Implement auto-nesting.

Now layouts can specify other layouts that should be nested in and
after the current one (if the layout is switched from the current one
and if it follows a paragraph in the current one).

This is particularly useful for things such as the beamer frames, where
particular layouts are practically always nested.

lib/doc/Customization.lyx

@@ -124,11 +124,12 @@ logicalmkup
 \papercolumns 1
 \papersides 2
 \paperpagestyle headings
-\tracking_changes false
+\tracking_changes true
 \output_changes false
 \html_math_output 0
 \html_css_as_file 0
 \html_be_strict true
+\author -712698321 "Jürgen Spitzmüller"
 \end_header
 
 \begin_body
@@ -14616,6 +14617,49 @@ protect
 not
 \emph default
  whether this command should itself be protected.)
+\change_inserted -712698321 1514479340
+
+\end_layout
+
+\begin_layout Description
+
+\change_inserted -712698321 1514479340
+\begin_inset Flex Code
+status collapsed
+
+\begin_layout Plain Layout
+
+\change_inserted -712698321 1514479340
+Nests
+\end_layout
+
+\end_inset
+
+ Includes a comma-separated list of layout names that should be nested in
+ and after the current one.
+ Only makes sense for nestable layouts (such as environments) 
+\begin_inset Quotes eld
+\end_inset
+
+
+\begin_inset Flex Code
+status collapsed
+
+\begin_layout Plain Layout
+
+\change_inserted -712698321 1514479340
+EndNests
+\end_layout
+
+\end_inset
+
+
+\begin_inset Quotes erd
+\end_inset
+
+.
+\change_unchanged
+
 \end_layout
 
 \begin_layout Description

lib/layouts/beamer.layout

@@ -6,7 +6,7 @@
 #   Richard Heck <rgheck@lyx.org>, Martin Vermeer <martin.vermeer@hut.fi> and probably others.
 
 
-Format 65
+Format 66
 
 #
 # GLOBAL SETTINGS
@@ -482,6 +482,12 @@ Style Frame
     EndFont
     AutoInsert     1
   EndArgument
+  Nests 
+	Standard,Itemize,Enumerate,Description,FrameTitle,FrameSubtitle,Column,
+	Columns,ColumnsCenterAligned,ColumnsTopAligned,Pause,Overprint,OverlayArea,Only,Block,
+	ExampleBlock,AlertBlock,Bibliography,Quotation,Quote,Verse,Corollary,Definition,Definitions,
+	Example,Examples,Fact,Lemma,Proof,Theorem,LyX-Code
+  EndNests
 End
 
 Style PlainFrame
@@ -665,6 +671,11 @@ Style Columns
     Family         Roman
     Color          latex
   EndFont
+  Nests 
+	Standard,Itemize,Enumerate,Description,Pause,Overprint,OverlayArea,Only,Block,
+	ExampleBlock,AlertBlock,Bibliography,Quotation,Quote,Verse,Corollary,Definition,Definitions,
+	Example,Examples,Fact,Lemma,Proof,Theorem,LyX-Code
+  EndNests
 End
 
 Style ColumnsCenterAligned
@@ -885,6 +896,10 @@ Style Block
     EndFont
     AutoInsert     1
   EndArgument
+  Nests 
+	Standard,Itemize,Enumerate,Description,Pause,Overprint,OverlayArea,Only,Quotation,
+	Quote,Verse,Corollary,Definition,Definitions,Example,Examples,Fact,Lemma,Proof,Theorem,LyX-Code
+  EndNests
 End
 
 Style ExampleBlock
@@ -1228,6 +1243,9 @@ Style Corollary
     LabelString    "Additional Theorem Text"
     Tooltip        "Additional text appended to the theorem header"
   EndArgument
+  Nests 
+	Standard,Itemize,Enumerate,Description,Pause,Overprint,OverlayArea,Only,LyX-Code
+  EndNests
 End
 
 Style Definition

lib/scripts/layout2layout.py

@@ -11,7 +11,7 @@
 # This script will update a .layout file to current format
 
 # The latest layout format is also defined in src/TextClass.cpp
-currentFormat = 65
+currentFormat = 66
 
 
 # Incremented to format 4, 6 April 2007, lasgouttes
@@ -220,6 +220,9 @@ currentFormat = 65
 # Incremented to format 65, 16 October 2017 by spitz
 # Color collapsable -> collapsible
 
+# Incremented to format 66, 28 December 2017 by spitz
+# New Layout tag "Nests ... EndNests"
+
 # Do not forget to document format change in Customization
 # Manual (section "Declaring a new text class").
 
@@ -469,6 +472,11 @@ def convert(lines, end_format):
                 i += 1
             continue
 
+        if format == 65:
+            # nothing to do.
+            i += 1
+            continue
+
         if format == 64:
             match = re.compile(b'(\\s*Color\\s+)(\\w+)', re.IGNORECASE).match(lines[i])
             if not match:

src/Layout.cpp

@@ -75,6 +75,7 @@ enum LayoutTags {
 	LT_NEED_PROTECT,
 	LT_NEWLINE,
 	LT_NEXTNOINDENT,
+	LT_NESTS,
 	LT_PAR_GROUP,
 	LT_PARINDENT,
 	LT_PARSEP,
@@ -239,6 +240,7 @@ bool Layout::readIgnoreForcelocal(Lexer & lex, TextClass const & tclass)
 		{ "leftmargin",     LT_LEFTMARGIN },
 		{ "margin",         LT_MARGIN },
 		{ "needprotect",    LT_NEED_PROTECT },
+		{ "nests",          LT_NESTS },
 		{ "newline",        LT_NEWLINE },
 		{ "nextnoindent",   LT_NEXTNOINDENT },
 		{ "obsoletedby",    LT_OBSOLETEDBY },
@@ -592,6 +594,17 @@ bool Layout::readIgnoreForcelocal(Lexer & lex, TextClass const & tclass)
 			break;
 		}
 
