1 files changed, 81 insertions, 8 deletions

diff --git a/include/drawinglayer/attribute/fillgradientattribute.hxx b/include/drawinglayer/attribute/fillgradientattribute.hxx
index 50a87a685f1a..11b87f1b3a32 100644
--- a/include/drawinglayer/attribute/fillgradientattribute.hxx
+++ b/include/drawinglayer/attribute/fillgradientattribute.hxx
@@ -21,11 +21,8 @@
 
 #include <drawinglayer/drawinglayerdllapi.h>
 #include <o3tl/cow_wrapper.hxx>
-
-namespace basegfx
-{
-class BColor;
-}
+#include <basegfx/color/bcolor.hxx>
+#include <vector>
 
 namespace drawinglayer::attribute
 {
@@ -46,14 +43,88 @@ class DRAWINGLAYER_DLLPUBLIC FillGradientAttribute
 public:
     typedef o3tl::cow_wrapper<ImpFillGradientAttribute> ImplType;
 
+    /* MCGR: Provide ColorSteps to the FillGradientAttribute
+
+       This is the needed combination of offset and color:
+
+       Offset is defined as:
+       - being in the range of [0.0 .. 1.0] (unit range)
+       - 0.0 being reserved for StartColor
+       - 1.0 being reserved for EndColor
+       - in-between offsets thus being in the range of ]0.0 .. 1.0[
+       - no two equal offsets are allowed
+         - this is an error, but will be ignored (maybe assert?)
+       - missing 1.0 entry (EndColor) is allowed
+       - at least one value (usually 0.0, StartColor) is required
+         - this allows to avoid massive testing in all places where
+           this data has to be accessed
+
+       Color is defined as:
+       - RGB with unit values [0.0 .. 1.0]
+
+       These definitions are packed in a std::vector<ColorStep> ColorSteps,
+       see typedef below. This array is sorted ascending by offsets, from
+       lowest to highest. Since all this primitive data definition is
+       read-only, this can be guaranteed by forcing/checking this in the
+       constructor.
+    */
+    class ColorStep
+    {
+    private:
+        double mfOffset;
+        basegfx::BColor maColor;
+
+    public:
+        ColorStep(double fOffset, const basegfx::BColor& rColor)
+            : mfOffset(fOffset)
+            , maColor(rColor)
+        {
+        }
+
+        double getOffset() const { return mfOffset; }
+        const basegfx::BColor& getColor() const { return maColor; }
+
+        bool operator<(const ColorStep& rCandidate) const
+        {
+            return getOffset() < rCandidate.getOffset();
+        }
+
+        bool operator==(const ColorStep& rCandidate) const
+        {
+            return getOffset() == rCandidate.getOffset() && getColor() == rCandidate.getColor();
+        }
+    };
+
+    typedef std::vector<ColorStep> ColorSteps;
+
 private:
     ImplType mpFillGradientAttribute;
 
 public:
+    /* MCGR: Adaptions for MultiColorGradients
+
+       To force providing start/end colors these are still part of the
+       constructor (see rStartColor/rEndColor). To also provide
+       GradientSteps these need to be handed over by ColorSteps data
+       if wanted/needed.
+
+       Start/EndColor will be added to the internal ColorSteps with
+       the according default offsets. A rigid correction/input data
+       testing is done by the construtor, including to sort the
+       ColorSteps by offset.
+
+       To access e.g. the StartColor, use getColorSteps().front(), and
+       getColorSteps().back(), accordingly, for EndColor. The existance
+       of at least one entry is guaranteed, so no need to check before
+       accessing using of front()/back() calls. If only one color entry
+       exists, start == end color is assumed, so not really a gradient
+       but (existing) fallbacks to filled polygon can trigger.
+    */
     /// constructors/assignmentoperator/destructor
     FillGradientAttribute(GradientStyle eStyle, double fBorder, double fOffsetX, double fOffsetY,
                           double fAngle, const basegfx::BColor& rStartColor,
-                          const basegfx::BColor& rEndColor, sal_uInt16 nSteps = 0);
+                          const basegfx::BColor& rEndColor, const ColorSteps* pColorSteps = nullptr,
+                          sal_uInt16 nSteps = 0);
     FillGradientAttribute();
     FillGradientAttribute(const FillGradientAttribute&);
     FillGradientAttribute(FillGradientAttribute&&);
@@ -64,6 +135,9 @@ public:
     // checks if the incarnation is default constructed
     bool isDefault() const;
 
+    // check if it is defined by a single color, then it is no gradient at all
+    bool hasSingleColor() const;
+
     // compare operator
     bool operator==(const FillGradientAttribute& rCandidate) const;
 
@@ -73,8 +147,7 @@ public:
     double getOffsetX() const;
     double getOffsetY() const;
     double getAngle() const;
-    const basegfx::BColor& getStartColor() const;
-    const basegfx::BColor& getEndColor() const;
+    const ColorSteps& getColorSteps() const;
     sal_uInt16 getSteps() const;
 };