Extend environment-split to an 'outer' split function

This fixes a major beamer UI flaw reported by several users.

lib/bind/de/menus.bind

@@ -112,6 +112,10 @@ Format 1
 \bind "M-a Up"			"outline-up"
 \bind "M-a Down"		"outline-down"
 
+
+\bind "M-a Return"		"environment-split"
+\bind "M-a S-Return"		"environment-split outer"
+
 # Obsolete Tastenbelegung: in die persönliche *.bind Datei kopieren und
 # auskommentieren wenn diese Tastenbelegung gewünscht ist.
 # \bind "M-a S-quotedbl"	"layout Section*"	# M-a S-2

lib/bind/menus.bind

@@ -125,6 +125,9 @@ Format 1
 \bind "M-p Up"			"outline-up"
 \bind "M-p Down"		"outline-down"
 
+\bind "M-p Return"		"environment-split"
+\bind "M-p S-Return"		"environment-split outer"
+
 
 # These are kept for backwards compatibility (only make sense on US keyboard)
 \bind "M-p S-at"		"layout Section*"	# M-p S-2

lib/ui/stdcontext.inc

@@ -318,6 +318,8 @@ Menuset
 		Item "Move Paragraph Up|o" "paragraph-move-up"
 		Item "Move Paragraph Down|v" "paragraph-move-down"
 		Separator
+		EnvironmentSeparators
+		Separator
 		OptItem "Promote Section|r" "outline-out"
 		OptItem "Demote Section|m" "outline-in"
 		OptItem "Move Section Down|D" "outline-down"

lib/ui/stdmenus.inc

@@ -133,6 +133,7 @@ Menuset
 # obvious what the context is for the others)
 		OptItem "Increase List Depth|I" "depth-increment"
 		OptItem "Decrease List Depth|D" "depth-decrement"
+		EnvironmentSeparators
 		OptItem "Dissolve Inset" "inset-dissolve"
 		OptItem "TeX Code Settings...|C" "inset-settings ert"
 # 'a' shortcut to match Insert entry, shouldn't clash with Table Settings
@@ -150,7 +151,6 @@ Menuset
 # This is in the Table submenu instead for now.
 #	OptItem "Table Settings...|a" "inset-settings tabular"
 		OptItem "Table Settings...|a" "layout-tabular"
-		OptItem "Split Environment|l" "environment-split"
 	End
 
 	Menu "edit_paste"

src/LyXAction.cpp

@@ -3682,7 +3682,9 @@ void LyXAction::init()
 /*!
  * \var lyx::FuncCode lyx::LFUN_ENVIRONMENT_SPLIT
  * \li Action: Splits the current environment with a Separator.
- * \li Syntax: environment-split
+ * \li Syntax: environment-split [outer]
+ * \li Params: outer: If this is given, LyX will split the outermost environment in
+ *                    the current nesting hierarchy.
  * \li Origin: spitz, 23 Dec 2012
  * \endvar
  */

src/Text3.cpp

@@ -1378,10 +1378,32 @@ void Text::dispatch(Cursor & cur, FuncRequest & cmd)
 	}
 
 	case LFUN_ENVIRONMENT_SPLIT: {
+		bool const outer = cmd.argument() == "outer";
 		Paragraph const & para = cur.paragraph();
-		docstring const layout = para.layout().name();
+		docstring layout = para.layout().name();
+		depth_type split_depth = cur.paragraph().params().depth();
+		if (outer) {
+			// check if we have an environment in our nesting hierarchy
+			pit_type pit = cur.pit();
+			Paragraph cpar = pars_[pit];
+			while (true) {
+				if (pit == 0 || cpar.params().depth() == 0)
+					break;
+				--pit;
+				cpar = pars_[pit];
+				if (cpar.params().depth() < split_depth
+				    && cpar.layout().isEnvironment()) {
+						layout = cpar.layout().name();
+						split_depth = cpar.params().depth();
+				}
+			}
+		}
 		if (cur.pos() > 0)
 			lyx::dispatch(FuncRequest(LFUN_PARAGRAPH_BREAK));
+		if (outer) {
+			while (cur.paragraph().params().depth() > split_depth)
+				lyx::dispatch(FuncRequest(LFUN_DEPTH_DECREMENT));
+		}
 		bool const morecont = cur.lastpos() > cur.pos();
 		lyx::dispatch(FuncRequest(LFUN_LAYOUT, "Separator"));
 		lyx::dispatch(FuncRequest(LFUN_PARAGRAPH_BREAK, "inverse"));
@@ -2892,8 +2914,28 @@ bool Text::getStatus(Cursor & cur, FuncRequest const & cmd,
 		break;
 	
 	case LFUN_ENVIRONMENT_SPLIT: {
-		if (cur.paragraph().layout().isEnvironment()
-		    && cur.buffer()->params().documentClass().hasLayout(from_ascii("Separator"))) {
+		if (!cur.buffer()->params().documentClass().hasLayout(from_ascii("Separator"))) {
+			enable = false;
+			break;
+		}
+		if (cmd.argument() == "outer") {
+			// check if we have an environment in our nesting hierarchy
+			bool res = false;
+			depth_type const current_depth = cur.paragraph().params().depth();
+			pit_type pit = cur.pit();
+			Paragraph cpar = pars_[pit];
+			while (true) {
+				if (pit == 0 || cpar.params().depth() == 0)
+					break;
+				--pit;
+				cpar = pars_[pit];
+				if (cpar.params().depth() < current_depth)
+					res = cpar.layout().isEnvironment();
+			}
+			enable = res;
+			break;
+		}
+		else if (cur.paragraph().layout().isEnvironment()) {
 			enable = true;
 			break;
 		}

