Subject: Re: Getting our tables to render better in PDF output
To: Tom Lane <tgl@sss.pgh.pa.us>, pgsql-docs@lists.postgresql.org
References: <20200212221818.GA15503@alvherre.pgsql>
 <23574.1581555393@sss.pgh.pa.us> <10810.1581883655@sss.pgh.pa.us>
From: Alexander Lakhin <exclusion@gmail.com>
Message-ID: <5d1f5b72-1b4a-6e15-6730-d94e2252a073@gmail.com>
Date: Mon, 17 Feb 2020 00:21:24 +0300
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.4.1
MIME-Version: 1.0
In-Reply-To: <10810.1581883655@sss.pgh.pa.us>
Content-Type: multipart/mixed;
 boundary="------------CE0EF25842A8E2B474A834DE"
Content-Language: en-US
Precedence: bulk

This is a multi-part message in MIME format.
--------------CE0EF25842A8E2B474A834DE
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit

Hello Tom,
> 16.02.2020 23:07, Tom Lane wrote:
>
>
> I poked at this a little bit, and found that I could get a pretty
> decent-looking result if I hacked the .fo file to contain
> "<fo:inline baseline-shift="10%">→</fo:inline>" rather than a bare
> right arrow.  (See attached screenshot, wherein the last rightarrow
> was fixed this way but the others weren't.)  However, I do not
> have much of a clue as to how such a fix might be injected into
> our stylesheets --- anybody have a suggestion?
Please look at the XSLT template for processing .fo before calling fop.
Maybe this can be done with just the existing stylesheet-fo.xsl, I'll
try to research this later.

Best regards,
Alexander


--------------CE0EF25842A8E2B474A834DE
Content-Type: text/x-patch; charset=UTF-8;
 name="shift_arrow_up.patch"
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
 filename="shift_arrow_up.patch"

diff --git a/doc/src/sgml/Makefile b/doc/src/sgml/Makefile
index 0401a515df8..3be29dba9f1 100644
--- a/doc/src/sgml/Makefile
+++ b/doc/src/sgml/Makefile
@@ -169,10 +169,14 @@ XSLTPROC_FO_FLAGS += --stringparam img.src.path '$(srcdir)/'
 %-A4.fo: stylesheet-fo.xsl %.sgml $(ALLSGML)
 	$(XMLLINT) $(XMLINCLUDE) --noout --valid $(word 2,$^)
 	$(XSLTPROC) $(XMLINCLUDE) $(XSLTPROCFLAGS) $(XSLTPROC_FO_FLAGS) --stringparam paper.type A4 -o $@ $(wordlist 1,2,$^)
+	$(XSLTPROC) $(XMLINCLUDE) $(XSLTPROCFLAGS) -o $@.tmp $(@D)/pg-customize-fo.xsl $@
+	mv $@.tmp $@
 
 %-US.fo: stylesheet-fo.xsl %.sgml $(ALLSGML)
 	$(XMLLINT) $(XMLINCLUDE) --noout --valid $(word 2,$^)
 	$(XSLTPROC) $(XMLINCLUDE) $(XSLTPROCFLAGS) $(XSLTPROC_FO_FLAGS) --stringparam paper.type USletter -o $@ $(wordlist 1,2,$^)
+	$(XSLTPROC) $(XMLINCLUDE) $(XSLTPROCFLAGS) -o $@.tmp $(@D)/pg-customize-fo.xsl $@
+	mv $@.tmp $@
 
 %.pdf: %.fo $(ALL_IMAGES)
 	$(FOP) -fo $< -pdf $@
diff --git a/doc/src/sgml/pg-customize-fo.xsl b/doc/src/sgml/pg-customize-fo.xsl
new file mode 100644
index 00000000000..ba3138e2a3d
--- /dev/null
+++ b/doc/src/sgml/pg-customize-fo.xsl
@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<xsl:stylesheet xmlns:fo="http://www.w3.org/1999/XSL/Format" version="1.0"
+    xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+
+  <xsl:template match="@*|node()">
+    <xsl:copy>
+      <xsl:apply-templates select="@*|node()"/>
+    </xsl:copy>
+  </xsl:template>
+
+  <xsl:template match="fo:block//text()">
+    <xsl:choose>
+      <xsl:when test='contains(., "&#8594;")'>
+        <xsl:call-template name="shift_arrow_up">
+          <xsl:with-param name="text" select="."/>
+        </xsl:call-template>
+      </xsl:when>
+      <xsl:otherwise>
+        <xsl:value-of select="."/>
+      </xsl:otherwise>
+    </xsl:choose>
+  </xsl:template>
+
+  <xsl:template name="shift_arrow_up">
+    <xsl:param name="text" />
+    <xsl:choose>
+      <xsl:when test='contains($text, "&#8594;")'>
+        <xsl:call-template name="shift_arrow_up">
+          <xsl:with-param name="text" select='substring-before($text, "&#8594;")'/>
+        </xsl:call-template>
+        <fo:inline baseline-shift="10%">&#8594;</fo:inline>
+        <xsl:call-template name="shift_arrow_up">
+          <xsl:with-param name="text" select='substring-after($text, "&#8594;")'/>
+        </xsl:call-template>
+      </xsl:when>
+      <xsl:otherwise>
+        <xsl:value-of select="$text"/>
+      </xsl:otherwise>
+    </xsl:choose>
+  </xsl:template>
+
+</xsl:stylesheet>

--------------CE0EF25842A8E2B474A834DE--