get rid of some foreach and Q_FOREACH constructs

See https://www.kdab.com/goodbye-q_foreach/

This is reduced to the places where the container is const or can be made const
without the need to always introduce an extra variable. Sadly qAsConst (Qt 5.7)
and std::as_const (C++17) are not available in all supported setups.

Also do some minor cleanups along the way.

Signed-off-by: Rolf Eike Beer <eike@sf-mail.de>

CodingStyle.md

@@ -156,6 +156,16 @@ other editors that implement this coding style, please add them here.
 	```
 	QLowEnergyService *service = qobject_cast<QLowEnergyService*>(sender());
 	```
+  - If the variable is a container that is only assigned to a local variable to
+	be able to use it in a range-based for loop
+	```
+	const auto l = device.serviceUuids();
+	for (QBluetoothUuid id: serviceUuids) {
+	```
+	The variable has also to be const to avoid that Qt containers will do a
+	deep copy when the range bases for loop will call the begin() method
+	internally.
+
 * text strings
   The default language of subsurface is US English so please use US English
   spelling and terminology.
@@ -173,7 +183,7 @@ other editors that implement this coding style, please add them here.
   This works by default in classes (indirectly) derived from QObject. Each
   string to be translated is associated with a context, which corresponds
   to the class name. Classes that are not derived from QObject can generate
-  the tr() functions by using the `Q_DECLARE_FUNCTIONS` macro:
+  the tr() functions by using the `Q_DECLARE_TR_FUNCTIONS` macro:
   ```
 	#include <QCoreApplication>
 

core/btdiscovery.cpp

@@ -198,8 +198,8 @@ void BTDiscovery::btDeviceDiscovered(const QBluetoothDeviceInfo &device)
 	this_d.name = device.name();
 	btPairedDevices.append(this_d);
 
-	QList<QBluetoothUuid> serviceUuids = device.serviceUuids();
+	const auto serviceUuids = device.serviceUuids();
-	foreach (QBluetoothUuid id, serviceUuids) {
+	for (QBluetoothUuid id: serviceUuids) {
 		addBtUuid(id);
 		qDebug() << id.toByteArray();
 	}

core/checkcloudconnection.cpp

@@ -76,11 +76,11 @@ bool CheckCloudConnection::checkServer()
 	return false;
 }
 
-void CheckCloudConnection::sslErrors(QList<QSslError> errorList)
+void CheckCloudConnection::sslErrors(const QList<QSslError> &errorList)
 {
 	if (verbose) {
 		qDebug() << "Received error response trying to set up https connection with cloud storage backend:";
-		Q_FOREACH (QSslError err, errorList) {
+		for (QSslError err: errorList) {
 			qDebug() << err.errorString();
 		}
 	}

core/checkcloudconnection.h

@@ -15,7 +15,7 @@ private:
 	QNetworkReply *reply;
 private
 slots:
-	void sslErrors(QList<QSslError> errorList);
+	void sslErrors(const QList<QSslError> &errorList);
 };
 
 #endif // CHECKCLOUDCONNECTION_H

core/cloudstorage.cpp

@@ -81,11 +81,11 @@ void CloudStorageAuthenticate::uploadError(QNetworkReply::NetworkError)
 	qDebug() << "Received error response from cloud storage backend:" << reply->errorString();
 }
 
-void CloudStorageAuthenticate::sslErrors(QList<QSslError> errorList)
+void CloudStorageAuthenticate::sslErrors(const QList<QSslError> &errorList)
 {
 	if (verbose) {
 		qDebug() << "Received error response trying to set up https connection with cloud storage backend:";
-		Q_FOREACH (QSslError err, errorList) {
+		for (QSslError err: errorList) {
 			qDebug() << err.errorString();
 		}
 	}

core/cloudstorage.h

@@ -16,7 +16,7 @@ signals:
 private
 slots:
 	void uploadError(QNetworkReply::NetworkError error);
-	void sslErrors(QList<QSslError> errorList);
+	void sslErrors(const QList<QSslError> &errorList);
 	void uploadFinished();
 private:
 	QNetworkReply *reply;

core/qt-ble.cpp

@@ -341,7 +341,7 @@ dc_status_t BLEObject::setHwCredit(unsigned int c)
 	return DC_STATUS_SUCCESS;
 }
 
-dc_status_t BLEObject::setupHwTerminalIo(QList<QLowEnergyCharacteristic> allC)
+dc_status_t BLEObject::setupHwTerminalIo(const QList<QLowEnergyCharacteristic> &allC)
 {	/* This initalizes the Terminal I/O client as described in
 	 * http://www.telit.com/fileadmin/user_upload/products/Downloads/sr-rf/BlueMod/TIO_Implementation_Guide_r04.pdf
 	 * Referenced section numbers below are from that document.