+		case LT_NESTS: {
+			docstring const nest = subst(subst(subst(lex.getLongString(from_ascii("EndNests")),
+						     from_ascii("\n"), docstring()),
+						     from_ascii(" "), docstring()),
+						     from_ascii("\t"), docstring());
+			vector<docstring> const nests =
+				getVectorFromString(nest);
+			nests_.insert(nests.begin(), nests.end());
+			break;
+		}
+
 		case LT_REFPREFIX: {
 			docstring arg;
 			lex >> arg;
@@ -1387,6 +1400,16 @@ void Layout::write(ostream & os) const
 		}
 		os << '\n';
 	}
+	if (!nests_.empty()) {
+		os << "\tNests ";
+		for (set<docstring>::const_iterator it = nests_.begin();
+		     it != nests_.end(); ++it) {
+			if (it != nests_.begin())
+				os << ',';
+			os << to_utf8(*it);
+		}
+		os << '\n';
+	}
 	if (refprefix.empty())
 		os << "\tRefPrefix OFF\n";
 	else

src/Layout.h

@@ -149,6 +149,8 @@ public:
 	///
 	std::set<std::string> const & requires() const { return requires_; }
 	///
+	std::set<docstring> const & nests() const { return nests_; }
+	///
 	std::string const & latexparam() const { return latexparam_; }
 	///
 	docstring leftdelim() const { return leftdelim_; }
@@ -468,6 +470,8 @@ private:
 	bool par_group_;
 	/// Packages needed for this layout
 	std::set<std::string> requires_;
+	/// Layouts that are by default nested after this one
+	std::set<docstring> nests_;
 	///
 	LaTeXArgMap latexargs_;
 	///

src/LyXAction.cpp

@@ -2313,8 +2313,9 @@ void LyXAction::init()
 /*!
  * \var lyx::FuncCode lyx::LFUN_LAYOUT
  * \li Action: Sets the layout (that is, environment) for the current paragraph.
- * \li Syntax: layout <LAYOUT>
+ * \li Syntax: layout <LAYOUT> [ignorenests]
  * \li Params: <LAYOUT>: the layout to use
+	       ignorenests: If specified, nesting advices will be ignored.
  * \endvar
  */
 		{ LFUN_LAYOUT, "layout", Noop, Layout },

src/Text3.cpp

@@ -1419,11 +1419,13 @@ void Text::dispatch(Cursor & cur, FuncRequest & cmd)
 		break;
 
 	case LFUN_LAYOUT: {
-		docstring layout = cmd.argument();
+		bool const ignorenests = cmd.getArg(1) == "ignorenests";
+		docstring layout = ignorenests ? from_utf8(cmd.getArg(0)) : cmd.argument();
 		LYXERR(Debug::INFO, "LFUN_LAYOUT: (arg) " << to_utf8(layout));
 
 		Paragraph const & para = cur.paragraph();
 		docstring const old_layout = para.layout().name();
+		set<docstring> nests = para.layout().nests();
 		DocumentClass const & tclass = bv->buffer().params().documentClass();
 
 		if (layout.empty())
@@ -1473,8 +1475,14 @@ void Text::dispatch(Cursor & cur, FuncRequest & cmd)
 			}
 		}
 
-		if (change_layout)
+		if (change_layout) {
 			setLayout(cur, layout);
+			bool do_nest = false;
+			if (cur.pit() > 0 && pars_[cur.pit() - 1].layout().name() == old_layout)
+				do_nest = !ignorenests;
+			if (do_nest && nests.find(layout) != nests.end())
+				lyx::dispatch(FuncRequest(LFUN_DEPTH_INCREMENT));
+		}
 
 		Layout::LaTeXArgMap args = tclass[layout].args();
 		Layout::LaTeXArgMap::const_iterator lait = args.begin();
@@ -1531,7 +1539,8 @@ void Text::dispatch(Cursor & cur, FuncRequest & cmd)
 				lyx::dispatch(FuncRequest(LFUN_DEPTH_DECREMENT));
 		}
 		DocumentClass const & tc = bv->buffer().params().documentClass();
-		lyx::dispatch(FuncRequest(LFUN_LAYOUT, tc.plainLayout().name()));
+		lyx::dispatch(FuncRequest(LFUN_LAYOUT, from_ascii("\"") + tc.plainLayout().name()
+					  + from_ascii("\" ignorenests")));
 		lyx::dispatch(FuncRequest(LFUN_SEPARATOR_INSERT, "plain"));
 		if (before) {
 			cur.backwardPos();
@@ -3173,7 +3182,8 @@ bool Text::getStatus(Cursor & cur, FuncRequest const & cmd,
 
 	case LFUN_LAYOUT: {
 		DocumentClass const & tclass = cur.buffer()->params().documentClass();
-		docstring layout = cmd.argument();
+		bool const ignorenests = cmd.getArg(1) == "ignorenests";
+		docstring layout = ignorenests ? from_utf8(cmd.getArg(0)) : cmd.argument();
 		if (layout.empty())
 			layout = tclass.defaultLayoutName();
 		enable = !owner_->forcePlainLayout() && tclass.hasLayout(layout);

src/TextClass.cpp

@@ -62,7 +62,7 @@ namespace lyx {
 // You should also run the development/tools/updatelayouts.py script,
 // to update the format of all of our layout files.
 //
-int const LAYOUT_FORMAT = 65; //spitz: Color collapsable -> collapsible.
+int const LAYOUT_FORMAT = 66; //spitz: New layout tag Nests
 
 
 // Layout format for the current lyx file format. Controls which format is