Clean up and modernize code

- static "new-style" signal->slot connections
- Fix a lot of things Clang-Tidy complained about
- Move includes to .cpp files and use forward decls in .h
- Don't use <QtWidgets> and <QtCore>, but specific includes instead

25 files changed, 452 insertions, 533 deletions

diff --git a/src/server/clicklabel/clicklabel.h b/src/server/clicklabel/clicklabel.h
index 4c5a898..cea024d 100644
--- a/src/server/clicklabel/clicklabel.h
+++ b/src/server/clicklabel/clicklabel.h
@@ -1,7 +1,6 @@
-#ifndef _CLICKLABEL_H_
-#define _CLICKLABEL_H_
+#ifndef PVS_CLICKLABEL_H_
+#define PVS_CLICKLABEL_H_
 
-#include <QtWidgets>
 #include <QLabel>
 
 /**
@@ -12,10 +11,10 @@ class ClickLabel : public QLabel
 	Q_OBJECT
 
 public:
-	ClickLabel(QWidget *parent);
+	explicit ClickLabel(QWidget *parent);
 
 protected:
-	void mouseReleaseEvent(QMouseEvent* e);
+	void mouseReleaseEvent(QMouseEvent* e) override;
 
 
 signals:
diff --git a/src/server/connectionframe/connectionframe.cpp b/src/server/connectionframe/connectionframe.cpp
index c2bba70..c6c20b8 100644
--- a/src/server/connectionframe/connectionframe.cpp
+++ b/src/server/connectionframe/connectionframe.cpp
@@ -16,46 +16,51 @@
 
 #include "connectionframe.h"
 #include "../mainwindow/mainwindow.h"
+#include "../../shared/util.h"
 #include "../net/client.h"
-#include <QImage>
-#include <cassert>
-#include <cmath>
 
-static QString style_student(
-    "QLabel{ background-color: #FFF; border-radius: 2px; color: black;} \
-	QGroupBox { background-color: #AAA; margin: 2px; border-radius: 4px}"
+#include <QImage>
+#include <QResizeEvent>
+#include <QBoxLayout>
+#include <QLabel>
+#include <QApplication>
+#include <QPainter>
+
+static const QString style_student(
+    "QLabel{ background-color: #FFF; border-radius: 2px; color: black;}"
+	" QGroupBox { background-color: #AAA; margin: 2px; border-radius: 4px}"
 );
-static QString style_tutor(
-    "QLabel{ background-color: #FFF; border-radius: 2px; color: black;} \
-	QGroupBox { background-color: #70C670; margin: 2px; border-radius: 4px}"
+static const QString style_tutor(
+    "QLabel{ background-color: #FFF; border-radius: 2px; color: black;}"
+	" QGroupBox { background-color: #70C670; margin: 2px; border-radius: 4px}"
 );
-static QString style_attention(
-    "QLabel{ background-color: #FFF; border-radius: 2px; color: black;} \
-	QGroupBox { background-color: #C88; margin: 2px; border-radius: 4px}"
+static const QString style_attention(
+    "QLabel{ background-color: #FFF; border-radius: 2px; color: black;}"
+	" QGroupBox { background-color: #C88; margin: 2px; border-radius: 4px}"
 );
-static QString style_selectedStudent(
-    "QLabel{ background-color: #FFF; border-radius: 2px; color: black; } \
-		QGroupBox { background-color: #ccebff; margin: 0px; border-radius: 4px; border: 4px solid #6C8CF0;}"
+static const QString style_selectedStudent(
+    "QLabel{ background-color: #FFF; border-radius: 2px; color: black; }"
+	" QGroupBox { background-color: #ccebff; margin: 0px; border-radius: 4px; border: 4px solid #6C8CF0;}"
 );
-static QString style_selectedTutor(
-    "QLabel{ background-color: #FFF; border-radius: 2px; color: black;} \
-		QGroupBox { background-color: #9f9; margin: 0px;  border-radius: 4px; border: 4px solid #6C8CF0;}"
+static const QString style_selectedTutor(
+    "QLabel{ background-color: #FFF; border-radius: 2px; color: black;}"
+	" QGroupBox { background-color: #9f9; margin: 0px;  border-radius: 4px; border: 4px solid #6C8CF0;}"
 );
-static QString style_selectedAttention(
-    "QLabel{ background-color: #FFF; border-radius: 2px; color: black;} \
-		QGroupBox { background-color: #E99; margin: 0px;  border-radius: 4px; border: 4px solid #6C8CF0;}"
+static const QString style_selectedAttention(
+    "QLabel{ background-color: #FFF; border-radius: 2px; color: black;}"
+	" QGroupBox { background-color: #E99; margin: 0px;  border-radius: 4px; border: 4px solid #6C8CF0;}"
 );
-static QString style_exam (
-    "QLabel{ background-color: #919191; color: black; } \
-		QGroupBox { background-color: #d35400; margin: 1px; border-radius: 4px}"
+static const QString style_exam (
+    "QLabel{ background-color: #919191; color: black; }"
+	" QGroupBox { background-color: #d35400; margin: 1px; border-radius: 4px}"
 );
-static QString style_exam_selected (
-    "QLabel{ background-color: #919191; color: black; } \
-		QGroupBox { background-color: #cc743a; margin: 1px; border-radius: 4px}"
+static const QString style_exam_selected (
+    "QLabel{ background-color: #919191; color: black; }"
+	" QGroupBox { background-color: #cc743a; margin: 1px; border-radius: 4px}"
 );
-static QString style_disconnected(
-    "QLabel{ background-color: #919191; border-radius: 2px; color: black; } \
-		QGroupBox { background-color: #7F7F7F; margin: 1px; border-radius: 4px}"
+static const QString style_disconnected(
+    "QLabel{ background-color: #919191; border-radius: 2px; color: black; }"
+	" QGroupBox { background-color: #7F7F7F; margin: 1px; border-radius: 4px}"
 );
 
 static QIcon *term = nullptr, *cam = nullptr, *eye = nullptr, *lock = nullptr;
@@ -70,9 +75,10 @@ bool ConnectionFrame::paintDisabled = false;
  * @param width
  * @param height
  */
-ConnectionFrame::ConnectionFrame(MainWindow* main, QWidget *parent, bool fromRoomplan) :
-	QGroupBox(parent), _client(nullptr), _timerId(0), _timerCounter(0), _isSelected(false), _isTutor(false),
-	_isFromRoomplan(fromRoomplan), _mainWindow(main)
+ConnectionFrame::ConnectionFrame(MainWindow* main, QWidget *parent, bool fromRoomplan)
+		: QGroupBox(parent)
+		, _isFromRoomplan(fromRoomplan)
+		, _mainWindow(main)
 {
 
 	//defines the ui-stuff
@@ -158,7 +164,7 @@ void ConnectionFrame::updateGeometry()
  */
 QLabel* ConnectionFrame::addIcon(const QIcon* icon)
 {
-	QLabel *label = new QLabel(this);
+	auto *label = new QLabel(this);
 	label->setPixmap(icon->pixmap(24, 24, QIcon::Normal, QIcon::On));
 	label->setAttribute(Qt::WA_TranslucentBackground);
 	label->hide();
@@ -174,17 +180,17 @@ QLabel* ConnectionFrame::addIcon(const QIcon* icon)
 void ConnectionFrame::assignClient(Client* client)
 {
 	assert(_client == nullptr);
-	connect( client, SIGNAL(disconnected()), this, SLOT(onClientDisconnected()) );
-	connect( client, SIGNAL(thumbUpdated(Client*, const QImage&)), this, SLOT(onThumbUpdated(Client*, const QImage&)) );
-	connect( client, SIGNAL(vncServerStateChange(Client*)), this, SLOT(updateAppearance()));
-	connect( client, SIGNAL(vncClientStateChange(Client*)), this, SLOT(updateAppearance()));
-	connect( client, SIGNAL(stateChanged()), this, SLOT(updateAppearance()));
 	_client = client;
+	connect(_client, &Client::disconnected, this, &ConnectionFrame::onClientDisconnected );
+	connect(_client, &Client::thumbUpdated, this, &ConnectionFrame::onThumbUpdated );
+	connect(_client, &Client::vncServerStateChange, this, &ConnectionFrame::updateAppearance);
+	connect(_client, &Client::vncClientStateChange, this, &ConnectionFrame::updateAppearance);
+	connect(_client, &Client::stateChanged, this, &ConnectionFrame::updateAppearance);
 	_computerId = client->ip();
 	updateLabels();
 	showDefaultThumb();
 	if (_timerId == 0)
-		_timerId = startTimer(1000 + qrand() % 150);
+		_timerId = startTimer(slxrand() % 150 + 1000);
 	this->updateAppearance();
 	_client->setTutor(_isTutor);
 }
@@ -382,8 +388,8 @@ void ConnectionFrame::updateAppearance()
 		} else {
 			this->setStyleSheet(style_disconnected);
 		}
-		for (QList<QLabel*>::iterator it(_icons.begin()); it != _icons.end(); ++it) {
-			(**it).hide();
+		for (auto *_icon : _icons) {
+			_icon->hide();
 		}
 		return;
 	}
@@ -448,3 +454,8 @@ void ConnectionFrame::onThumbUpdated(Client* client, const QImage& thumb)
 	this->update();
 }
 
+void ConnectionFrame::resizeEvent(QResizeEvent *event) {
+	calcDesiredThumbSize(event->size());
+	QGroupBox::resizeEvent(event);
+}
+
diff --git a/src/server/connectionframe/connectionframe.h b/src/server/connectionframe/connectionframe.h
index 1d004e6..cfebe85 100644
--- a/src/server/connectionframe/connectionframe.h
+++ b/src/server/connectionframe/connectionframe.h
@@ -1,9 +1,14 @@
-#ifndef _CONNECTIONFRAME_H_
-#define _CONNECTIONFRAME_H_
-#include <QtWidgets>
-#include "../net/client.h"
+#ifndef PVS_CONNECTIONFRAME_H_
+#define PVS_CONNECTIONFRAME_H_
+
+#include <QGroupBox>
+#include <utility>
+
+class QBoxLayout;
+class QLabel;
 
 class MainWindow;
+class Client;
 
 /**
  * Class for representing the clients of current session, with a specific frame
@@ -34,11 +39,11 @@ private:
 	QPoint _gridPosition;
 	QSize _desiredThumbSize;
 
-	Client *_client;
+	Client *_client{};
 
-	int _timerId, _timerCounter;
-	bool _isSelected;
-	bool _isTutor;
+	int _timerId{}, _timerCounter{};
+	bool _isSelected{};
+	bool _isTutor{};
 	bool _isFromRoomplan;
 
 	void showDefaultThumb();
@@ -52,35 +57,39 @@ public:
 	static bool paintDisabled;
 
 	ConnectionFrame(MainWindow* main, QWidget* parent, bool fromRoomplan = false);
-	virtual ~ConnectionFrame();
+	~ConnectionFrame() override;
 
-	const inline QPoint getGridPosition() const { return _gridPosition; }
+	const QPoint& getGridPosition() const { return _gridPosition; }
 	void setGridPosition(int x, int y);
 	void setGridPosition(const QPoint& pos);
 	void updateGeometry();
 
 	void assignClient(Client *client);
 	void setSelection(bool selected);
-	inline bool isSelected() { return _isSelected; }
+	bool isSelected() const { return _isSelected; }
 
 	const QString& computerId() const { return _computerId; }
-	void setComputerId(QString computerId) { if (_client != nullptr) return; _computerId = computerId; updateLabels(); }
+	void setComputerId(QString computerId) {
+		if (_client != nullptr)
+			return;
+		_computerId = std::move(computerId); updateLabels();
+	}
 	Client* client() const { return _client; }
 