src/frontends/qt4/Menus.cpp

@@ -47,10 +47,12 @@
 #include "LyXRC.h"
 #include "lyxfind.h"
 #include "Paragraph.h"
+#include "ParagraphParameters.h"
 #include "ParIterator.h"
 #include "Session.h"
 #include "SpellChecker.h"
 #include "TextClass.h"
+#include "Text.h"
 #include "TocBackend.h"
 #include "Toolbars.h"
 #include "WordLangTuple.h"
@@ -185,7 +187,9 @@ public:
 		Captions,
 		/** This is the list of captions available
 		in the InsetCaption context menu. */
-		SwitchCaptions
+		SwitchCaptions,
+		/** Commands to separate environments. */
+		EnvironmentSeparation
 	};
 
 	explicit MenuItem(Kind kind) : kind_(kind), optional_(false) {}
@@ -363,6 +367,7 @@ public:
 	void expandLanguageSelector(Buffer const * buf);
 	void expandArguments(BufferView const *, bool switcharg = false);
 	void expandCaptions(Buffer const * buf, bool switchcap = false);
+	void expandEnvironmentSeparators(BufferView const *);
 	///
 	ItemList items_;
 	///
@@ -474,7 +479,8 @@ void MenuDefinition::read(Lexer & lex)
 		md_arguments,
 		md_switcharguments,
 		md_captions,
-		md_switchcaptions
+		md_switchcaptions,
+		md_env_separators
 	};
 
 	LexerKeyword menutags[] = {
@@ -488,6 +494,7 @@ void MenuDefinition::read(Lexer & lex)
 		{ "documents", md_documents },
 		{ "elements", md_elements },
 		{ "end", md_endmenu },
+		{ "environmentseparators", md_env_separators },
 		{ "exportformats", md_exportformats },
 		{ "floatinsert", md_floatinsert },
 		{ "floatlistinsert", md_floatlistinsert },
@@ -651,6 +658,10 @@ void MenuDefinition::read(Lexer & lex)
 			add(MenuItem(MenuItem::SwitchCaptions));
 			break;
 
+		case md_env_separators:
+			add(MenuItem(MenuItem::EnvironmentSeparation));
+			break;
+
 		case md_optsubmenu:
 		case md_submenu: {
 			lex.next(true);
@@ -1649,6 +1660,47 @@ void MenuDefinition::expandCaptions(Buffer const * buf, bool switchcap)
 	}
 }
 
+
+void MenuDefinition::expandEnvironmentSeparators(BufferView const * bv)
+{
+	if (!bv)
+		return;
+
+	Paragraph const par = bv->cursor().paragraph();
+	docstring const curlayout = par.layout().name();
+	docstring outerlayout;
+	depth_type current_depth = par.params().depth();
+	// check if we have an environment in our nesting hierarchy
+	pit_type pit = bv->cursor().pit();
+	Paragraph cpar = bv->buffer().text().getPar(pit);
+	while (true) {
+		if (pit == 0 || cpar.params().depth() == 0)
+			break;
+		--pit;
+		cpar = bv->buffer().text().getPar(pit);
+		if (cpar.params().depth() < current_depth
+		    && cpar.layout().isEnvironment()) {
+				outerlayout = cpar.layout().name();
+				current_depth = cpar.params().depth();
+		}
+	}
+	if (par.layout().isEnvironment()) {
+		docstring const label =
+			    bformat(_("Start New Environment (%1$s)"),
+				    translateIfPossible(curlayout));
+		add(MenuItem(MenuItem::Command, toqstr(label),
+			     FuncRequest(LFUN_ENVIRONMENT_SPLIT)));
+	}
+	if (!outerlayout.empty()) {
+	    docstring const label =
+			bformat(_("Start New Parent Environment (%1$s)"),
+				translateIfPossible(outerlayout));
+	    add(MenuItem(MenuItem::Command, toqstr(label),
+			     FuncRequest(LFUN_ENVIRONMENT_SPLIT,
+					 from_ascii("outer"))));
+	}
+}
+
 } // namespace anon
 
 
@@ -1793,7 +1845,8 @@ struct Menus::Impl {
 	/** The entries with the following kind are expanded to a
 	    sequence of Command MenuItems: Lastfiles, Documents,
 	    ViewFormats, ExportFormats, UpdateFormats, Branches,
-	    Indices, Arguments, SwitchArguments, Captions, SwitchCaptions
+	    Indices, Arguments, SwitchArguments, Captions, SwitchCaptions,
+	    EnvironmentSeparation
 	*/
 	void expand(MenuDefinition const & frommenu, MenuDefinition & tomenu,
 		BufferView const *) const;
@@ -2030,6 +2083,10 @@ void Menus::Impl::expand(MenuDefinition const & frommenu,
 			tomenu.expandCaptions(buf, true);
 			break;
 
+		case MenuItem::EnvironmentSeparation:
+			tomenu.expandEnvironmentSeparators(bv);
+			break;
+
 		case MenuItem::Submenu: {
 			MenuItem item(*cit);
 			item.setSubmenu(MenuDefinition(cit->submenuname()));