Drag, Drop and Swap - Page 7

Now that we know which two movie clips were just affected, we need to find out which one was already there and set its location equal to the ball that originally got dragged. This is where the Swap code comes in.

If (/:resident1 = /:ballnum)
    Set Property ("/ball" & /:resident2, X Position) = 
        GetProperty ("/target" & /:first, _x)
    Set Property ("/ball" & /:resident2, Y Position) = 
        GetProperty ("/target" & /:first, _y)
    Set Property ("/balla" & /:resident2, X Position) = 
        GetProperty ("/target" & /:first, _x)
    Set Property ("/balla" & /:resident2, Y Position) = 
        GetProperty ("/target" & /:first, _y)
    Set Variable: "/:ballpos" & /:resident2 = /:first
Else
    Set Property ("/ball" & /:resident1, X Position) = 
        GetProperty ("/target" & /:first, _x)
    Set Property ("/ball" & /:resident1, Y Position) = 
        GetProperty ("/target" & /:first, _y)
    Set Property ("/balla" & /:resident1, X Position) = 
        GetProperty ("/target" & /:first, _x)
    Set Property ("/balla" & /:resident1, Y Position) = 
        GetProperty ("/target" & /:first, _y)
    Set Variable: "/:ballpos" & /:resident1 = /:first
End If

This if statement says that if resident1 is the ball that got dragged in the first place, then resident two must be the one that needs to swap, so move resident2 to the place where resident1 was. If resident1 is not the original ball that was dragged, then the the original ball must have been resident2, so go ahead and swap resident1 to the location where resident2 was originally.

That's is folks. Let me run through the drop and swap part really quick in English now as if you are dragging ball1 and dropping it on target4, which currently contains ball4.

When you drop ball1, if it is not over target 4, it snaps back to its original position and nothing else happens. If you do drop ball1 onto target4, then first, ball1 and balla1 move to the same location as target 4. After that it checks to see which two balls are on target 4, in this case, ball1 and ball4 are there. Then it finds out which ball was originally there, and moves it to the target that ball1 was on before you dragged it. So now ball4 is on the first target you dragged ball1 from, and ball1 is on the target ball4 was at. It swaps!