Add TOC of external materials. (#7790, partial)

Known issues (non-regressions):

* The TOC is not updated immediately after an external material inset is
  inserted. See TocBackend::updateItem().

src/TocBackend.cpp

@@ -80,6 +80,8 @@ docstring const TocItem::asString() const
 	return prefix + str_;
 }
 
+namespace {
+
 // convert a DocIterator into an argument to LFUN_PARAGRAPH_GOTO 
 docstring paragraph_goto_arg(DocIterator const & dit)
 {
@@ -88,6 +90,8 @@ docstring paragraph_goto_arg(DocIterator const & dit)
 		convert<docstring>(s.pos());
 }
 
+} // namespace anon
+
 FuncRequest TocItem::action() const
 {
 	if (action_.action() == LFUN_UNKNOWN_ACTION) {

src/TocBackend.h

@@ -56,6 +56,7 @@ enum TocType {
 	LISTING,//"listings"
 	FLOAT,//"figure", "table", "algorithm", user-defined (from layout?)
 	MATH_MACRO,//"math-macro"
+	EXTERNAL,//"external"
 	SENSELESS,//"senseless"
 	TOC_TYPE_COUNT
 }

src/frontends/qt4/qt_helpers.cpp

@@ -608,6 +608,8 @@ QString guiName(string const & type, BufferParams const & bp)
 		return qt_("Graphics");
 	if (type == "equation")
 		return qt_("Equations");
+	if (type == "external")
+		return qt_("External material");
 	if (type == "footnote")
 		return qt_("Footnotes");
 	if (type == "listing")

src/insets/InsetExternal.cpp

@@ -30,6 +30,7 @@
 #include "MetricsInfo.h"
 #include "OutputParams.h"
 #include "output_latex.h"
+#include "TocBackend.h"
 
 #include "frontends/alert.h"
 #include "frontends/Application.h"
@@ -372,6 +373,33 @@ bool InsetExternalParams::read(Buffer const & buffer, Lexer & lex)
 }
 
 
+namespace {
+
+docstring screenLabel(InsetExternalParams const & params,
+			    Buffer const & buffer)
+{
+	external::Template const * const ptr =
+		external::getTemplatePtr(params);
+	if (!ptr)
+		// FIXME UNICODE
+		return bformat((_("External template %1$s is not installed")),
+					from_utf8(params.templatename()));
+	// FIXME UNICODE
+	docstring gui = _(ptr->guiName);
+	gui += ": ";
+
+	if (params.filename.empty())
+		gui += "???";
+	else
+		gui += from_utf8(params.filename.relFileName(buffer.filePath()));
+
+	return gui;
+}
+
+} // namespace anon
+
+
+
 InsetExternal::InsetExternal(Buffer * buf)
 	: Inset(buf), renderer_(new RenderButton)
 {
@@ -460,6 +488,17 @@ bool InsetExternal::getStatus(Cursor & cur, FuncRequest const & cmd,
 }
 
 
+void InsetExternal::addToToc(DocIterator const & cpit, bool output_active,
+							 UpdateType) const
+{
+	DocIterator pit = cpit;
+	pit.push_back(CursorSlice(const_cast<InsetExternal &>(*this)));
+	shared_ptr<Toc> toc = buffer().tocBackend().toc("external");
+	docstring str = screenLabel(params_, buffer());
+	toc->push_back(TocItem(pit, 0, str, output_active));
+}
+
+
 bool InsetExternal::showInsetDialog(BufferView * bv) const
 {
 	bv->showDialog("external", params2string(params(), bv->buffer()),
@@ -498,28 +537,6 @@ graphics::Params get_grfx_params(InsetExternalParams const & eparams)
 	return gparams;
 }
 
-
-docstring screenLabel(InsetExternalParams const & params,
-			    Buffer const & buffer)
-{
-	external::Template const * const ptr =
-		external::getTemplatePtr(params);
-	if (!ptr)
-		// FIXME UNICODE
-		return bformat((_("External template %1$s is not installed")),
-					from_utf8(params.templatename()));
-	// FIXME UNICODE
-	docstring gui = _(ptr->guiName);
-	gui += ": ";
-
-	if (params.filename.empty())
-		gui += "???";
-	else
-		gui += from_utf8(params.filename.relFileName(buffer.filePath()));
-
-	return gui;
-}
-
 } // namespace anon
 
 

src/insets/InsetExternal.h

@@ -120,6 +120,9 @@ public:
 	bool setMouseHover(BufferView const * bv, bool mouse_hover) const;
 	///
 	bool clickable(int, int) const { return true; }
+	///
+	void addToToc(DocIterator const & di, bool output_active,
+				  UpdateType utype) const;
 private:
 	///
 	InsetExternal(InsetExternal const &);