cory@gloom.UUCP (Cory Kempf) (12/21/88)
The subject says it all. What I want to know is, is there a way to test for the existance of a specific object from within a hypertalk script? (ie a card, button, field, etc?) Prefferably by name? I would rather avoid writting yet another XCMD for this if I can avoid it. Thanks, +C -- Cory (...your bravest dreams, your worst nightmare...) Kempf UUCP: encore.com!gloom!cory "...it's a mistake in the making." -KT
eduard@uva.UUCP (Eduard de Jong) (12/23/88)
Newsgroups: comp.sys.mac.hypercard Subject: Re: HyperCard on floppies Summary: Non-boot disks must be mounted by startup application. Expires: References: <29693@tut.cis.ohio-state.edu> Sender: Reply-To: eduard@uva.UUCP (Eduard de Jong) Followup-To: Distribution: world Organization: Faculteit Wiskunde & Informatica, Universiteit van Amsterdam Keywords: Startup, mounting disks. In article <29693@tut.cis.ohio-state.edu> Howard P. Marvel asks: > 1. How do I delay until the 2d disk is recognized? This problem may be explained by looking at the MACs boot procedure. It runs (scematicaly) like this: At Boot_time only the boot disk is mounted by the boot code; the system can subsequently be read using the standard FileManager calls. Any floppydrives or SCSI devices connected to the machine and recognised at boot_time (ie powered and running) are put in the event queue with a "DiskInsert Event" message. However, any drivers needed for the disks are loaded at boot_time. Normally the Finder will directly after its is launched cause the disks to be mounted when it discovers them at its first calls to GetNextEvent. This expose leads to a possible solution: If HC, as I expect, correctly handles DiskInsert events all you need is an Idle-handler in the Home stack that goes to your stack on the other disk. This should work as I figure HC posts Idle messages only after it has seen and processed any real events (like KeyDown & DiskInsert &c.). Hope you get this working now. --No fancy signature-- Eduard K. de Jong Frz.
jdevoto@well.UUCP (Jeanne DeVoto) (12/23/88)
You can check for the existence of a card by noting that a failed "go"
command sets the value of the result function. A script would look like
this:
on mouseDown
lock screen -- hide following shenanigans from users
go to card "Am I Here?"
if the result is not empty then
-- card doesn't exist
else
-- it does exist
go recent card -- get back where you came from
end if
unlock screen
end mouseDown
The only way I know of to test for the existence of a field or button
is to use a repeat loop to step through each field (or button) on the
current card and check whether that one is the one you want.
jeanne a. e. devoto
jdevoto@well.UUCP