Changed many functions in the abstract *Link classes to be const. This...

Changed many functions in the abstract *Link classes to be const. This facilitates setting other functions as const. The metadata for specific links are reset when the links are added.

src/comm/LinkInterface.cpp

-//#include "LinkInterface.h"
-
-//LinkInterface::~LinkInterface()
-//{
-
-//}

src/comm/LinkInterface.h

@@ -54,19 +54,19 @@ public:
      * The ID is an unsigned integer, starting at 0
      * @return ID of this link
      **/
-    virtual int getId() = 0;
+    virtual int getId() const = 0;
 
     /**
      * @brief Get the human readable name of this link
      */
-    virtual QString getName() = 0;
+    virtual QString getName() const = 0;
 
     /**
      * @brief Determine the connection status
      *
      * @return True if the connection is established, false otherwise
      **/
-    virtual bool isConnected() = 0;
+    virtual bool isConnected() const = 0;
 
     /* Connection characteristics */
 
@@ -83,7 +83,7 @@ public:
      * @see getCurrentDataRate() For the data rate of the last transferred chunk
      * @see getMaxDataRate() For the maximum data rate
      **/
-    virtual qint64 getNominalDataRate() = 0;
+    virtual qint64 getNominalDataRate() const = 0;
 
     /**
      * @brief Full duplex support of this interface.
@@ -93,7 +93,7 @@ public:
      *
      * @return True if the interface supports full duplex, false otherwise
      **/
-    virtual bool isFullDuplex() = 0;
+    virtual bool isFullDuplex() const = 0;
 
     /**
      * @brief Get the link quality.
@@ -103,7 +103,7 @@ public:
      *
      * @return The link quality in integer percent or -1 if not supported
      **/
-    virtual int getLinkQuality() = 0;
+    virtual int getLinkQuality() const = 0;
 
     /**
      * @Brief Get the long term (complete) mean of the data rate
@@ -150,7 +150,7 @@ public:
      *
      * @return The number of sent bits
      **/
-    virtual qint64 getBitsSent() = 0;
+    virtual qint64 getBitsSent() const = 0;
 
     /**
      * @Brief Get the total number of bits received
@@ -158,7 +158,7 @@ public:
      * @return The number of received bits
      * @bug Decide if the bits should be counted fromt the instantiation of the interface or if the counter should reset on disconnect.
      **/
-    virtual qint64 getBitsReceived() = 0;
+    virtual qint64 getBitsReceived() const = 0;
 
     /**
      * @brief Connect this interface logically

src/comm/LinkManager.cc

@@ -98,6 +98,8 @@ void LinkManager::addProtocol(LinkInterface* link, ProtocolInterface* protocol)
         connect(link, SIGNAL(connected(bool)), protocol, SLOT(linkStatusChanged(bool)));
         // Store the connection information in the protocol links map
         protocolLinks.insertMulti(protocol, link);
+        // Make sure the protocol clears its metadata for this link.
+        protocol->resetMetadataForLink(link);
     }
     //qDebug() << __FILE__ << __LINE__ << "ADDED LINK TO PROTOCOL" << link->getName() << protocol->getName() << "NEW SIZE OF LINK LIST:" << protocolLinks.size();
 }

src/comm/MAVLinkProtocol.cc

@@ -63,14 +63,11 @@ MAVLinkProtocol::MAVLinkProtocol() :
     // Start heartbeat timer, emitting a heartbeat at the configured rate
     connect(heartbeatTimer, SIGNAL(timeout()), this, SLOT(sendHeartbeat()));
     heartbeatTimer->start(1000/heartbeatRate);
-    for (int i = 0; i < MAVLINK_COMM_NUM_BUFFERS; i++)
-    {
-        totalReceiveCounter[i] = 0;
-        totalLossCounter[i] = 0;
-        totalErrorCounter[i] = 0;
-        currReceiveCounter[i] = 0;
-        currLossCounter[i] = 0;
-    }
+
+    // All the *Counter variables are not initialized here, as they should be initialized
+    // on a per-link basis before those links are used. @see resetMetadataForLink().
+
+    // Initialize the list for tracking dropped messages to invalid.
     for (int i = 0; i < 256; i++)
     {
         for (int j = 0; j < 256; j++)
@@ -178,6 +175,16 @@ QString MAVLinkProtocol::getLogfileName()
     }
 }
 
