logic: Use all available cores when setting indexer threads to 0 (issue #342)

src/lib_gui/utility/utilityApp.cpp

@@ -1,6 +1,7 @@
 #include "utility/utilityApp.h"
 
 #include <QProcess>
+#include <QThread>
 #include <qprocessordetection.h>
 
 #include "utility/utilityString.h"
@@ -35,3 +36,8 @@ ApplicationArchitectureType utility::getApplicationArchitectureType()
 #endif
 	return APPLICATION_ARCHITECTURE_UNKNOWN;
 }
+
+int utility::getIdealThreadCount()
+{
+	return QThread::idealThreadCount();
+}

src/lib_gui/utility/utilityApp.h

@@ -10,6 +10,8 @@ namespace utility
 	std::string executeProcess(const std::string& command, const std::string& workingDirectory = "");
 
 	ApplicationArchitectureType getApplicationArchitectureType();
+
+	int getIdealThreadCount();
 }
 
 #endif // UTILITY_APP_H