How do I determine objects in a group?

Jeanne A. E. DeVoto jeanne at
Fri Feb 8 18:00:01 EST 2002

At 2:04 PM -0800 2/8/2002, Zac Elston wrote:
>The user can select only one circle from a group of circles.  I use a
>backgroundcolor change to indicate selection.  So basically I have to change
>a property of an object within a group while resetting the same property of
>all the other objects in that group.
> I can write a script for each circle
>On mouseup
>Put name into varX
>Set the backgroundcolor of graphic 1 to red
>Set the backgroundcolor of graphic 2 to gray
>Set the backgroundcolor of graphic 3 to gray
>End mouseup
>And change the red to match the graphic being pressed.
>But that seems tedious.

It is. Here you'll want to put the script in question higher in the message
hierarchy. The right way to do this, I think, is to put it into the group

  on mouseUp
    if word 2 of the name of the target is not "graphic" then pass mouseUp
    -- do your stuff here
  end mouseUp

This gives you just one handler for the entire group. Now, since the user
can highlight only one circle, one way to handle keeping track of this
would be to set a custom property (let's call it "redCircle") for the group
to hold the currently-highlited circle. Then when you switch to another
circle, you only have to change the previously-highlited one, instead of
changing them all:

  on mouseUp
    if word 1 of the name of the target is not "graphic" then pass mouseUp
    if the redCircle of me is not empty
    then set the backgroundColor of graphic ID (the redCircle of me) to gray
    set the backgroundColor of the target to red
    set the redCircle of me to the short ID of the target
  end mouseUp

Jeanne A. E. DeVoto ~ jeanne at
Runtime Revolution Limited - Power to the Developer!

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