+void MAVLinkProtocol::resetMetadataForLink(const LinkInterface *link)
+{
+    int linkId = link->getId();
+    totalReceiveCounter[linkId] = 0;
+    totalLossCounter[linkId] = 0;
+    totalErrorCounter[linkId] = 0;
+    currReceiveCounter[linkId] = 0;
+    currLossCounter[linkId] = 0;
+}
+
 void MAVLinkProtocol::linkStatusChanged(bool connected)
 {
     LinkInterface* link = qobject_cast<LinkInterface*>(QObject::sender());
@@ -205,7 +212,6 @@ void MAVLinkProtocol::linkStatusChanged(bool connected)
 }
 
 /**
- * The bytes are copied by calling the LinkInterface::readBytes() method.
  * This method parses all incoming bytes and constructs a MAVLink packet.
  * It can handle multiple links in parallel, as each link has it's own buffer/
  * parsing state machine.

src/comm/MAVLinkProtocol.h

@@ -128,23 +128,27 @@ public:
      * Retrieve a total of all successfully parsed packets for the specified link.
      * @returns -1 if this is not available for this protocol, # of packets otherwise.
      */
-    qint32 getReceivedPacketCount(LinkInterface *link) const {
+    qint32 getReceivedPacketCount(const LinkInterface *link) const {
         return totalReceiveCounter[link->getId()];
     }
     /**
      * Retrieve a total of all parsing errors for the specified link.
      * @returns -1 if this is not available for this protocol, # of errors otherwise.
      */
-    qint32 getParsingErrorCount(LinkInterface *link) const {
+    qint32 getParsingErrorCount(const LinkInterface *link) const {
         return totalErrorCounter[link->getId()];
     }
     /**
      * Retrieve a total of all dropped packets for the specified link.
      * @returns -1 if this is not available for this protocol, # of packets otherwise.
      */
-    qint32 getDroppedPacketCount(LinkInterface *link) const {
+    qint32 getDroppedPacketCount(const LinkInterface *link) const {
         return totalLossCounter[link->getId()];
     }
+    /**
+     * Reset the counters for all metadata for this link.
+     */
+    virtual void resetMetadataForLink(const LinkInterface *link);
 
 public slots:
     /** @brief Receive bytes from a communication interface */

src/comm/MAVLinkSimulationLink.cc

@@ -988,22 +988,22 @@ bool MAVLinkSimulationLink::connectLink(bool connect)
  *
  * @return True if link is connected, false otherwise.
  **/
-bool MAVLinkSimulationLink::isConnected()
+bool MAVLinkSimulationLink::isConnected() const
 {
     return _isConnected;
 }
 
-int MAVLinkSimulationLink::getId()
+int MAVLinkSimulationLink::getId() const
 {
     return id;
 }
 
-QString MAVLinkSimulationLink::getName()
+QString MAVLinkSimulationLink::getName() const
 {
     return name;
 }
 
-qint64 MAVLinkSimulationLink::getNominalDataRate()
+qint64 MAVLinkSimulationLink::getNominalDataRate() const
 {
     /* 100 Mbit is reasonable fast and sufficient for all embedded applications */
     return 100000000;
@@ -1031,12 +1031,12 @@ qint64 MAVLinkSimulationLink::getMaxUpstream()
     return 0;
 }
 
-qint64 MAVLinkSimulationLink::getBitsSent()
+qint64 MAVLinkSimulationLink::getBitsSent() const
 {
     return 0;
 }
 