-	inline bool isTutor() { return _isTutor; }
-	inline bool isFromRoomplan() { return _isFromRoomplan; }
+	bool isTutor() const { return _isTutor; }
+	bool isFromRoomplan() const { return _isFromRoomplan; }
 	void setTutor(bool b);
 
 protected:
-	void resizeEvent(QResizeEvent* event) { calcDesiredThumbSize(event->size()); }
-	void mouseDoubleClickEvent(QMouseEvent* event);
-	void mouseReleaseEvent(QMouseEvent* e);
-	void enterEvent(QEvent* event);
-	void leaveEvent(QEvent* event);
-	void mousePressEvent(QMouseEvent* event);
-	void mouseMoveEvent(QMouseEvent* event);
-	void paintEvent(QPaintEvent *event);
-	void timerEvent(QTimerEvent* event);
+	void resizeEvent(QResizeEvent* event) override;
+	void mouseDoubleClickEvent(QMouseEvent* event) override;
+	void mouseReleaseEvent(QMouseEvent* e) override;
+	void enterEvent(QEvent* event) override;
+	void leaveEvent(QEvent* event) override;
+	void mousePressEvent(QMouseEvent* event) override;
+	void mouseMoveEvent(QMouseEvent* event) override;
+	void paintEvent(QPaintEvent *event) override;
+	void timerEvent(QTimerEvent* event) override;
 
 signals:
 	void frameMoving(ConnectionFrame* frame);
diff --git a/src/server/helpwindow/helpwindow.cpp b/src/server/helpwindow/helpwindow.cpp
index 152cf0d..f6f1f10 100644
--- a/src/server/helpwindow/helpwindow.cpp
+++ b/src/server/helpwindow/helpwindow.cpp
@@ -22,7 +22,7 @@ HelpWindow::HelpWindow(const QList<QAction*> &actions, QWidget *parent) :
 			break;
 		}
 	}
-	QGridLayout *layout = new QGridLayout(this);
+	auto *layout = new QGridLayout(this);
 	layout->setSpacing(2);
 	QSizePolicy sizePol(QSizePolicy::Minimum, QSizePolicy::Preferred);
 	QList<QLabel*> wrapLabels;
@@ -31,24 +31,24 @@ HelpWindow::HelpWindow(const QList<QAction*> &actions, QWidget *parent) :
 	for (QAction *action : actions) {
 		if (action->icon().isNull() || action->text().isEmpty())
 			continue;
-		QLabel *icon = new QLabel(this);
+		auto *icon = new QLabel(this);
 		icon->setPixmap(action->icon().pixmap(iconSize, iconSize, QIcon::Normal, QIcon::Off));
 		icon->setMinimumSize(iconSize + 5, iconSize + 2);
 		layout->addWidget(icon, row, 0, 3, 1, Qt::AlignTop | Qt::AlignLeft);
-		QLabel *headline = new QLabel(action->toolTip(), this);
+		auto *headline = new QLabel(action->toolTip(), this);
 		QFont boldFont = headline->font();
 		boldFont.setBold(true);
 		headline->setFont(boldFont);
 		headline->setAlignment(Qt::AlignTop | Qt::AlignLeft);
 		layout->addWidget(headline, row, 1, Qt::AlignTop);
-		QLabel *description = new QLabel(action->text(), this);
+		auto *description = new QLabel(action->text(), this);
 		description->setWordWrap(true);
 		description->setAlignment(Qt::AlignTop | Qt::AlignLeft);
 		description->setSizePolicy(sizePol);
 		wrapLabels.append(description);
 		layout->addWidget(description, row + 1, 1, Qt::AlignTop);
 		layout->setRowStretch(row + 2, 1);
-		QFrame *line = new QFrame();
+		auto *line = new QFrame();
 		line->setFrameShape(QFrame::HLine);
 		line->setFrameShadow(QFrame::Sunken);
 		layout->addWidget(line, row + 3, 0, 1, 2);
@@ -57,12 +57,12 @@ HelpWindow::HelpWindow(const QList<QAction*> &actions, QWidget *parent) :
 	layout->setColumnStretch(1, 1);
 	// Add close button
 	layout->setRowStretch(row++, 1000);
-	QPushButton *close = new QPushButton(tr("Close"), this);
+	auto *close = new QPushButton(tr("Close"), this);
 	QFont bigFont = close->font();
 	bigFont.setPointSize(20);
 	close->setFont(bigFont);
 	close->setDefault(true);
-	connect(close, SIGNAL(clicked()), this, SLOT(hide()));
+	connect(close, &QPushButton::clicked, this, &HelpWindow::hide);
 	layout->addWidget(close, row++, 0, 1, 2);
 	this->setFixedWidth(600);
 	this->setSizePolicy(sizePol);
diff --git a/src/server/main.cpp b/src/server/main.cpp
index f804c1a..d975f80 100644
--- a/src/server/main.cpp
+++ b/src/server/main.cpp
@@ -1,27 +1,25 @@
-#include <iostream>
-#include <stdlib.h>
 #include "mainwindow/mainwindow.h"
 #include "serverapp/serverapp.h"
 
-using std::cout;
-using std::endl;
+#include <QDebug>
 
 void usage()
 {
-	cout << "USAGE pvsmgr [OPTIONS]" << endl;
-	cout << "OPTIONS: " << endl;
-	cout << "--manager-only" << endl;
-	cout << "    pvsmgr terminates if this computer is not a manager of a room" << endl;
-	cout << "--config=INIFILE" << endl;
-	cout << "    read configuration from INIFILE instead of default path (/opt/openslx/pvs2/pvs2.ini) " << endl;
-	cout << "--usage" << endl;
-	cout << "    shows this message" << endl;
+	puts(
+		"USAGE pvsmgr [OPTIONS]\n"
+		"OPTIONS: \n"
+		"--manager-only\n"
+		"    pvsmgr terminates if this computer is not a manager of a room\n"
+		"--config=INIFILE\n"
+		"    read configuration from INIFILE instead of default path (/opt/openslx/pvs2/pvs2.ini) \n"
+		"--usage\n"
+		"    shows this message\n"
+	);
 }
 
 
 int main(int argc, char** argv)
 {
-	qsrand(uint(QDateTime::currentMSecsSinceEpoch()));
 	ServerApp app(argc, argv);
 
 	for (QString a : app.arguments()) {
diff --git a/src/server/mainwindow/mainwindow.cpp b/src/server/mainwindow/mainwindow.cpp
index b63545f..e8247d0 100644
--- a/src/server/mainwindow/mainwindow.cpp
+++ b/src/server/mainwindow/mainwindow.cpp
@@ -16,11 +16,13 @@
 // Self
 #include "mainwindow.h"
 // QT stuff
-#include <QtWidgets>
-#include <QFileDialog>
 #include <QSvgRenderer>
 #include <QPainter>
 #include <QImage>
+#include <QMessageBox>
+#include <QCloseEvent>
+#include <QDialogButtonBox>
+#include <QScreen>
 // Other custom UI elements
 #include "../serverapp/serverapp.h"
 #include "../clicklabel/clicklabel.h"
@@ -32,16 +34,12 @@
 #include "../net/listenserver.h"
 #include "../net/client.h"
 #include "../net/discoverylistener.h"
-#include "../net/filedownloader.h"
 // Others
 #include "../../shared/settings.h"
 #include "../util/platform/screensaver.h"
 // Auto-generated ui class
 #include "ui_mainwindow.h"
 
-#include <iostream>
-#include <vector>
-
 #define sStrTutorNdef MainWindow::tr("No tutor defined.")
 #define sStrTutorOffline MainWindow::tr("Tutor is offline.")
 #define sStrSourceNdef MainWindow::tr("Please select a projection source.")
@@ -49,33 +47,24 @@
 #define sStrDestNdef MainWindow::tr("Please select a projection destination.")
 #define sStrDestOffline MainWindow::tr("The projection destination is offline.")
 #define sStrSourceDestSame MainWindow::tr("Selected projection target is tutor.")
-#define sStrClientOnline MainWindow::tr("Selected client is currently online.")
 #define sStrNoDestAv MainWindow::tr("No projection destination available.")
 
-using std::vector;
-using std::cout;
-using std::endl;
-
 /**
  * Initialize MainWindow and ListenServer.
  * @param ipListUrl
  * @param parent
  */
-MainWindow::MainWindow(QWidget* parent) :
-	QMainWindow(parent), ui(new Ui::MainWindow), _tbIconSize(24), _tbArea(Qt::LeftToolBarArea),
-	_lastClientCount(0)
+MainWindow::MainWindow(QWidget* parent)
+		: QMainWindow(parent)
+		, ui(new Ui::MainWindow)
+		, _mode(Mode::Multicast)
 {
 	qDebug() << "MainWindow(parent)";
-	_mode = Mode::Multicast;
-	_streamingSource = 0;
 
 	/* default value, these will be updated a room is loaded */
 	_tilesX = 10;
 	_tilesY = 10;
 
-	_virtCols = 0;
-	_virtRows = 0;
-
 	_sessionNameWindow = new SessionNameWindow(this);
 	_reloadWindow = new ReloadRoomWindow(this);
 	_reloadWindow->setWindowTitle(tr("Reload Room"));
@@ -113,26 +102,26 @@ MainWindow::MainWindow(QWidget* parent) :
 	serverApp->setExam(false);
 
 	// Close button in tool bar
-	connect(ui->action_Exit, SIGNAL(triggered()), this, SLOT(onButtonExit()));
-	connect(ui->action_TutorToAll, SIGNAL(triggered()), this, SLOT(onButtonTutorToAll()));
-	connect(ui->action_StudentToTutor, SIGNAL(triggered()), this, SLOT(onButtonStudentToTutor()));
-	connect(ui->action_StudentToTutorExclusive, SIGNAL(triggered()), this, SLOT(onButtonStudentToTutorExclusive()));
-	connect(ui->action_TutorToStudent, SIGNAL(triggered()), this, SLOT(onButtonTutorToStudent()));
-	connect(ui->action_StopProjection, SIGNAL(triggered()), this, SLOT(onButtonStopProjection()));
-	connect(ui->action_SetAsTutor, SIGNAL(triggered()), this, SLOT(onButtonSetAsTutor()));
-	connect(ui->action_SetAsTutor, SIGNAL(triggered()), this, SLOT(onButtonStopProjection()));
-	connect(ui->action_Lock, SIGNAL(toggled(bool)), this, SLOT(onButtonLock(bool)));
-	connect(ui->action_LockSingle, SIGNAL(triggered()), this, SLOT(onButtonLockSingle()));
-	connect(ui->action_Help, SIGNAL(triggered()), this, SLOT(onButtonHelp()));
-	connect(ui->actionReload_Room_Configuration, SIGNAL(triggered()), this, SLOT(onButtonReloadRoomConfig()));
-	connect(ui->action_DeleteClient, SIGNAL(triggered()), this, SLOT(onDeleteClient()));
+	connect(ui->action_Exit, &QAction::triggered, this, &MainWindow::onButtonExit);
+	connect(ui->action_TutorToAll, &QAction::triggered, this, &MainWindow::onButtonTutorToAll);
+	connect(ui->action_StudentToTutor, &QAction::triggered, this, &MainWindow::onButtonStudentToTutor);
+	connect(ui->action_StudentToTutorExclusive, &QAction::triggered, this, &MainWindow::onButtonStudentToTutorExclusive);
+	connect(ui->action_TutorToStudent, &QAction::triggered, this, &MainWindow::onButtonTutorToStudent);
+	connect(ui->action_StopProjection, &QAction::triggered, this, &MainWindow::onButtonStopProjection);
+	connect(ui->action_SetAsTutor, &QAction::triggered, this, &MainWindow::onButtonSetAsTutor);
+	connect(ui->action_SetAsTutor, &QAction::triggered, this, &MainWindow::onButtonStopProjection);
+	connect(ui->action_Lock, &QAction::toggled, this, &MainWindow::onButtonLock);
+	connect(ui->action_LockSingle, &QAction::triggered, this, &MainWindow::onButtonLockSingle);
+	connect(ui->action_Help, &QAction::triggered, this, &MainWindow::onButtonHelp);
+	connect(ui->actionReload_Room_Configuration, &QAction::triggered, this, &MainWindow::onButtonReloadRoomConfig);
+	connect(ui->action_DeleteClient, &QAction::triggered, this, &MainWindow::onDeleteClient);
 
