MouseMove . . . err?

[Scott Rossi]

Recently, Richmond Mathewson wrote:

> Just knocked together a silly little stack with 4 buttons called
> "X1", "X2", "X3" and "X4". Now I want them to chase my cursor in
> a quad shape, and to do that I popped this script into my card:
> 
> on mouseMove
>   set the moveSpeed to 10000
>   put item 1 of the mouseLoc into MISHKA1
>    put item 2 of the mouseLoc into MISHKA2
>    move btn "X1" to (MISHKA1 + 40), (MISHKA2 + 40)
>    move btn "X2" to (MISHKA1 - 40), (MISHKA2 + 40)
>    move btn "X3" to (MISHKA1 + 40), (MISHKA2 - 40)
>    move btn "X4" to (MISHKA1 - 40), (MISHKA2 - 40)
> end mouseMove
> 
> [ find "MISHKA.rev" at revOnline, under 'Richmond' ]
> 
> but the buttons behave a bit oddly (cannot describe it, has to
> be seen to be understood).


As mentioned by others, it is dangerous to put time-intensive events in the
mouseMove handler because you risk locking up Rev and having to abort.  At
the very least, include a trigger that can disable the move events -- make
sure you have some "out" from the script, just in case.  And if you want
near-asynchronous movement (not clear if you do), you need to lock/unlock
moves.

I might do something like this:

on mouseMove X,Y
   if the hilite of btn "chase" then send "moveThem X,Y" to me
end mouseMove

on moveThem X,Y
   set the moveSpeed to 1000
   lock moves
   move btn "X1" to X+40,Y+40 without waiting
   move btn "X2" to X-40,Y+40 without waiting
   move btn "X3" to X+40,Y-40 without waiting
   move btn "X4" to X-40,Y-40 without waiting
   unlock moves
end moveThem



BTW, you don't need to poll the mouseLoc in a mouseMove handler -- mouse
tracking is handled by the engine, with horizontal and vertical coordinates
included in two parameters sent with the mouseMove message.


Regards,

Scott Rossi
Creative Director
Tactile Media, Multimedia & Design