logic: made parsing interruptable by introducing TaskScheduler

This change introduces the TaskScheduler, which queues and processes Tasks on a separate thread. The Task class provides
a common interface for deriving all specific tasks. A task can split it's processing into multiple update calls. The
TaskScheduler will update a task until it is finished or interrupt it when necessary. TaskGroups can be used to bundle
multiple Tasks together. So far only TaskGroupSequential was implemented which runs the Tasks in the set order.

TaskParseCxx utilizes the CxxParser to parse each source file in a single update call. Parsing can be interrupted using
the ESC key. The Statusbar shows the parsing progress.

src/lib/Project.cpp

@@ -6,7 +6,7 @@
 
 #include "data/access/StorageAccessProxy.h"
 #include "data/graph/Token.h"
-#include "data/parser/cxx/CxxParser.h"
+#include "data/parser/cxx/TaskParseCxx.h"
 #include "settings/ApplicationSettings.h"
 #include "settings/ProjectSettings.h"
 
@@ -24,29 +24,31 @@ Project::~Project()
 bool Project::loadProjectSettings(const std::string& projectSettingsFile)
 {
 	bool success = ProjectSettings::getInstance()->load(projectSettingsFile);
-	if(success)
+	if (success)
 	{
 		m_projectSettingsFilepath = projectSettingsFile;
+
+		createFileManager();
 	}
 	return success;
 }
 
-bool Project::saveProjectSettings( const std::string& projectSettingsFile )
+bool Project::saveProjectSettings(const std::string& projectSettingsFile)
 {
-	if(!projectSettingsFile.empty())
+	if (projectSettingsFile.size())
 	{
 		m_projectSettingsFilepath = projectSettingsFile;
-		ProjectSettings::getInstance()->save(projectSettingsFile);
 	}
-	else if (!m_projectSettingsFilepath.empty())
-	{
-		ProjectSettings::getInstance()->save(m_projectSettingsFilepath);
-	}
-	else
+
+	if (!m_projectSettingsFilepath.size())
 	{
 		return false;
 	}
-	LOG_INFO_STREAM(<< "Projectsettings saved in File: " << m_projectSettingsFilepath);
+
+	ProjectSettings::getInstance()->save(m_projectSettingsFilepath);
+
+	LOG_INFO_STREAM(<< "ProjectSettings saved to file: " << m_projectSettingsFilepath);
+
 	return true;
 }
 
@@ -54,12 +56,21 @@ void Project::clearProjectSettings()
 {
 	m_projectSettingsFilepath.clear();
 	ProjectSettings::getInstance()->clear();
+
+	m_fileManager.reset();
 }
 
 bool Project::setSourceDirectoryPath(const std::string& sourceDirectoryPath)
 {
 	m_projectSettingsFilepath = sourceDirectoryPath + "/ProjectSettings.xml";
-	return ProjectSettings::getInstance()->setSourcePaths(std::vector<std::string>(1, sourceDirectoryPath));
+	bool success = ProjectSettings::getInstance()->setSourcePaths(std::vector<std::string>(1, sourceDirectoryPath));
+
+	if (success)
+	{
+		createFileManager();
+	}
+
+	return success;
 }
 
 void Project::clearStorage()
@@ -72,25 +83,13 @@ void Project::clearStorage()
 
 void Project::parseCode()
 {
-	std::shared_ptr<ProjectSettings> projSettings = ProjectSettings::getInstance();
-	std::shared_ptr<ApplicationSettings> appSettings = ApplicationSettings::getInstance();
-
-	std::vector<std::string> sourcePaths = projSettings->getSourcePaths();
-	if (!sourcePaths.size())
+	if (!m_fileManager)
 	{
+		LOG_ERROR("No FileManger was created.");
 		return;
 	}
 
-	std::vector<std::string> includePaths(sourcePaths);
-
-	// TODO: move this creation to another place (after projectsettings have been loaded)
-	if (!m_fileManager)
-	{
-		std::vector<std::string> sourceExtensions = ProjectSettings::getInstance()->getSourceExtensions();
-		std::vector<std::string> includeExtensions = ProjectSettings::getInstance()->getHeaderExtensions();
-
-		m_fileManager = std::make_shared<FileManager>(sourcePaths, includePaths, sourceExtensions, includeExtensions);
-	}
+	std::shared_ptr<ProjectSettings> projSettings = ProjectSettings::getInstance();
 
 	m_fileManager->fetchFilePaths();
 	std::set<FilePath> addedFilePaths = m_fileManager->getAddedFilePaths();
@@ -109,36 +108,59 @@ void Project::parseCode()
 
 	if (filesToParse.size() == 0)
 	{
-		MessageFinishedParsing(0, 0, m_storage->getErrorCount()).dispatch();
+		MessageFinishedParsing(0, 0, 0, m_storage->getErrorCount()).dispatch();
 		return;
 	}
 
+	Task::dispatch(std::make_shared<TaskParseCxx>(
+		m_storage.get(),
+		m_fileManager.get(),
+		getParserArguments(),
+		filesToParse
+	));
+}
+
+void Project::createFileManager()
+{
+	std::shared_ptr<ProjectSettings> projSettings = ProjectSettings::getInstance();
+
+	std::vector<std::string> sourcePaths(projSettings->getSourcePaths());
+	std::vector<std::string> includePaths(sourcePaths);
+
+	std::vector<std::string> sourceExtensions = projSettings->getSourceExtensions();
+	std::vector<std::string> includeExtensions = projSettings->getHeaderExtensions();
+
+	if (sourcePaths.size())
+	{
+		m_fileManager = std::make_shared<FileManager>(sourcePaths, includePaths, sourceExtensions, includeExtensions);
+	}
+}
+
+Parser::Arguments Project::getParserArguments() const
+{
+	std::shared_ptr<ProjectSettings> projSettings = ProjectSettings::getInstance();
+	std::shared_ptr<ApplicationSettings> appSettings = ApplicationSettings::getInstance();
+
 	Parser::Arguments args;
 
+	if (!m_fileManager)
+	{
+		LOG_ERROR("No FileManger was created.");
+		return args;
+	}
+
 	utility::append(args.compilerFlags, projSettings->getCompilerFlags());
 	utility::append(args.compilerFlags, appSettings->getCompilerFlags());
 
 	// Add the include paths as HeaderSearchPaths as well, so clang will also look here when searching include files.
-	utility::append(args.systemHeaderSearchPaths, includePaths);
+	utility::append(args.systemHeaderSearchPaths, m_fileManager->getIncludePaths());
 	utility::append(args.systemHeaderSearchPaths, projSettings->getHeaderSearchPaths());
 	utility::append(args.systemHeaderSearchPaths, appSettings->getHeaderSearchPaths());
 
 	utility::append(args.frameworkSearchPaths, projSettings->getFrameworkSearchPaths());
 	utility::append(args.frameworkSearchPaths, appSettings->getFrameworkSearchPaths());
 
-	CxxParser parser(m_storage.get(), m_fileManager.get());
-
-	float duration = utility::duration(
-		[&]()
-		{
-			parser.parseFiles(filesToParse, args);
-		}
-	);
-
-	// m_storage->logGraph();
-	// m_storage->logLocations();
-
-	MessageFinishedParsing(filesToParse.size(), duration, m_storage->getErrorCount()).dispatch();
+	return args;
 }
 
 Project::Project(StorageAccessProxy* storageAccessProxy)