@@ -479,16 +479,16 @@ dc_status_t qt_ble_open(void **io, dc_context_t *, const char *devaddr, dc_user_
 			return r;
 		}
 	} else {
-		foreach (const QLowEnergyCharacteristic &c, list) {
+		for (const QLowEnergyCharacteristic &c: list) {
 			if (!is_read_characteristic(c))
 				continue;
 
 			qDebug() << "Using read characteristic" << c.uuid();
 
-			QList<QLowEnergyDescriptor> l = c.descriptors();
+			const QList<QLowEnergyDescriptor> l = c.descriptors();
 			QLowEnergyDescriptor d = l.first();
 
-			foreach (const QLowEnergyDescriptor &tmp, l) {
+			for (const QLowEnergyDescriptor &tmp: l) {
 				if (tmp.type() == QBluetoothUuid::ClientCharacteristicConfiguration) {
 					d = tmp;
 					break;

core/qt-ble.h

@@ -35,7 +35,7 @@ public slots:
 	void characteristcStateChanged(const QLowEnergyCharacteristic &c, const QByteArray &value);
 	void characteristicWritten(const QLowEnergyCharacteristic &c, const QByteArray &value);
 	void writeCompleted(const QLowEnergyDescriptor &d, const QByteArray &value);
-	dc_status_t setupHwTerminalIo(QList<QLowEnergyCharacteristic>);
+	dc_status_t setupHwTerminalIo(const QList<QLowEnergyCharacteristic> &allC);
 	dc_status_t setHwCredit(unsigned int c);
 private:
 	QVector<QLowEnergyService *> services;

core/qthelper.cpp

@@ -1144,7 +1144,7 @@ QStringList imageExtensionFilters()
 QStringList videoExtensionFilters()
 {
 	QStringList filters;
-	foreach (const QString &format, videoExtensionsList)
+	for (const QString &format: videoExtensionsList)
 		filters.append("*" + format);
 	return filters;
 }
@@ -1506,9 +1506,9 @@ int parse_seabear_header(const char *filename, char **params, int pnr)
 
 	parseLine = f.readLine().trimmed();
 
-	QStringList currColumns = parseLine.split(';');
+	const QStringList currColumns = parseLine.split(';');
 	unsigned short index = 0;
-	Q_FOREACH (QString columnText, currColumns) {
+	for (const QString &columnText: currColumns) {
 		if (columnText == "Time") {
 			params[pnr++] = strdup("timeField");
 			params[pnr++] = intdup(index++);

desktop-widgets/locationinformation.cpp

@@ -75,11 +75,11 @@ void LocationInformationWidget::mergeSelectedDiveSites()
 				 QMessageBox::Ok, QMessageBox::Cancel) != QMessageBox::Ok)
 		return;
 
-	QModelIndexList selection = ui.diveSiteListView->selectionModel()->selectedIndexes();
+	const QModelIndexList selection = ui.diveSiteListView->selectionModel()->selectedIndexes();
 	// std::vector guarantees contiguous storage and can therefore be passed to C-code
 	std::vector<struct dive_site *> selected_dive_sites;
 	selected_dive_sites.reserve(selection.count());
-	Q_FOREACH (const QModelIndex &idx, selection) {
+	for (const QModelIndex &idx: selection) {
 		dive_site *ds = idx.data(LocationInformationModel::DIVESITE_ROLE).value<dive_site *>();
 		if (ds)
 			selected_dive_sites.push_back(ds);

desktop-widgets/printer.cpp

@@ -77,8 +77,8 @@ void Printer::flowRender()
 	// get all references to dontbreak divs
 	int start = 0, end = 0;
 	int fullPageResolution = webView->page()->mainFrame()->contentsSize().height();
-	QWebElementCollection dontbreak = webView->page()->mainFrame()->findAllElements(".dontbreak");
+	const QWebElementCollection dontbreak = webView->page()->mainFrame()->findAllElements(".dontbreak");
-	foreach (QWebElement dontbreakElement, dontbreak) {
+	for (QWebElement dontbreakElement: dontbreak) {
 		if ((dontbreakElement.geometry().y() + dontbreakElement.geometry().height()) - start < pageSize.height()) {
 			// One more element can be placed
 			end = dontbreakElement.geometry().y() + dontbreakElement.geometry().height();

