When is message passing required?

Paul Dupuis paul at researchware.com
Mon May 23 19:42:06 CEST 2016

First, thanks for all the responses, but I should have been clearer.

I do know the LC message hierarchy and I know the difference between
pass, send, dispatch, etc.

What I was looking for is which messages, if intercepted, prevent a
normally expected action in LiveCode. Richard's example of
"CloseStackRequest" or my example of "rawKeyDown" fit this bill.

"Normally" (and yes that can be subjective), you expect key presses to
cause characters to appear or clicking in a closebox of a window to
close the window. If the messages corresponding to those are trapped
without passing the message, the event/action is not performed by the

This was an exercise in curiosity, not any particular coding problem. I
was curious if anyone has compiled a list of those messages that the
engine would perform a default action if the message is not trapped.

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