Kerry Thompson wrote
>> I have a query the answer to which i hope is very simple. When we give a
>> behaviour script the mouseup handler is followd by "me" . What does this
>> stand for?
>
> Briefly, "me" is the instance of the behavior or parent script--in your
> case, probably a behavior attached to a sprite.
You can also think of the "me" a being like the identity or address of the
behaviour or script object.
Handlers in moviescripts can be called by just using their name, but the
handlers contained in a behaviour or object are kept separate. To access a
handler in a behaviour, you must address the behaviour containing the
handler.
For example, say you had 10 behaviours with "on Dance" handlers in them. If
you type "Dance" into the message window, director has no way of knowing
which behaviour is meant to get the "Dance" message (if you had "on Dance"
in a movieScript, it would get the message though, since handlers in
moviescripts do not need to be addressed).
If you type "sendSprite(1, #Dance)" or call(#Dance, sprite(1)", you are
specifying which behaviour you want to send the message to. So when Director
sends the behaviour the 'Dance' message, it also includes the address (the
reference to the object) as the first parameter. By convention, this
reference is called "me", but you could call it anything you wanted.
If you were never going to send parameters with the "Dance" message, then
you could probably not bother including "me" in the handler name. For
example, a behaviour like this will work
property spriteNum
on dance
put "Sprite " & spriteNum & " is dancing"
end
Its probably a good idea to always include the "me" parameter, though,
because the "me" paramter is still sent with the message, even though you
are not catching it.
A common error is forgetting to include "me", and sending the behaviour a
message with a parameter - for example
on dance style
put style
end
[message window] sendSprite(1, #dance, #ska)
This will not work as expected because the first parameter will be the
object reference, not the expected one.
To make things more complicated, consider this behaviour:
on dance me, style
showStyle(style)
end
on showStyle style
put style
end
[message window] sendSprite(1, #dance, #ska)
the #dance message gets sent to the behaviour, the first parameter is the
address, which we're ignoring, and we get the dance style from the second
parameter. So far so good. The dance handler then calls the unaddressed
"showStyle" handler. If this handler is in the behaviour, it will be found
and no address is sent with it as a parameter (same as if it was in a
moviescript). That will work fine. However, if the showStyle handler was in
a different behaviour, then we'd get an error message because Director
wouldnt know where to find it.
Luke
[To remove yourself from this list, or to change to digest mode, go to
http://www.penworks.com/LUJ/lingo-l.cgi To post messages to the list,
email [EMAIL PROTECTED] (Problems, email [EMAIL PROTECTED])
Lingo-L is for learning and helping with programming Lingo. Thanks!]
