character to justify text -- spacer graphic implementation

[Brian Yennie]

This uses a naive algorithm and has limitations, but it's a fun  
experiment.
Create a scrolling text field and a 1x1 empty image object.

Paste this into the field script and type away.

on keyDown c
   lock screen
   do "put c into"&& (the selectedChunk)
   fullJustify (the id of me), (the id of image "spacer")
   unlock screen
end keyDown

on fullJustify fldID, imageID
   local i, targetWidth

   put fullFieldLineWidth(fldID) into targetWidth

   put 1 into i

   lock screen
   replace numToChar(0) with empty in fld id fldID
   put the formattedText of fld id fldID into fld id fldID

   repeat for each line l in fld id fldID
     put (targetWidth - the formattedWidth of line i of fld id fldID)  
into tLineGaps[i]
     add 1 to i
   end repeat

   put 1 into i
   repeat for each line l in fld id fldID
     put padLine(l, tLineGaps[i], numToChar(0)) into line i of fld id  
fldID
     add 1 to i
   end repeat

   put 1 into i
   repeat for each char c in fld id fldID
     if (char i of fld 1 is numToChar(0)) then
       set the imageSource of char i of fld id fldID to imageID
     end if
     add 1 to i
   end repeat
   unlock screen

end fullJustify

function fullFieldLineWidth fldID
   put (the width of fld id fldID) into targetWidth
   subtract (2* the borderWidth of fld id fldID) from targetWidth
   subtract (item 1 of the margins of fld id fldID) from targetWidth
   get (item 3 of the margins of fld id fldID)
   if (it is empty) then subtract (item 1 of the margins of fld id  
fldID) from targetWidth
   else subtract (item 3 of the margins of fld id fldID) from  
targetWidth
   if (the vScrollbar of fld id fldID) then subtract the  
scrollbarWidth of fld id fldID from targetWidth
   return targetWidth
end fullFieldLineWidth

function padLine l, pixels
   put empty into tmp1
   put 0 into spaceCount
   repeat for each char c in l
     if (c is space) then add 1 to spaceCount
   end repeat
   if (spaceCount = 0) then return l
   put (pixels div spaceCount) into spacePadding
   put (pixels mod spaceCount) into leftoverPads
   repeat for each char c in l
     if (c is space) then
       repeat spacePadding
         put numToChar(0) after tmp1
       end repeat
     end if
     put c after tmp1
   end repeat
   repeat for each char c in tmp1
     if (c is space) AND (leftoverPads > 0) then
       put numToChar(0) after tmp2
       subtract 1 from leftoverPads
     end if
     put c after tmp2
   end repeat

   return tmp2
end padLine