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>

4 files changed, 34 insertions, 48 deletions

diff --git a/toolkit/source/awt/stylesettings.cxx b/toolkit/source/awt/stylesettings.cxx
index 65218b33aa32..6d6419090c38 100644
--- a/toolkit/source/awt/stylesettings.cxx
+++ b/toolkit/source/awt/stylesettings.cxx
@@ -145,7 +145,7 @@ namespace toolkit
             VclPtr<vcl::Window> pWindow = i_rData.pOwningWindow->GetWindow();
             AllSettings aAllSettings = pWindow->GetSettings();
             StyleSettings aStyleSettings = aAllSettings.GetStyleSettings();
-            (aStyleSettings.*i_pSetter)( Color(i_nColor) );
+            (aStyleSettings.*i_pSetter)( Color(ColorTransparency, i_nColor) );
             aAllSettings.SetStyleSettings( aStyleSettings );
             pWindow->SetSettings( aAllSettings );
         }
diff --git a/toolkit/source/awt/vclxgraphics.cxx b/toolkit/source/awt/vclxgraphics.cxx
index 54f6286b8993..3125a0341030 100644
--- a/toolkit/source/awt/vclxgraphics.cxx
+++ b/toolkit/source/awt/vclxgraphics.cxx
@@ -168,28 +168,28 @@ void VCLXGraphics::setTextColor( sal_Int32 nColor )
 {
     SolarMutexGuard aGuard;
 
-    maTextColor = Color( nColor );
+    maTextColor = Color( ColorTransparency, nColor );
 }
 
 void VCLXGraphics::setTextFillColor( sal_Int32 nColor )
 {
     SolarMutexGuard aGuard;
 
-    maTextFillColor = Color( nColor );
+    maTextFillColor = Color( ColorTransparency, nColor );
 }
 
 void VCLXGraphics::setLineColor( sal_Int32 nColor )
 {
     SolarMutexGuard aGuard;
 
-    maLineColor = Color( nColor );
+    maLineColor = Color( ColorTransparency, nColor );
 }
 
 void VCLXGraphics::setFillColor( sal_Int32 nColor )
 {
     SolarMutexGuard aGuard;
 
-    maFillColor = Color( nColor );
+    maFillColor = Color( ColorTransparency, nColor );
 }
 
 void VCLXGraphics::setRasterOp( awt::RasterOperation eROP )
@@ -436,7 +436,7 @@ void VCLXGraphics::drawGradient( sal_Int32 x, sal_Int32 y, sal_Int32 width, sal_
         return;
 
     InitOutputDevice( InitOutDevFlags::COLORS );
-    Gradient aGradient(static_cast<GradientStyle>(rGradient.Style), Color(rGradient.StartColor), Color(rGradient.EndColor));
+    Gradient aGradient(static_cast<GradientStyle>(rGradient.Style), Color(ColorTransparency, rGradient.StartColor), Color(ColorTransparency, rGradient.EndColor));
     aGradient.SetAngle(Degree10(rGradient.Angle));
     aGradient.SetBorder(rGradient.Border);
     aGradient.SetOfsX(rGradient.XOffset);
diff --git a/toolkit/source/awt/vclxwindow.cxx b/toolkit/source/awt/vclxwindow.cxx
index 18ce820ab417..1e7c15918ab4 100644
--- a/toolkit/source/awt/vclxwindow.cxx
+++ b/toolkit/source/awt/vclxwindow.cxx
@@ -1126,7 +1126,7 @@ void VCLXWindow::setBackground( sal_Int32 nColor )
     if ( !GetWindow() )
         return;
 
-    Color aColor(nColor);
+    Color aColor(ColorTransparency, nColor);
     GetWindow()->SetBackground( aColor );
     GetWindow()->SetControlBackground( aColor );
 
@@ -1199,7 +1199,7 @@ void VCLXWindow::setForeground( sal_Int32 nColor )
 
     if ( GetWindow() )
     {
-        GetWindow()->SetControlForeground( Color(nColor) );
+        GetWindow()->SetControlForeground( Color(ColorTransparency, nColor) );
     }
 }
 
@@ -1252,7 +1252,7 @@ namespace toolkit
         AllSettings aSettings = _pWindow->GetSettings();
         StyleSettings aStyleSettings = aSettings.GetStyleSettings();
 
-        (aStyleSettings.*pSetter)( Color( nColor ) );
+        (aStyleSettings.*pSetter)( Color( ColorTransparency, nColor ) );
 
