How do I change the taskbar icon using XIconifyWindow?

I am programming in Linux and using X11 for my desktop. I would like to change the images of a minimized window in the taskbar.

I am using Fluxbox.

I am currently using XIconifyWindow when the user clicks to minimize the window.

How can I control the little square icon on the taskbar when the user has minimized it?

Thank.

Thank you for your help. The code I'm using to minify looks something like this:

void minWin(Window window, bool yes) const
{
  if(yes)
  {
    XIconifyWindow(display, window, DefaultScreen(display));
  }else{
    XMapWindow(display, window);
  }
}

      

        
        
        
      

    

So how would I put some code to set an icon based on some property?

how

if myProp == "green" set green icon
       else set red icon