MCGR: 1st additions to OOXML MCGR import

This change provides 1st changes to get Gradients with
muti color stops imported from MSO in the oox import
filter. It supports currently multiple ColorStops and
transparency. Also 'border'(s) should work, but
-remember- this is work in progress.

Since it is work in progress it is currently and
temporaily secured by ENV VAR "MCGR_TEST=0", so when
not using this the master version will not be touched
at all.

The number defines various ColorStop tests, 0 for none,
but some changes are active, e.g. MSO import. You may
try 1 or 16 to see all your Gradients hard replaced by
something using that feature.
I will take care fo cleaning this up again when the
feature progresses/gets complete.

Change-Id: I92e10d8cd5150733741a6def20a542abf97bd903
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/149682
Tested-by: Jenkins
Reviewed-by: Armin Le Grand <Armin.Le.Grand@me.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/basegfx/source/tools/gradienttools.cxx b/basegfx/source/tools/gradienttools.cxx
index a98eeddf641c..49cf831da262 100644
--- a/basegfx/source/tools/gradienttools.cxx
+++ b/basegfx/source/tools/gradienttools.cxx
@@ -264,6 +264,38 @@ namespace basegfx
 
     namespace utils
     {
+        /* Tooling method to check if a ColorStop vector is defined
+           by a single color. It returns true if this is the case.
+           If true is returned, rSingleColor contains that single
+           color for convenience.
+           NOTE: If no ColorStop is defined, a fallback to BColor-default
+                 (which is black) and true will be returned
+        */
+        bool isSingleColor(const ColorStops& rColorStops, BColor& rSingleColor)
+        {
+            if (rColorStops.empty())
+            {
+                rSingleColor = BColor();
+                return true;
+            }
+
+            if (1 == rColorStops.size())
+            {
+                rSingleColor = rColorStops.front().getStopColor();
+                return true;
+            }
+
+            rSingleColor = rColorStops.front().getStopColor();
+
+            for (auto const& rCandidate : rColorStops)
+            {
+                if (rCandidate.getStopColor() != rSingleColor)
+                    return false;
+            }
+
+            return true;
+        }
+
         /* Tooling method to reverse ColorStops, including offsets.
            When also mirroring offsets a valid sort keeps valid.
         */