Problem with changing background colors in JPanels

Question

Hi,
I have made an applet with Grid Layout and I have added JPanels in each grid. I have assigned a background color to all panels.
Now what i am trying to do is, change the clicked JPanel's background color to "blue" on a mouse click and convert the previous changed JPanel's background to originally assigned color.
This is the code that I have used:
JPanel temp=null, m;
String tempc, m_color;
public void mouseClicked(MouseEvent me)
          m=(JPanel)me.getComponent();
          if(m!=temp)
          m_color=m.getBackground().toString();   // retaining current background color so as to change later
          m.setBackground(Color.blue);
               if(temp!=null) 
                    temp.setBackground(Color.getColor(tempc));  // change back to original color
          tempc=m_color;       //tempc and m_color are Strings
          temp=m;               //temp and m are JPanels
     }When I am executing the above logic, background color changes to blue on a mouse click but the previously changed JPanel is not changing back to original color.
Can anyone please tell where is the above logic going wrong??
Thanks
Rohan

Answer 1

Hi Camickr,
I tried to do it without changing Color to Strings but i was getting an error in the line temp.setBackground(Color.tempc);, so i decided to change it to String and retrieve it's value in the method.
SSCCE for my code is:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.text.*;
import java.lang.reflect.InvocationTargetException;
<applet code="test" width=400 height=400>
</applet>
public class test extends JApplet
     JPanel t[][]=new JPanel[8][8];
     JPanel p[][];
     public void init()
     try{
     SwingUtilities.invokeAndWait(new Runnable()
          public void run()
               t=makeGUI(8,8);
               logic(t,8,8);
     }catch(InterruptedException e){e.printStackTrace();}
     catch(InvocationTargetException e){e.printStackTrace();}
/* Board*/
private JPanel[][] makeGUI(int rows, int cols)
    p = new JPanel[rows][cols];
    Container contentPane = getContentPane();
    contentPane.setLayout(new GridLayout(rows, cols));
    for (int i = 0; i < rows; i++)
      for (int j = 0; j < cols; j++)
        p[i][j] = new JPanel();
        contentPane.add(p[i][j]);
        if (i % 2 == j % 2)
          p[i][j].setBackground(Color.white);
          else
          p[i][j].setBackground(Color.darkGray);
     return p;
private void logic(JPanel p[][], int rows, int cols)     
          for (int i = 0; i < rows; i++)
          for (int j = 0; j < cols; j++)
          final int k=i, l=j;
          p[i][j].addMouseListener(new MouseListener()
               JPanel temp=null,m;
               String tempc, m_color;
               public void mouseClicked(MouseEvent me)
                    m=(JPanel)me.getComponent();
                    if(m!=temp)
                    m_color=m.getBackground().toString();     //retaining current background color
                    m.setBackground(Color.blue);
                    if(temp!=null)     // this method sets the panel
                         {               //     to its original color
                         temp.setBackground(Color.getColor(tempc));
                    tempc=m_color;     //color Strings
                    temp=m;          //JPanels
               public void mouseEntered(MouseEvent me){}
               public void mouseExited(MouseEvent me){}
               public void mousePressed(MouseEvent me){}
               public void mouseReleased(MouseEvent me){}
}