 	/* Stuff for the button lock */
 	//Setup a timeout
 	_buttonLockTimer = new QTimer(this);
 	_buttonLockTimer->setSingleShot(true);
 	_buttonLockTimer->setInterval(BUTTON_BLOCK_TIME);
-	connect(_buttonLockTimer, SIGNAL(timeout()), this, SLOT(enableButtons()));
+	connect(_buttonLockTimer, &QTimer::timeout, this, &MainWindow::enableButtons);
 	// Define the locking buttons
 	_lockingButtons
 			<< ui->action_DeleteClient
@@ -146,18 +135,18 @@ MainWindow::MainWindow(QWidget* parent) :
 			<< ui->action_StopProjection;
 
 	// Clicking the session name label shows the edit field for it
-	connect(_sessionNameLabel, SIGNAL(clicked()), this, SLOT(onSessionNameClick()));
+	connect(_sessionNameLabel, &ClickLabel::clicked, this, &MainWindow::onSessionNameClick);
 	// Listen to updates to the session name through the session name window
-	connect(_sessionNameWindow, SIGNAL(updateSessionName()), this,
-	        SLOT(onSessionNameUpdate()));
+	connect(_sessionNameWindow, &SessionNameWindow::updateSessionName,
+			this, &MainWindow::onSessionNameUpdate);
 
 	setAttribute(Qt::WA_QuitOnClose);
 	setUnifiedTitleAndToolBarOnMac(true);
 	this->showMaximized(); // show the Mainwindow maximized
 
-	_listenServer = new ListenServer(CLIENT_PORT);
-	connect(_listenServer, SIGNAL(newClient(Client*)), this, SLOT(onClientConnected(Client*)));
-	_discoveryListener = new DiscoveryListener();
+	auto *ls = new ListenServer(CLIENT_PORT, this);
+	connect(ls, &ListenServer::newClient, this, &MainWindow::onClientConnected);
+	new DiscoveryListener(this);
 
 	// Finally
 	this->onSessionNameUpdate(); // Just make lable visible.
@@ -174,8 +163,8 @@ void MainWindow::clientCountChanged()
 	int clientCount = 0;
 
 
-	for (auto it = _clientFrames.begin(); it != _clientFrames.end(); ++it) {
-		Client* c = (*it)->client();
+	for (auto * frame : _clientFrames) {
+		Client* c = frame->client();
 		if (c != nullptr) {
 			bool b = c->isExamMode();
 			examClientCount += b ? 1 : 0;
@@ -240,7 +229,7 @@ static int distance(QPoint a, QPoint b)
  * @param toIgnore, ignore this connectionframe when considering free slots
  * @return the free slot
  */
-QPoint MainWindow::closestFreeSlot(const QPoint preferredPixels, const ConnectionFrame* toIgnore)
+QPoint MainWindow::closestFreeSlot(const QPoint &preferredPixels, const ConnectionFrame* toIgnore)
 {
 	const bool pickFirstOne = ( preferredPixels == QPoint(-1, -1) );
 	const QSize& clientSize = serverApp->getCurrentRoom()->clientSize;
@@ -249,11 +238,11 @@ QPoint MainWindow::closestFreeSlot(const QPoint preferredPixels, const Connectio
 	memset(grid, 0, sizeof(bool) * size_t(_tilesX * _tilesY)); /* set everything to false */
 
 	/* fill grid */
-	for (auto  it = _clientFrames.begin(); it != _clientFrames.end(); ++it) {
+	for (auto * frame : _clientFrames) {
 
-		if (*it == toIgnore) { continue; }
+		if (frame == toIgnore) { continue; }
 
-		const QPoint p = (*it)->getGridPosition();
+		const QPoint p = frame->getGridPosition();
 
 		for (int x = p.x(); x < p.x() + clientSize.width(); x++) {
 			for (int y = p.y(); y < p.y() + clientSize.height(); y++) {
@@ -322,7 +311,7 @@ void MainWindow::placeFrameInFreeSlot(ConnectionFrame* frame, QPoint preferredPi
  */
 ConnectionFrame* MainWindow::createFrame(const QString &computerId, const QPoint* gridPosition, bool fromRoomplan)
 {
-	ConnectionFrame *cf = new ConnectionFrame(this, ui->frmRoom, fromRoomplan);
+	auto *cf = new ConnectionFrame(this, ui->frmRoom, fromRoomplan);
 	if (gridPosition == nullptr) {
 		placeFrameInFreeSlot(cf);
 	} else {
@@ -331,9 +320,9 @@ ConnectionFrame* MainWindow::createFrame(const QString &computerId, const QPoint
 	cf->setComputerId(computerId);
 	_clientFrames.append(cf);
 	cf->show();
-	connect(cf, SIGNAL(frameMoved(ConnectionFrame *)), this, SLOT(onFrameDropped(ConnectionFrame *)));
-	connect(cf, SIGNAL(clicked(ConnectionFrame *)), this, SLOT(onFrameClicked(ConnectionFrame *)));
-	connect(cf, SIGNAL(frameMoving(ConnectionFrame *)), this, SLOT(onFrameMoving(ConnectionFrame *)));
+	connect(cf, &ConnectionFrame::frameMoved, this, &MainWindow::onFrameDropped);
+	connect(cf, &ConnectionFrame::clicked, this, &MainWindow::onFrameClicked);
+	connect(cf, &ConnectionFrame::frameMoving, this, &MainWindow::onFrameMoving);
 	return cf;
 }
 
@@ -364,10 +353,10 @@ void MainWindow::tellClientCurrentSituation(Client* client)
  */
 Client* MainWindow::getClientFromId(int id)
 {
-	for (QList<ConnectionFrame*>::iterator it(_clientFrames.begin()); it != _clientFrames.end(); ++it) {
-		if ((*it)->client() != nullptr) {
-			if ((*it)->client()->id() == id)
-				return (*it)->client();
+	for (auto * frame : _clientFrames) {
+		if (frame->client() != nullptr) {
+			if (frame->client()->id() == id)
+				return frame->client();
 		}
 	}
 	return nullptr;
@@ -381,9 +370,9 @@ Client* MainWindow::getClientFromId(int id)
  */
 ConnectionFrame* MainWindow::getTutorFrame()
 {
-	for (QList<ConnectionFrame*>::iterator it(_clientFrames.begin()); it != _clientFrames.end(); ++it) {
-		if (((*it) != nullptr) && ((*it)->isTutor()))
-			return (*it);
+	for (auto * frame : _clientFrames) {
+		if ((frame != nullptr) && (frame->isTutor()))
+			return frame;
 	}
 	return nullptr;
 }
@@ -396,9 +385,9 @@ ConnectionFrame* MainWindow::getTutorFrame()
  */
 ConnectionFrame* MainWindow::getSelectedFrame()
 {
-	for (QList<ConnectionFrame*>::iterator it(_clientFrames.begin()); it != _clientFrames.end(); ++it) {
-		if (((*it) != nullptr) && ((*it)->isSelected()))
-			return (*it);
+	for (auto * frame : _clientFrames) {
+		if ((frame != nullptr) && (frame->isSelected()))
+			return frame;
 	}
 	return nullptr;
 }
@@ -469,8 +458,8 @@ void MainWindow::resizeEvent(QResizeEvent* /* e */ )
 	const QSize& clientSize = room->clientSize;
 
 	// Check if any frames have been moved beyond the room dimensions
-	for (auto it = _clientFrames.begin(); it != _clientFrames.end(); ++it) {
-		QPoint bounds = (*it)->getGridPosition();
+	for (auto * frame : _clientFrames) {
+		QPoint bounds = frame->getGridPosition();
 		while (bounds.x() + clientSize.width() > newGridSize.width()) {
 			newGridSize += QSize(1, 0);
 		}
@@ -498,16 +487,16 @@ void MainWindow::resizeEvent(QResizeEvent* /* e */ )
 	const int maxY = _tilesY - clientSize.height();
 
 	/* Bring back frames which are now out of the screen */
-	for (auto it = _clientFrames.begin(); it != _clientFrames.end(); ++it) {
-		const QPoint gp = (*it)->getGridPosition();
+	for (auto * frame : _clientFrames) {
+		const QPoint gp = frame->getGridPosition();
 		if ( gp.x() > maxX || gp.y() > maxY ) {
-			placeFrameInFreeSlot(*it, (*it)->pos());
+			placeFrameInFreeSlot(frame, frame->pos());
 		}
 	}
 
 	/* Resize all connection windows */
-	for (auto it = _clientFrames.begin(); it != _clientFrames.end(); ++it) {
-		(*it)->updateGeometry();
+	for (auto * frame : _clientFrames) {
+		frame->updateGeometry();
 	}
 
 	/* update background image label */
@@ -580,10 +569,10 @@ void MainWindow::reset(bool lock)
 	}
 
 	// Unlock all clients
-	for (QList<ConnectionFrame*>::iterator it(_clientFrames.begin()); it != _clientFrames.end(); ++it) {
-		if ((*it)->client() != nullptr) {
-			(*it)->client()->lockScreen(lock);
-			(*it)->client()->removeAttention();
+	for (auto * frame : _clientFrames) {
+		if (frame->client() != nullptr) {
+			frame->client()->lockScreen(lock);
+			frame->client()->removeAttention();
 		}
 	}
 
@@ -595,6 +584,7 @@ void MainWindow::reset(bool lock)
 
 void MainWindow::onFrameMoving(ConnectionFrame* connectionFrame)
 {
+	// Get where the frame would be placed, and show a blue shadow in that spot
 	QPoint slot = closestFreeSlot(connectionFrame->pos(), connectionFrame);
 	_dropMarker->setGeometry(slot.x() * getTileWidthPx(), slot.y() * getTileHeightPx(), connectionFrame->width(), connectionFrame->height());
 	if (!_dropMarker->isVisible()) {
@@ -611,11 +601,8 @@ void MainWindow::onFrameMoving(ConnectionFrame* connectionFrame)
 void MainWindow::onFrameDropped(ConnectionFrame* connectionFrame)
 {
 	_dropMarker->hide();
-	// if (_tilesX <= 0 || _tilesY <= 0) return;
 	const QPoint preferredPixels = connectionFrame->pos();
 	placeFrameInFreeSlot(connectionFrame, preferredPixels);
-
-	//resizeEvent(nullptr);
 }
 
 /**
@@ -626,7 +613,7 @@ void MainWindow::onFrameClicked(ConnectionFrame* frame)
 {
 	_dropMarker->hide();
 	ConnectionFrame *current = getSelectedFrame();
-	// If same frame is clicked again,, do nothing
+	// If same frame is clicked again, do nothing
 	if (current == frame)
 		return;
 
@@ -710,19 +697,19 @@ void MainWindow::startVncServerIfNecessary(int from)
 
 void MainWindow::onButtonReloadRoomConfig()
 {
-	connect(_reloadWindow->buttonBox(), SIGNAL(accepted()), this, SLOT(onReloadRoomOk()));
-	connect(_reloadWindow->buttonBox(), SIGNAL(rejected()), this, SLOT(onReloadRoomCancel()));
+	connect(_reloadWindow->buttonBox(), &QDialogButtonBox::accepted, this, &MainWindow::onReloadRoomOk);
+	connect(_reloadWindow->buttonBox(), &QDialogButtonBox::rejected, this, &MainWindow::onReloadRoomCancel);
 	QList<QString> keyList = serverApp->getRooms().keys();
-	for (QList<QString>::iterator it = keyList.begin(); it != keyList.end() ; it++) {
-		_reloadWindow->addRoom(*it);
+	for (const auto & it : keyList) {
+		_reloadWindow->addRoom(it);
 	}
 	_reloadWindow->show();
 }
 
 void MainWindow::onReloadRoomCancel()
 {
-	disconnect(_reloadWindow->buttonBox(), SIGNAL(accepted()), this, SLOT(onReloadRoomOk()));
-	disconnect(_reloadWindow->buttonBox(), SIGNAL(rejected()), this, SLOT(onReloadRoomCancel()));
+	disconnect(_reloadWindow->buttonBox(), &QDialogButtonBox::accepted, this, &MainWindow::onReloadRoomOk);
+	disconnect(_reloadWindow->buttonBox(), &QDialogButtonBox::rejected, this, &MainWindow::onReloadRoomCancel);
 	_reloadWindow->clearRoomList();
 	_reloadWindow->hide();
 }
@@ -730,7 +717,7 @@ void MainWindow::onReloadRoomCancel()
 void MainWindow::reloadCurrentRoom()
 {
 	/* delete old image */
-	if (_backgroundImage != nullptr) {delete _backgroundImage; }
+	delete _backgroundImage;
 	_backgroundImage = nullptr;
 
 	const Room *room = serverApp->getCurrentRoom();
@@ -742,8 +729,8 @@ void MainWindow::reloadCurrentRoom()
 
