I'm just creating an overlay visualizing statistical data by colors (similar to a rain overlay using dark blue for a rain forrest, and white for a desert - but in my case for a different purpose). Now I got the overlay working almost fine (the image used seems not to be 100% scaled, but it works), so I can use it. But to give it to someone else, I'd need to add a legend explaining the colors used.

What I want the elgend to be like (ideal case) is:
  • using an image stored inside the .kmz file holding the legend info
  • fixed position relative to the window, not to the map
  • automatically "pop up" when the overlay is displayed, and automatically close when it's no longer on the screen
  • user should be able to manually close it if not needed

Is this somehow possible - and if, how to achieve it?

Thank you in advance for your help and suggestions,