-qint64 MAVLinkSimulationLink::getBitsReceived()
+qint64 MAVLinkSimulationLink::getBitsReceived() const
 {
     return 0;
 }
@@ -1061,13 +1061,13 @@ qint64 MAVLinkSimulationLink::getMaxDownstream()
     return 0;
 }
 
-bool MAVLinkSimulationLink::isFullDuplex()
+bool MAVLinkSimulationLink::isFullDuplex() const
 {
     /* Full duplex is no problem when running in pure software, but this is a serial simulation */
     return false;
 }
 
-int MAVLinkSimulationLink::getLinkQuality()
+int MAVLinkSimulationLink::getLinkQuality() const
 {
     /* The Link quality is always perfect when running in software */
     return 100;

src/comm/MAVLinkSimulationLink.h

@@ -50,7 +50,7 @@ class MAVLinkSimulationLink : public LinkInterface
 public:
     MAVLinkSimulationLink(QString readFile="", QString writeFile="", int rate=5, QObject* parent = 0);
     ~MAVLinkSimulationLink();
-    bool isConnected();
+    bool isConnected() const;
     qint64 bytesAvailable();
 
     void run();
@@ -59,7 +59,7 @@ public:
     bool disconnect();
 
     /* Extensive statistics for scientific purposes */
-    qint64 getNominalDataRate();
+    qint64 getNominalDataRate() const;
     qint64 getTotalUpstream();
     qint64 getShortTermUpstream();
     qint64 getCurrentUpstream();
@@ -68,20 +68,20 @@ public:
     qint64 getShortTermDownstream();
     qint64 getCurrentDownstream();
     qint64 getMaxDownstream();
-    qint64 getBitsSent();
-    qint64 getBitsReceived();
-
-    QString getName();
-    int getId();
-    int getBaudRate();
-    int getBaudRateType();
-    int getFlowType();
-    int getParityType();
-    int getDataBitsType();
-    int getStopBitsType();
-
-    int getLinkQuality();
-    bool isFullDuplex();
+    qint64 getBitsSent() const;
+    qint64 getBitsReceived() const;
+
+    QString getName() const;
+    int getId() const;
+    int getBaudRate() const;
+    int getBaudRateType() const;
+    int getFlowType() const;
+    int getParityType() const;
+    int getDataBitsType() const;
+    int getStopBitsType() const;
+
+    int getLinkQuality() const;
+    bool isFullDuplex() const;
 
 public slots:
     void writeBytes(const char* data, qint64 size);

src/comm/OpalLink.cc

@@ -411,12 +411,12 @@ void OpalLink::run()
 //    qDebug() << "OpalLink::run():: Starting the thread";
 }
 
-int OpalLink::getId()
+int OpalLink::getId() const
 {
     return id;
 }
 
-QString OpalLink::getName()
+QString OpalLink::getName() const
 {
     return name;
 }
@@ -427,7 +427,7 @@ void OpalLink::setName(QString name)
     emit nameChanged(this->name);
 }
 
-bool OpalLink::isConnected()
+bool OpalLink::isConnected() const
 {
     return connectState;
 }
@@ -505,12 +505,12 @@ bool OpalLink::disconnect()
  *
  */
 
-qint64 OpalLink::getNominalDataRate()
+qint64 OpalLink::getNominalDataRate() const
 {
     return 0; //unknown
 }
 
-int OpalLink::getLinkQuality()
+int OpalLink::getLinkQuality() const
 {
     return -1; //not supported
 }
@@ -541,18 +541,18 @@ qint64 OpalLink::getMaxUpstream()
     return 0; //unknown
 }
 
-qint64 OpalLink::getBitsSent()
+qint64 OpalLink::getBitsSent() const
 {
     return bitsSentTotal;
 }
 
-qint64 OpalLink::getBitsReceived()
+qint64 OpalLink::getBitsReceived() const
 {
     return bitsReceivedTotal;
 }
 