 		/* place connection frames */
 		for (auto it = room->clientPositions.begin(); it != room->clientPositions.end(); ++it) {
-			QString computerId = it.key();
-			QPoint pos = it.value();
+			const QString& computerId = it.key();
+			const QPoint& pos = it.value();
 
 			ConnectionFrame *cf = createFrame(computerId, &pos, true);
 			onFrameDropped(cf);
@@ -764,7 +751,7 @@ void MainWindow::reloadCurrentRoom()
 			qDebug() << "set background image path: " << imgPath;
 			if (imgPath.endsWith("svg")) {
 				/* render once with maximal screen size */
-				const QSize &s  =  QApplication::desktop()->screenGeometry().size(); // ui->frmRoom->geometry().size();
+				QSize s = QGuiApplication::screenAt(geometry().center())->size();
 				QSvgRenderer renderer(imgPath);
 				_backgroundImage = new QImage(s, QImage::Format_ARGB32);
 				_backgroundImage->fill(Qt::lightGray); /* background color */
@@ -794,12 +781,12 @@ void MainWindow::onReloadRoomOk()
 				"Note that all clients will be deleted."),
 			QMessageBox::Yes | QMessageBox::No, QMessageBox::Yes);
 	if (ret == QMessageBox::Yes) {
-		disconnect(_reloadWindow->buttonBox(), SIGNAL(accepted()), this, SLOT(onReloadRoomOk()));
-		disconnect(_reloadWindow->buttonBox(), SIGNAL(rejected()), this, SLOT(onReloadRoomCancel()));
+		disconnect(_reloadWindow->buttonBox(), &QDialogButtonBox::accepted, this, &MainWindow::onReloadRoomOk);
+		disconnect(_reloadWindow->buttonBox(), &QDialogButtonBox::rejected, this, &MainWindow::onReloadRoomCancel);
 		// Delete all clients.
-		for (QList<ConnectionFrame*>::iterator it = _clientFrames.begin(); it != _clientFrames.end(); it++) {
-			(*it)->hide();
-			(*it)->deleteLater();
+		for (auto * frame : _clientFrames) {
+			frame->hide();
+			frame->deleteLater();
 		}
 		_clientFrames.clear();
 
@@ -864,9 +851,9 @@ void MainWindow::onButtonTutorToAll()
 		}
 
 		// Set all clients as watchers of tutor. Except for the tutors desired source, which hase to be none
-		for (QList<ConnectionFrame*>::iterator it(_clientFrames.begin()); it != _clientFrames.end(); ++it)
-			if ((*it)->client() != nullptr)
-				(*it)->client()->setDesiredProjectionSource((*it)->client() == getTutorFrame()->client() ? NO_SOURCE : getTutorFrame()->client()->id());
+		for (auto * frame : _clientFrames)
+			if (frame->client() != nullptr)
+				frame->client()->setDesiredProjectionSource(frame->client() == getTutorFrame()->client() ? NO_SOURCE : getTutorFrame()->client()->id());
 
 		disableButtons();
 		_mode = Mode::Broadcast;
@@ -913,7 +900,7 @@ void MainWindow::onButtonTutorToStudent()
 
 		disableButtons();
         int numClients = 0;
-        for (auto c : _clientFrames) {
+        for (auto * c : _clientFrames) {
             if (c->client() != nullptr && c->client()->desiredProjectionSource() == sourceClient->id()) {
                 numClients++;
             }
@@ -1035,10 +1022,10 @@ void MainWindow::onButtonLockSingle()
 		client->lockScreen(newState);
 		if (!newState) {
 			// If no more clients are locked, reset button
-			for (QList<ConnectionFrame*>::iterator it(_clientFrames.begin()); it != _clientFrames.end(); ++it) {
-				if ((*it)->client() == nullptr)
+			for (auto * frame : _clientFrames) {
+				if (frame->client() == nullptr)
 					continue;
-				if ((*it)->client()->isLocked())
+				if (frame->client()->isLocked())
 					return;
 			}
 			ui->action_Lock->setChecked(false);
@@ -1089,8 +1076,8 @@ void MainWindow::onButtonSetAsTutor()
  */
 void MainWindow::onClientConnected(Client* client)
 {
-	connect(client, SIGNAL(authenticating(Client*, ClientLogin*)), this, SLOT(onClientAuthenticating(Client*, ClientLogin*)));
-	connect(client, SIGNAL(authenticated(Client*)), this, SLOT(onClientAuthenticated(Client*)));
+	connect(client, &Client::authenticating, this, &MainWindow::onClientAuthenticating);
+	connect(client, &Client::authenticated, this, &MainWindow::onClientAuthenticated);
 }
 
 /**
@@ -1105,7 +1092,7 @@ void MainWindow::onClientConnected(Client* client)
  */
 void MainWindow::onClientAuthenticating(Client* client, ClientLogin* request)
 {
-	disconnect(client, SIGNAL(authenticating(Client*, ClientLogin*)), this, SLOT(onClientAuthenticating(Client*, ClientLogin*)));
+	disconnect(client, &Client::authenticating, this, &MainWindow::onClientAuthenticating);
 	/* copy examMode */
 	client->setExamMode(request->examMode);
 
@@ -1116,8 +1103,8 @@ void MainWindow::onClientAuthenticating(Client* client, ClientLogin* request)
 	int addnum = 1;
 	do {
 		inuse = false;
-		for (QList<ConnectionFrame*>::iterator it(_clientFrames.begin()); it != _clientFrames.end(); ++it) {
-			Client *c = (**it).client();
+		for (auto * frame : _clientFrames) {
+			Client *c = frame->client();
 			if (c == nullptr)
 				continue;
 			if (!c->isAuthed())
@@ -1133,10 +1120,11 @@ void MainWindow::onClientAuthenticating(Client* client, ClientLogin* request)
 			}
 		}
 	} while (inuse && addnum < 100);
-	if (inuse)
+	if (inuse) {
 		request->accept = false;
-	else
+	} else {
 		request->name = check;
+	}
 }
 
 /**
@@ -1151,14 +1139,14 @@ void MainWindow::onClientAuthenticating(Client* client, ClientLogin* request)
  */
 void MainWindow::onClientAuthenticated(Client* client)
 {
-	disconnect(client, SIGNAL(authenticated(Client*)), this, SLOT(onClientAuthenticated(Client*)));
-	connect(client, SIGNAL(vncServerStateChange(Client*)), this, SLOT(onVncServerStateChange(Client*)));
-	connect(client, SIGNAL(vncClientStateChange(Client*)), this, SLOT(onVncClientStateChange(Client*)));
+	disconnect(client, &Client::authenticated, this, &MainWindow::onClientAuthenticated);
+	connect(client, &Client::vncServerStateChange, this, &MainWindow::onVncServerStateChange);
+	connect(client, &Client::vncClientStateChange, this, &MainWindow::onVncClientStateChange);
 	ConnectionFrame *existing = nullptr;
 	ConnectionFrame *cf = nullptr;
-	for (QList<ConnectionFrame*>::iterator it(_clientFrames.begin()); it != _clientFrames.end(); ++it) {
-		if ((*it)->computerId() == client->ip()) {
-			existing = *it;
+	for (auto * frame : _clientFrames) {
+		if (frame->computerId() == client->ip()) {
+			existing = frame;
 		}
 	}
 
@@ -1170,7 +1158,7 @@ void MainWindow::onClientAuthenticated(Client* client)
 	}
 
 	cf->assignClient(client);
-	connect(client, SIGNAL(disconnected()), this, SLOT(clientCountChanged()));
+	connect(client, &Client::disconnected, this, &MainWindow::clientCountChanged);
 	tellClientCurrentSituation(client);
 	clientCountChanged();
 }
@@ -1203,13 +1191,13 @@ void MainWindow::onVncServerStateChange(Client* client)
 		client->lockScreen(false);
 	} else {
 		// VNC server stopped on some client or failed to start - reset local pending projection information
-		for (QList<ConnectionFrame*>::iterator it(_clientFrames.begin()); it != _clientFrames.end(); ++it) {
-			if ((*it)->client() != nullptr) {
-				if ((*it)->client()->desiredProjectionSource() == client->id()) {
-					(*it)->client()->setDesiredProjectionSource(NO_SOURCE);
-					(*it)->client()->stopVncClient();
+		for (auto * frame : _clientFrames) {
+			if (frame->client() != nullptr) {
+				if (frame->client()->desiredProjectionSource() == client->id()) {
+					frame->client()->setDesiredProjectionSource(NO_SOURCE);
+					frame->client()->stopVncClient();
 					if (_mode == Mode::LockedUnicast)
-						(*it)->client()->lockScreen(true);
+						frame->client()->lockScreen(true);
 				}
 			}
 		}
@@ -1250,14 +1238,14 @@ void MainWindow::onVncClientStateChange(Client* client)
 			 * the new connect.
 			 */
 			bool serverHasWatchers = false;
-			for (QList<ConnectionFrame*>::iterator it(_clientFrames.begin()); it != _clientFrames.end(); ++it)
-				if ((*it)->client() != nullptr)
-					if ((*it)->client()->desiredProjectionSource() == client->projectionSource()) {
+			for (auto * frame : _clientFrames)
+				if (frame->client() != nullptr)
+					if (frame->client()->desiredProjectionSource() == client->projectionSource()) {
 						serverHasWatchers = true;
 						break;
 					}
 
-			if ( !serverHasWatchers ) {
+			if (!serverHasWatchers) {
 				Client* c = getClientFromId(client->projectionSource());
 				if (c != nullptr)
 					c->stopVncServer();
diff --git a/src/server/mainwindow/mainwindow.h b/src/server/mainwindow/mainwindow.h
index 86499af..d4967f8 100644
--- a/src/server/mainwindow/mainwindow.h
+++ b/src/server/mainwindow/mainwindow.h
@@ -1,9 +1,7 @@
-#ifndef _MAINWINDOW_H_
-#define _MAINWINDOW_H_
+#ifndef PVS_MAINWINDOW_H_
+#define PVS_MAINWINDOW_H_
 
-#include <QtWidgets>
 #include <QMainWindow>
-#include "../net/client.h"
 
 class SessionNameWindow;
 class ConnectionFrame;
@@ -11,6 +9,11 @@ class ListenServer;
 class DiscoveryListener;
 class HelpWindow;
 class ReloadRoomWindow;
+class ClientLogin;
+class Client;
+class ClickLabel;
+
+class QLabel;
 
 namespace Ui
 {
@@ -27,8 +30,8 @@ class MainWindow : public QMainWindow
 
 public:
 
-	MainWindow(QWidget *parent = 0);
-	~MainWindow();
+	explicit MainWindow(QWidget *parent = nullptr);
+	~MainWindow() override;
 
 	QRect calcFrameGeometry(ConnectionFrame* frame) const;
 
