Cleanup: make DCDeviceData a "normal" singleton

DCDeviceData was using that weird pattern where the instance
variable was set in the constructor. There is no apparent
reason to do so, therefore convert to a "normal" singleton.

Access that directly in QMLManager instead of saving it in
a member variable first.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

core/downloadfromdcthread.cpp

@@ -24,7 +24,6 @@ static QString str_error(const char *fmt, ...)
 	return str;
 }
 
-
 static void updateRememberedDCs()
 {
 	QString current = qPrefDiveComputer::vendor() + " - " + qPrefDiveComputer::product() + " - " + qPrefDiveComputer::device();
@@ -254,7 +253,6 @@ void show_computer_list()
 		qDebug() << msg;
 	}
 }
-DCDeviceData *DCDeviceData::m_instance = NULL;
 
 DCDeviceData::DCDeviceData()
 {
@@ -276,18 +274,12 @@ DCDeviceData::DCDeviceData()
 #else
 	data.libdc_log = false;
 #endif
-	if (m_instance) {
-		qDebug() << "already have an instance of DCDevieData";
-		return;
-	}
-	m_instance = this;
 }
 
 DCDeviceData *DCDeviceData::instance()
 {
-	if (!m_instance)
+	static DCDeviceData self;
-		m_instance = new DCDeviceData;
+	return &self;
-	return m_instance;
 }
 
 QStringList DCDeviceData::getProductListFromVendor(const QString &vendor)

core/downloadfromdcthread.h

@@ -51,7 +51,6 @@ public:
 	void setSaveDump(bool dumpMode);
 	void setSaveLog(bool saveLog);
 private:
-	static DCDeviceData *m_instance;
 	device_data_t data;
 
 	// Bluetooth name is managed outside of libdivecomputer

mobile-widgets/qmlmanager.cpp

@@ -144,7 +144,6 @@ QMLManager::QMLManager() : m_locationServiceEnabled(false),
 	m_updateSelectedDive(-1),
 	m_selectedDiveTimestamp(0),
 	alreadySaving(false),
-	m_device_data(new DCDeviceData),
 	m_pluggedInDeviceName("")
 {
 	LOG_STP("qmlmgr starting");
@@ -1673,117 +1672,117 @@ void QMLManager::setStatusbarColor(QColor)
 
 QString QMLManager::DC_vendor() const
 {
-	return m_device_data->vendor();
+	return DCDeviceData::instance()->vendor();
 }
 
 QString QMLManager::DC_product() const
 {
-	return m_device_data->product();
+	return DCDeviceData::instance()->product();
 }
 
 QString QMLManager::DC_devName() const
 {
-	return m_device_data->devName();
+	return DCDeviceData::instance()->devName();
 }
 
 QString QMLManager::DC_devBluetoothName() const
 {
-	return m_device_data->devBluetoothName();
+	return DCDeviceData::instance()->devBluetoothName();
 }
 
 QString QMLManager::DC_descriptor() const
 {
-	return m_device_data->descriptor();
+	return DCDeviceData::instance()->descriptor();
 }
 
 bool QMLManager::DC_forceDownload() const
 {
-	return m_device_data->forceDownload();
+	return DCDeviceData::instance()->forceDownload();
 }
 
 bool QMLManager::DC_bluetoothMode() const
 {
-	return m_device_data->bluetoothMode();
+	return DCDeviceData::instance()->bluetoothMode();
 }
 
 bool QMLManager::DC_createNewTrip() const
 {
-	return m_device_data->createNewTrip();
+	return DCDeviceData::instance()->createNewTrip();
 }
 
 bool QMLManager::DC_saveDump() const
 {
-	return m_device_data->saveDump();
+	return DCDeviceData::instance()->saveDump();
 }
 
 int QMLManager::DC_deviceId() const
 {
-	return m_device_data->deviceId();
+	return DCDeviceData::instance()->deviceId();
 }
 
 void QMLManager::DC_setDeviceId(int deviceId)
 {
-	m_device_data->setDeviceId(deviceId);
+	DCDeviceData::instance()->setDeviceId(deviceId);
 }
 
 void QMLManager::DC_setVendor(const QString& vendor)
 {
-	m_device_data->setVendor(vendor);
+	DCDeviceData::instance()->setVendor(vendor);
 }
 
 void QMLManager::DC_setProduct(const QString& product)
 {
-	m_device_data->setProduct(product);
+	DCDeviceData::instance()->setProduct(product);
 }
 
 void QMLManager::DC_setDevName(const QString& devName)
 {
-	m_device_data->setDevName(devName);
+	DCDeviceData::instance()->setDevName(devName);
 }
 
 void QMLManager::DC_setDevBluetoothName(const QString& devBluetoothName)
 {
-	m_device_data->setDevBluetoothName(devBluetoothName);
+	DCDeviceData::instance()->setDevBluetoothName(devBluetoothName);
 }
 
 void QMLManager::DC_setBluetoothMode(bool mode)
 {
-	m_device_data->setBluetoothMode(mode);
+	DCDeviceData::instance()->setBluetoothMode(mode);
 }
 
 void QMLManager::DC_setForceDownload(bool force)
 {
-	m_device_data->setForceDownload(force);
+	DCDeviceData::instance()->setForceDownload(force);
 }
 
 void QMLManager::DC_setCreateNewTrip(bool create)
 {
-	m_device_data->setCreateNewTrip(create);
+	DCDeviceData::instance()->setCreateNewTrip(create);
 }
 
 void QMLManager::DC_setSaveDump(bool dumpMode)
 {
-	m_device_data->setSaveDump(dumpMode);
+	DCDeviceData::instance()->setSaveDump(dumpMode);
 }
 
 QStringList QMLManager::getProductListFromVendor(const QString &vendor)
 {
-	return m_device_data->getProductListFromVendor(vendor);
+	return DCDeviceData::instance()->getProductListFromVendor(vendor);
 }
 
 int QMLManager::getMatchingAddress(const QString &vendor, const QString &product)
 {
-	return m_device_data->getMatchingAddress(vendor, product);
+	return DCDeviceData::instance()->getMatchingAddress(vendor, product);
 }
 
 int QMLManager::getDetectedVendorIndex()
 {
-	return m_device_data->getDetectedVendorIndex();
+	return DCDeviceData::instance()->getDetectedVendorIndex();
 }
 
 int QMLManager::getDetectedProductIndex(const QString &currentVendorText)
 {
-	return m_device_data->getDetectedProductIndex(currentVendorText);
+	return DCDeviceData::instance()->getDetectedProductIndex(currentVendorText);
 }
 
 int QMLManager::getConnectionIndex(const QString &deviceSubstr)