 
-bool OpalLink::isFullDuplex()
+bool OpalLink::isFullDuplex() const
 {
     return false;
 }

src/comm/OpalLink.h

@@ -71,22 +71,22 @@ public:
     OpalLink();
     /* Connection management */
 
-    int getId();
-    QString getName();
-    bool isConnected();
+    int getId() const;
+    QString getName() const;
+    bool isConnected() const;
 
     /* Connection characteristics */
 
 
-    qint64 getNominalDataRate();
-    bool isFullDuplex();
-    int getLinkQuality();
+    qint64 getNominalDataRate() const;
+    bool isFullDuplex() const;
+    int getLinkQuality() const;
     qint64 getTotalUpstream();
     qint64 getTotalDownstream();
     qint64 getCurrentUpstream();
     qint64 getMaxUpstream();
-    qint64 getBitsSent();
-    qint64 getBitsReceived();
+    qint64 getBitsSent() const;
+    qint64 getBitsReceived() const;
 
     bool connect();
 

src/comm/ProtocolInterface.h

@@ -57,19 +57,25 @@ public:
      * @param link The link to return metadata about.
      * @returns -1 if this is not available for this protocol, # of packets otherwise.
      */
-    virtual qint32 getReceivedPacketCount(LinkInterface *link) const = 0;
+    virtual qint32 getReceivedPacketCount(const LinkInterface *link) const = 0;
     /**
      * Retrieve a total of all parsing errors for the specified link.
      * @param link The link to return metadata about.
      * @returns -1 if this is not available for this protocol, # of errors otherwise.
      */
-    virtual qint32 getParsingErrorCount(LinkInterface *link) const = 0;
+    virtual qint32 getParsingErrorCount(const LinkInterface *link) const = 0;
     /**
      * Retrieve a total of all dropped packets for the specified link.
      * @param link The link to return metadata about.
      * @returns -1 if this is not available for this protocol, # of packets otherwise.
      */
-    virtual qint32 getDroppedPacketCount(LinkInterface *link) const = 0;
+    virtual qint32 getDroppedPacketCount(const LinkInterface *link) const = 0;
+    /**
+     * Reset the received, error, and dropped counts for the given link. Useful for
+     * when reconnecting a link.
+     * @param link The link to reset metadata for.
+     */
+    virtual void resetMetadataForLink(const LinkInterface *link) = 0;
 
 public slots:
     virtual void receiveBytes(LinkInterface *link, QByteArray b) = 0;

src/comm/SerialLink.cc

@@ -698,7 +698,7 @@ bool SerialLink::hardwareConnect()
  *
  * @return True if link is connected, false otherwise.
  **/
-bool SerialLink::isConnected()
+bool SerialLink::isConnected() const
 {
     if (port) {
         return port->isOpen();
@@ -707,12 +707,12 @@ bool SerialLink::isConnected()
     }
 }
 
-int SerialLink::getId()
+int SerialLink::getId() const
 {
     return id;
 }
 
-QString SerialLink::getName()
+QString SerialLink::getName() const
 {
     return name;
 }
@@ -728,7 +728,7 @@ void SerialLink::setName(QString name)
   * This function maps baud rate constants to numerical equivalents.
   * It relies on the mapping given in qportsettings.h from the QSerialPort library.
   */
-qint64 SerialLink::getNominalDataRate()
+qint64 SerialLink::getNominalDataRate() const
 {
     qint64 dataRate = 0;
     switch (portSettings.baudRate()) {
@@ -844,12 +844,12 @@ qint64 SerialLink::getMaxUpstream()
     return 0; // TODO
 }
 
-qint64 SerialLink::getBitsSent()
+qint64 SerialLink::getBitsSent() const
 {
     return bitsSentTotal;
 }
 
