tools: add AsRGBHexString to Color + unit test

AsRGBHexString returns the Color as a RGB hex string. For example
"00ff00" for green color.

Change-Id: Ia95c7f9eb6d9aefc3ca989046fa8d76b7b7f9e8f

include/tools/color.hxx

@@ -162,6 +162,10 @@ public:
     TOOLS_DLLPUBLIC friend SvStream&    ReadColor( SvStream& rIStream, Color& rColor );
     TOOLS_DLLPUBLIC friend SvStream&    WriteColor( SvStream& rOStream, const Color& rColor );
 
+    // Return color as RGB hex string
+    // for example "00ff00" for green color
+    OUString AsRGBHexString();
+
     // get ::basegfx::BColor from this color
     ::basegfx::BColor getBColor() const { return ::basegfx::BColor(GetRed() / 255.0, GetGreen() / 255.0, GetBlue() / 255.0); }
 };

tools/CppunitTest_tools_test.mk

@@ -19,6 +19,7 @@ $(eval $(call gb_CppunitTest_add_exception_objects,tools_test, \
     tools/qa/cppunit/test_reversemap \
     tools/qa/cppunit/test_stream \
     tools/qa/cppunit/test_urlobj \
+    tools/qa/cppunit/test_color \
 ))
 
 $(eval $(call gb_CppunitTest_use_api,tools_test, \

tools/qa/cppunit/test_color.cxx

+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <sal/types.h>
+#include "cppunit/TestAssert.h"
+#include "cppunit/TestFixture.h"
+#include "cppunit/extensions/HelperMacros.h"
+#include "cppunit/plugin/TestPlugIn.h"
+#include <tools/color.hxx>
+
+namespace
+{
+
+class Test: public CppUnit::TestFixture
+{
+public:
+    void test_asRGBColor();
+
+    CPPUNIT_TEST_SUITE(Test);
+    CPPUNIT_TEST(test_asRGBColor);
+    CPPUNIT_TEST_SUITE_END();
+};
+
+void Test::test_asRGBColor()
+{
+    Color aColor;
+    aColor = COL_BLACK;
+    CPPUNIT_ASSERT_EQUAL(aColor.AsRGBHexString(), OUString("000000"));
+
+    aColor = COL_WHITE;
+    CPPUNIT_ASSERT_EQUAL(aColor.AsRGBHexString(), OUString("ffffff"));
+
+    aColor = COL_RED;
+    CPPUNIT_ASSERT_EQUAL(aColor.AsRGBHexString(), OUString("800000"));
+
+    aColor = COL_TRANSPARENT;
+    CPPUNIT_ASSERT_EQUAL(aColor.AsRGBHexString(), OUString("ffffff"));
+
+    aColor = COL_BLUE;
+    CPPUNIT_ASSERT_EQUAL(aColor.AsRGBHexString(), OUString("000080"));
+
+    aColor.SetRed(0x12);
+    aColor.SetGreen(0x34);
+    aColor.SetBlue(0x56);
+    CPPUNIT_ASSERT_EQUAL(aColor.AsRGBHexString(), OUString("123456"));
+
+    aColor = COL_AUTO;
+    CPPUNIT_ASSERT_EQUAL(aColor.AsRGBHexString(), OUString("ffffff"));
+}
+
+CPPUNIT_TEST_SUITE_REGISTRATION(Test);
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */

tools/source/generic/color.cxx

@@ -232,6 +232,13 @@ SvStream& Color::Write( SvStream& rOStm, bool bNewFormat )
     return rOStm;
 }
 
+OUString Color::AsRGBHexString()
+{
+    std::stringstream ss;
+    ss << std::hex << std::setfill ('0') << std::setw(6) << GetRGBColor();
+    return OUString::createFromAscii(ss.str().c_str());
+}
+
 #define COL_NAME_USER       ((sal_uInt16)0x8000)
 
 SvStream& ReadColor( SvStream& rIStream, Color& rColor )