funny. at the right, the suggestions pointed me to the solution. this was achived calling the function from the main class passing "this" trough the arguments. 

I just responded, but realized that you had answered yourself ten minutes earlier...

this is a Java keyword that always contains the value of the current class. So, for example, in the main sketch, it holds a PApplet. In the thread, it is a different class. Many libraries use a reference to a PApplet internally to access its functionality; that is, drawing to the screen, and accessing its functions. PApplet is not highlighted by the PDE because users are not expected to use it.

thanks