         aSettings.SetStyleSettings( aStyleSettings );
         _pWindow->SetSettings( aSettings, true );
@@ -1597,10 +1597,9 @@ void VCLXWindow::setProperty( const OUString& PropertyName, const css::uno::Any&
             }
             else
             {
-                sal_Int32 nColor = 0;
-                if ( Value >>= nColor )
+                Color aColor;
+                if ( Value >>= aColor )
                 {
-                    Color aColor( nColor );
                     pWindow->SetControlBackground( aColor );
                     pWindow->SetBackground( aColor );
                     switch ( eWinType )
@@ -1627,12 +1626,11 @@ void VCLXWindow::setProperty( const OUString& PropertyName, const css::uno::Any&
             }
             else
             {
-                sal_Int32 nColor = 0;
+                Color nColor ;
                 if ( Value >>= nColor )
                 {
-                    Color aColor( nColor );
-                    pWindow->SetTextColor( aColor );
-                    pWindow->SetControlForeground( aColor );
+                    pWindow->SetTextColor( nColor );
+                    pWindow->SetControlForeground( nColor );
                 }
             }
         break;
@@ -1643,12 +1641,9 @@ void VCLXWindow::setProperty( const OUString& PropertyName, const css::uno::Any&
             }
             else
             {
-                sal_Int32 nColor = 0;
+                Color nColor;
                 if ( Value >>= nColor )
-                {
-                    Color aColor( nColor );
-                    pWindow->SetTextLineColor( aColor );
-                }
+                    pWindow->SetTextLineColor( nColor );
             }
         break;
         case BASEPROPERTY_FILLCOLOR:
@@ -1656,12 +1651,9 @@ void VCLXWindow::setProperty( const OUString& PropertyName, const css::uno::Any&
                 pWindow->SetFillColor();
             else
             {
-                sal_Int32 nColor = 0;
+                Color nColor;
                 if ( Value >>= nColor )
-                {
-                    Color aColor( nColor );
-                    pWindow->SetFillColor( aColor );
-                }
+                    pWindow->SetFillColor( nColor );
             }
         break;
         case BASEPROPERTY_LINECOLOR:
@@ -1669,12 +1661,9 @@ void VCLXWindow::setProperty( const OUString& PropertyName, const css::uno::Any&
                 pWindow->SetLineColor();
             else
             {
-                sal_Int32 nColor = 0;
+                Color nColor;
                 if ( Value >>= nColor )
-                {
-                    Color aColor( nColor );
-                    pWindow->SetLineColor( aColor );
-                }
+                    pWindow->SetLineColor( nColor );
             }
         break;
         case BASEPROPERTY_BORDER:
diff --git a/toolkit/source/awt/vclxwindows.cxx b/toolkit/source/awt/vclxwindows.cxx
index d7404132d545..a589db2cd3a1 100644
--- a/toolkit/source/awt/vclxwindows.cxx
+++ b/toolkit/source/awt/vclxwindows.cxx
@@ -118,20 +118,20 @@ namespace toolkit
         }
         else
         {
-            sal_Int32 nBackgroundColor = 0;
+            Color nBackgroundColor;
             _rColorValue >>= nBackgroundColor;
-            aStyleSettings.SetFaceColor( Color(nBackgroundColor) );
+            aStyleSettings.SetFaceColor( nBackgroundColor );
 
             // for the real background (everything except the buttons and the thumb),
             // use an average between the desired color and "white"
             Color aWhite( COL_WHITE );
-            Color aBackground( nBackgroundColor );
-            aBackground.SetRed( ( aBackground.GetRed() + aWhite.GetRed() ) / 2 );
-            aBackground.SetGreen( ( aBackground.GetGreen() + aWhite.GetGreen() ) / 2 );
-            aBackground.SetBlue( ( aBackground.GetBlue() + aWhite.GetBlue() ) / 2 );
-            aStyleSettings.SetCheckedColor( aBackground );
+            Color aCheckedBackground( nBackgroundColor );
+            aCheckedBackground.SetRed( ( aCheckedBackground.GetRed() + aWhite.GetRed() ) / 2 );
+            aCheckedBackground.SetGreen( ( aCheckedBackground.GetGreen() + aWhite.GetGreen() ) / 2 );
+            aCheckedBackground.SetBlue( ( aCheckedBackground.GetBlue() + aWhite.GetBlue() ) / 2 );
+            aStyleSettings.SetCheckedColor( aCheckedBackground );
 
-            sal_Int32 nBackgroundLuminance = Color( nBackgroundColor ).GetLuminance();
+            sal_Int32 nBackgroundLuminance = nBackgroundColor.GetLuminance();
             sal_Int32 nWhiteLuminance = COL_WHITE.GetLuminance();
 
             Color aLightShadow( nBackgroundColor );
@@ -6354,7 +6354,7 @@ void VCLXProgressBar::setForegroundColor( sal_Int32 nColor )
     VclPtr<vcl::Window> pWindow = GetWindow();
     if ( pWindow )
     {
-        pWindow->SetControlForeground( Color(nColor) );
+        pWindow->SetControlForeground( Color(ColorTransparency, nColor) );
     }
 }
 
@@ -6365,7 +6365,7 @@ void VCLXProgressBar::setBackgroundColor( sal_Int32 nColor )
     VclPtr<vcl::Window> pWindow = GetWindow();
     if ( pWindow )
     {
-        Color aColor( nColor );
+        Color aColor( ColorTransparency, nColor );
         pWindow->SetBackground( aColor );
         pWindow->SetControlBackground( aColor );
         pWindow->Invalidate();
@@ -6450,12 +6450,9 @@ void VCLXProgressBar::setProperty( const OUString& PropertyName, const css::uno:
                 }
                 else
                 {
-                    sal_Int32 nColor = 0;
+                    Color nColor;
                     if ( Value >>= nColor )
-                    {
-                        Color aColor( nColor );
-                        pWindow->SetControlForeground( aColor );
-                    }
+                        pWindow->SetControlForeground( nColor );
                 }
             }
         }
@@ -7834,9 +7831,9 @@ void SAL_CALL SVTXDateField::setProperty( const OUString& PropertyName, const cs
             pSubEdit->SetTextLineColor();
         else
         {
-            sal_Int32 nColor = 0;
+            Color nColor;
             if ( Value >>= nColor )
-                pSubEdit->SetTextLineColor( Color( nColor ) );
+                pSubEdit->SetTextLineColor( nColor );
         }
         break;
     }