Lingo Dictionary > G-K > on isOKToAttach |
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on isOKToAttach
Syntax
on isOKToAttach me, spriteType, spriteNum
Description
Built-in handler; you can add this handler to a behavior in order to check the type of sprite the behavior is being attached to and prevent the behavior from being attached to inappropriate sprite types.
When the behavior is attached to a sprite, the handler executes and Director passes to it the type of the sprite and its sprite number. The me
argument contains a reference to the behavior that is being attached to the sprite.
This handler runs before the on getPropertyDescriptionList
handler.
The Lingo author can check for two types of sprites. #graphic
includes all graphic cast members, such as shapes, bitmaps, digital video, text, and so on. #script
indicates the behavior was attached to the script channel. In this case, the spriteNum
is 1.
For each of these sprite types, the handler must return TRUE
or FALSE
. A value of TRUE
indicates that the behavior can be attached to the sprite. A value of FALSE
prevents the behavior from being attached to the sprite.
If the behavior contains no on isOKToAttach
handler, then the behavior can be attached to any sprite or frame.
This handler will only be called during the initial attachment of the behavior to the sprite or script channel and will not be called again when any other changes are made to the sprite.
Example
This statement checks the sprite type the behavior is being attached to and returns TRUE
for any graphic sprite except a shape and FALSE
for the script channel:
on isOKToAttach me, spriteType, spriteNum case spriteType of #graphic: -- any graphic sprite type return sprite(spriteNum).member.type <> #shape -- works for everything but shape cast members #script: --the frame script channel return FALSE -- doesn't work as a frame script end case
end
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