Grant a long-standing wish of Lars's: LyX now functions even if we have

no text classes for some reason (e.g., a corrupt textclass.lst). We
still give the user a chance to reconfigure (Bo's idea).

I wonder if we still really need to "restart LyX to make use of any
updated document class specifications". What would happen if we just
reloaded?


git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@34081 a592a061-630c-0410-9148-cb99ea01b6c8

src/LayoutFile.cpp

@@ -99,40 +99,26 @@ LayoutFile & LayoutFileList::operator[](string const & classname)
 // Reads LyX textclass definitions according to textclass config file
 bool LayoutFileList::read()
 {
+	bool success = false;
 	Lexer lex;
 	FileName const real_file = libFileSearch("", "textclass.lst");
-	LYXERR(Debug::TCLASS, "Reading textclasses from `" << real_file << '\'');
+	LYXERR(Debug::TCLASS, "Reading textclasses from `" << real_file << "'.");
 
 	if (real_file.empty()) {
-		lyxerr << "LayoutFileList::Read: unable to find "
-			  "textclass file  `"
-		       << to_utf8(makeDisplayPath(real_file.absFilename(), 1000))
-		       << "'. Exiting." << endl;
-		return false;
-		// This causes LyX to end... Not a desirable behaviour. Lgb
-		// What do you propose? That the user gets a file dialog
-		// and is allowed to hunt for the file? (Asger)
-		// more that we have a layout for minimal.cls statically
-		// compiled in... (Lgb)
-	}
-
-	if (!lex.setFile(real_file)) {
-		lyxerr << "LayoutFileList::Read: "
-			"lyxlex was not able to set file: "
-		       << real_file << endl;
-	}
-
-	if (!lex.isOK()) {
-		lyxerr << "LayoutFileList::Read: unable to open "
-			  "textclass file  `"
-		       << to_utf8(makeDisplayPath(real_file.absFilename(), 1000))
-		       << "'\nCheck your installation. LyX can't continue."
-		       << endl;
-		return false;
-	}
-
+		LYXERR0("LayoutFileList::Read: unable to find textclass file  `"
+		    << makeDisplayPath(real_file.absFilename(), 1000)
+		    << "'.");
+		success = false;
+	} else if (!lex.setFile(real_file)) {
+		LYXERR0("LayoutFileList::Read: lyxlex was not able to set file: "
+		       << real_file << '.');
+	} else if (!lex.isOK()) {
+		LYXERR0("LayoutFileList::Read: unable to open textclass file  `"
+		       << makeDisplayPath(real_file.absFilename(), 1000)
+		       << "'\nCheck your installation.");
+	} else {
+		// we have a file we can read.
 		bool finished = false;
-	// Parse config-file
 		LYXERR(Debug::TCLASS, "Starting parsing of textclass.lst");
 		while (lex.isOK() && !finished) {
 			LYXERR(Debug::TCLASS, "\tline by line");
@@ -168,17 +154,19 @@ bool LayoutFileList::read()
 					tmpl->load();
 				}
 				classmap_[fname] = tmpl;
-		}
-	}
-	LYXERR(Debug::TCLASS, "End of parsing of textclass.lst");
+			} // end of switch
+		} // end of while loop
+		LYXERR(Debug::TCLASS, "End parsing of textclass.lst");
+		success = true;
+	} // end of else
 
-	// lyx will start with an empty classmap_, but only reconfigure is allowed
-	// in this case. This gives users a second chance to configure lyx if
-	// initial configuration fails. (c.f. bug 2829)
+	// LyX will start with an empty classmap_. This is OK because
+	// (a) we will give the user a chance to reconfigure (see bug 2829) and
+	// (b) even if that fails, we can use addEmptyClass() to get some basic
+	// functionality.
 	if (classmap_.empty())
-		lyxerr << "LayoutFileList::Read: no textclasses found!"
-		       << endl;
-	return true;
+		LYXERR0("LayoutFileList::Read: no textclasses found!");
+	return success;
 }
 
 
@@ -346,26 +334,10 @@ LayoutFileIndex defaultBaseclass()
 	if (LayoutFileList::get().haveClass("article"))
 		return string("article");
 	if (LayoutFileList::get().empty())
-		return string();
+		// we'll call it that, since this gives the user a chance to
+		// have a functioning document when things improve.
+		return string("article");
 	return LayoutFileList::get().classList().front();
 }
 
-
-
-// Reads the style files
-bool LyXSetStyle()
-{
-	LYXERR(Debug::TCLASS, "LyXSetStyle: parsing configuration...");
-
-	if (!LayoutFileList::get().read()) {
-		LYXERR(Debug::TCLASS, "LyXSetStyle: an error occured "
-			"during parsing.\n             Exiting.");
-		return false;
-	}
-
-	LYXERR(Debug::TCLASS, "LyXSetStyle: configuration parsed.");
-	return true;
-}
-
-
 } // namespace lyx

src/LayoutFile.h

@@ -29,10 +29,6 @@ namespace lyx {
 
 class Layout;
 
-/// Reads the style files
-extern bool LyXSetStyle();
-
-
 /// Index into LayoutFileList. Basically a 'strong typedef'.
 class LayoutFileIndex {
 public:

src/LyX.cpp

@@ -502,16 +502,16 @@ void LyX::execCommands()
 	// aknowledged.
 
 	// if reconfiguration is needed.
-	while (LayoutFileList::get().empty()) {
+	if (LayoutFileList::get().empty()) {
 		switch (Alert::prompt(
 			_("No textclass is found"),
-			_("LyX cannot continue because no textclass is found. "
-				"You can either reconfigure normally, or reconfigure using "
-				"default textclasses, or quit LyX."),
+			_("LyX will have minimal functionality because no textclasses "
+				"have been found. You can either try to reconfigure LyX normally, "
+				"try to reconfigure using only the defaults, or continue."),
 			0, 2,
 			_("&Reconfigure"),
-			_("&Use Default"),
-			_("&Exit LyX")))
+			_("&Use Defaults"),
+			_("&Continue")))
 		{
 		case 0:
 			// regular reconfigure
@@ -523,8 +523,7 @@ void LyX::execCommands()
 				" --without-latex-config"));
 			break;
 		default:
-			lyx::dispatch(FuncRequest(LFUN_LYX_QUIT));
-			return;
+			break;
 		}
 	}
 	
@@ -762,10 +761,9 @@ bool LyX::init()
 	// Set the language defined by the user.
 	setRcGuiLanguage();
 
-	// Load the layouts
 	LYXERR(Debug::INIT, "Reading layouts...");
-	if (!LyXSetStyle())
-		return false;
+	// Load the layouts
+	LayoutFileList::get().read();
 	//...and the modules
 	theModuleList.read();