Rename DocumentCLass:plainInsetLayout() to InsetLayout::undefined()

This makes the code easier to understand.

src/CutAndPaste.cpp

@@ -883,10 +883,10 @@ void switchBetweenClasses(DocumentClassConstPtr oldone,
 			docstring const layoutName = iit->layoutName();
 			docstring const & n = newone->insetLayout(layoutName).name();
 			bool const is_undefined = n.empty() ||
-				n == DocumentClass::plainInsetLayout().name();
+				n == InsetLayout::undefined().name();
 			docstring const & oldn = oldone->insetLayout(layoutName).name();
 			bool const was_undefined = oldn.empty() ||
-				oldn == DocumentClass::plainInsetLayout().name();
+				oldn == InsetLayout::undefined().name();
 			if (!is_undefined || was_undefined)
 				continue;
 

src/TextClass.cpp

@@ -1869,13 +1869,7 @@ InsetLayout const & DocumentClass::insetLayout(docstring const & name) const
 		n = n.substr(0, i);
 	}
 	// Layout "name" not found.
-	return plainInsetLayout();
+	return InsetLayout::undefined();
-}
-
-
-InsetLayout const & DocumentClass::plainInsetLayout() {
-	static const InsetLayout plain_insetlayout_;
-	return plain_insetlayout_;
 }
 
 

src/TextClass.h

@@ -448,8 +448,6 @@ public:
 	/// If that doesn't work either, an empty object returns (shouldn't
 	/// happen).  -- Idea JMarc, comment MV
 	InsetLayout const & insetLayout(docstring const & name) const;
-	/// a plain inset layout for use as a default
-	static InsetLayout const & plainInsetLayout();
 	/// add a new layout \c name if it does not exist in layoutlist_
 	/// \return whether we had to add one.
 	bool addLayoutIfNeeded(docstring const & name) const;

src/insets/Inset.cpp

@@ -241,7 +241,7 @@ docstring Inset::layoutName() const
 InsetLayout const & Inset::getLayout() const
 {
 	if (!buffer_)
-		return DocumentClass::plainInsetLayout();
+		return InsetLayout::undefined();
 	return buffer().params().documentClass().insetLayout(layoutName());
 }
 
@@ -622,7 +622,7 @@ bool Inset::covers(BufferView const & bv, int x, int y) const
 bool Inset::undefined() const
 {
 	docstring const & n = getLayout().name();
-	return n.empty() || n == DocumentClass::plainInsetLayout().name();
+	return n.empty() || n == InsetLayout::undefined().name();
 }
 
 

src/insets/InsetFlex.cpp

@@ -49,7 +49,7 @@ InsetFlex::InsetFlex(InsetFlex const & in)
 InsetLayout const & InsetFlex::getLayout() const
 {
 	if (!buffer_)
-		return DocumentClass::plainInsetLayout();
+		return InsetLayout::undefined();
 
 	DocumentClass const & dc = buffer().params().documentClass();
 	docstring const dname = from_utf8(name_);
@@ -102,7 +102,7 @@ bool InsetFlex::getStatus(Cursor & cur, FuncRequest const & cmd,
 			InsetLyXType const type =
 				translateLyXType(to_utf8(cmd.argument()));
 			if (il.lyxtype() == type
-			    || (il.name() == DocumentClass::plainInsetLayout().name()
+			    || (il.name() == InsetLayout::undefined().name()
 				    && type == InsetLyXType::CHARSTYLE)) {
 				FuncRequest temp_cmd(cmd.action());
 				return InsetCollapsible::getStatus(cur, temp_cmd, flag);
@@ -127,7 +127,7 @@ void InsetFlex::doDispatch(Cursor & cur, FuncRequest & cmd)
 				translateLyXType(to_utf8(cmd.argument()));
 
 			if (il.lyxtype() == type
-			    || (il.name() == DocumentClass::plainInsetLayout().name()
+			    || (il.name() == InsetLayout::undefined().name()
 				    && type == InsetLyXType::CHARSTYLE)) {
 				FuncRequest temp_cmd(cmd.action());
 				InsetCollapsible::doDispatch(cur, temp_cmd);

src/insets/InsetLayout.cpp

@@ -59,6 +59,12 @@ InsetLaTeXType translateLaTeXType(std::string const & str)
 } // namespace
 
 
+InsetLayout const & InsetLayout::undefined() {
+	static const InsetLayout undefined_;
+	return undefined_;
+}
+
+
 bool InsetLayout::read(Lexer & lex, TextClass const & tclass,
 	bool validating)
 {

src/insets/InsetLayout.h

@@ -56,6 +56,9 @@ class InsetLayout {
 public:
 	///
 	InsetLayout() { labelfont_.setColor(Color_insetlabel); }
+	/// a plain inset layout for when there is no inset layout
+	static InsetLayout const & undefined();
+
 	///
 	bool read(support::Lexer & lexrc, TextClass const & tclass,
 			bool validating = false);