update combobox cellview background color to transparent on style-set signal.

CCBUG: 269872

src/animations/oxygencomboboxdata.cpp

@@ -42,6 +42,7 @@ namespace Oxygen
 
         // connect signals
         _stateChangeId.connect( G_OBJECT(widget), "state-changed", G_CALLBACK( stateChangeEvent ), this );
+        _styleSetId.connect( G_OBJECT(widget), "style-set", G_CALLBACK( styleSetEvent ), this );
 
         // initialize cell view
         initializeCellView( widget );
@@ -62,6 +63,7 @@ namespace Oxygen
         #endif
 
         _stateChangeId.disconnect();
+        _styleSetId.disconnect();
 
         // clear pointers to widgets
         _target = 0L;
@@ -361,4 +363,8 @@ namespace Oxygen
     void ComboBoxData::stateChangeEvent( GtkWidget*, GtkStateType, gpointer data )
     { static_cast<ComboBoxData*>( data )->updateCellViewColor(); }
 
+    //________________________________________________________________________________
+    void ComboBoxData::styleSetEvent( GtkWidget*, GtkStyle*, gpointer data )
+    { static_cast<ComboBoxData*>( data )->updateCellViewColor(); }
+
 }

src/animations/oxygencomboboxdata.h

@@ -135,7 +135,7 @@ namespace Oxygen
         static gboolean enterNotifyEvent( GtkWidget*, GdkEventCrossing*, gpointer );
         static gboolean leaveNotifyEvent( GtkWidget*, GdkEventCrossing*, gpointer );
         static void stateChangeEvent( GtkWidget*, GtkStateType, gpointer );
-
+        static void styleSetEvent( GtkWidget*, GtkStyle*, gpointer );
 
         //@}
 
@@ -147,9 +147,17 @@ namespace Oxygen
         //! drop-down list, if set
         GtkWidget* _list;
 
+        //!@name signals
+        //@{
+
         //! state change signal
         Signal _stateChangeId;
 
+        //! style set
+        Signal _styleSetId;
+
+        //@}
+
         // handle child registration
         class ChildData
         {