<refentry xmlns="http://docbook.org/ns/docbook"
	  xmlns:src="http://nwalsh.com/xmlns/litprog/fragment"
	  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
	  xmlns:xlink="http://www.w3.org/1999/xlink"
	  version="5.0"
	  xml:id="header.column.widths">
<refmeta>
<refentrytitle>header.column.widths</refentrytitle>
<refmiscinfo role="type"></refmiscinfo>
</refmeta>
<refnamediv>
<refname>header.column.widths</refname>
<refpurpose>Specify relative widths of header areas</refpurpose>
</refnamediv>

<refsynopsisdiv>
<src:fragment xml:id="header.column.widths.frag">
<xsl:param name="header.column.widths" select="'1 1 1'"/>
</src:fragment>
</refsynopsisdiv>

<refsect1><title>Description</title>

<para>Page headers in print output use a three column table to
position text at the left, center, and right side of the header on the
page. This parameter lets you specify the relative sizes of the three
columns. The default value is "1 1 1".</para>

<para>The parameter value must be three numbers, separated by white
space. The first number represents the relative width of the left
header for single-sided output, or the inside header for double-sided
output. The second number is the relative width of the center header.
The third number is the relative width of the right header for
single-sided output, or the outside header for double-sided output.
</para>

<para>The numbers are used to specify the column widths for the table
that makes up the header area. In the FO output, this looks like:
</para>

<programlisting>&lt;fo:table-column column-number="1" 
    column-width="proportional-column-width(1)"/&gt;</programlisting>

<para>The <literal>proportional-column-width()</literal> function
computes a column width by dividing its argument by the total of the
arguments for all the columns, and then multiplying the result by the
width of the whole table (assuming all the column specs use the
function). Its argument can be any positive integer or floating point
number. Zero is an acceptable value, although some FO processors may
warn about it, in which case using a very small number might be more
satisfactory.
</para>

<para>For example, the value "1 2 1" means the center header should
have twice the width of the other areas. A value of "0 0 1" means the
entire header area is reserved for the right (or outside) header text.
Note that to keep the center area centered on the page, the left and
right values must be the same. A specification like "1 2 3" means the
center area is no longer centered on the page since the right area is
three times the width of the left area.
</para>

</refsect1>
</refentry>
