Swap sprite with if/then

Question

Hi,
How would I write a script that would when sprite clicked
would swap sprite then when clicked on again would swap back to
original sprite.
This is the script I am doing - and not working. I am
obviously a beginner but learning.
on mouseUp
if the memberNum of (clickOn) = 3 then
memberNum = 4
If the memberNum of (clickOn) = 4 then
memberNum = 3
end
Thanks for the help.

Answer 1

I suppose I should offer a bit of explanation, so that you
can learn
from it. First of all to be more accurate, you are not
swapping a
sprite. You are swapping the sprite's member property.
There is no reason to use the clickOn, as the mouseUp event
is received
by the sprite, and he already knows who he is (in a manner of
speaking).
Also you are using 2 if/then statements, where an
if/then/else makes
more sense.
You will want to avoid hard coding of things like a
membernum. Why? Well
suppose that you need this same "toggling" behavior on 10
different
sprites. With the hard coding, you will have to have 10
different
scripts, one for each sprite. They will all be identical,
with the
exception of the membernum. So one would have 3 & 4, the
next 5 & 6, 7 &
8, etc.
What happens if you decide to move things around in your
cast? You just
broke those 10 scripts. What happens if you decide that you
want to add
something, like a "beep" sound when the image changes. Well
now you have
to add that new code to 10 scripts.
One behavior can handle the job, so there is no good reason
to not to do
it with one. The key is in the declaring of your own sprite
properties.
In the code, I defined a property called "pOriginalMember".
Notice that
this gets set during the beginSprite event. Thus I can
attaqch this
behavior to any number of sprites. Each will automatically
remember the
member that it started with.
The other property is "pSwapMember". This will hold a
reference to the
member which is to be used for the toggle. The property is
declared in
the getPropertyDescriptionList handler. You will want to read
up on that
as it is quite useful. The property has to be set using
Director's
property inspector, under the behavior tab, double clicking
the
behavior. A dialog box will appear and let you set the value
of
pSwapMember for a particular instance.
This is how one behavior can be utilized over and over. It
will also not
be broken by rearranging the cast. You can update the script
if needed,
without having to do so in multiple behaviors. Taking this
approach will
save you lots of time and effort over the long run.
There is