tdf#103978 textboxhelper: syncProperty OPAQUE (wrap in background)

Although the containing shape is in the background (and thus the
normal paragraph text is still visible), the shape's text
was still painting over top of the normal paragraph text because
the textbox was set as opaque and not transparent.

Setting the textbox to sync the opacity value of its containing shape.

Change-Id: I02477e2fa7def1f13590afcaa7c6564dd79d6406
Reviewed-on: https://gerrit.libreoffice.org/39672
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Justin Luth <justin_luth@sil.org>
(cherry picked from commit cc438f60d6ad0855f754dd32da9c9a80c7cabf92)
Reviewed-on: https://gerrit.libreoffice.org/44430
Reviewed-by: Andras Timar <andras.timar@collabora.com>
diff --git a/sw/qa/extras/uiwriter/data/tdf103978_backgroundTextShape.docx b/sw/qa/extras/uiwriter/data/tdf103978_backgroundTextShape.docx
new file mode 100644
index 0000000..b99b65e
--- /dev/null
+++ b/sw/qa/extras/uiwriter/data/tdf103978_backgroundTextShape.docx
Binary files differ
diff --git a/sw/qa/extras/uiwriter/uiwriter.cxx b/sw/qa/extras/uiwriter/uiwriter.cxx
index 5d9e9df..a06d13f 100644
--- a/sw/qa/extras/uiwriter/uiwriter.cxx
+++ b/sw/qa/extras/uiwriter/uiwriter.cxx
@@ -211,6 +211,7 @@ public:
    void testTdf87922();
    void testTdf77014();
    void testTdf92648();
    void testTdf103978_backgroundTextShape();
    void testTdf96515();
    void testTdf96943();
    void testTdf96536();
@@ -347,6 +348,7 @@ public:
    CPPUNIT_TEST(testTdf87922);
    CPPUNIT_TEST(testTdf77014);
    CPPUNIT_TEST(testTdf92648);
    CPPUNIT_TEST(testTdf103978_backgroundTextShape);
    CPPUNIT_TEST(testTdf96515);
    CPPUNIT_TEST(testTdf96943);
    CPPUNIT_TEST(testTdf96536);
@@ -4003,6 +4005,25 @@ void SwUiWriterTest::testTdf92648()
    CPPUNIT_ASSERT_EQUAL(sal_Int32(5), nCount);
}

void SwUiWriterTest::testTdf103978_backgroundTextShape()
{
    SwDoc* pDoc = createDoc("tdf103978_backgroundTextShape.docx");

    // there is only one shape. It has an attached textbox
    bool bShapeIsOpaque = getProperty<bool>(getShape(1), "Opaque");
    CPPUNIT_ASSERT_EQUAL_MESSAGE("Shape is in the foreground", false, bShapeIsOpaque );
    sal_Int32 nCount = 0;
    for (const SwFrameFormat* pFormat : *pDoc->GetSpzFrameFormats())
    {
        if (!SwTextBoxHelper::isTextBox(pFormat, RES_FLYFRMFMT))
            continue;
        CPPUNIT_ASSERT_EQUAL_MESSAGE("Textbox syncs the shape's transparency", bShapeIsOpaque, pFormat->GetOpaque().GetValue() );
        ++nCount;
    }
    //ensure that we don't skip the for loop without an error
    CPPUNIT_ASSERT_EQUAL_MESSAGE("Number of TextBoxes", sal_Int32(1), nCount);
}

void SwUiWriterTest::testTdf96515()
{
    // Enable hide whitespace mode.
diff --git a/sw/source/core/doc/textboxhelper.cxx b/sw/source/core/doc/textboxhelper.cxx
index 9a88ba9..39ac1ff 100644
--- a/sw/source/core/doc/textboxhelper.cxx
+++ b/sw/source/core/doc/textboxhelper.cxx
@@ -514,6 +514,9 @@ void SwTextBoxHelper::syncProperty(SwFrameFormat* pShape, sal_uInt16 nWID, sal_u
                break;
            }
            break;
        case RES_OPAQUE:
            aPropertyName = UNO_NAME_OPAQUE;
            break;
        }

        if (!aPropertyName.isEmpty())