MS Write Import Filter for KWord - How to Perfect the Filter
$Date: 2003-05-09 15:50:03 +0200 (Fri, 09 May 2003) $
Clarence Dang <dang@kde.org>


No import filter, let alone software or hardware, is perfect.  And this
includes the MS Write Import Filter...

This filter appears to be feature-complete, except for OLE and what is
mentioned here.

This document discusses where and why the filter is not perfect (! :)) and
whether or not these problems should or can be fixed.  In the world of filter
development, it is important to consider even minute details (within reason).


Problems that could be fixed in the future
------------------------------------------

1. Linespacing

MS Write renders text with an uncommon form of linespacing (where the
text is aligned to the bottom).

This has been discussed on koffice-devel and has resulted in a
work-around: use of the OFFSETS tag to "fake" space before each line.
Unfortunately, this is not perfect esp. the trailing linespacing at the
end of the paragraph and where paragraphs span more than one line.
This feature is now disabled by default and cannot be turned on because of
stability problems with the dialog!

Word97 can import this kind of linespacing, despite the fact that it too
doesn't ordinarily do linespacing like MS Write does so perhaps this may be
fixed in the future?

2. Positioning of Headers, Footers & Main Text Frame

The following things in an MS Write document are known:

##########    <-- top of header
# Header #
##########

##########    <-- top of body
#        #
#        #
#  BODY  #
#        #
#        #
##########    <-- bottom of body

##########
# Footer #
##########    <-- bottom of footer

If "Word Processing" mode is selected, spHeadBody and spFootBody would have
to be specified.  From the information given above, however, these two cannot
be computed in advance.  If "DTP" mode is selected, we would need KWord to
support expanding frames upwards for the footer (since we only know the bottom
of the footer but not the top).

In other words, AFAIK, the current KWord file format does not allow the
specification of the exact position of each frame.

See my post "Specifying exact frame positions" to the koffice-devel mailinglist
on 2002-01-27 and the number of responses I got to it.

Also, the concept of Margins are different in MS Write.  In MS Write,
the top and bottom margins of the document refer to the position of the
body frame on the paper.  While in KWord, it refers to the position of
the topmost text frame (which could be the header) and the bottom-most
text frame (which could be the footer).  So the import filter adjusts
the margins of the page, based on the positions of the header and footer.

3. Image Positions

In MS Write, the user can position an image a certain number of points
from the left margin.

In KWord, it is impossible to do this (for anchored images, which are
required to maintain the relative positions of surrounding text and the
image), at the moment (see my post "Images and Stores" to koffice-devel on
2002-01-26).  So at the moment, paragraph indenting is used to emulate it.


Problems that will probably never be fixed
------------------------------------------

1. Rendering Differences Between KWord and MS Write

KWord renders with slightly more/less space than MS Write for images,
text etc.  This is what I would call a fundamental difference between
word-processors and so cannot be avoided (realistically) and the exact
amount of spacing is not specified by MS anyway.

Obviously, this would mean that KWord will read a document and produce
more/less pages than MS Write would with the same document, leading on
to point (2):

2. Page Table is Ignored

Some MS Write documents contain a "Page Table" (created when the user
clicks "Repaginate"), which specifies where pages start and end esp. for
printing purposes.  However due to the previous point (1) and the fact
that the pageTable can get so out of sync with the document anyway esp. if
the user doesn't "Repaginate" the document everytime s/he changes it,
the pageTable is completely ignored in this import filter (see the empty
MSWrite::Generator::writePageNew implementation).


What you can do to help
--------------------------------------------------------

1. Contribute to LibMSWrite (http://sourceforge.net/projects/libmswrite/)

2. Fix something in the KOffice end of the filter (mswriteimport.*)

3. Send me an email telling me what I've done wrong

All help is appreciated (just remember to send me an email so that efforts
are not duplicated and so that I can add you to the credits section :)!


--