Class FollowThing

       object --+        
                |        
timeline.Timeline --+    
                    |    
                Thing --+
                        |
                       FollowThing

In a FollowThing, you provide a path drawing function and then whatever you add to this Thing will follow that path.

Use

Typical use:

 class FollowPath(FollowThing):
         def __init__(self ):
                 FollowThing.__init__(self)
                 self.keys  (40, self.path)
                 self.dot = Dot() # This will follow the path!
                 self.add(self.dot)
         def path(self,ctx):
             ## This is where you draw the path.
                 ## Here we use a path id taken from an Inkscape SVG file.
                 ## However, you can also use the normal pyCairo drawing commands
                 ## and construct a path in any way you like.
                 ## Simply remember -- do not stroke or fill the path!
                 bos["foll:swoopy"].draw(ctx)

.

Notes

There is no notion (yet) of orienting the thing that follows (the path) to the path itself. The maths is over my head! Waaay over.