Should "return True" be also added to the app menu handlers? or just
the window handlers?
It should be added to any handler -- whether in an app, a window, or a
control -- that deals with a menu selection such that the menu
selection
should not be passed to the next thing in line.
Example: If your window has a FilePrint menu handler that puts up a
dialog,
then it should return true, whether the user cancels the dialog or
not. Even
though ultimately nothing got printed, the menu selection itself was
handled; i.e. the FilePrint handler took responsibility for all
subsequent
processing.
Contrast this with an Event (noting that a menu handlers is basically a
specialized kind of event) like KeyDown. This returns a Boolean
indicating
"handled" just like a menu handler, and it is not uncommon for, say, an
EditField to handle certain keys but not others, so its KeyDown event
would
sometimes return true and sometimes false.
In practice, most menu handlers return true, whereas with Events it's
more
situation-dependent. The difference is that Events are predefined for
all
controls whether they are used or not, but Menu Handlers are added by
the
programmer only as needed, and it's unusual for a menu selection to be
examined and passed on.
lj
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