Java Swing Colour Chooser Throwing Error

Question

So I'm trying to implement a colour chooser that will then take that colour and pass it to another class to be used, but it's throwing up the error

"Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: javax.swing.colorchooser.DefaultColorSelectionModel cannot be cast to javax.swing.JColorChooser"

every time I click a colour.

The code I'm using is:

For the actual JColorChooser :

JColorChooser RGB = new JColorChooser(Color.GREEN);
RGB.getSelectionModel().addChangeListener(this);
RGB.setAlignmentX(newPolyButton.LEFT_ALIGNMENT);
RGB.setMinimumSize(new Dimension(50, 25));
RGB.setPreferredSize(new Dimension(125, 25));

And for the listener:

public void stateChanged(ChangeEvent c) {
JColorChooser RGB = (JColorChooser)c.getSource();
Color poly = RGB.getColor();
imagePanel.setColor(poly);
}

And in the other class, imagePanel , I use:

public void setColor(Color poly) {
ImagePanel.poly = poly;
}

Can anyone see where I'm going with this? I was previously using a combo box with some manually input colours to choose from.

Any help greatly appreciated, thanks!

Answer 1

In your stateChanged method, c.getSource() returns a DefaultColorSelectionModel and not the reference to your JColorChooser .

However, JColorChooser is usually used to open a color dialog that returns a Color when closed using the OK button.

Color color = JColorChooser.showDialog(parent, title, initialColor);
if (color != null) {
  // do something with the chosen color
}

Answer 2

From your code

RGB.getSelectionModel().addChangeListener(this);
RGB.setAlignmentX(newPolyButton.LEFT_ALIGNMENT);

You are adding the ChangeListener to the Selection Modal for your RGB instance.

javax.swing.JColorChooser.getSelectionModel() will return an instance of DefaultColorSelectionModel .

Hence, you get a ClassCastException in your call (JColorChooser)c.getSource(); .

UPDATE

From How to Use Color Choosers Java Tutorial :

tcc.getSelectionModel().addChangeListener(this);
. . .
public void stateChanged(ChangeEvent e) {
    Color newColor = tcc.getColor();
    banner.setForeground(newColor);
}

When the state changes, you will want to get the new color as a property of the Color Chooser instead of attempting to get the Source of the ChangeEvent and cast it.

Hope this helps!