Multicolumn Printing (Text Flow)
depstein at att.net
depstein at att.net
Wed Nov 17 12:35:35 EST 2004
I like Cubist's binary search idea, but I recall that when I originally stepped through the text by "word" rather than by "char" I was stymied by the fact that a quoted series of words is understood as a single word, even though a proper page break could fall within that series. I assume a binary search by char would work. Thanks.
David Epstein
> sez depstein at att.net:
> >Here's another approach to the text overflow calculation:
> Nice idea, but do you really need to test every character in sequence? I
> was under the impression that Rev doesn't believe in hyphenation, so you could
> speed up this handler by testing words rather than characters; a further
> speedup could be gained by starting with the entire field (what if the text
> doesn't
> actually overflow?) and doing a binary search. With that in mind, here's my
> modified version of your handler ('ware the line wraps!)...
function ExtraText2 FldName
-- removes from fld FldName, and returns, the htmlText that overflows size of
fld FldName
put (the number of words in fld FldName) into WordKount
put max (WordKount div 2, 1) into DerDelta
put the height of fld FldName into DerHeight
put the formattedHeight of word 1 to WordKount of fld FldName into
CurrentHeight
if CurrentHeight <= DerHeight then return "" -- no overflow, right?
-- now comes the binary search
put WordKount into HiEnd
put CurrentHeight into MaxH
put DerDelta into LoEnd
put the formattedHeight of word 1 to LoEnd of fld Fldname into MinH
repeat
put max (DerDelta div 2, 1) into DerDelta
if MinH > DerHeight then -- even the minimum is too long
put LoEnd into HiEnd
put MinH into MaxH
subtract DerDelta from LoEnd
put the formattedHeight of word 1 to LoEnd of fld Fldname into MinH
else if MinH = DerHeight then -- *just* right!
return the htmlText of word (LoEnd + 1) to -1 of fld FldName
else -- the minimum is too small
if MaxH - MinH = 1 then -- we've discovered the overflow point
return the htmlText of word (LoEnd + 1) to -1 of fld FldName
end if
add DerDelta to LoEnd
end if
put the formattedHeight of word 1 to LoEnd of fld Fldname into MinH
end repeat
end extraText2
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