Gui: Colorful/Greyable overlay status in icons

===============================================

Before this implementation, specific status via former mergeOverlayIcon() was greyed out
with the visibility.

With this commit, the developer has two options:

a) override mergeGreyableOverlayIcons, in which case the overlay will
be greyed out when the item is greyed out as per former mergeOverlayIcon()

b) override mergeColorfulOverlayIcons, in which case the overlay will
be superimposed after the icon is greyed out as it is the case for stardard
error and recompute flags.

src/Mod/Part/Gui/ViewProviderAttachExtension.cpp

@@ -50,7 +50,7 @@ ViewProviderAttachExtension::ViewProviderAttachExtension()
     initExtensionType(ViewProviderAttachExtension::getExtensionClassTypeId());
 }
 
-QIcon ViewProviderAttachExtension::extensionMergeOverlayIcons(const QIcon & orig) const
+QIcon ViewProviderAttachExtension::extensionMergeColorfullOverlayIcons (const QIcon & orig) const
 {
     QIcon mergedicon = orig;
 

src/Mod/Part/Gui/ViewProviderAttachExtension.h

@@ -39,7 +39,7 @@ public:
     ViewProviderAttachExtension(void);
     virtual ~ViewProviderAttachExtension() = default;
 
-    virtual QIcon extensionMergeOverlayIcons(const QIcon & orig) const override;
+    virtual QIcon extensionMergeColorfullOverlayIcons (const QIcon & orig) const override;
 
     virtual void extensionUpdateData(const App::Property*) override;
     virtual void extensionSetupContextMenu(QMenu*, QObject*, const char*) override;

src/Mod/PartDesign/Gui/ViewProvider.cpp

@@ -221,7 +221,7 @@ void ViewProvider::setTipIcon(bool onoff) {
     signalChangeIcon();
 }
 
-QIcon ViewProvider::mergeOverlayIcons (const QIcon & orig) const
+QIcon ViewProvider::mergeColorfulOverlayIcons (const QIcon & orig) const
 {
     QIcon mergedicon = orig;
 
@@ -248,7 +248,7 @@ QIcon ViewProvider::mergeOverlayIcons (const QIcon & orig) const
 
     }
 
-    return Gui::ViewProvider::mergeOverlayIcons(mergedicon);
+    return Gui::ViewProvider::mergeColorfulOverlayIcons (mergedicon);
 }
 
 bool ViewProvider::onDelete(const std::vector<std::string> &)

src/Mod/PartDesign/Gui/ViewProvider.h

@@ -70,6 +70,8 @@ public:
 
     virtual PyObject* getPyObject(void) override;
 
+    virtual QIcon mergeColorfulOverlayIcons (const QIcon & orig) const override;
+
 protected:
     virtual void setupContextMenu(QMenu* menu, QObject* receiver, const char* member) override;
     virtual bool setEdit(int ModNum) override;
@@ -77,8 +79,6 @@ protected:
 
     virtual bool onDelete(const std::vector<std::string> &) override;
 
-    virtual QIcon mergeOverlayIcons (const QIcon & orig) const override;
-
     /**
      * Returns a newly create dialog for the part to be placed in the task view
      * Must be reimplemented in subclasses.

src/Mod/PartDesign/Gui/ViewProviderLoft.cpp

@@ -174,6 +174,6 @@ QIcon ViewProviderLoft::getIcon(void) const {
         str += QString::fromLatin1("Subtractive_");
 
     str += QString::fromLatin1("Loft.svg");
-    return PartDesignGui::ViewProvider::mergeOverlayIcons(Gui::BitmapFactory().pixmap(str.toStdString().c_str()));
+    return PartDesignGui::ViewProvider::mergeGreyableOverlayIcons(Gui::BitmapFactory().pixmap(str.toStdString().c_str()));
 }
 

src/Mod/PartDesign/Gui/ViewProviderPipe.cpp

@@ -207,6 +207,6 @@ QIcon ViewProviderPipe::getIcon(void) const {
         str += QString::fromLatin1("Subtractive_");
 
     str += QString::fromLatin1("Pipe.svg");
-    return PartDesignGui::ViewProvider::mergeOverlayIcons(Gui::BitmapFactory().pixmap(str.toStdString().c_str()));
+    return PartDesignGui::ViewProvider::mergeGreyableOverlayIcons(Gui::BitmapFactory().pixmap(str.toStdString().c_str()));
 }
 

src/Mod/PartDesign/Gui/ViewProviderPrimitive.cpp

@@ -172,5 +172,5 @@ QIcon ViewProviderPrimitive::getIcon(void) const {
     }
 
     str += QString::fromLatin1(".svg");
-    return PartDesignGui::ViewProvider::mergeOverlayIcons(Gui::BitmapFactory().pixmap(str.toStdString().c_str()));
+    return PartDesignGui::ViewProvider::mergeGreyableOverlayIcons(Gui::BitmapFactory().pixmap(str.toStdString().c_str()));
 }

src/Mod/TechDraw/Gui/ViewProviderCosmeticExtension.cpp

@@ -47,7 +47,7 @@ ViewProviderCosmeticExtension::ViewProviderCosmeticExtension()
     initExtensionType(ViewProviderCosmeticExtension::getExtensionClassTypeId());
 }
 
-QIcon ViewProviderCosmeticExtension::extensionMergeOverlayIcons(const QIcon & orig) const
+QIcon ViewProviderCosmeticExtension::extensionMergeGreyableOverlayIcons(const QIcon & orig) const
 {
     QIcon mergedicon = orig;
 

src/Mod/TechDraw/Gui/ViewProviderCosmeticExtension.h

@@ -39,7 +39,7 @@ public:
     ViewProviderCosmeticExtension(void);
     virtual ~ViewProviderCosmeticExtension() = default;
 
-    virtual QIcon extensionMergeOverlayIcons(const QIcon & orig) const override;
+    virtual QIcon extensionMergeGreyableOverlayIcons(const QIcon & orig) const override;
 
     virtual void extensionUpdateData(const App::Property*) override;