DOCBOOK-APPS: DocBook XSL-FO: content-width="scale-to-fit"

[Bernd Kuemmerlen <bkuemmer at gmx dot net>]

Hello there,

recently, we have started to use the DocBook XSL stylesheets together 
with the RenderX XEP formatter.

Since we have documents with quite large images, we would like to have 
them rescaled in the final pdf output according to the available space. 
The XEP Renderer can do this with the following declaration:

<fo:external-graphic src="url(img/large-image.gif)"
content-width="scale-to-fit"
content-height="100%"
width="100%"/>

This scales the image if it is wider than the currently available width.

With the current distribution of the XSL Stylesheets, it is not possible 
at all to set content-width="scale-to-fit". It seems that in until rev 
1.14 of fo/graphics.xsl, the scalefit attribute of imagedata etc. set 
the content-width and content-height to "scale-to-fit", but this was 
removed when the graphics support was redone 
<http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/docbook/xsl/fo/graphics.xsl.diff?r1=1.14&r2=1.15>.

What are your opinions on this matter? I think that the scalefit 
attribute should be considered in some way. For XEP, it would be best if 
scalefit would set content-width and content-height to "scale-to-fit" 
only if contentdepth and contentwidth are not explicitely set. But I 
have no idea about what implications this does make for other FO 
processors, so I would be thankful if some people here could enlighten me.

I have also filed a RFE at 
<http://sourceforge.net/tracker/?func=detail&aid=685806&group_id=21935&atid=373750>, 
so you might comment there as well.

Thanks for any comments
	Bernd