Re: [xmlroff] DocBook to PDF with xmlroff

[Tony G. <Ton...@Su...>]

Tony Graham <Ton...@Su...> writes:
> Tim Waugh <tw...@re...> writes:
>> On Thu, Mar 10, 2005 at 04:41:49PM +0000, Tony Graham wrote:
> ..
>> Oh, now that I look more closely, it's the fo:external-graphic ones I
>> wanted.  The background-image things were for 'draft'-type watermarks,
>> and they come from docbook-xsl.
>>
>> So is that more difficult?
>
> Oh, yes.
>
> The simple answer:

For the record...

>  - Implement the graphic handing in FoDocGP that used to be in
>    FoDocPDF.

I.e., implement these commands from libfo/fo-doc-commands.h for
FoDocGP:

void          fo_doc_place_image     (FoDoc        *fo_doc,
				      gint          image,
				      gfloat        x,
				      gfloat        y,
				      gfloat        scale);
gint          fo_doc_open_image_file (FoDoc        *fo_doc,
				      const char   *imagetype,
				      const char   *filename,
				      const char   *stringparam,
				      gint          intparam);
void          fo_doc_close_image     (FoDoc        *fo_doc,
				      gint          image);

In practice, it would be okay to modify the fo-doc-commands.h commands
since these were based on PDFlib functions and PDFlib is no longer
used.

>  - Modify PangoXSL to walk the PangoLayout after it's been rendered
>    and call the callback for each graphic.

Actually, modify fo_doc_gp_render_layout_lines() to add something
similar to pangopdf_layout_lines() after the
gnome_print_pango_layout() call to iterate through each PangoAttribute
of each run of each line of fo_area_layout_get_layout (area_layout) to
find any callback attributes similarly to what was done in
pangopdflib.c in the PangoPDF project:

	  if (attr_type == pango_attr_callback_get_type ())
	    {
	      GValue values[1] = { { 0, } };

	      g_value_init (&values[0], G_TYPE_POINTER);
	      g_value_set_pointer (&values[0], pdf_doc);

#if 0
	      g_message ("Got a callback: callback: %p",
			 ((PangoAttrPointer *) attr)->pointer);
#endif

	      PDF_translate (pdf_doc,
			     ((float) x) / PANGO_SCALE,
			     ((float) y) / PANGO_SCALE);

	      g_closure_invoke (((GClosure *) ((PangoAttrPointer *) attr)->pointer),
				NULL,
				1,
				values,
				NULL);
	      PDF_translate (pdf_doc,
			     - (((float) x) / PANGO_SCALE),
			     - (((float) y) / PANGO_SCALE));
	    }

(See
http://cvs.sourceforge.net/viewcvs.py/pangopdf/pangopdf/pango/pangopdflib.c?rev=1.6&view=auto)

Regards,


Tony.