@@ -38,24 +41,17 @@ private:
 	Ui::MainWindow    *ui;
 	SessionNameWindow *_sessionNameWindow;
 	HelpWindow        *_helpWindow;
-	ReloadRoomWindow	*_reloadWindow;
-	QLabel            *_sessionNameLabel;
-	int               _tbIconSize;
-	Qt::ToolBarArea   _tbArea;
+	ReloadRoomWindow  *_reloadWindow;
+	ClickLabel        *_sessionNameLabel;
 	int  _tilesX;
 	int  _tilesY;
 	QImage* _backgroundImage = nullptr;
 	QLabel* _examModeLabel = nullptr;
 
-
-	/* virtual columns to preserve the aspect ratio of the loaded room */
-	int _virtCols;
-	int _virtRows;
-
 	// Button block stuff
 	QTimer              *_buttonLockTimer;
 	QList<QAction*>     _lockingButtons;
-        static const qint64 BUTTON_BLOCK_TIME = 2000;
+	static const qint64 BUTTON_BLOCK_TIME = 2000;
 
 	// Management stuff
 	enum class Mode
@@ -66,19 +62,16 @@ private:
 	    LockedUnicast,
 	    None
 	} _mode;
-	int _streamingSource;
+	int _streamingSource{};
 
 	QList<ConnectionFrame*> _clientFrames;
         QWidget *_dropMarker;
-	ListenServer            *_listenServer;
-	DiscoveryListener       *_discoveryListener;
 
-	int _lastClientCount;
+	int _lastClientCount{};
 
-        QPoint closestFreeSlot(const QPoint preferredPixels, const ConnectionFrame* toIgnore);
+	QPoint closestFreeSlot(const QPoint &preferredPixels, const ConnectionFrame* toIgnore);
 	void placeFrameInFreeSlot(ConnectionFrame* frame, QPoint preferred = QPoint(-1, -1));
 	ConnectionFrame* createFrame(const QString &computerId = QString(), const QPoint *gridPosition = nullptr, bool fromRoomplan = false);
-	void savePosition(ConnectionFrame *cf);
 	void startVncServerIfNecessary(int from);
 	void tellClientCurrentSituation(Client* client);
 	void reset(bool lock = false);
@@ -86,19 +79,19 @@ private:
 	ConnectionFrame* getTutorFrame();
 	ConnectionFrame* getSelectedFrame();
 
-	void closeEvent(QCloseEvent *e);
-	void changeEvent(QEvent *e);
-	void resizeEvent(QResizeEvent *e);
-	void mouseReleaseEvent(QMouseEvent* e);
+	void closeEvent(QCloseEvent *e) override;
+	void changeEvent(QEvent *e) override;
+	void resizeEvent(QResizeEvent *e) override;
+	void mouseReleaseEvent(QMouseEvent* e) override;
 
 	int getTileWidthPx() const;
 	int getTileHeightPx() const;
 
-        void updateContextButtonStates();
+	void updateContextButtonStates();
 
 	void reloadCurrentRoom();
 
-        void vncOneOnOne(bool exclusive);
+	void vncOneOnOne(bool exclusive);
 
 protected slots:
 	void disableButtons();
@@ -126,8 +119,8 @@ protected slots:
 	void onButtonExit();
 	void onButtonHelp();
 	// connection frame
-        void onFrameMoving(ConnectionFrame* frame);
-        void onFrameDropped(ConnectionFrame* frame);
+	void onFrameMoving(ConnectionFrame* frame);
+	void onFrameDropped(ConnectionFrame* frame);
 	void onFrameClicked(ConnectionFrame* frame);
 	// Net
 	void onClientConnected(Client* client);
diff --git a/src/server/net/certmanager.cpp b/src/server/net/certmanager.cpp
index 5d8d824..968535a 100644
--- a/src/server/net/certmanager.cpp
+++ b/src/server/net/certmanager.cpp
@@ -18,19 +18,20 @@
 #define CERTSTORAGE ".config/openslx/pvs2/"
 
 #include "certmanager.h"
-#include <QMap>
+#include "../../shared/util.h"
+
+#include <QHash>
 #include <QDir>
 #include <QDebug>
 #include <QFileInfo>
-#include <QSettings>
 #include <QMessageBox>
-#include <QApplication>
-#include <cstdlib>
+#include <QProcess>
+#include <QCoreApplication>
 
 namespace CertManager
 {
-static QMap<QString, QSslCertificate> _certs;
-static QMap<QString, QSslKey> _keys;
+static QHash<QString, QSslCertificate> _certs;
+static QHash<QString, QSslKey> _keys;
 
 static void generateFiles(QString& key, QString& cert);
 static bool loadFiles(QString& keyFile, QString& certFile, QSslKey &key, QSslCertificate &cert);
@@ -44,7 +45,7 @@ bool getPrivateKeyAndCert(const QString &name, QSslKey &key, QSslCertificate &ce
 	}
 	QString certDir = QDir::homePath().append("/").append(CERTSTORAGE);
 	if (!QDir::root().mkpath(certDir)) {
-		certDir = QString("/tmp/") + QString::number(qrand()) + "-" + QString::number(qrand()) + "/";
+		certDir = QString("/tmp/") + QString::number(slxrand()) + "-" + QString::number(slxrand()) + "/";
 		QDir::root().mkpath(certDir);
 	}
 	QString certFile = certDir.append(name);
@@ -66,11 +67,11 @@ bool getPrivateKeyAndCert(const QString &name, QSslKey &key, QSslCertificate &ce
 
 void fatal()
 {
-	QMessageBox::critical(nullptr, QCoreApplication::trUtf8("OpenSSL error", "CertManager"),
-			QCoreApplication::trUtf8("Could not generate certificates for secure connections.\n"
+	QMessageBox::critical(nullptr, QObject::tr("OpenSSL error", "CertManager"),
+			QObject::tr("Could not generate certificates for secure connections.\n"
 			"PVS will not work.\n\n"
 			"Press OK to quit.", "CertManager"));
-	qApp->exit(1);
+	QCoreApplication::exit(1);
 }
 
 static bool loadFiles(QString& keyFile, QString& certFile, QSslKey &key, QSslCertificate &cert)
@@ -95,14 +96,18 @@ static bool loadFiles(QString& keyFile, QString& certFile, QSslKey &key, QSslCer
 
 static void generateFiles(QString& key, QString& cert)
 {
-	char tmp[1000];
-	remove(key.toLocal8Bit().data());
-	remove(cert.toLocal8Bit().data());
-	snprintf(tmp, 1000,
-			 "openssl req -x509 -nodes -days 5000 -newkey rsa:4096 -subj '/C=DE/ST=BaWue/L=Freiburg/CN=openslx.org' -keyout \"%s\" -out \"%s\"",
-			 key.toLocal8Bit().data(), cert.toLocal8Bit().data());
-	system(tmp);
-	snprintf(tmp, 1000, "chmod 0600 \"%s\" \"%s\"", key.toLocal8Bit().data(), cert.toLocal8Bit().data());
-	system(tmp);
+	QProcess p;
+	QFile::remove(key);
+	QFile::remove(cert);
+	p.setProcessChannelMode(QProcess::ForwardedChannels);
+	p.start(QStringLiteral("openssl"), {
+		"req", "-x509", "-nodes", "-days", "5000", "-newkey", "rsa:4096",
+		"-subj", "'/C=DE/ST=BaWue/L=Freiburg/CN=openslx.org'",
+		"-keyout", key, "-out", cert
+	});
+	p.waitForFinished();
+	p.start(QStringLiteral("chmod"), { "0600", key, cert });
+	p.waitForFinished(500);
 }
+
 }
diff --git a/src/server/net/client.cpp b/src/server/net/client.cpp
index 977eb84..08dfc9a 100644
--- a/src/server/net/client.cpp
+++ b/src/server/net/client.cpp
@@ -9,46 +9,46 @@
 #include "../serverapp/serverapp.h"
 #include "../../shared/settings.h"
 #include "../../shared/util.h"
+
 #include <QPixmap>
 #include <cassert>
 #include <QNetworkInterface>
+#include <QTcpSocket>
+#include <QSslSocket>
 
 #define CHALLENGE_LEN 20
 
 int Client::_clientIdCounter = 0;
-Client::Client(QTcpSocket* socket) : _socket(socket)
+Client::Client(QTcpSocket* socket)
+		: _socket(socket)
 {
 	assert(socket != nullptr);
-	_authed = 0;
-	_projectionSource = 0;
 	_desiredSource = NO_SOURCE;
-	_isActiveVncClient = false;
-	_vncPort = 0;
-	_isTutor = false;
-	_locked = false;
-	_wantsAttention = false;
-
+	_socket->setParent(this);
 	_id = ++_clientIdCounter;
 	//_ip = _socket->peerAddress().toString();
 	qDebug("*** Client %s created.", qPrintable(_socket->peerAddress().toString()));
 	// Connect important signals
-	connect(_socket, SIGNAL(disconnected()),
-	        this, SLOT(disconnect()));
-	connect(_socket, SIGNAL(error(QAbstractSocket::SocketError)),
-	        this, SLOT(disconnect()));
-	connect(_socket, SIGNAL(sslErrors(const QList<QSslError> &)),
-	        this, SLOT(disconnect()));
-	connect(_socket, SIGNAL(readyRead()),
-	        this, SLOT(onDataArrival()));
+	connect(_socket, &QTcpSocket::disconnected,
+	        this, &Client::disconnect);
+	connect(_socket, &QTcpSocket::errorOccurred,
+	        this, &Client::disconnect);
+	auto *ssl = qobject_cast<QSslSocket*>(_socket);
+	if (ssl != nullptr) {
+		connect(ssl, QOverload<const QList<QSslError> &>::of(&QSslSocket::sslErrors),
+				this, &Client::disconnect);
+	}
+	connect(_socket, &QTcpSocket::readyRead,
+	        this, &Client::onDataArrival);
 	// Send challenge
 	_challenge.resize(CHALLENGE_LEN);
 	for (int i = 0; i < CHALLENGE_LEN; ++i) {
-		_challenge[i] = char(qrand() & 0xff);
+		_challenge[i] = char(slxrand() & 0xff);
 	}
-	NetworkMessage msgChlng;
-	msgChlng.setField(_ID, _CHALLENGE);
-	msgChlng.setField(_CHALLENGE, _challenge);
-	msgChlng.writeMessage(_socket);
+	NetworkMessage msgChallenge;
+	msgChallenge.setField(_ID, _CHALLENGE);
+	msgChallenge.setField(_CHALLENGE, _challenge);
+	msgChallenge.writeMessage(_socket);
 	// give client 3 seconds to complete handshake
 	_timerIdAuthTimeout = startTimer(3000);
 	_timerPingTimeout = startTimer(3000);
@@ -58,7 +58,6 @@ Client::Client(QTcpSocket* socket) : _socket(socket)
 Client::~Client()
 {
 	qDebug() << "*** Client"  << _host  << " destroyed.";
-	_socket->deleteLater();
 }
 
 void Client::timerEvent(QTimerEvent* event)
@@ -302,7 +301,7 @@ void Client::stopVncClient()
  * Checks if client and manager runs on same machine.
  * @return Return true, if pvsmanager is running on client.
  */
-bool Client::isManagerMachine()
+bool Client::isManagerMachine() const
 {
 	foreach (const QHostAddress & address, QNetworkInterface::allAddresses())
 	if (address != QHostAddress(QHostAddress::LocalHost)
@@ -334,3 +333,8 @@ void Client::disconnect()
 	this->deleteLater();
 	emit disconnected();
 }
+
+QString Client::ip() const
+{
+	return _socket->peerAddress().toString();
+}
diff --git a/src/server/net/client.h b/src/server/net/client.h
index 3d5158b..3b95321 100644
--- a/src/server/net/client.h
+++ b/src/server/net/client.h
@@ -1,13 +1,13 @@
 #ifndef CLIENT_H_
 #define CLIENT_H_
 
-#include <QtCore>
-#include <QHostAddress>
-#include <QAbstractSocket>
-#include <QTcpSocket>
 #include "../../shared/networkmessage.h"
 
+#include <QByteArray>
+
 //class QSslSocket;
+class QTcpSocket;
+class Client;
 
