proposal for a third functionality:
automatic class creation based on existing code which is not yet OOP.

This automatic class creation is re-factoring of Code.

What I mean is, you have a Code that is not OOP but should be:
http://processing.org/learning/topics/bounce.html

I'll show it with this example.

You then start your automatic class creation wizard
and tell it the name of the new class (ball)
then you mark the existing (!) lines and tell it those are the objects properties:

1. int size = 60;       // Width of the shape
   float xpos, ypos;    // Starting position of shape    
   
   float xspeed = 2.8;  // Speed of the shape
   float yspeed = 2.2;  // Speed of the shape
   
   int xdirection = 1;  // Left or Right
   int ydirection = 1;  // Top to Bottom

Then you mark some lines and tell the wizard that's your constructor:

1.   // Set the starting position of the shape
     xpos = width/2;
     ypos = height/2;

Then you mark some lines and tell the wizard that's your method 1 (and enter it's name when it's not a function already):

1. // Update the position of the shape
   
2. xpos = xpos + ( xspeed * xdirection );
   
3. ypos = ypos + ( yspeed * ydirection );

      name of the method: move()

Then you mark some lines and tell the wizard that's your method 2 (and enter it's name):

1.   // Test to see if the shape exceeds the boundaries of the screen
     // If it does, reverse its direction by multiplying by -1
     if (xpos > width-size || xpos < 0) {
       xdirection *= -1;
     }
     if (ypos > height-size || ypos < 0) {
       ydirection *= -1;
     }

      name of the method: collisionCheck


And a 3rd method:

1.   // Draw the shape
     ellipse(xpos+size/2, ypos+size/2, size, size);

      name of the method: display


Then you tell your wizard to finish and he puts together the new class.

In the places where he removed the old lines he puts in the code for calling the new method (e.g. ball.display(); )

That could be helpful.

Greetings, Chrisir 

This is a great idea for a tool!  Look forward to your proposal.

@shiffman: Looks like InitSketchFromTemplate (but I never tried it).
That's also a functionality found in some clipboard managers (independent of running software, then), like CLCL for Windows (there are many others on all systems, that's just my favorite...).

@Chrisir: original and interesting. Perhaps it would need a refactoring context menu, like selecting lines, then in a context menu, Move to... and display a number of existing classes, and a category (fields, constructors, methods...).
Slightly faster and probably more educative than simple copy & paste.

@Chrisir: Great idea. Yeah I think that feature will be very much usable to beginners. They initially do not think in OO manner. They just code it. So giving it the functionality to refactor the existing code into class will be great. Thanks a lot for the idea.

@Dan: What about implementing it as a separate tool. So then we have a automatic class creation wizard(initial suggestion) and a automatic code generation tool(Your suggestion). You can create code blocks like draw(), onMouseClick(), if(), for(). (Some what like generation feature of eclipse IDE). What is you idea?

phi.lho thanks for the comments. These feed-backs help a lot to come out with a good proposal.

Tishan.