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>

3 files changed, 10 insertions, 12 deletions

diff --git a/sfx2/source/control/recentdocsview.cxx b/sfx2/source/control/recentdocsview.cxx
index 8bb669f2cf4e..be9b179d66d4 100644
--- a/sfx2/source/control/recentdocsview.cxx
+++ b/sfx2/source/control/recentdocsview.cxx
@@ -137,10 +137,10 @@ RecentDocsView::RecentDocsView(std::unique_ptr<weld::ScrolledWindow> xWindow, st
     setItemMaxTextLength( 30 );
     setItemDimensions( mnItemMaxSize, mnItemMaxSize, gnTextHeight, gnItemPadding );
 
-    maFillColor = Color(officecfg::Office::Common::Help::StartCenter::StartCenterThumbnailsBackgroundColor::get());
-    maTextColor = Color(officecfg::Office::Common::Help::StartCenter::StartCenterThumbnailsTextColor::get());
-    maHighlightColor = Color(officecfg::Office::Common::Help::StartCenter::StartCenterThumbnailsHighlightColor::get());
-    maHighlightTextColor = Color(officecfg::Office::Common::Help::StartCenter::StartCenterThumbnailsHighlightTextColor::get());
+    maFillColor = Color(ColorTransparency, officecfg::Office::Common::Help::StartCenter::StartCenterThumbnailsBackgroundColor::get());
+    maTextColor = Color(ColorTransparency, officecfg::Office::Common::Help::StartCenter::StartCenterThumbnailsTextColor::get());
+    maHighlightColor = Color(ColorTransparency, officecfg::Office::Common::Help::StartCenter::StartCenterThumbnailsHighlightColor::get());
+    maHighlightTextColor = Color(ColorTransparency, officecfg::Office::Common::Help::StartCenter::StartCenterThumbnailsHighlightTextColor::get());
     mfHighlightTransparence = 0.25;
 
     UpdateColors();
diff --git a/sfx2/source/control/templatedefaultview.cxx b/sfx2/source/control/templatedefaultview.cxx
index f92309c93389..da174413e578 100644
--- a/sfx2/source/control/templatedefaultview.cxx
+++ b/sfx2/source/control/templatedefaultview.cxx
@@ -31,10 +31,10 @@ TemplateDefaultView::TemplateDefaultView(std::unique_ptr<weld::ScrolledWindow> x
     updateThumbnailDimensions(nItemMaxSize);
 
     // startcenter specific settings
-    maFillColor = Color(officecfg::Office::Common::Help::StartCenter::StartCenterThumbnailsBackgroundColor::get());
-    maTextColor = Color(officecfg::Office::Common::Help::StartCenter::StartCenterThumbnailsTextColor::get());
-    maHighlightColor = Color(officecfg::Office::Common::Help::StartCenter::StartCenterThumbnailsHighlightColor::get());
-    maHighlightTextColor = Color(officecfg::Office::Common::Help::StartCenter::StartCenterThumbnailsHighlightTextColor::get());
+    maFillColor = Color(ColorTransparency, officecfg::Office::Common::Help::StartCenter::StartCenterThumbnailsBackgroundColor::get());
+    maTextColor = Color(ColorTransparency, officecfg::Office::Common::Help::StartCenter::StartCenterThumbnailsTextColor::get());
+    maHighlightColor = Color(ColorTransparency, officecfg::Office::Common::Help::StartCenter::StartCenterThumbnailsHighlightColor::get());
+    maHighlightTextColor = Color(ColorTransparency, officecfg::Office::Common::Help::StartCenter::StartCenterThumbnailsHighlightTextColor::get());
     mfHighlightTransparence = 0.25;
 
     UpdateColors();
diff --git a/sfx2/source/sidebar/Theme.cxx b/sfx2/source/sidebar/Theme.cxx
index 140d203a495a..6ad2b891657c 100644
--- a/sfx2/source/sidebar/Theme.cxx
+++ b/sfx2/source/sidebar/Theme.cxx
@@ -744,11 +744,9 @@ void Theme::ProcessNewValue (
         }
         case PT_Color:
         {
-            sal_Int32 nColorValue (0);
+            Color nColorValue;
             if (rValue >>= nColorValue)
-            {
-                maColors[nIndex] = Color(nColorValue);
-            }
+                maColors[nIndex] = nColorValue;
             break;
         }
         case PT_Integer: