tdf#36709 Add loext:text-indent supporting font-relative units

This change adds an ODF font-relative first-line indent paragraph style
attribute as a LibreOffice extension. The corresponding ODF standard
change is tracked by OFFICE-4165.

This change only implements what is minimally necessary to serialize,
deserialize, and check for ODF files containing this attribute. Further
changes are necessary.

* Added cssLength to schema, which is equivalent to length but also
  allows ic and em as units.
* Added loext:text-indent to schema as a paragraph style attribute. This
  attribute is equivalent to fo:text-indent, but accepts cssLength
  instead of length.
* Added XML_TYPE_UNIT_MEASURE to the ODF parser, which currently accepts
  only the font-relative measures and forces fallback in other cases.
* Added loext:text-indent to the ODF parser. This attribute accepts
  font-relative metrics, and will behave as an import-only alias for
  fo:text-indent in other cases.
* Updated SvxFirstLineIndentItem to handle unit-denominated measures.
* Added proof-of-concept indentation handler to Writer. This
  implementation is incomplete and temporary, and will be revised in
  future changes.

Change-Id: I7eb5c7382093cb18a9b0afbf93dacb34ba1d35ef
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/175941
Tested-by: Jenkins
Reviewed-by: Jonathan Clark <jonathan@libreoffice.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/schema/libreoffice/OpenDocument-v1.4+libreoffice-schema.rng b/schema/libreoffice/OpenDocument-v1.4+libreoffice-schema.rng
index a805123d7e24..5f53d50c8526 100644
--- a/schema/libreoffice/OpenDocument-v1.4+libreoffice-schema.rng
+++ b/schema/libreoffice/OpenDocument-v1.4+libreoffice-schema.rng
@@ -3098,6 +3098,25 @@ xmlns:loext="urn:org:documentfoundation:names:experimental:office:xmlns:loext:1.
     </rng:optional>
   </rng:define>
 
+  <!-- https://issues.oasis-open.org/browse/OFFICE-4165 -->
+  <rng:define name="cssLength">
+    <rng:data type="string">
+      <rng:param name="pattern">-?([0-9]+(\.[0-9]*)?|\.[0-9]+)((cm)|(mm)|(in)|(pt)|(pc)|(px)|(ic)|(em))</rng:param>
+    </rng:data>
+  </rng:define>
+
+  <!-- https://issues.oasis-open.org/browse/OFFICE-4165 -->
+  <rng:define name="style-paragraph-properties-attlist" combine="interleave">
+    <rng:optional>
+      <rng:attribute name="loext:text-indent">
+        <rng:choice>
+          <rng:ref name="cssLength"/>
+          <rng:ref name="percent"/>
+        </rng:choice>
+      </rng:attribute>
+    </rng:optional>
+  </rng:define>
+
   <!-- TODO no proposal -->
   <rng:define name="chart-data-point-attlist" combine="interleave">
     <rng:optional>