Add command line parser for help and version infos (#44)

CMakeLists.txt

@@ -7,6 +7,7 @@ project(kaidan)
 set(APPLICATION_ID "harbour.kaidan")
 set(APPLICATION_NAME "kaidan")
 set(APPLICATION_DISPLAY_NAME "Kaidan")
+set(APPLICATION_DESCRIPTION "Cross platform XMPP client")
 
 # Version
 set(VERSION_MAJOR 0)
@@ -66,6 +67,7 @@ target_compile_definitions(${PROJECT_NAME} PRIVATE
 	APPLICATION_ID="${APPLICATION_ID}"
 	APPLICATION_NAME="${APPLICATION_NAME}"
 	APPLICATION_DISPLAY_NAME="${APPLICATION_DISPLAY_NAME}"
+	APPLICATION_DESCRIPTION="${APPLICATION_DESCRIPTION}"
 
 	VERSION_STRING="${VERSION_STRING}"
 )

src/main.cpp

 // Qt
+#include <QCommandLineParser>
+#include <QCommandLineOption>
+#include <QDebug>
 #include <QGuiApplication>
 #include <QQmlApplicationEngine>
 #include <QQuickView>
@@ -11,16 +14,72 @@
 #include "RosterController.h"
 #include "RosterItem.h"
 
+enum CommandLineParseResult
+{
+	CommandLineOk,
+	CommandLineError,
+	CommandLineVersionRequested,
+	CommandLineHelpRequested
+};
+
+CommandLineParseResult parseCommandLine(QCommandLineParser &parser, QString *errorMessage)
+{
+	// add all possible arguments
+	QCommandLineOption helpOption = parser.addHelpOption();
+	QCommandLineOption versionOption = parser.addVersionOption();
+
+	// parse arguments
+	if (!parser.parse(QGuiApplication::arguments()))
+	{
+		*errorMessage = parser.errorText();
+		return CommandLineError;
+	}
+
+	// check for special cases
+	if (parser.isSet(versionOption))
+		return CommandLineVersionRequested;
+
+	if (parser.isSet(helpOption))
+		return CommandLineHelpRequested;
+
+	// if nothing special happened, return OK
+	return CommandLineOk;
+}
+
 int main(int argc, char *argv[])
 {
 	qmlRegisterType<RosterController>(APPLICATION_ID, 1, 0, "RosterController");
 	qmlRegisterType<RosterItem>(APPLICATION_ID, 1, 0, "RosterItem");
 
+	// create a qt app
 	QGuiApplication app(argc, argv);
 	QGuiApplication::setApplicationName(APPLICATION_NAME);
 	QGuiApplication::setApplicationDisplayName(APPLICATION_DISPLAY_NAME);
 	QGuiApplication::setApplicationVersion(VERSION_STRING);
 
+	// create parser and add a description
+	QCommandLineParser parser;
+	parser.setApplicationDescription(QString(APPLICATION_DISPLAY_NAME) +
+		" - " + QString(APPLICATION_DESCRIPTION));
+
+	// parse the arguments
+	QString commandLineErrorMessage;
+	switch (parseCommandLine(parser, &commandLineErrorMessage))
+	{
+		case CommandLineError:
+			qDebug() << commandLineErrorMessage;
+			return 1;
+		case CommandLineVersionRequested:
+			parser.showVersion();
+			return 0;
+		case CommandLineHelpRequested:
+			parser.showHelp();
+			return 0;
+		case CommandLineOk:
+			qDebug() << "Successfully parsed command line input.";
+			break;
+	}
+
 	QtEventLoop eventLoop;
 	BoostNetworkFactories networkFactories(&eventLoop);