desktop-widgets/tab-widgets/TabDiveStatistics.cpp

@@ -21,8 +21,8 @@ TabDiveStatistics::TabDiveStatistics(QWidget *parent) : TabBase(parent), ui(new
 	ui->timeLimits->overrideMinToolTipText(tr("Shortest dive"));
 	ui->timeLimits->overrideAvgToolTipText(tr("Average length of all selected dives"));
 
-	Q_FOREACH (QObject *obj, children()) {
+	const auto l = findChildren<QLabel *>(QString(), Qt::FindDirectChildrenOnly);
-		if (QLabel *label = qobject_cast<QLabel *>(obj))
+	for (QLabel *label: l) {
 		label->setAlignment(Qt::AlignHCenter);
 	}
 }

desktop-widgets/tab-widgets/maintab.cpp

@@ -1271,14 +1271,13 @@ void MainTab::saveTaggedStrings(const QVector<dive *> &selectedDives)
 
 int MainTab::diffTaggedStrings(QString currentString, QString displayedString, QStringList &addedList, QStringList &removedList)
 {
-	QStringList displayedList, currentList;
+	const QStringList currentList = currentString.split(',', QString::SkipEmptyParts);
-	currentList = currentString.split(',', QString::SkipEmptyParts);
+	const QStringList displayedList = displayedString.split(',', QString::SkipEmptyParts);
-	displayedList = displayedString.split(',', QString::SkipEmptyParts);
+	for (const QString &tag: currentList) {
-	Q_FOREACH ( const QString tag, currentList) {
 		if (!displayedList.contains(tag, Qt::CaseInsensitive))
 			removedList << tag.trimmed();
 	}
-	Q_FOREACH (const QString tag, displayedList) {
+	for (const QString &tag: displayedList) {
 		if (!currentList.contains(tag, Qt::CaseInsensitive))
 			addedList << tag.trimmed();
 	}

desktop-widgets/tagwidget.cpp

@@ -70,7 +70,8 @@ void TagWidget::highlight()
 {
 	removeAllBlocks();
 	int lastPos = 0;
-	Q_FOREACH (const QString& s, text().split(QChar(','), QString::SkipEmptyParts)) {
+	const auto l = text().split(QChar(','), QString::SkipEmptyParts);
+	for (const QString &s: l) {
 		QString trimmed = s.trimmed();
 		if (trimmed.isEmpty())
 			continue;

desktop-widgets/templatelayout.cpp

@@ -19,20 +19,20 @@ int getTotalWork(print_options *printOptions)
 
 void find_all_templates()
 {
-	const QString ext(".html");
+	const QLatin1String ext(".html");
 	grantlee_templates.clear();
 	grantlee_statistics_templates.clear();
 	QDir dir(getPrintingTemplatePathUser());
-	QStringList list = dir.entryList(QDir::Files | QDir::NoDotAndDotDot);
+	const QStringList list = dir.entryList(QDir::Files | QDir::NoDotAndDotDot);
-	foreach (const QString& filename, list) {
+	for (const QString &filename: list) {
 		if (filename.at(filename.size() - 1) != '~' && filename.endsWith(ext))
 			grantlee_templates.append(filename);
 	}
 
 	// find statistics templates
 	dir.setPath(getPrintingTemplatePathUser() + QDir::separator() + "statistics");
-	list = dir.entryList(QDir::Files | QDir::NoDotAndDotDot);
+	const QStringList stat = dir.entryList(QDir::Files | QDir::NoDotAndDotDot);
-	foreach (const QString& filename, list) {
+	for (const QString &filename: stat) {
 		if (filename.at(filename.size() - 1) != '~' && filename.endsWith(ext))
 			grantlee_statistics_templates.append(filename);
 	}
@@ -66,12 +66,14 @@ void copy_bundled_templates(QString src, QString dst, QStringList *templateBacku
 	QDir dir(src);
 	if (!dir.exists())
 		return;
-	foreach (QString d, dir.entryList(QDir::Dirs | QDir::NoDotAndDotDot)) {
+	const auto dirs = dir.entryList(QDir::Dirs | QDir::NoDotAndDotDot);
+	for (const QString &d: dirs) {
 		QString dst_path = dst + QDir::separator() + d;
 		dir.mkpath(dst_path);
 		copy_bundled_templates(src + QDir::separator() + d, dst_path, templateBackupList);
 	}
