MQTT::Client Class Reference

The Client class. More...

#include <Client.h>

Inheritance diagram for MQTT::Client:

Collaboration diagram for MQTT::Client:

Public Slots
void	loadCaFile ()
void	connectToHost ()
void	toggleConnection ()
void	disconnectFromHost ()
void	setQos (const quint8 qos)
void	lookup (const QString &host)
void	setPort (const quint16 port)
void	setHost (const QString &host)
void	setRetain (const bool retain)
void	setClientMode (const int mode)
void	setTopic (const QString &topic)
void	loadCaFile (const QString &path)
void	setSslProtocol (const int index)
void	setSslEnabled (const bool enabled)
void	setUsername (const QString &username)
void	setPassword (const QString &password)
void	setKeepAlive (const quint16 keepAlive)
void	setMqttVersion (const int versionIndex)

Signals
void	qosChanged ()
void	portChanged ()
void	hostChanged ()
void	topicChanged ()
void	retainChanged ()
void	usernameChanged ()
void	passwordChanged ()
void	keepAliveChanged ()
void	connectedChanged ()
void	caFilePathChanged ()
void	clientModeChanged ()
void	sslEnabledChanged ()
void	sslProtocolChanged ()
void	mqttVersionChanged ()
void	lookupActiveChanged ()

Public Member Functions
quint8	qos () const
bool	retain () const
quint16	port () const
QString	host () const
QString	topic () const
int	clientMode () const
int	sslProtocol () const
int	mqttVersion () const
bool	sslEnabled () const
QString	username () const
QString	password () const
quint16	keepAlive () const
bool	lookupActive () const
bool	isSubscribed () const
bool	isConnectedToHost () const
StringList	qosLevels () const
StringList	clientModes () const
StringList	mqttVersions () const
StringList	sslProtocols () const
QString	caFilePath () const
quint16	defaultPort () const
QString	defaultHost () const

Static Public Member Functions
static Client &	instance ()

Properties
quint16	port
quint8	qos
QString	host
bool	retain
quint16	keepAlive
QString	topic
int	mqttVersion
int	clientMode
QString	username
QString	password
bool	sslEnabled
int	sslProtocol
bool	isConnectedToHost
bool	lookupActive
StringList	mqttVersions
StringList	clientModes
StringList	qosLevels
StringList	sslProtocols
quint16	defaultPort
QString	defaultHost
QString	caFilePath

Private Slots
void	sendData ()
void	resetStatistics ()
void	onConnectedChanged ()
void	lookupFinished (const QHostInfo &info)
void	onError (const QMQTT::ClientError error)
void	onFrameReceived (const QByteArray &frame)
void	onSslErrors (const QList< QSslError > &errors)
void	onMessageReceived (const QMQTT::Message &message)

Private Member Functions
	Client ()
	Client (Client &&)=delete
	Client (const Client &)=delete
Client &	operator= (Client &&)=delete
Client &	operator= (const Client &)=delete
	~Client ()
void	regenerateClient ()

Private Attributes
QString	m_topic
bool	m_sslEnabled
int	m_sslProtocol
bool	m_lookupActive
QString	m_caFilePath
quint16	m_sentMessages
MQTTClientMode	m_clientMode
QVector< QByteArray >	m_frames
QPointer< QMQTT::Client >	m_client
QSslConfiguration	m_sslConfiguration

Detailed Description

The Client class.

Implements a simple MQTT client, which allows Serial Studio to upload received frames to a MQTT broker so that other devices and/or services can make use of that information. By acting as a MQTT subscriber, Serial Studio can display & process frames from a remote Serial Studio instance that is setup as a MQTT publisher. As you might notice, this has a lot of interesting applications.

For example, you can receive frames from a CanSat mission and display them almost in real-time in another location, such as the "ground control" centre or by the media team which streams the GCS display on the internet as the mission is developing.

Constructor & Destructor Documentation

Client() [1/3]

MQTT::Client::Client ( )

explicitprivate

Constructor function

Client() [2/3]

MQTT::Client::Client ( Client &&  )

privatedelete

Client() [3/3]

MQTT::Client::Client ( const Client &  )

privatedelete

~Client()

MQTT::Client::~Client ( )

private

Destructor function

Member Function Documentation

caFilePath()

QString MQTT::Client::caFilePath

(

)

const

Returns the path of the currently loaded *.ca file

caFilePathChanged

void MQTT::Client::caFilePathChanged ( )

signal

clientMode()

int MQTT::Client::clientMode

(

)

const

Returns the client mode, which can have the following values:

• Publisher
• Subscriber

clientModeChanged

void MQTT::Client::clientModeChanged ( )

signal

clientModes()

StringList MQTT::Client::clientModes

(

)

const

Returns a list with the available client operation modes.

connectedChanged

void MQTT::Client::connectedChanged ( )

signal

connectToHost

void MQTT::Client::connectToHost ( )

slot

Tries to establish a TCP connection with the MQTT broker/server.

