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From: chh9@quads.uchicago.edu (Conrad Halton Halling)
Newsgroups: comp.sys.mac.hypercard
Subject: Re: HC find quirks
Message-ID: <1990Sep18.000821.4752@midway.uchicago.edu>
Date: 18 Sep 90 00:08:21 GMT
References: <1990Sep14.223831.17977@athena.mit.edu> <1990Sep14.232310.5317@midway.uchicago.edu> <1990Sep17.134816.4589@athena.mit.edu>
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In article <1990Sep17.134816.4589@athena.mit.edu>
shawn@e40-008-11.athena [signed:  shawn@athena.mit.edu]
(Shawn O'Donnell) writes:

>[stuff deleted]
>I tried the two searches manually, and they worked properly.  In the 
>script, though, they don't work.  I don't think I'm doing anything 
>between the two find commands that should disturb the process...
>[stuff deleted]

After much experimentation, I have found the answer to Shawn's problem:

*** Have the script click at some safe location (such as 0, 0) after ***
*** the first find command.  This resets some internal marker in     ***
*** HyperCard (what, I don't know, but it works!).  The next find in ***
*** a different field will begin on the same card.                   ***

Lengthy details follow:

When the two searches are done manually, as soon as you begin typing in
the message box, you'll notice that the box around the text from the
first find disappears; the result is that you have reset the find command
simply by typing into the text box. 

Here is how I set up my experimental stack:

Background "Index" contains a single card which contains 
bg fld "index" with the following contents:

Subject_1
  Topic_1
  Topic_2
  Topic_3
Subject_2
  Topic_1
  Topic_2
  Topic_3
Subject_3
  Topic_1
Subject_4
  Topic_1
  Topic_2
  
Background "ItemCards" contains as many cards as you like, with
bg fld "subject" and bg fld "topic".
     put "Subject_1" into fld "subject" of cd 1 of bg "itemCards"
     put "Topic_1" into fld "topic" of cd 1 of bg "itemCards"
     put "Topic_2" into fld "topic" of cd 2 of bg "itemCards"
          [if the cards are in order, the subject field can remain empty.]
     etc.

Lock the text of fld "index" of bg "index" and place the following
handler into the script of fld "index":

on mouseUp
  -- put the selectedLine into variable lineSelection and highlight
  -- the selectedLine for visual feedback
  set cursor to watch
  lock screen
  get the clickLoc
  set lockText of field "Index" to false
  click at it
  put the selectedLine into lineSelection
  set the lockText of field "index" to true
  unlock screen
  select lineSelection
  
  -- hide results of find commands and card movements
  lock screen
  
  -- put the contents of the selectedLine into variable lineText
  -- the "do" command is necessary here; otherwise lineText will
  -- contain the text in lineSelection ("line X of bkgnd fld 1").
  do "put " & lineSelection & " into lineText"
  
  -- find the subject and topic; topics begin with space & space
  put empty into subjectText
  put empty into topicText
  if char 1 of lineText is space then
    put lineSelection into tempSelection
    repeat until subjectText is not empty
      -- back up one line
      put ((word 2 of tempSelection) - 1) into word 2 of tempSelection
      do "put " & tempSelection & " into tempText"
      if char 1 of tempText <> space then
        put tempText into subjectText
        put lineText into topicText
      end if
    end repeat
  else
    put lineText into subjectText
  end if
  
  -- find the first card with the subject
  -- You have to go to the first card of bg "itemCards" before
  -- performing the find; if you don't, even though you have requested 
  -- 'bg fld "subject"', for some reason this gets translated by HyperCard
  -- into "bkgnd fld 1", and HyperCard simply finds the subject in 
  -- fld "index" of bg "index" (which is "bkgnd fld 1").
  go to card 1 of bg "ItemCards"
  find subjectText in fld "subject"

  -- click at a safe location where there is no button or field that
  -- will respond to a mouseDown or mouseUp; this resets the find
  -- command so it will begin the next search with the current card
  click at 0, 0
  
  -- find the first card with the topic
  if topicText is not empty then
    find topicText in fld "topic"
    click at 0,0
  end if
  
  unlock screen
  
end mouseUp


This script has been tested, and I know it works.  Many odd things
about the behavior of HyperCard turned up during my experimentation;
these are described in the comments of the script.

Since I don't have a definitive description of HyperCard, my approach
to writing scripts is to experiment until I find what works.  Everytime
I try something, I learn something new.

I saved my stack; if you, Shawn (or anyone else), want it, e-mail a request
BY FRIDAY (after which I will discard the stack) and I will send you a
binHexed Stuffit archive by e-mail.

--
Conrad Halling
chh9@midway.uchicago.edu