-qint64 SerialLink::getBitsReceived()
+qint64 SerialLink::getBitsReceived() const
 {
     return bitsReceivedTotal;
 }
@@ -871,54 +871,54 @@ qint64 SerialLink::getMaxDownstream()
     return 0; // TODO
 }
 
-bool SerialLink::isFullDuplex()
+bool SerialLink::isFullDuplex() const
 {
     /* Serial connections are always half duplex */
     return false;
 }
 
-int SerialLink::getLinkQuality()
+int SerialLink::getLinkQuality() const
 {
     /* This feature is not supported with this interface */
     return -1;
 }
 
-QString SerialLink::getPortName()
+QString SerialLink::getPortName() const
 {
     return porthandle;
 }
 
-int SerialLink::getBaudRate()
+int SerialLink::getBaudRate() const
 {
     return getNominalDataRate();
 }
 
-int SerialLink::getBaudRateType()
+int SerialLink::getBaudRateType() const
 {
     return portSettings.baudRate();
 }
 
-int SerialLink::getFlowType()
+int SerialLink::getFlowType() const
 {
     return portSettings.flowControl();
 }
 
-int SerialLink::getParityType()
+int SerialLink::getParityType() const
 {
     return portSettings.parity();
 }
 
-int SerialLink::getDataBitsType()
+int SerialLink::getDataBitsType() const
 {
     return portSettings.dataBits();
 }
 
-int SerialLink::getStopBitsType()
+int SerialLink::getStopBitsType() const
 {
     return portSettings.stopBits();
 }
 
-int SerialLink::getDataBits()
+int SerialLink::getDataBits() const
 {
     int ret = -1;
     switch (portSettings.dataBits()) {
@@ -941,7 +941,7 @@ int SerialLink::getDataBits()
     return ret;
 }
 
-int SerialLink::getStopBits()
+int SerialLink::getStopBits() const
 {
     int ret = -1;
     switch (portSettings.stopBits()) {

src/comm/SerialLink.h

@@ -71,47 +71,47 @@ public:
     /** @brief Get a list of the currently available ports */
     QVector<QString>* getCurrentPorts();
 
-    bool isConnected();
+    bool isConnected() const;
     qint64 bytesAvailable();
 
     /**
      * @brief The port handle
      */
-    QString getPortName();
+    QString getPortName() const;
     /**
      * @brief The human readable port name
      */
-    QString getName();
-    int getBaudRate();
-    int getDataBits();
-    int getStopBits();
+    QString getName() const;
+    int getBaudRate() const;
+    int getDataBits() const;
+    int getStopBits() const;
 
     // ENUM values
-    int getBaudRateType();
-    int getFlowType();
-    int getParityType();
-    int getDataBitsType();
-    int getStopBitsType();
+    int getBaudRateType() const;
+    int getFlowType() const;
+    int getParityType() const;
+    int getDataBitsType() const;
+    int getStopBitsType() const;
 
     /* Extensive statistics for scientific purposes */
-    qint64 getNominalDataRate();
+    qint64 getNominalDataRate() const;
     qint64 getTotalUpstream();
     qint64 getCurrentUpstream();
     qint64 getMaxUpstream();
     qint64 getTotalDownstream();
     qint64 getCurrentDownstream();
     qint64 getMaxDownstream();
-    qint64 getBitsSent();
-    qint64 getBitsReceived();
+    qint64 getBitsSent() const;
+    qint64 getBitsReceived() const;
 
     void loadSettings();
     void writeSettings();
 
     void run();
 
