Please help! Simple problem, I'm sure...

Question

Hi All!
I would love any help anyone could provide on this. I have
shied away from defining my own classes with Actionscript cause it
seems so complicated, but I would feel very triumphant and
confident if I could get this to work with your help. I have
attached all code and Output.
I would also love any advice on best coding practices if
anyone sees anything in here that is technically wrong, even if it
will work...
Thanks!
Graham

Answer 1

that's right, the 1009 is being caused because at the point
where the 'return' is in the getColor method, at the time when the
call is made randomX and randomY have not yet been defined. I
should have realized that in the first place :D and RR is right,
it's much better to define the handler as a method of the class,
rather than a 'nested' function.
one thing that's still causing problems here - you are using
the class to actually 'load' the image - it seems like the class
should only 'target' an existing instance of the image (loader) and
find the pixel value. in this case you could use the 'return'
method to instantly 'grab' a pixel value - but as it is there is a
delay while the image gets loaded, then 'finds' the pixel value.
the problem here is that in the timeline you are asking for an
'instant' return value - see the problem :)
so, it seems to me that there are a couple of ways to go
about it -
1) instantiate the image load 'outside' the class and then
use the class to target a random pixel 'after' the load is
completed
2) pass the variable instance to the class so that when the
onComplete handler fires it assigns the value to the variable on
the timeline.
however in 2) there will still be a 'delay' in the
processing, so the variable will not get defined for 'a little
while' this may cause other problems in the operating code if you
wish to use the value an time soon (by that i mean in terms of
'program speed' which may only be milliseconds - but can be enough
to cause other errors)
I would go with the first option - keeping the class specific
to 'getting the color' and do the loading outside the class - or
even with another class. I would use the onComplete handler on the
timeline to call the ColorGetter class method getColor() and pass
the loader instance to that method, construct a quick bmp, and find
the value.
Your class structure looks pretty good - although i think
that you should place the import statements outside the class
definition within the package, as is common - and you should
specify the 'var' types with either 'public' or 'private'
as far as the 'return' type goes - whenever you designate a
'return' statement that passes a value back to the calling
statement, the 'type' must be designated in place of 'void' - this
tells the compiler to operate the code and assign the value being
returned to the variable where the call was made.