) {
lstHighlights.remove(toRemove);
setDirty(true);
}
}
public Color getHighlight() {
return highlightColor;
}
/**
* Does a recursive search of all the child components of the supplied
* parent looking for the supplied child
*
* @param parent
* @param child
* @return true if the child resides within the parent's hierarchy,
* otherwise false
*/
public boolean contains(Container parent, Component child) {
boolean contains = false;
if (child.getParent() != null) {
if (child.getParent().equals(parent)) {
contains = true;
} else {
for (Component comp : parent.getComponents()) {
if (comp instanceof Container) {
if (contains((Container) comp, child)) {
contains = true;
break;
}
}
}
}
}
return contains;
}
@Override
protected void paintLayer(Graphics2D g2, JXLayer<? extends JPanel> l) {
super.paintLayer(g2, l);
Graphics2D c = (Graphics2D) g2.create();
JComponent view = l.getView();
while (view instanceof JXLayer) {
view = (JComponent) ((JXLayer) view).getView();
}
for (WeakReference<Component> wr : lstHighlights) {
Component comp = wr.get();
if (comp != null && contains(view, comp)) {
// A cache here would be VERY useful, would need to be mainatined
// against the component instance as well as the component
// size properties...
BufferedImage img = new BufferedImage(comp.getWidth(), comp.getHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = img.createGraphics();
g2d.setComposite(AlphaComposite.Clear);
g2d.fillRect(0, 0, img.getWidth(), img.getHeight());
g2d.setComposite(AlphaComposite.SrcOver);
comp.printAll(g2d);
g2d.dispose();
BufferedImage glow = GlowEffectFactory.generateGlow(img, 8, getHighlight(), 0.75f);
Point point = comp.getLocation();
point = SwingUtilities.convertPoint(comp.getParent(), point, view);
int x = point.x - ((glow.getWidth() - comp.getWidth()) / 2);
int y = point.y - ((glow.getHeight() - comp.getHeight()) / 2);
c.drawImage(glow, x, y, l);
}
}
c.dispose();
}
}
Validation model related class (I like to use interfaces and abstract implementations to provide flexibility to the API and reduce the coupling where I can). My original prototype had the UI layer and model separated and updated via the ChangeListener support, but I combined them here for simplicity…
public class DefaultValidationHighlightModel extends AbstractValidationHighlightModel {
private HighlightComponentUI ui;
public DefaultValidationHighlightModel(HighlightComponentUI ui) {
this.ui = ui;
}
@Override
public void addInvalidField(Component comp) {
if (!ui.contains(comp)) {
ui.addHighlight(comp);
fireStateChanged();
}
}
@Override
public void removeInvalidField(Component comp) {
if (ui.contains(comp)) {
ui.removeHighlight(comp);
fireStateChanged();
}
}
@Override
public Component[] getInvalidFields() {
return ui.getHighlightedComponents();
}
}
public abstract class AbstractValidationHighlightModel implements IValidationHighlightModel {
private EventListenerList listenerList;
public EventListenerList getListenerList() {
if (listenerList == null) {
listenerList = new EventListenerList();
}
return listenerList;
}
@Override
public void addChangeListener(ChangeListener listener) {
getListenerList().add(ChangeListener.class, listener);
}
@Override
public void removeChangeListener(ChangeListener listener) {
getListenerList().remove(ChangeListener.class, listener);
}
protected ChangeListener[] getChangeListeners() {
return getListenerList().getListeners(ChangeListener.class);
}
protected void fireStateChanged() {
ChangeListener[] listeners = getChangeListeners();
if (listeners != null && listeners.length > 0) {
ChangeEvent evt = new ChangeEvent(this);
for (ChangeListener listener : listeners) {
listener.stateChanged(evt);
}
}
}
}
public interface IValidationHighlightModel {
public void addInvalidField(Component comp);
public void removeInvalidField(Component comp);
public Component[] getInvalidFields();
public void addChangeListener(ChangeListener listener);
public void removeChangeListener(ChangeListener listener);
}
public static class GlowEffectFactory {
public static BufferedImage createCompatibleImage(int width, int height) {
return createCompatibleImage(width, height, Transparency.TRANSLUCENT);
}
public static BufferedImage createCompatibleImage(Dimension size) {
return createCompatibleImage(size.width, size.height);
}
public static BufferedImage createCompatibleImage(int width, int height, int transparency) {
GraphicsConfiguration gc = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice().getDefaultConfiguration();
BufferedImage image = gc.createCompatibleImage(width, height, transparency);
image.coerceData(true);
return image;
}
public static BufferedImage applyMask(BufferedImage sourceImage, BufferedImage maskImage, int method) {
BufferedImage maskedImage = null;
if (sourceImage != null) {
int width = maskImage.getWidth(null);
int height = maskImage.getHeight(null);
maskedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
Graphics2D mg = maskedImage.createGraphics();
int x = (width - sourceImage.getWidth(null)) / 2;
int y = (height - sourceImage.getHeight(null)) / 2;
mg.drawImage(sourceImage, x, y, null);
mg.setComposite(AlphaComposite.getInstance(method));
mg.drawImage(maskImage, 0, 0, null);
mg.dispose();
}
return maskedImage;
}
public static BufferedImage generateBlur(BufferedImage imgSource, int size, Color color, float alpha) {
GaussianFilter filter = new GaussianFilter(size);
int imgWidth = imgSource.getWidth();
int imgHeight = imgSource.getHeight();
BufferedImage imgBlur = createCompatibleImage(imgWidth, imgHeight);
Graphics2D g2 = imgBlur.createGraphics();
g2.drawImage(imgSource, 0, 0, null);
g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_IN, alpha));
g2.setColor(color);
g2.fillRect(0, 0, imgSource.getWidth(), imgSource.getHeight());
g2.dispose();
imgBlur = filter.filter(imgBlur, null);
return imgBlur;
}
public static BufferedImage generateBlur(BufferedImage imgSource, int size) {
GaussianFilter filter = new GaussianFilter(size);
int imgWidth = imgSource.getWidth();
int imgHeight = imgSource.getHeight();
BufferedImage imgBlur = createCompatibleImage(imgWidth, imgHeight);
Graphics2D g2 = imgBlur.createGraphics();
g2.drawImage(imgSource, 0, 0, null);
g2.dispose();
imgBlur = filter.filter(imgBlur, null);
return imgBlur;
}
public static BufferedImage generateGlow(BufferedImage imgSource, int size, Color color, float alpha) {
int imgWidth = imgSource.getWidth() + (size * 2);
int imgHeight = imgSource.getHeight() + (size * 2);
BufferedImage imgMask = createCompatibleImage(imgWidth, imgHeight);
Graphics2D g2 = imgMask.createGraphics();
int x = Math.round((imgWidth - imgSource.getWidth()) / 2f);
int y = Math.round((imgHeight - imgSource.getHeight()) / 2f);
g2.drawImage(imgSource, x, y, null);
g2.dispose();
// ---- Blur here ---
BufferedImage imgGlow = generateBlur(imgMask, size, color, alpha);
// ---- Blur here ----
imgGlow = applyMask(imgGlow, imgMask, AlphaComposite.DST_OUT);
return imgGlow;
}
}
Caveats
This requires JXLayer (I was using version 3) (which no longer seem to be available on the net…) and SwingX (I was using version 1.6.4)
I’ve put all the source code of JXLayer (version 3) and Piet’s examples into a single zip and I would suggest, if you are interested, you grab a copy and store it some where safe.
You will also need JHLabs filters