Add transition between changing colors Java

Question

Hello I have the following code which shows an empty white JPanel that changes from white to grey when I hover mouse over the JPanel. Here is the code:

package demos;

import java.awt.Color;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class Panel extends JFrame{
    private JPanel panel = new JPanel();
    public Panel(){
        panel.addMouseListener(new MouseListener(){
            @Override
            public void mouseClicked(MouseEvent e) {
            }
            @Override
            public void mouseEntered(MouseEvent e) {
                panel.setBackground(Color.GRAY);
            }
            @Override
            public void mouseExited(MouseEvent e) {
                panel.setBackground(Color.white);
            }
            @Override
            public void mousePressed(MouseEvent e) {
            }
            @Override
            public void mouseReleased(MouseEvent e) {
            }
        });
        this.setSize(400,400);
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);
        this.setContentPane(panel);
    }
    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable(){
            public void run(){
                new Panel().show();
            }
        });
    }
}

Now my question is.Can i add a transition before changing from one color to another?

Thanks for your time

This might help: http://stackoverflow.com/questions/17042458/how-to-add-a-time-delay-in-jframe — RaminS, Aug 19 '16 at 21:15
[`javax.swing.Timer`](https://docs.oracle.com/javase/7/docs/api/javax/swing/Timer.html) — Jonny Henly, Aug 19 '16 at 21:15
I agree, this is a duplicate -- which is why I made my answer a community wiki. — Hovercraft Full Of Eels, Aug 19 '16 at 21:28

score 1 · Answer 1 · edited Aug 19 '16 at 21:50

Now my question is.Can i add a delay efore changing from one color to another?

Yes,

First interpolate some colors between the current color and the desired color. A simple linear interpolation will do just fine.
Create an ArrayList<Color> and fill it with your interpolated colors, in order.
Use a Swing Timer.
In the Timers ActionListener:
- Change the JPanels color with the next color in the ArrayList.
- Advance an int index variable, the one that you use in the get(...) method on the ArrayList.
- Call repaint() on the JPanel.
- Continue doing this until the panel is the color that you want. At this point, stop the Timer.

Add transition between changing colors Java

1 Answers1