 #define NO_SOURCE 0
 
@@ -26,32 +26,32 @@ class Client : public QObject
 
 public:
 	explicit Client(QTcpSocket* socket);
-	~Client();
+	~Client() override;
 
 	// Getters
-        inline bool     isAuthed() const { return _authed == 2; }
-	inline const QString& name() const { return _name; }
-	inline const QString& host() const { return _host; }
-	inline const QString  ip() const { return _socket->peerAddress().toString(); }
-        inline int      id() const { return _id; }
-        inline bool     isActiveVncClient() const { return _isActiveVncClient; }
-        inline bool     isActiveVncServer() const { return _vncPort > 0; }
-        inline bool     isLocked() const { return _locked; }
-        inline int      desiredProjectionSource() const { return _desiredSource; }
-        inline int      projectionSource() const { return _projectionSource; }
-        inline int      isExamMode() const { return _isExamMode; }
-        inline bool     wantsAttention() const { return _wantsAttention; }
-	inline void     removeAttention() { if (!_wantsAttention) return; removeAttentionInternal(); }
+	bool     isAuthed() const { return _authed == 2; }
+	const QString& name() const { return _name; }
+	const QString& host() const { return _host; }
+	QString  ip() const;
+	int      id() const { return _id; }
+	bool     isActiveVncClient() const { return _isActiveVncClient; }
+	bool     isActiveVncServer() const { return _vncPort > 0; }
+	bool     isLocked() const { return _locked; }
+	int      desiredProjectionSource() const { return _desiredSource; }
+	int      projectionSource() const { return _projectionSource; }
+	int      isExamMode() const { return _isExamMode; }
+	bool     wantsAttention() const { return _wantsAttention; }
+	void     removeAttention() { if (!_wantsAttention) return; removeAttentionInternal(); }
 
 	// Setters
-        inline void setTutor(bool enable) { _isTutor = enable; }
-	inline void setDesiredProjectionSource(int id) {_desiredSource = id;}
-	inline void setExamMode(bool mode) { _isExamMode = mode; }
+	void setTutor(bool enable) { _isTutor = enable; }
+	void setDesiredProjectionSource(int id) { _desiredSource = id; }
+	void setExamMode(bool mode) { _isExamMode = mode; }
 
 	//Send message stuff
 	void startVncServer();
 	void stopVncServer();
-	void startVncClient(Client const * const to );
+	void startVncClient(const Client * to);
 	void stopVncClient();
 	void lockScreen(bool);
 	void requestThumb(const QSize& size);
@@ -59,8 +59,8 @@ public:
 private:
 
 	QTcpSocket * const _socket;
-	bool           _locked;
-	int            _authed; // 0 = challenge sent, awaiting reply 1 = challenge ok, client challenge replied, awaiting login, 2 = ESTABLISHED
+	bool           _locked{};
+	int            _authed{}; // 0 = challenge sent, awaiting reply 1 = challenge ok, client challenge replied, awaiting login, 2 = ESTABLISHED
 	QString        _name;
 	QString        _host;
 	QByteArray     _challenge;
@@ -69,26 +69,26 @@ private:
 	int            _timerIdAuthTimeout, _timerPingTimeout;
 	int            _id; // this client's unique id
 	QString        _vncRwPass, _vncRoPass;
-	int            _vncPort; // VNCserver state. Greater 0 -> active on this port. Equals 0 -> no server.
+	int            _vncPort{}; // VNCserver state. Greater 0 -> active on this port. Equals 0 -> no server.
 	int            _desiredSource; // The source the client shall be connected to
-	int            _projectionSource; // The source the client was or is connected to (depends on _isActiveVncClient)
-	bool           _isActiveVncClient; // VNCclient state. indicating that the client is displaying a remote screen via VNC
-	bool           _isTutor; // Flag indicating that the client has been set as a tutor
-	bool		      _isExamMode;
-	bool           _wantsAttention; // Flag telling whether the client activated the "i want attention" button
+	int            _projectionSource{}; // The source the client was or is connected to (depends on _isActiveVncClient)
+	bool           _isActiveVncClient{}; // VNCclient state. indicating that the client is displaying a remote screen via VNC
+	bool           _isTutor{}; // Flag indicating that the client has been set as a tutor
+	bool           _isExamMode{};
+	bool           _wantsAttention{}; // Flag telling whether the client activated the "i want attention" button
 	QByteArray     _rawRemoteScreen;
 
 
 	static int     _clientIdCounter;
 
-	bool isManagerMachine();
+	bool isManagerMachine() const;
 
 	void handleMsg();
 	void sendMessage(NetworkMessage& message);
 	void removeAttentionInternal();
 
 protected:
-	void timerEvent(QTimerEvent* event);
+	void timerEvent(QTimerEvent* event) override;
 
 signals:
 	void authenticating(Client* client, ClientLogin* request);
diff --git a/src/server/net/discoverylistener.cpp b/src/server/net/discoverylistener.cpp
index b0f0df4..d644259 100644
--- a/src/server/net/discoverylistener.cpp
+++ b/src/server/net/discoverylistener.cpp
@@ -29,23 +29,20 @@
 /**
  * @brief DiscoveryListener::DiscoveryListener
  */
-DiscoveryListener::DiscoveryListener() :
-	_socket(this), _counterResetPos(0)
+DiscoveryListener::DiscoveryListener(QObject *parent)
+		: _socket(this)
 {
-	if (!_socket.bind(QHostAddress::AnyIPv4, SERVICE_DISCOVERY_PORT))
+	if (!_socket.bind(QHostAddress::AnyIPv4, SERVICE_DISCOVERY_PORT)) {
 		qFatal("Could not bind to service discovery port %d", int(SERVICE_DISCOVERY_PORT));
-	connect(&_socket, SIGNAL(readyRead()), this, SLOT(onReadyRead()));
-	for (int i = 0; i < SD_PACKET_TABLE_SIZE; ++i)
-		_packetCounter[i] = 0;
+	}
+	connect(&_socket, &QUdpSocket::readyRead, this, &DiscoveryListener::onReadyRead);
 	startTimer((SPAM_MODERATE_AT_ONCE * SPAM_MODERATE_INTERVAL) / SD_PACKET_TABLE_SIZE + 1);
 }
 
 /**
  * @brief DiscoveryListener::~DiscoveryListener
  */
-DiscoveryListener::~DiscoveryListener()
-{
-}
+DiscoveryListener::~DiscoveryListener() = default;
 
 /**
  * @brief hash
@@ -57,8 +54,8 @@ static quint16 hash(const QHostAddress& host)
 	static quint16 seed1 = 0, seed2 = 0;
 	while (seed1 == 0) { // Make sure the algorithm uses different seeds each time the program is
 		// run to prevent hash collision attacks
-		seed1 = quint16(qrand() & 0xffff);
-		seed2 = quint16(qrand() & 0xffff);
+		seed1 = quint16(slxrand() & 0xffff);
+		seed2 = quint16(slxrand() & 0xffff);
 	}
 	quint8 data[16], len;
 	if (host.protocol() == QAbstractSocket::IPv4Protocol) {
@@ -79,8 +76,8 @@ static quint16 hash(const QHostAddress& host)
 	} else {
 		// Durr?
 		len = 2;
-		data[0] = quint8(qrand());
-		data[1] = quint8(qrand());
+		data[0] = quint8(slxrand());
+		data[1] = quint8(slxrand());
 	}
 	quint16 result = 0;
 	quint16 mod = seed1;
diff --git a/src/server/net/discoverylistener.h b/src/server/net/discoverylistener.h
index 64d4351..47a4295 100644
--- a/src/server/net/discoverylistener.h
+++ b/src/server/net/discoverylistener.h
@@ -8,12 +8,14 @@
 #ifndef DISCOVERYLISTENER_H_
 #define DISCOVERYLISTENER_H_
 
-#include <QtCore>
+#include <QObject>
 #include <QUdpSocket>
 #include "../../shared/networkmessage.h"
 
 #define SD_PACKET_TABLE_SIZE 20000
 
+class QTimerEvent;
+
 class DiscoveryListener : public QObject
 {
 	Q_OBJECT
@@ -21,16 +23,16 @@ class DiscoveryListener : public QObject
 private:
 	QUdpSocket _socket;
 	NetworkMessage _packet;
-	int _counterResetPos;
+	int _counterResetPos{};
 
-	quint8 _packetCounter[SD_PACKET_TABLE_SIZE]; // count packets per source address to ignore spammers
+	quint8 _packetCounter[SD_PACKET_TABLE_SIZE]{}; // count packets per source address to ignore spammers
 
 protected:
-	void timerEvent(QTimerEvent* event);
+	void timerEvent(QTimerEvent* event) override;
 
 public:
-	DiscoveryListener();
-	virtual ~DiscoveryListener();
+	explicit DiscoveryListener(QObject *parent);
+	~DiscoveryListener() override;
 
 private slots:
 	void onReadyRead();
diff --git a/src/server/net/filedownloader.cpp b/src/server/net/filedownloader.cpp
deleted file mode 100644
index b930869..0000000
--- a/src/server/net/filedownloader.cpp
+++ /dev/null
@@ -1,41 +0,0 @@
-/*
- * FileDownloader.cpp
- *
- *  Created on: Mar 7, 2014
- *      Author: nils
- */
-
-#include <QFileInfo>
-
-#include "filedownloader.h"
-
-FileDownloader::FileDownloader(QObject *parent) :
-	QObject(parent)
-{
-	connect(&m_WebCtrl, SIGNAL(finished(QNetworkReply*)),
-	        SLOT(fileDownloaded(QNetworkReply*)));
-}
-
-FileDownloader::~FileDownloader()
-{
-
-}
-
-void FileDownloader::connectSlot(QObject* obj, const char* slot)
-{
-	QObject::connect(this, SIGNAL(downloaded(QByteArray&)),
-	                 obj, slot);
-}
-
-void FileDownloader::fileDownloaded(QNetworkReply* pReply)
-{
-	QByteArray downloadedData = pReply->readAll();
-	//emit a signal
-	pReply->deleteLater();
-	emit downloaded(downloadedData);
-}
-
-void FileDownloader::downloadFile(const QUrl& fileUrl)
-{
-	m_WebCtrl.get(QNetworkRequest(fileUrl));
-}
diff --git a/src/server/net/filedownloader.h b/src/server/net/filedownloader.h
deleted file mode 100644
index 227af50..0000000
--- a/src/server/net/filedownloader.h
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- * filedownloader.h
- *
- *  Created on: Mar 7, 2014
- *      Author: nils
- */
-
-#ifndef FILEDOWNLOADER_H_
-#define FILEDOWNLOADER_H_
-
-#include <QObject>
-#include <QByteArray>
-#include <QNetworkAccessManager>
-#include <QNetworkRequest>
-#include <QNetworkReply>
-
-class FileDownloader : public QObject
-{
-	Q_OBJECT
-public:
-	explicit FileDownloader(QObject *parent = 0);
-
-	virtual ~FileDownloader();
-
-	void downloadFile(const QUrl& fileUrl);
-
-	void connectSlot(QObject* obj, const char* slot);
-
-	QByteArray downloadedData() const;
-
-signals:
-	void downloaded(QByteArray& downloadedData);
-
-private slots:
-
-	void fileDownloaded(QNetworkReply* pReply);
-
-private:
-
-	QNetworkAccessManager m_WebCtrl;
-
-};
-
-#endif /* FILEDOWNLOADER_H_ */
diff --git a/src/server/net/listenserver.cpp b/src/server/net/listenserver.cpp
index 0438fb4..27a1412 100644
--- a/src/server/net/listenserver.cpp
+++ b/src/server/net/listenserver.cpp
@@ -1,18 +1,20 @@
 #include "listenserver.h"
 #include "client.h"
+
 #include <QSslSocket>
 
