Extract JavaFX source code from JAR file?

Question

I want to extract the source code of our project from .jar file which uses .java and .fx(Javafx). We use Javafx for frontend design. When i extract using JavaDecompiler tools , the .java files are correctly showing but .fx (javafx) files are not showing exactly as our source code.

For example, I decompiled our .jar file it showed the .fx class as follows :

   ......
   if ((this.VFLG$panelW & 0x5) == 4)

   {

     this.VFLG$panelW = ((short)varFlags$);return varNewValue$;

   }

   return this.$panelW;
  }
  .....