-    int getLinkQuality();
-    bool isFullDuplex();
-    int getId();
+    int getLinkQuality() const;
+    bool isFullDuplex() const;
+    int getId() const;
 
 public slots:
     bool setPortName(QString portName);

src/comm/SerialLinkInterface.h

@@ -43,16 +43,16 @@ class SerialLinkInterface : public LinkInterface
 
 public:
     virtual QVector<QString>* getCurrentPorts() = 0;
-    virtual QString getPortName() = 0;
-    virtual int getBaudRate() = 0;
-    virtual int getDataBits() = 0;
-    virtual int getStopBits() = 0;
-
-    virtual int getBaudRateType() = 0;
-    virtual int getFlowType() = 0;
-    virtual int getParityType() = 0;
-    virtual int getDataBitsType() = 0;
-    virtual int getStopBitsType() = 0;
+    virtual QString getPortName() const = 0;
+    virtual int getBaudRate() const = 0;
+    virtual int getDataBits() const = 0;
+    virtual int getStopBits() const = 0;
+
+    virtual int getBaudRateType() const = 0;
+    virtual int getFlowType() const = 0;
+    virtual int getParityType() const = 0;
+    virtual int getDataBitsType() const = 0;
+    virtual int getStopBitsType() const = 0;
 
 public slots:
     virtual bool setPortName(QString portName) = 0;

src/comm/UDPLink.cc

@@ -354,17 +354,17 @@ bool UDPLink::hardwareConnect(void)
  *
  * @return True if link is connected, false otherwise.
  **/
-bool UDPLink::isConnected()
+bool UDPLink::isConnected() const
 {
     return connectState;
 }
 
-int UDPLink::getId()
+int UDPLink::getId() const
 {
     return id;
 }
 
-QString UDPLink::getName()
+QString UDPLink::getName() const
 {
     return name;
 }
@@ -376,7 +376,7 @@ void UDPLink::setName(QString name)
 }
 
 
-qint64 UDPLink::getNominalDataRate()
+qint64 UDPLink::getNominalDataRate() const
 {
     return 54000000; // 54 Mbit
 }
@@ -399,12 +399,12 @@ qint64 UDPLink::getMaxUpstream()
     return 0; // TODO
 }
 
-qint64 UDPLink::getBitsSent()
+qint64 UDPLink::getBitsSent() const
 {
     return bitsSentTotal;
 }
 
-qint64 UDPLink::getBitsReceived()
+qint64 UDPLink::getBitsReceived() const
 {
     return bitsReceivedTotal;
 }
@@ -427,12 +427,12 @@ qint64 UDPLink::getMaxDownstream()
     return 0; // TODO
 }
 
-bool UDPLink::isFullDuplex()
+bool UDPLink::isFullDuplex() const
 {
     return true;
 }
 
-int UDPLink::getLinkQuality()
+int UDPLink::getLinkQuality() const
 {
     /* This feature is not supported with this interface */
     return -1;

src/comm/UDPLink.h

@@ -49,7 +49,7 @@ public:
     //UDPLink(QHostAddress host = "239.255.76.67", quint16 port = 7667);
     ~UDPLink();
 
-    bool isConnected();
+    bool isConnected() const;
     qint64 bytesAvailable();
     int getPort() const {
         return port;
@@ -58,33 +58,33 @@ public:
     /**
      * @brief The human readable port name
      */
-    QString getName();
-    int getBaudRate();
-    int getBaudRateType();
-    int getFlowType();
-    int getParityType();
-    int getDataBitsType();
-    int getStopBitsType();
-    QList<QHostAddress> getHosts() {
+    QString getName() const;
+    int getBaudRate() const;
+    int getBaudRateType() const;
+    int getFlowType() const;
+    int getParityType() const;
+    int getDataBitsType() const;
+    int getStopBitsType() const;
+    QList<QHostAddress> getHosts() const {
         return hosts;
     }
 
     /* Extensive statistics for scientific purposes */
-    qint64 getNominalDataRate();
+    qint64 getNominalDataRate() const;
     qint64 getTotalUpstream();
     qint64 getCurrentUpstream();
     qint64 getMaxUpstream();
     qint64 getTotalDownstream();
     qint64 getCurrentDownstream();
     qint64 getMaxDownstream();
-    qint64 getBitsSent();
-    qint64 getBitsReceived();
+    qint64 getBitsSent() const;
+    qint64 getBitsReceived() const;
 
     void run();
 