-#define MAX_CLIENTS 50
 /**
  * Initialize listenServer to listen on specific port.
  * And connect Signal newConnection() with Slot newClientConnection().
  * @param port
  */
-ListenServer::ListenServer(quint16 port)
+ListenServer::ListenServer(quint16 port, QObject *parent)
+		: QObject(parent)
+		, _server(this)
 {
 	if (!_server.listen(QHostAddress::AnyIPv4, port) || !_server.isListening())
 		qFatal("Cannot bind to TCP port %d (incoming SSL clients)", int(port));
-	connect(&_server, SIGNAL(newConnection()), this, SLOT(newClientConnection()));
+	connect(&_server, &SslServer::newConnection, this, &ListenServer::newClientConnection);
 }
 
 ListenServer::~ListenServer()
@@ -32,7 +34,7 @@ void ListenServer::newClientConnection()
 {
 	QTcpSocket* sock;
 	while ((sock = _server.nextPendingConnection()) != nullptr) {
-		Client* client = new Client(sock); // TODO: what happens with disconnected clients
+		auto* client = new Client(sock); // TODO: what happens with disconnected clients
 		emit newClient(client);
 	}
 }
diff --git a/src/server/net/listenserver.h b/src/server/net/listenserver.h
index 640da23..4ad363d 100644
--- a/src/server/net/listenserver.h
+++ b/src/server/net/listenserver.h
@@ -18,8 +18,8 @@ private:
 	SslServer _server;
 
 public:
-	explicit ListenServer(quint16 port);
-	virtual ~ListenServer();
+	explicit ListenServer(quint16 port, QObject *parent);
+	~ListenServer() override;
 
 private slots:
 	void newClientConnection();
diff --git a/src/server/net/sslserver.cpp b/src/server/net/sslserver.cpp
index b2da034..2dfa84c 100644
--- a/src/server/net/sslserver.cpp
+++ b/src/server/net/sslserver.cpp
@@ -21,7 +21,9 @@
 #include "certmanager.h"
 #include <unistd.h>
 
-SslServer::SslServer() : QTcpServer(nullptr), _timer(new QTimer(this))
+SslServer::SslServer(QObject *parent)
+		: QTcpServer(parent)
+		, _timer(new QTimer(this))
 {
 	connect(_timer, &QTimer::timeout, [=]() {
 		if (_pending.empty())
@@ -43,9 +45,11 @@ SslServer::SslServer() : QTcpServer(nullptr), _timer(new QTimer(this))
 SslServer::~SslServer()
 {
 	_timer->stop();
-	for (QSslSocket *sock : _pending.keys()) {
+	auto keys = _pending.keys();
+	for (QSslSocket *sock : keys) {
 		sock->deleteLater();
 	}
+	_pending.clear();
 }
 
 /**
@@ -64,7 +68,7 @@ void SslServer::incomingConnection(qintptr socketDescriptor)
 		::close(int(socketDescriptor));
 		return;
 	}
-	QSslSocket *serverSocket = new QSslSocket(nullptr);
+	auto *serverSocket = new QSslSocket(nullptr);
 	connect(serverSocket, QOverload<const QList<QSslError> &>::of(&QSslSocket::sslErrors), this, &SslServer::sslErrors);
 	serverSocket->setPrivateKey(key);
 	serverSocket->setLocalCertificate(cert);
@@ -93,8 +97,8 @@ void SslServer::incomingConnection(qintptr socketDescriptor)
 void SslServer::sslErrors(const QList<QSslError>& errors)
 {
 	qDebug() << "Client caused sslErrors before connection:";
-	for (QList<QSslError>::const_iterator it = errors.begin(); it != errors.end(); it++) {
-		qDebug() << it->errorString();
+	for (const auto & error : errors) {
+		qDebug() << error.errorString();
 	}
 
 }
diff --git a/src/server/net/sslserver.h b/src/server/net/sslserver.h
index 03d947a..c74e56c 100644
--- a/src/server/net/sslserver.h
+++ b/src/server/net/sslserver.h
@@ -35,11 +35,11 @@ private slots:
 	void sslErrors ( const QList<QSslError> & errors );
 
 public:
-	explicit SslServer();
-	virtual ~SslServer();
+	explicit SslServer(QObject *parent);
+	~SslServer() override;
 
 protected:
-	void incomingConnection(qintptr handle);
+	void incomingConnection(qintptr handle) override;
 	QHash<QSslSocket*, qint64> _pending; // Queue for connected but unencrypted connections
 	QTimer* _timer;
 };
diff --git a/src/server/numerickeyboard/numerickeyboard.cpp b/src/server/numerickeyboard/numerickeyboard.cpp
index d819a58..e6677aa 100644
--- a/src/server/numerickeyboard/numerickeyboard.cpp
+++ b/src/server/numerickeyboard/numerickeyboard.cpp
@@ -1,10 +1,5 @@
-#include "src/server/numerickeyboard/numerickeyboard.h"
+#include "numerickeyboard.h"
 #include "ui_numerickeyboard.h"
-#include <iostream>
-
-using std::cout;
-using std::endl;
-
 
 NumericKeyboard::NumericKeyboard(QWidget *parent) :
 	QGroupBox(parent),
@@ -12,20 +7,20 @@ NumericKeyboard::NumericKeyboard(QWidget *parent) :
 {
 	ui->setupUi(this);
 	/* das geht leider nicht ? */
-//    connect(ui->button_0, SIGNAL (clicked(bool)), this, SLOT (relayDigit(0)));
+//    connect(ui->button_0, &QPushButton::clicked, this, &NumericKeyboard::relayDigit);
 
-	connect(ui->button_0, SIGNAL (clicked(bool)), this, SLOT (relayDigit0()));
-	connect(ui->button_1, SIGNAL (clicked(bool)), this, SLOT (relayDigit1()));
-	connect(ui->button_2, SIGNAL (clicked(bool)), this, SLOT (relayDigit2()));
-	connect(ui->button_3, SIGNAL (clicked(bool)), this, SLOT (relayDigit3()));
-	connect(ui->button_4, SIGNAL (clicked(bool)), this, SLOT (relayDigit4()));
-	connect(ui->button_5, SIGNAL (clicked(bool)), this, SLOT (relayDigit5()));
-	connect(ui->button_6, SIGNAL (clicked(bool)), this, SLOT (relayDigit6()));
-	connect(ui->button_7, SIGNAL (clicked(bool)), this, SLOT (relayDigit7()));
-	connect(ui->button_8, SIGNAL (clicked(bool)), this, SLOT (relayDigit8()));
-	connect(ui->button_9, SIGNAL (clicked(bool)), this, SLOT (relayDigit9()));
+	connect(ui->button_0, &QPushButton::clicked, this, &NumericKeyboard::relayDigit0);
+	connect(ui->button_1, &QPushButton::clicked, this, &NumericKeyboard::relayDigit1);
+	connect(ui->button_2, &QPushButton::clicked, this, &NumericKeyboard::relayDigit2);
+	connect(ui->button_3, &QPushButton::clicked, this, &NumericKeyboard::relayDigit3);
+	connect(ui->button_4, &QPushButton::clicked, this, &NumericKeyboard::relayDigit4);
+	connect(ui->button_5, &QPushButton::clicked, this, &NumericKeyboard::relayDigit5);
+	connect(ui->button_6, &QPushButton::clicked, this, &NumericKeyboard::relayDigit6);
+	connect(ui->button_7, &QPushButton::clicked, this, &NumericKeyboard::relayDigit7);
+	connect(ui->button_8, &QPushButton::clicked, this, &NumericKeyboard::relayDigit8);
+	connect(ui->button_9, &QPushButton::clicked, this, &NumericKeyboard::relayDigit9);
 
-	connect(ui->button_del, SIGNAL (clicked(bool)), this, SLOT(relayDelete()));
+	connect(ui->button_del, &QPushButton::clicked, this, &NumericKeyboard::relayDelete);
 }
 
 NumericKeyboard::~NumericKeyboard()
diff --git a/src/server/numerickeyboard/numerickeyboard.h b/src/server/numerickeyboard/numerickeyboard.h
index 3ece99c..6db3de3 100644
--- a/src/server/numerickeyboard/numerickeyboard.h
+++ b/src/server/numerickeyboard/numerickeyboard.h
@@ -14,7 +14,7 @@ class NumericKeyboard : public QGroupBox
 
 public:
 	explicit NumericKeyboard(QWidget *parent = 0);
-	~NumericKeyboard();
+	~NumericKeyboard() override;
 
 private:
 	Ui::NumericKeyboard *ui;
diff --git a/src/server/reloadroomwindow/reloadroomwindow.h b/src/server/reloadroomwindow/reloadroomwindow.h
index 2baf53f..67c2a94 100644
--- a/src/server/reloadroomwindow/reloadroomwindow.h
+++ b/src/server/reloadroomwindow/reloadroomwindow.h
@@ -16,7 +16,7 @@ class ReloadRoomWindow : public QDialog
 
 public:
 	explicit ReloadRoomWindow(QWidget *parent = nullptr);
-	~ReloadRoomWindow();
+	~ReloadRoomWindow() override;
 
     QDialogButtonBox* buttonBox() const;
 
diff --git a/src/server/serverapp/serverapp.cpp b/src/server/serverapp/serverapp.cpp
index 2cc237a..933517b 100644
--- a/src/server/serverapp/serverapp.cpp
+++ b/src/server/serverapp/serverapp.cpp
@@ -1,15 +1,15 @@
 #include <QTranslator>
 #include <QNetworkInterface>
+#include <QSettings>
+#include <QLibraryInfo>
 
 #include "serverapp.h"
+#include "../../shared/util.h"
 
 static QSize minimalGridSize(const QMap<QString, QPoint>& clientPositions, QSize& clientSize);
 
 ServerApp::ServerApp(int& argc, char** argv)
-	: QApplication(argc, argv),
-		_mainWindow(nullptr),
-		_managerOnly(false),
-		_isExam(false)
+	: QApplication(argc, argv)
 {
 	setOrganizationName("openslx");
 	setOrganizationDomain("openslx.org");
@@ -22,19 +22,19 @@ ServerApp::ServerApp(int& argc, char** argv)
 	// If started in manager-only mode, and there is no current room
 	// after reading the config, exit right away
 	if (_managerOnly && _currentRoom == "") {
-		::exit(0);
+		QApplication::exit(0);
 		return;
 	}
 
 	// System strings
-	QTranslator *qtTranslator = new QTranslator(this);
+	auto *qtTranslator = new QTranslator(this);
 	if (!qtTranslator->load(QLocale::system(), "qt", "_", QLibraryInfo::location(QLibraryInfo::TranslationsPath))) {
 		qDebug() << "Loading system translations failed" << QLibraryInfo::location(QLibraryInfo::TranslationsPath);
 	} else {
 		installTranslator(qtTranslator);
 	}
 	// App specific
-	QTranslator *translator = new QTranslator(this);
+	auto *translator = new QTranslator(this);
 	if (!translator->load(QLocale::system(), ":", "l_")) {
 		qDebug() << "Loading app translations failed";
 	} else {
@@ -43,20 +43,20 @@ ServerApp::ServerApp(int& argc, char** argv)
 
 	/* Set the global path of the settings */
 	QSettings::setPath(QSettings::IniFormat, QSettings::SystemScope, "/opt/");
-	QSharedPointer<QSettings> sys = getSettings();
+	QSettings* sys = getSettings();
 	qDebug() << "System settings are in:" << sys->fileName();
 
-	_mainWindow = new MainWindow();
+	new MainWindow();
 }
 
 QStringList ServerApp::parseParameters()
 {
 	QStringList rest;
-	for (QString a : QApplication::arguments()) {
-		if (a == "--manager-only") {
+	for (const QString& a : QApplication::arguments()) {
+		if (a == QStringLiteral("--manager-only")) {
 			_managerOnly = true;
 			break;
-		} else if (a.startsWith("--config=")) {
+		} else if (a.startsWith(QStringLiteral("--config="))) {
 			_iniPath = a.mid(9);
 		} else {
 			rest << a;
@@ -73,17 +73,20 @@ QStringList ServerApp::arguments()
 
 void ServerApp::loadRooms()
 {
-	QSharedPointer<QSettings> conf = getSettings();
+	QSettings* conf = getSettings();
 
