[cl-typesetting-devel] Formatting across pages bug not quite dead.

[Peter Seibel]

Peter Seibel <peter at javamonkey.com> writes:

> "Marc Battyani" <marc.battyani at fractalconcept.com> writes:
> 
> > "Peter Seibel" <peter at javamonkey.com> writes:
> > 
> > > Hmmm. The formatting across pages bug that we thought was fixed seems
> > > to be back. Check out the top of page 5 in:
> > >
> > >   <http://www.gigamonkeys.com/book/another-formatting-bug.pdf>
> > >
> > > If I get a chance I'll try to investigate more but I figured I'd let
> > > you know while it's still somewhat fresh in your mind.
> > 
> > I will look at this. Looking at your example, it seems that only 2 pages are
> > affected. Are they different in some way ?
> 
> Not from my point of view. The only pattern that I can see (given this
> limited data set) is that in both cases where the formatting is
> broken, the first line on the new page contains character formatting
> that gets broken across the line (i.e. it starts on the first line and
> ends on the second line). On page 3 it's the ":if-exists" which is set
> in Courier and on page 5 it's the "WRITE-CHAR" which is set in
> Courier-Bold. In both cases that same formatting seems to get picked
> up by the beginning of the line.

And that indeed seems to be the pattern as this standalone example shows:

(defun bug (&optional (file #P"/tmp/hello.pdf"))
  (let ((width 612)
        (height 792)
        (margins '(108 36 108 108))
        (header-height (- 108 36)))
    (pdf:with-document ()
      (let ((content (typeset::compile-text 
                      () 
                      (dotimes (i 20) 
                        (typeset::paragraph
                         (:h-align :left :font "Times-Roman" :font-size 12)
                         (typeset::vspace 12)
                         (dotimes (j 20)
                           (cond
                            ((and (= i 2) (= j 19))
                             (typeset::put-string 
                              (format nil "~d. " j))
                             (typeset::with-style (:font "Courier-Bold")
                                                  (typeset::put-string "The quick"))
                             (typeset::put-string " brown fox jumps over the lazy dog. "))
                            (t
                             (typeset::put-string 
                              (format nil "~d. The quick brown fox jumps over the lazy dog. " j))))))))))

        (loop for page-number from 1
            for header = (typeset::compile-text 
                          ()
                          (typeset::paragraph
                           (:h-align :right :font "Times-Roman" :font-size 12)
                           (typeset::put-string "HEADER") :eol))
            while (typeset::boxes content)
            do 
              (destructuring-bind (left &optional (top left) (right left) (bottom top)) margins
                (let ((x left)
                      (y (- height top))
                      (dx (- width left right))
                      (dy (- height top bottom)))
                  (pdf:with-page (:bounds (vector 0 0 width height))
                    (pdf:with-saved-state
                      (typeset::stroke (typeset::make-filled-vbox header dx header-height :top) x y))
                    (typeset::stroke (typeset::make-filled-vbox content  dx (- dy header-height) :top) x (- y header-height)))))))
      (pdf:write-document file))))

-Peter

-- 
Peter Seibel                                      peter at javamonkey.com

         Lisp is the red pill. -- John Fraser, comp.lang.lisp