tdf#86790: Add support for a word-style styleref

STYLEREF is a field type in Word which changes its content based on
nearby paragraphs. For example, upon creating a styleref referencing
"Heading 1" you will see the text of the nearest "Heading 1"-styled
paragraph that is above the field.

This patch implements STYLEREF in Writer as a cross-reference. By using
"insert>cross-reference>styles" you'll be presented with a list of
styles. Selecting one and clicking "insert" will create a field which
has text from the "most relevant" instance of the style. To find the
most relevant instance we first search up for paragraphs with the style,
and if there are any we take the closest. If there weren't any, we
search down for paragraphs with the style.

This patch also updates our use of STYLEREF for chapters exported to
docx by using it for all chapters not only those in headers and footers.
This allows us to approximate more chapter field functionality even when
moving between Writer and Word.

Finally, this patch adds some tests for STYLEREF:
- testTdf86790 tests that the "sample file with STYLEREF" document from
tdf#86790 has the correct fields
- testStyleRefSearchUp tests that the STYLEREF searches up when there
are bits of text both above and below it
- testStyleRefSearchDown tests that the STYLEREF searches down when
there are bits of text below it only
- testMarginalStyleRef tests that the STYLEREF searches from the page
top when it is placed in a footer
- testFootnotetyleRef tests that the STYLEREF searches from the
reference mark when it is placed in a footnote

Still TODO:
- [  ] Update documentation
- [  ] Implement reverse-searching (\l) and nondelimiter
suppression (\t)
- Probably these 2 will be in a followup patch

Change-Id: I25dd7a6940abee5651a784b9059fe23b32547d6c
Signed-off-by: Skyler Grey <skyler.grey@collabora.com>
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/157456
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/xmloff/inc/txtflde.hxx b/xmloff/inc/txtflde.hxx
index 8670cac40cf6..459dea29f550 100644
--- a/xmloff/inc/txtflde.hxx
+++ b/xmloff/inc/txtflde.hxx
@@ -119,6 +119,7 @@ enum FieldIdEnum {
     FIELD_ID_REF_BOOKMARK,          // get reference field (bookmark)
     FIELD_ID_REF_FOOTNOTE,          // get reference field (footnote)
     FIELD_ID_REF_ENDNOTE,           // get reference field (endnote)
+    FIELD_ID_REF_STYLE,             // styleref field
     FIELD_ID_DDE,                   // DDE field
 
     FIELD_ID_BIBLIOGRAPHY,          // bibliography index entry