make the Color constructors explicitly specify transparency

to reduce the churn, we leave the existing constructor in place,
and add a clang plugin to detect when the value passed to the
existing constructor may contain transparency/alpha data.

i.e. we leave expressions like Color(0xffffff) alone, but
warn about any non-constant expression, and any expression
like Color(0xff000000)

Change-Id: Id2ce58e08882d9b7bd0b9f88eca97359dcdbcc8c
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/109362
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

2 files changed, 8 insertions, 8 deletions

diff --git a/editeng/source/items/frmitems.cxx b/editeng/source/items/frmitems.cxx
index 589bde044152..184bf21cd994 100644
--- a/editeng/source/items/frmitems.cxx
+++ b/editeng/source/items/frmitems.cxx
@@ -1084,7 +1084,7 @@ bool SvxShadowItem::PutValue( const uno::Any& rVal, sal_uInt8 nMemberId )
             sal_Int32 nTransparence = 0;
             if ((rVal >>= nTransparence) && !o3tl::checked_multiply<sal_Int32>(nTransparence, 255, nTransparence))
             {
-                Color aColor(aShadow.Color);
+                Color aColor(ColorTransparency, aShadow.Color);
                 aColor.SetAlpha(255 - rtl::math::round(float(nTransparence) / 100));
                 aShadow.Color = sal_Int32(aColor);
             }
@@ -1106,7 +1106,7 @@ bool SvxShadowItem::PutValue( const uno::Any& rVal, sal_uInt8 nMemberId )
         }
 
         nWidth = bConvert ? convertMm100ToTwip(aShadow.ShadowWidth) : aShadow.ShadowWidth;
-        Color aSet(aShadow.Color);
+        Color aSet(ColorTransparency, aShadow.Color);
         aShadowColor = aSet;
     }
 
@@ -1439,7 +1439,7 @@ namespace
 bool
 lcl_lineToSvxLine(const table::BorderLine& rLine, SvxBorderLine& rSvxLine, bool bConvert, bool bGuessWidth)
 {
-    rSvxLine.SetColor( Color(rLine.Color));
+    rSvxLine.SetColor( Color(ColorTransparency, rLine.Color));
     if ( bGuessWidth )
     {
         rSvxLine.GuessLinesWidths( rSvxLine.GetBorderLineStyle(),
@@ -2735,7 +2735,7 @@ bool SvxLineItem::PutValue( const uno::Any& rVal, sal_uInt8 nMemId )
 
         switch ( nMemId )
         {
-            case MID_FG_COLOR:      pLine->SetColor( Color(nVal) ); break;
+            case MID_FG_COLOR:      pLine->SetColor( Color(ColorTransparency, nVal) ); break;
             case MID_LINE_STYLE:
                 pLine->SetBorderLineStyle(static_cast<SvxBorderLineStyle>(nVal));
             break;
diff --git a/editeng/source/items/textitem.cxx b/editeng/source/items/textitem.cxx
index e83d08b35504..e63b9c786e1d 100644
--- a/editeng/source/items/textitem.cxx
+++ b/editeng/source/items/textitem.cxx
@@ -990,7 +990,7 @@ bool SvxTextLineItem::PutValue( const uno::Any& rVal, sal_uInt8 nMemberId )
     break;
     case MID_TL_COLOR:
     {
-        sal_Int32 nCol = 0;
+        Color nCol;
         if( !( rVal >>= nCol ) )
             bRet = false;
         else
@@ -998,7 +998,7 @@ bool SvxTextLineItem::PutValue( const uno::Any& rVal, sal_uInt8 nMemberId )
             // Keep transparence, because it contains the information
             // whether the font color or the stored color should be used
             sal_uInt8 nAlpha = mColor.GetAlpha();
-            mColor = Color( nCol );
+            mColor = nCol;
             mColor.SetAlpha( nAlpha );
         }
     }
@@ -1354,7 +1354,7 @@ bool SvxBackgroundColorItem::QueryValue( uno::Any& rVal, sal_uInt8 nMemberId ) c
 bool SvxBackgroundColorItem::PutValue( const uno::Any& rVal, sal_uInt8 nMemberId )
 {
     nMemberId &= ~CONVERT_TWIPS;
-    sal_Int32 nColor = 0;
+    Color nColor;
     Color aColor = SvxColorItem::GetValue();
 
     switch( nMemberId )
@@ -1369,7 +1369,7 @@ bool SvxBackgroundColorItem::PutValue( const uno::Any& rVal, sal_uInt8 nMemberId
         {
             if(!(rVal >>= nColor))
                 return false;
-            SvxColorItem::SetValue( Color(nColor) );
+            SvxColorItem::SetValue( nColor );
             break;
         }
     }