tdf#132246, tdf#155735: Add support for SourceAlpha

Change-Id: I8feae2447b17e15113ca45fe46c0d68cb6b6ab71
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/153550
Tested-by: Jenkins
Reviewed-by: Xisco Fauli <xiscofauli@libreoffice.org>

2 files changed, 46 insertions, 0 deletions

diff --git a/basegfx/source/color/bcolormodifier.cxx b/basegfx/source/color/bcolormodifier.cxx
index 829b0abda659..52f34a69f205 100644
--- a/basegfx/source/color/bcolormodifier.cxx
+++ b/basegfx/source/color/bcolormodifier.cxx
@@ -69,6 +69,25 @@ namespace basegfx
         return "invert";
     }
 
+    BColorModifier_alpha::~BColorModifier_alpha()
+    {
+    }
+
+    bool BColorModifier_alpha::operator==(const BColorModifier& rCompare) const
+    {
+        return dynamic_cast< const BColorModifier_alpha* >(&rCompare) != nullptr;
+    }
+
+    ::basegfx::BColor BColorModifier_alpha::getModifiedColor(const ::basegfx::BColor& /*aSourceColor*/) const
+    {
+        return ::basegfx::BColor(0.0, 0.0, 0.0);
+    }
+
+    OUString BColorModifier_alpha::getModifierName() const
+    {
+        return "alpha";
+    }
+
     BColorModifier_luminance_to_alpha::~BColorModifier_luminance_to_alpha()
     {
     }
diff --git a/basegfx/test/BColorModifierTest.cxx b/basegfx/test/BColorModifierTest.cxx
index 6be160ce43ae..5a4b941e1c44 100755
--- a/basegfx/test/BColorModifierTest.cxx
+++ b/basegfx/test/BColorModifierTest.cxx
@@ -378,6 +378,32 @@ public:
         CPPUNIT_ASSERT(aBColorModifier->operator==(*aBColorModifier2));
     }
 
+    void testAlpha()
+    {
+        const basegfx::BColorModifierSharedPtr aBColorModifier
+            = std::make_shared<basegfx::BColorModifier_alpha>();
+
+        CPPUNIT_ASSERT_EQUAL(maBlack, aBColorModifier->getModifiedColor(maWhite));
+        CPPUNIT_ASSERT_EQUAL(maBlack, aBColorModifier->getModifiedColor(maGray));
+        CPPUNIT_ASSERT_EQUAL(maBlack, aBColorModifier->getModifiedColor(maBlack));
+
+        CPPUNIT_ASSERT_EQUAL(maBlack, aBColorModifier->getModifiedColor(maRed));
+        CPPUNIT_ASSERT_EQUAL(maBlack, aBColorModifier->getModifiedColor(maGreen));
+        CPPUNIT_ASSERT_EQUAL(maBlack, aBColorModifier->getModifiedColor(maBlue));
+        CPPUNIT_ASSERT_EQUAL(maBlack, aBColorModifier->getModifiedColor(maYellow));
+        CPPUNIT_ASSERT_EQUAL(maBlack, aBColorModifier->getModifiedColor(maMagenta));
+        CPPUNIT_ASSERT_EQUAL(maBlack, aBColorModifier->getModifiedColor(maCyan));
+
+        CPPUNIT_ASSERT(aBColorModifier->operator==(*aBColorModifier));
+        const basegfx::BColorModifierSharedPtr aBColorModifierInvert
+            = std::make_shared<basegfx::BColorModifier_invert>();
+        CPPUNIT_ASSERT(*aBColorModifier != *aBColorModifierInvert);
+
+        const basegfx::BColorModifierSharedPtr aBColorModifier2
+            = std::make_shared<basegfx::BColorModifier_alpha>();
+        CPPUNIT_ASSERT(aBColorModifier->operator==(*aBColorModifier2));
+    }
+
     CPPUNIT_TEST_SUITE(bcolormodifier);
     CPPUNIT_TEST(testGray);
     CPPUNIT_TEST(testInvert);
@@ -389,6 +415,7 @@ public:
     CPPUNIT_TEST(testMatrix);
     CPPUNIT_TEST(testIdentityMatrix);
     CPPUNIT_TEST(testBlackAndWhite);
+    CPPUNIT_TEST(testAlpha);
     CPPUNIT_TEST_SUITE_END();
 };