Regarding custom events

Question

I got some difficulties using custom event listeners.
What I would like to achieve is pretty simple. With a bunch
of movable fruits, when dragging one of them(this becomes the
'active' object) to collide with others(these are the 'inactive
objects'), I need Flash to tell me who is colliding whom.
So I setup the Fruit Class, with the ability to dispatch and
listen the custom event: "EXECUTE_HITTEST". For me the code looks
good, but there's must be something wrong...
The full .fla & .as files can be downloaded
here, and you can
preview
the
snapshot here.
Thanks in advance.
It's in the .zip file as well but for your convenience I just
put the Fruit Class here:
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Answer 1

your event (and everything else in your class) is specific to
class instances. no two instances can communicate with each other
directly.
you can create another class that contains references to them
all, but that won't get you any further than using each instance to
get to the root timeline which then allows access to the others.
there are several strategies for increasing efficiency of
hitTests. i like to use a grid.
imagine the stage divided into a grid. if your objects are
not changing position with time t, you have an easy task. if they
change position with time, you'll have more work to do.
but for each time t, each grid contains a list of objects
within it. for each time t, each object has a property referencing
the grid within which it's contained.
when you want to perform a hittest for a particular object,
check its grid. then execute a hittest against all objects in that
grid and the eight (assuming rectangular shaped) surrounding grids.
there are several strategies for picking a grid size. but, in
general, you don't want grids to be so small that when you check
for collisions, you have to check beyond the surrounding 8 plus the
center grid.