-    int getLinkQuality();
-    bool isFullDuplex();
-    int getId();
+    int getLinkQuality() const;
+    bool isFullDuplex() const;
+    int getId() const;
 
 public slots:
     void setAddress(QHostAddress host);

src/comm/XbeeLink.cpp

@@ -32,7 +32,7 @@ XbeeLink::~XbeeLink()
 	this->disconnect();
 }
 
-QString XbeeLink::getPortName()
+QString XbeeLink::getPortName() const
 {
 	QString portName;
 	for(unsigned int i = 0;i<this->m_portNameLength;i++)
@@ -42,7 +42,7 @@ QString XbeeLink::getPortName()
 	return portName;
 }
 
-int XbeeLink::getBaudRate()
+int XbeeLink::getBaudRate() const
 {
 	return this->m_baudRate;
 }
@@ -104,32 +104,32 @@ bool XbeeLink::setBaudRate(int rate)
 	return retVal;
 }
 
-int XbeeLink::getId()
+int XbeeLink::getId() const
 {
 	return this->m_id;
 }
 
-QString XbeeLink::getName()
+QString XbeeLink::getName() const
 {
 	return this->m_name;
 }
 
-bool XbeeLink::isConnected()
+bool XbeeLink::isConnected() const
 {
 	return this->m_connected;
 }
 
-qint64 XbeeLink::getNominalDataRate()
+qint64 XbeeLink::getNominalDataRate() const
 {
 	return this->m_baudRate;
 }
 
-bool XbeeLink::isFullDuplex()
+bool XbeeLink::isFullDuplex() const
 {
 	return false;
 }
 
-int XbeeLink::getLinkQuality()
+int XbeeLink::getLinkQuality() const
 {
 	return -1; // TO DO:
 }
@@ -149,12 +149,12 @@ qint64 XbeeLink::getMaxUpstream()
 	return 0; // TO DO:
 }
 
-qint64 XbeeLink::getBitsSent()
+qint64 XbeeLink::getBitsSent() const
 {
 	return 0; // TO DO:
 }
 
-qint64 XbeeLink::getBitsReceived()
+qint64 XbeeLink::getBitsReceived() const
 {
 	return 0; // TO DO:
 }

src/comm/XbeeLink.h

@@ -20,8 +20,8 @@ public:
 	~XbeeLink();
 	
 public: // virtual functions from XbeeLinkInterface
-	QString getPortName();
-	int getBaudRate();
+    QString getPortName() const;
+    int getBaudRate() const;
 
 public slots: // virtual functions from XbeeLinkInterface
 	bool setPortName(QString portName);
@@ -30,20 +30,20 @@ public slots: // virtual functions from XbeeLinkInterface
 	bool setRemoteAddressLow(quint32 low);
 
 public: // virtual functions from LinkInterface
-	int getId();
-	QString getName();
-	bool isConnected();
-	qint64 getNominalDataRate();
-	bool isFullDuplex();
-	int getLinkQuality();
-	qint64 getTotalUpstream();
-	qint64 getCurrentUpstream();
-	qint64 getMaxUpstream();
-	qint64 getBitsSent();
-	qint64 getBitsReceived();
-	bool connect();
-	bool disconnect();
-	qint64 bytesAvailable();
+    int getId() const;
+    QString getName() const;
+    bool isConnected() const;
+    qint64 getNominalDataRate() const;
+    bool isFullDuplex() const;
+    int getLinkQuality() const;
+    qint64 getTotalUpstream();
+    qint64 getCurrentUpstream();
+    qint64 getMaxUpstream();
+    qint64 getBitsSent() const;
+    qint64 getBitsReceived() const;
+    bool connect();
+    bool disconnect();
+    qint64 bytesAvailable();
 
 public slots: // virtual functions from LinkInterface
 	void writeBytes(const char *bytes, qint64 length);