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xsl-foapache-fop

Position a scaled-down background image at the bottom of the body region

I need to display a large background image on the cover page. That image needs:

  1. To be shrunk to the width of region-body.
  2. To be positioned exactly at the bottom of region-body.

Using background-image is not an option since the image needs to be scaled. So I print the image in a long region-before that extends below the region-body. It works.

Then I try to position the image at the bottom of region-before using absolute-position="absolute" and bottom="0cm". Unfortunately, bottom does not work the way I expected. (The image stays to the top.)

<?xml version="1.0" encoding="UTF-8"?> 
<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">
    <fo:layout-master-set>
        <fo:simple-page-master master-name="section1-cover" page-height="11in" page-width="8.5in"
            margin-top="1cm" margin-bottom="0">
            <fo:region-before region-name="xsl-region-before" extent="11in - 1cm  - .75in"
                background-color="beige"/>
            <fo:region-body margin-top="1cm" margin-bottom=".75in" margin-right=".395in"
                margin-left=".395in"/>
            <fo:region-after region-name="xsl-region-after" extent=".75in" background-color="orange"/>
        </fo:simple-page-master>
    </fo:layout-master-set>
    <fo:page-sequence master-reference="section1-cover">
        <fo:static-content flow-name="xsl-region-before">
            <fo:block-container margin-right=".395in" margin-left=".395in"
                absolute-position="absolute" bottom="0cm">
            <!-- I expected that block-container to go down to the bottom -->
                <fo:block line-height=".5">
                <!-- line-height="1" seems more logical but yields unwanted extra space -->
                    <fo:external-graphic src="url('cover-background.jpg')" width="100%"
                        content-width="scale-down-to-fit"/></fo:block>
            </fo:block-container>
        </fo:static-content>
        <fo:flow flow-name="xsl-region-body">
            <fo:block font-size="28pt">Title</fo:block>
        </fo:flow>
    </fo:page-sequence>
</fo:root>

Does anyone have a solution?

Note: I don’t want to position that image from the top, since I cannot reliably compute the image height after scaling.

Note: It has to work in FOP.

Solution

  • Use <fo:region-before display-align="after" /> (and omit the fo:block-container). See https://www.w3.org/TR/xsl11/#display-align.

    The FOP conformance page (https://xmlgraphics.apache.org/fop/compliance.html) states that FOP has partial conformance, so YMMV.

    In the words of Larry Wall, there is more than one way to do it:

    <fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">
  <fo:layout-master-set>
    <fo:simple-page-master
        master-name="section1-cover"
        page-height="11in" page-width="8.5in">
      <fo:region-body
          margin-top="1cm"
          margin-bottom="0.75in"
          background-color="beige" />
      <fo:region-after
          region-name="xsl-region-after"
          extent=".75in"
          background-color="orange" />
    </fo:simple-page-master>
  </fo:layout-master-set>
  <fo:page-sequence master-reference="section1-cover">
    <fo:flow flow-name="xsl-region-body">
      <fo:block-container
          absolute-position="absolute"
          bottom="0in"
          left="0.395in"
          right="0.395in"
          display-align="after">
        <fo:block line-height="0">
          <fo:external-graphic
              src="url('cover-background.jpg')"
              width="100%"
              content-width="scale-down-to-fit"/>
        </fo:block>
      </fo:block-container>
      <fo:block
          margin-left="0.375in"
          margin-right="0.375in"
          font-size="28pt">Title</fo:block>
    </fo:flow>
  </fo:page-sequence>
</fo:root>

    Tested with both AH Formatter V6.5 and FOP.