-	if (!conf->contains("rooms")) { qDebug() << "Invalid config file (no rooms are set)!"; return; }
+	if (!conf->contains(QStringLiteral("rooms"))) {
+		qDebug() << "Invalid config file (no rooms are set)!";
+		return;
+	}
 	QStringList rooms = conf->value("rooms").toStringList();
 
-	for (QString roomId : rooms) {
+	for (const QString& roomId : rooms) {
 		conf->beginGroup(roomId);
 		QString roomName = conf->value("name").toString();
 
 		/* fallback to the old format where the room id was actually just the name */
-		if (roomName == "") {
+		if (roomName.isEmpty()) {
 			roomName = roomId;
 		}
 		if (!conf->contains("mgrIP")) {
@@ -114,8 +117,8 @@ void ServerApp::loadRooms()
 		}
 
 		foreach (const QHostAddress & address, QNetworkInterface::allAddresses()) {
-			if (address != QHostAddress(QHostAddress::LocalHost) && mgrIP == address.toString()) {
-				qDebug("Found this ip in config.");
+			if (!address.isBroadcast() && !address.isLoopback() && !address.isMulticast() && mgrIP == address.toString()) {
+				qDebug() << "Found own ip in config.";
 				_currentRoom = roomName;
 			}
 		}
@@ -133,18 +136,17 @@ void ServerApp::loadRooms()
 	}
 }
 
-const Room* ServerApp::getCurrentRoom()
+const Room* ServerApp::getCurrentRoom() const
 {
-	if (_rooms.contains(_currentRoom)) {
-		return _rooms[_currentRoom];
-	} else {
-		static Room* defaultRoom = nullptr;
-		if (defaultRoom == nullptr) {
-			defaultRoom = new Room(QMap<QString,
-			                       QPoint>(), QSize(8, 6), QSize(1, 1), "", "");
-		}
-		return defaultRoom;
+	auto *room = _rooms.value(_currentRoom);
+	if (room != nullptr)
+		return room;
+	static Room* defaultRoom = nullptr;
+	if (defaultRoom == nullptr) {
+		defaultRoom = new Room(QMap<QString,
+							   QPoint>(), QSize(8, 6), QSize(1, 1), "", "");
 	}
+	return defaultRoom;
 }
 void ServerApp::setSessionName(const QString& name)
 {
@@ -154,20 +156,20 @@ void ServerApp::setSessionName(const QString& name)
 
 void ServerApp::setSessionName()
 {
-	const QString name = QString::number(qrand() % 9000 + 1000);
+	const QString name = QString::number(slxrand() % 9000 + 1000);
 	_sessionName = name;
 	_sessionNameArray = name.toUtf8();
 }
 
-QSharedPointer<QSettings> ServerApp::getSettings()
+QSettings * ServerApp::getSettings()
 {
-	QSharedPointer<QSettings> set;
-	if (_iniPath == "") {
+	QSettings *set;
+	if (_iniPath.isEmpty()) {
 		/* default location (system scope) */
-		set = QSharedPointer<QSettings>(new QSettings(QSettings::IniFormat, QSettings::SystemScope, "openslx/pvs2", "pvs2"));
+		set = new QSettings(QSettings::IniFormat, QSettings::SystemScope, "openslx/pvs2", "pvs2", this);
 	} else {
 		/* use _iniPath to find ini file */
-		set = QSharedPointer<QSettings>(new QSettings(_iniPath, QSettings::IniFormat));
+		set = new QSettings(_iniPath, QSettings::IniFormat, this);
 	}
 	set->setIniCodec("UTF-8");
 	return set;
@@ -182,14 +184,15 @@ static QSize minimalGridSize(const QMap<QString, QPoint>& clientPositions, QSize
 	int x = 0;
 	int y = 0;
 
-	for (auto it = clientPositions.begin(); it != clientPositions.end(); ++it) {
-		QPoint pos = it.value();
-		if (pos.x() > x) { x = pos.x(); }
-		if (pos.y() > y) { y = pos.y(); }
-
+	for (const auto &pos : clientPositions) {
+		if (pos.x() > x) {
+			x = pos.x();
+		}
+		if (pos.y() > y) {
+			y = pos.y();
+		}
 	}
 	/* need a little extra space */
-	QSize size(x + clientSize.width(), y + clientSize.height());
-	return size;
+	return QSize(x + clientSize.width(), y + clientSize.height());
 }
 
diff --git a/src/server/serverapp/serverapp.h b/src/server/serverapp/serverapp.h
index e0a1351..b2b16c5 100644
--- a/src/server/serverapp/serverapp.h
+++ b/src/server/serverapp/serverapp.h
@@ -1,14 +1,16 @@
 #ifndef SERVERAPP_H
 #define SERVERAPP_H
 
+#include "../mainwindow/mainwindow.h"
+
 #include <QApplication>
 #include <QStringList>
 #include <QMap>
 
-#include "../mainwindow/mainwindow.h"
+class QSettings;
 
 struct Room {
-	Room(QMap<QString, QPoint> cPos, QSize grid, QSize client, QString image, QString tutor) :
+	Room(const QMap<QString, QPoint> &cPos, const QSize &grid, const QSize &client, const QString &image, const QString &tutor) :
 		clientPositions(cPos),
 		gridSize(grid),
 		clientSize(client),
@@ -23,12 +25,12 @@ struct Room {
 
 
 /* define a macro `serverApp` that can be used anywhere in the program and
- * returns a reference to the current ClientApp instance */
+ * returns a reference to the current ServerApp instance */
 
 #if defined(serverApp)
 #undef serverApp
 #endif
-#define serverApp (static_cast<ServerApp*>(QCoreApplication::instance()))
+#define serverApp (static_cast<ServerApp*>(QCoreApplication::instance())) // NOLINT(cppcoreguidelines-pro-type-static-cast-downcast)
 
 /* this class is supposed to (after complete refactoring) to encapsulate all
  * state of the application.  At the moment, the state is distributed within
@@ -42,15 +44,14 @@ class ServerApp : public QApplication
 
 private:
 	QStringList _arguments;
-	MainWindow* _mainWindow;
 
 	QString _sessionName;
 	QByteArray _sessionNameArray;
 	QMap<QString, Room*> _rooms;
 	QString _currentRoom;
 
-	bool _managerOnly;
-	bool _isExam;
+	bool _managerOnly{};
+	bool _isExam{};
 	QString _iniPath;
 
 	QStringList parseParameters();
@@ -64,20 +65,16 @@ public:
 
 
 	/* getters */
-	const QString& sessionName() 		    { return _sessionName; }
-	const QByteArray& sessionNameArray()    { return _sessionNameArray; }
-	const QMap<QString, Room*> & rooms()    { return _rooms; }
-	const QString& getCurrentRoomName()     { return _currentRoom; }
-	const QMap<QString, Room*>& getRooms()  { return _rooms; }
-	bool isExam() 							{ return _isExam; }
-	bool isManagerOnly()					{ return _managerOnly; }
-	const Room* getCurrentRoom();
-	QSharedPointer<QSettings> getSettings();
+	const QString &sessionName() const            { return _sessionName; }
+	const QByteArray &sessionNameArray() const    { return _sessionNameArray; }
+	const QMap<QString, Room *> &getRooms() const { return _rooms; }
+	bool isExam() const                           { return _isExam; }
+	const Room* getCurrentRoom() const;
+	QSettings * getSettings();
 
 	/* setters */
 	void setSessionName(const QString& name);
 	void setSessionName();
-	void setIniPath(QString s) { _iniPath = s; };
 	void setCurrentRoom(const QString& room) { _currentRoom = room; }
 	void setExam(bool exam) { _isExam = exam; }
 
diff --git a/src/server/sessionnamewindow/sessionnamewindow.cpp b/src/server/sessionnamewindow/sessionnamewindow.cpp
index f79efbf..74aa05d 100644
--- a/src/server/sessionnamewindow/sessionnamewindow.cpp
+++ b/src/server/sessionnamewindow/sessionnamewindow.cpp
@@ -9,32 +9,30 @@
  #
  # General information about OpenSLX can be found at http://openslx.org/
  # -----------------------------------------------------------------------------
- # mainWindow.cpp
- This is the Main class for the pvsManager. The GUI is contructed here.
- # -----------------------------------------------------------------------------
  */
 
-#include <QtWidgets>
 #include "sessionnamewindow.h"
+#include "ui_sessionnamewindow.h"
 #include "../serverapp/serverapp.h"
 #include "../numerickeyboard/numerickeyboard.h"
-#include "ui_sessionnamewindow.h"
-
+#include "../../shared/util.h"
 
-SessionNameWindow::SessionNameWindow(QWidget *parent) :
-	QDialog(parent), ui(new Ui::SessionName)
+#include <QCloseEvent>
 
+SessionNameWindow::SessionNameWindow(QWidget *parent)
+		: QDialog(parent)
+		, ui(new Ui::SessionName)
 {
 	ui->setupUi(this);
-	connect(ui->bboxOkCancel, SIGNAL(accepted()),  this, SLOT(onOkClicked()));
-	connect(ui->bboxOkCancel, SIGNAL(rejected()), this, SLOT(close()));
-	connect(ui->cmdRandom, SIGNAL(clicked(bool)), this, SLOT(onGenerateRandomName()));
+	connect(ui->bboxOkCancel, &QDialogButtonBox::accepted,  this, &SessionNameWindow::onOkClicked);
+	connect(ui->bboxOkCancel, &QDialogButtonBox::rejected, this, &SessionNameWindow::close);
+	connect(ui->cmdRandom, &QPushButton::clicked, this, &SessionNameWindow::onGenerateRandomName);
 
 	/* add a virtual numeric keyboard */
-	NumericKeyboard *keyboard = new NumericKeyboard();
+	auto *keyboard = new NumericKeyboard();
 	ui->keyboard_placeholder->addWidget(keyboard);
-	connect(keyboard, SIGNAL(digitTyped(int)), this, SLOT(onDigitTyped(int)));
-	connect(keyboard, SIGNAL(digitDelete()), this, SLOT(onDigitDelete()));
+	connect(keyboard, &NumericKeyboard::digitTyped, this, &SessionNameWindow::onDigitTyped);
+	connect(keyboard, &NumericKeyboard::digitDelete, this, &SessionNameWindow::onDigitDelete);
 
 }
 
@@ -73,7 +71,7 @@ void SessionNameWindow::onOkClicked()
 
 void SessionNameWindow::onGenerateRandomName()
 {
-	ui->lineEditName->setText(QString::number(qrand() % 9000 + 1000));
+	ui->lineEditName->setText(QString::number(slxrand() % 9000 + 1000));
 }
 
 /** deletes the last digit of the saved sessionname */
diff --git a/src/server/sessionnamewindow/sessionnamewindow.h b/src/server/sessionnamewindow/sessionnamewindow.h
index e46b895..024df48 100644
--- a/src/server/sessionnamewindow/sessionnamewindow.h
+++ b/src/server/sessionnamewindow/sessionnamewindow.h
@@ -1,8 +1,7 @@
-#ifndef _SESSIONNAMEWINDOW_H_
-#define _SESSIONNAMEWINDOW_H_
-
-#include <QtWidgets>
+#ifndef PVS_SESSIONNAMEWINDOW_H_
+#define PVS_SESSIONNAMEWINDOW_H_
 
+#include <QDialog>
 
 namespace Ui
 {
@@ -17,13 +16,13 @@ private:
 	Ui::SessionName *ui;
 
 public:
-	SessionNameWindow(QWidget *parent = 0);
-	~SessionNameWindow();
+	explicit SessionNameWindow(QWidget *parent = nullptr);
+	~SessionNameWindow() override;
 
 	void show(const QString& name);
 
 protected:
-	void closeEvent(QCloseEvent *e);
+	void closeEvent(QCloseEvent *e) override;
 
 private slots:
 	void onOkClicked();