-	foreach (QString f, dir.entryList(QDir::Files)) {
+	const auto files = dir.entryList(QDir::Files);
+	for (const QString &f: files) {
 		QFile fileSrc(src + QDir::separator() + f);
 		QFile fileDest(dst + QDir::separator() + f);
 		if (fileDest.exists()) {

mobile-widgets/qmlmanager.cpp

@@ -599,7 +599,7 @@ void QMLManager::handleSslErrors(const QList<QSslError> &errors)
 {
 	auto *reply = qobject_cast<QNetworkReply *>(sender());
 	setStartPageText(RED_FONT + tr("Cannot open cloud storage: Error creating https connection") + END_FONT);
-	Q_FOREACH (QSslError e, errors) {
+	for (QSslError e: errors) {
 		appendTextToLog(e.errorString());
 	}
 	reply->abort();
@@ -1761,8 +1761,8 @@ void QMLManager::setStatusbarColor(QColor)
 void QMLManager::retrieveBluetoothName()
 {
 	QString name = DC_devName();
-	QList<BTDiscovery::btVendorProduct> btDCs = BTDiscovery::instance()->getBtDcs();
+	const QList<BTDiscovery::btVendorProduct> btDCs = BTDiscovery::instance()->getBtDcs();
-	foreach (BTDiscovery::btVendorProduct btDC, btDCs) {
+	for (BTDiscovery::btVendorProduct btDC: btDCs) {
 		qDebug() << "compare" <<name << btDC.btpdi.address;
 		if (name.contains(btDC.btpdi.address))
 			DC_setDevBluetoothName(btDC.btpdi.name);

profile-widget/divetooltipitem.cpp

@@ -272,8 +272,9 @@ void ToolTipItem::refresh(const QPointF &pos)
 	}
 	entryToolTip.first->setPixmap(tissues);
 
-	Q_FOREACH (QGraphicsItem *item, scene()->items(pos, Qt::IntersectsItemBoundingRect
+	const auto l = scene()->items(pos, Qt::IntersectsItemBoundingRect, Qt::DescendingOrder,
-		,Qt::DescendingOrder, scene()->views().first()->transform())) {
+			scene()->views().first()->transform());
+	for (QGraphicsItem *item: l) {
 		if (!item->toolTip().isEmpty())
 			addToolTip(item->toolTip());
 	}

profile-widget/profilewidget2.cpp

@@ -1101,9 +1101,9 @@ bool ProfileWidget2::eventFilter(QObject *object, QEvent *event)
 #endif
 
 template <typename T>
-static void hideAll(T &container)
+static void hideAll(const T &container)
 {
-	Q_FOREACH (auto *item, container)
+	for (auto *item: container)
 		item->setVisible(false);
 }
 

qt-models/divelistmodel.cpp

@@ -144,12 +144,12 @@ DiveListModel::DiveListModel(QObject *parent) : QAbstractListModel(parent)
 	m_instance = this;
 }
 
-void DiveListModel::addDive(QList<dive *>listOfDives)
+void DiveListModel::addDive(const QList<dive *> &listOfDives)
 {
 	if (listOfDives.isEmpty())
 		return;
 	beginInsertRows(QModelIndex(), rowCount(), rowCount() + listOfDives.count() - 1);
-	foreach (dive *d, listOfDives) {
+	for (dive *d: listOfDives) {
 		m_dives.append(new DiveObjectHelper(d));
 	}
 	endInsertRows();

qt-models/divelistmodel.h

@@ -44,7 +44,7 @@ public:
 
 	static DiveListModel *instance();
 	DiveListModel(QObject *parent = 0);
-	void addDive(QList<dive *> listOfDives);
+	void addDive(const QList<dive *> &listOfDives);
 	void addAllDives();
 	void insertDive(int i, DiveObjectHelper *newDive);
 	void removeDive(int i);

subsurface-helper.cpp

@@ -76,8 +76,8 @@ void run_ui()
 	// same directory the executable was started from <bundle>/Contents/MacOS/
 	// To work around this we need to manually copy the components at install time
 	// to Contents/Frameworks/qml and make sure that we add the correct import path
-	QStringList importPathList = engine.importPathList();
+	const QStringList importPathList = engine.importPathList();
-	Q_FOREACH (QString importPath, importPathList) {
+	for (QString importPath: importPathList) {
 		if (importPath.contains("MacOS"))
 			engine.addImportPath(importPath.replace("MacOS", "Frameworks"));
 	}