defaultHost()

QString MQTT::Client::defaultHost ( ) const

inline

defaultPort()

quint16 MQTT::Client::defaultPort ( ) const

inline

disconnectFromHost

void MQTT::Client::disconnectFromHost ( )

slot

Disconnects from the MQTT broker/server

host()

QString MQTT::Client::host

(

)

const

Returns the IP address of the MQTT broker/server

hostChanged

void MQTT::Client::hostChanged ( )

signal

instance()

MQTT::Client & MQTT::Client::instance ( )

static

Returns a pointer to the only instance of this class

isConnectedToHost()

bool MQTT::Client::isConnectedToHost

(

)

const

Returns true if the MQTT module is connected to a MQTT broker/server.

isSubscribed()

bool MQTT::Client::isSubscribed

(

)

const

Returns true if the MQTT module is connected to the broker, the topic is not empty and the client is configured to act as an MQTT subscriber.

keepAlive()

quint16 MQTT::Client::keepAlive

(

)

const

Returns the keep-alive timeout interval used by the MQTT client.

keepAliveChanged

void MQTT::Client::keepAliveChanged ( )

signal

loadCaFile [1/2]

void MQTT::Client::loadCaFile ( )

slot

Prompts the user to select a *.ca file and loads the certificate into the SSL configuration.

loadCaFile [2/2]

void MQTT::Client::loadCaFile ( const QString &  path )

slot

Reads the CA file in the given path and loads it into the SSL configuration handler for the MQTT connection.

lookup

void MQTT::Client::lookup ( const QString &  host )

slot

Performs a DNS lookup for the given host name

lookupActive()

bool MQTT::Client::lookupActive

(

)

const

Returns true if the MQTT module is currently performing a DNS lookup of the MQTT broker/server domain.

lookupActiveChanged

void MQTT::Client::lookupActiveChanged ( )

signal

lookupFinished

void MQTT::Client::lookupFinished ( const QHostInfo &  info )

privateslot

Sets the host IP address when the lookup finishes. If the lookup fails, the error code/string shall be shown to the user in a messagebox.

mqttVersion()

int MQTT::Client::mqttVersion

(

)

const

Returns the index of the MQTT version, corresponding to the list returned by the mqttVersions() function.

mqttVersionChanged

void MQTT::Client::mqttVersionChanged ( )

signal

mqttVersions()

StringList MQTT::Client::mqttVersions

(

)

const

Returns a list with the supported MQTT versions

onConnectedChanged

void MQTT::Client::onConnectedChanged ( )

privateslot

Subscribe/unsubscripe to the set MQTT topic when the connection state is changed.

onError

void MQTT::Client::onError ( const QMQTT::ClientError  error )

privateslot

Displays any MQTT-related error with a GUI message-box

onFrameReceived

void MQTT::Client::onFrameReceived ( const QByteArray &  frame )

privateslot

Registers the given frame data to the list of frames that shall be published to the MQTT broker/server

onMessageReceived

void MQTT::Client::onMessageReceived ( const QMQTT::Message &  message )

privateslot

Reads the given MQTT message and instructs the IO::Manager module to process received data directly.

onSslErrors

void MQTT::Client::onSslErrors ( const QList< QSslError > &  errors )

privateslot

Displays the SSL errors that occur and allows the user to decide if he/she wants to ignore those errors.

operator=() [1/2]

Client & MQTT::Client::operator= ( Client &&  )

privatedelete

operator=() [2/2]

Client & MQTT::Client::operator= ( const Client &  )

privatedelete

password()

QString MQTT::Client::password

(

)

const

Returns the MQTT password

passwordChanged

void MQTT::Client::passwordChanged ( )

signal

port()

quint16 MQTT::Client::port

(

)

const

Returns the TCP port number used for the MQTT connection

portChanged

void MQTT::Client::portChanged ( )

signal

qos()

quint8 MQTT::Client::qos

(

)

const

Returns the quality-of-service option, available values:

• 0: at most once
• 1: at least once
• 2: exactly once

qosChanged

void MQTT::Client::qosChanged ( )

signal

qosLevels()

StringList MQTT::Client::qosLevels

(

)

const

Returns a list with the available quality-of-service modes.

regenerateClient()

void MQTT::Client::regenerateClient ( )

private

Creates a new MQTT client instance, this approach is required in order to allow the MQTT module to support both non-encrypted and TLS connections.

resetStatistics

void MQTT::Client::resetStatistics ( )

privateslot

Clears the JSON frames & sets the sent messages to 0

retain()

bool MQTT::Client::retain

(

)

const

Returns true if the retain flag is enabled

retainChanged

void MQTT::Client::retainChanged ( )

signal

sendData

void MQTT::Client::sendData ( )

privateslot

Publishes all the received data to the MQTT broker

setClientMode

void MQTT::Client::setClientMode ( const int  mode )

slot

Changes the operation mode of the MQTT client. Possible values are:

