fdo#62617 display groups on multiple layers correctly

It is possible to group objects from different layers, so it is an error
to rely on layer ID when checking visibility of a group. This problem
was partially obscured by the fact that SdrObjGroup::GetLayer() returns
0 if its subobjects are on different layers and 0 is a valid layer ID.

Change-Id: I0ef75544a26817154642185864cafd4e6734fa38

svx/inc/svx/sdr/contact/viewobjectcontactofgroup.hxx

@@ -40,6 +40,9 @@ namespace sdr
 
             // This method recursively paints the draw hierarchy.
             virtual drawinglayer::primitive2d::Primitive2DSequence getPrimitive2DSequenceHierarchy(DisplayInfo& rDisplayInfo) const;
+
+        private:
+            virtual bool isPrimitiveVisibleOnAnyLayer(const SetOfByte& aLayers) const;
         };
     } // end of namespace contact
 } // end of namespace sdr

svx/inc/svx/sdr/contact/viewobjectcontactofsdrobj.hxx

@@ -25,6 +25,7 @@
 //////////////////////////////////////////////////////////////////////////////
 // predeclarations
 class SdrObject;
+class SetOfByte;
 
 //////////////////////////////////////////////////////////////////////////////
 
@@ -34,6 +35,14 @@ namespace sdr
     {
         class SVX_DLLPUBLIC ViewObjectContactOfSdrObj : public ViewObjectContact
         {
+            /** Test whether the primitive is visible on any layer from @c aLayers
+
+                This should be overriden by ViewObjectContacts of SDR classes
+                that have subparts which can be on different layers (that is,
+                SdrObjGroup .-)
+              */
+            virtual bool isPrimitiveVisibleOnAnyLayer(const SetOfByte& aLayers) const;
+
         protected:
             const SdrObject& getSdrObject() const;
 

svx/source/sdr/contact/viewobjectcontactofgroup.cxx

@@ -25,6 +25,7 @@
 #include <drawinglayer/primitive2d/groupprimitive2d.hxx>
 #include <basegfx/tools/canvastools.hxx>
 #include <svx/sdr/contact/viewcontact.hxx>
+#include <svx/svdobj.hxx>
 
 //////////////////////////////////////////////////////////////////////////////
 
@@ -98,6 +99,14 @@ namespace sdr
             }
             return xRetval;
         }
+
+        bool ViewObjectContactOfGroup::isPrimitiveVisibleOnAnyLayer(const SetOfByte& aLayers) const
+        {
+            SetOfByte aObjectLayers;
+            getSdrObject().getMergedHierarchyLayerSet(aObjectLayers);
+            aObjectLayers &= aLayers;
+            return !aObjectLayers.IsEmpty();
+        }
     } // end of namespace contact
 } // end of namespace sdr
 

svx/source/sdr/contact/viewobjectcontactofsdrobj.cxx

@@ -48,12 +48,17 @@ namespace sdr
         {
         }
 
+        bool ViewObjectContactOfSdrObj::isPrimitiveVisibleOnAnyLayer(const SetOfByte& aLayers) const
+        {
+            return aLayers.IsSet(getSdrObject().GetLayer());
+        }
+
         bool ViewObjectContactOfSdrObj::isPrimitiveVisible(const DisplayInfo& rDisplayInfo) const
         {
             const SdrObject& rObject = getSdrObject();
 
             // Test layer visibility
-            if(!rDisplayInfo.GetProcessLayers().IsSet(rObject.GetLayer()))
+            if(!isPrimitiveVisibleOnAnyLayer(rDisplayInfo.GetProcessLayers()))
             {
                 return false;
             }