• Publisher
• Subscriber

setHost

void MQTT::Client::setHost ( const QString &  host )

slot

Changes the IP address of the MQTT broker/host

setKeepAlive

void MQTT::Client::setKeepAlive ( const quint16  keepAlive )

slot

Sets the maximum time interval that is permitted to elapse between the point at which the Client finishes transmitting one Control Packet and the point it starts sending the next packet.

setMqttVersion

void MQTT::Client::setMqttVersion ( const int  versionIndex )

slot

Changes the MQTT version used to connect to the MQTT broker/server

setPassword

void MQTT::Client::setPassword ( const QString &  password )

slot

Changes the password used to connect to the MQTT broker/server

setPort

void MQTT::Client::setPort ( const quint16  port )

slot

Changes the TCP port number used for the MQTT communications.

setQos

void MQTT::Client::setQos ( const quint8  qos )

slot

Changes the quality of service level of the MQTT client.

setRetain

void MQTT::Client::setRetain ( const bool  retain )

slot

If set to true, the retain flag shall be appended to the MQTT message so that new clients connecting to the broker will immediately receive the last "good" message.

setSslEnabled

void MQTT::Client::setSslEnabled ( const bool  enabled )

slot

Enables/disables SSL/TLS communications with the MQTT broker

setSslProtocol

void MQTT::Client::setSslProtocol ( const int  index )

slot

Changes the SSL protocol version to use for the MQTT connection.

setTopic

void MQTT::Client::setTopic ( const QString &  topic )

slot

Changes the MQTT topic used by the client.

setUsername

void MQTT::Client::setUsername ( const QString &  username )

slot

Changes the username used to connect to the MQTT broker/server

sslEnabled()

bool MQTT::Client::sslEnabled

(

)

const

Returns true if SSL/TLS is enabled

sslEnabledChanged

void MQTT::Client::sslEnabledChanged ( )

signal

sslProtocol()

int MQTT::Client::sslProtocol

(

)

const

Returns the selected SSL/TLS protocol index

sslProtocolChanged

void MQTT::Client::sslProtocolChanged ( )

signal

sslProtocols()

StringList MQTT::Client::sslProtocols

(

)

const

Returns a list with the supported SSL/TLS protocols

toggleConnection

void MQTT::Client::toggleConnection ( )

slot

Connects/disconnects the application from the current MQTT broker. This function is used as a convenience for the connect/disconnect button.

topic()

QString MQTT::Client::topic

(

)

const

Returns the MQTT topic used

topicChanged

void MQTT::Client::topicChanged ( )

signal

username()

QString MQTT::Client::username

(

)

const

Returns the MQTT username

usernameChanged

void MQTT::Client::usernameChanged ( )

signal

Member Data Documentation

m_caFilePath

QString MQTT::Client::m_caFilePath

private

m_client

QPointer<QMQTT::Client> MQTT::Client::m_client

private

m_clientMode

MQTTClientMode MQTT::Client::m_clientMode

private

m_frames

QVector<QByteArray> MQTT::Client::m_frames

private

m_lookupActive

bool MQTT::Client::m_lookupActive

private

m_sentMessages

quint16 MQTT::Client::m_sentMessages

private

m_sslConfiguration

QSslConfiguration MQTT::Client::m_sslConfiguration

private

m_sslEnabled

bool MQTT::Client::m_sslEnabled

private

m_sslProtocol

int MQTT::Client::m_sslProtocol

private

m_topic

QString MQTT::Client::m_topic

private

Property Documentation

caFilePath

QString MQTT::Client::caFilePath

read

clientMode

int MQTT::Client::clientMode

readwrite

clientModes

StringList MQTT::Client::clientModes

read

defaultHost

QString MQTT::Client::defaultHost

read

defaultPort

quint16 MQTT::Client::defaultPort

read

host

QString MQTT::Client::host

readwrite

isConnectedToHost

bool MQTT::Client::isConnectedToHost

read

keepAlive

quint16 MQTT::Client::keepAlive

readwrite

lookupActive

bool MQTT::Client::lookupActive

read

mqttVersion

int MQTT::Client::mqttVersion

readwrite

mqttVersions

StringList MQTT::Client::mqttVersions

read

password

QString MQTT::Client::password

readwrite

port

quint16 MQTT::Client::port

readwrite

qos

quint8 MQTT::Client::qos

readwrite

qosLevels

StringList MQTT::Client::qosLevels

read

retain

bool MQTT::Client::retain

readwrite

sslEnabled

bool MQTT::Client::sslEnabled

readwrite

sslProtocol

int MQTT::Client::sslProtocol

readwrite

sslProtocols

StringList MQTT::Client::sslProtocols

read

topic

QString MQTT::Client::topic

readwrite

username

QString MQTT::Client::username

readwrite

---

The documentation for this class was generated from the following files:

• /Users/alex/Documents/GitHub/Serial-Studio/src/MQTT/Client.h
• /Users/alex/Documents/GitHub/Serial-Studio/src/MQTT/Client.cpp