KDNSSD::ServiceBrowser Class Reference

#include <KDNSSD/ServiceBrowser>

Inheritance diagram for KDNSSD::ServiceBrowser:

Public Types
enum	State { Working , Stopped , Unsupported }

Signals
void	finished ()
void	serviceAdded (KDNSSD::RemoteService::Ptr service)
void	serviceRemoved (KDNSSD::RemoteService::Ptr service)

Public Member Functions
	ServiceBrowser (const QString &type, bool autoResolve=false, const QString &domain=QString(), const QString &subtype=QString())
bool	isAutoResolving () const
QList< RemoteService::Ptr >	services () const
virtual void	startBrowse ()
Public Member Functions inherited from QObject
	QObject (QObject *parent)
QBindable< QString >	bindableObjectName ()
bool	blockSignals (bool block)
const QObjectList &	children () const const
QMetaObject::Connection	connect (const QObject *sender, const char *signal, const char *method, Qt::ConnectionType type) const const
void	deleteLater ()
void	destroyed (QObject *obj)
bool	disconnect (const char *signal, const QObject *receiver, const char *method) const const
bool	disconnect (const QObject *receiver, const char *method) const const
void	dumpObjectInfo () const const
void	dumpObjectTree () const const
QList< QByteArray >	dynamicPropertyNames () const const
virtual bool	event (QEvent *e)
virtual bool	eventFilter (QObject *watched, QEvent *event)
T	findChild (const QString &name, Qt::FindChildOptions options) const const
QList< T >	findChildren (const QRegularExpression &re, Qt::FindChildOptions options) const const
QList< T >	findChildren (const QString &name, Qt::FindChildOptions options) const const
QList< T >	findChildren (Qt::FindChildOptions options) const const
bool	inherits (const char *className) const const
void	installEventFilter (QObject *filterObj)
bool	isQuickItemType () const const
bool	isWidgetType () const const
bool	isWindowType () const const
void	killTimer (int id)
virtual const QMetaObject *	metaObject () const const
void	moveToThread (QThread *targetThread)
QString	objectName () const const
void	objectNameChanged (const QString &objectName)
QObject *	parent () const const
QVariant	property (const char *name) const const
	Q_CLASSINFO (Name, Value)
	Q_EMIT Q_EMIT
	Q_ENUM (...)
	Q_ENUM_NS (...)
	Q_ENUMS (...)
	Q_FLAG (...)
	Q_FLAG_NS (...)
	Q_FLAGS (...)
	Q_GADGET Q_GADGET
	Q_GADGET_EXPORT (EXPORT_MACRO)
	Q_INTERFACES (...)
	Q_INVOKABLE Q_INVOKABLE
	Q_MOC_INCLUDE Q_MOC_INCLUDE
	Q_NAMESPACE Q_NAMESPACE
	Q_NAMESPACE_EXPORT (EXPORT_MACRO)
	Q_OBJECT Q_OBJECT
	Q_PROPERTY (...)
	Q_REVISION Q_REVISION
	Q_SET_OBJECT_NAME (Object)
	Q_SIGNAL Q_SIGNAL
	Q_SIGNALS Q_SIGNALS
	Q_SLOT Q_SLOT
	Q_SLOTS Q_SLOTS
T	qobject_cast (const QObject *object)
T	qobject_cast (QObject *object)
	QT_NO_NARROWING_CONVERSIONS_IN_CONNECT QT_NO_NARROWING_CONVERSIONS_IN_CONNECT
void	removeEventFilter (QObject *obj)
void	setObjectName (const QString &name)
void	setObjectName (QAnyStringView name)
void	setParent (QObject *parent)
bool	setProperty (const char *name, const QVariant &value)
bool	setProperty (const char *name, QVariant &&value)
bool	signalsBlocked () const const
int	startTimer (int interval, Qt::TimerType timerType)
int	startTimer (std::chrono::milliseconds interval, Qt::TimerType timerType)
QThread *	thread () const const

Static Public Member Functions
static QString	getLocalHostName ()
static State	isAvailable ()
static QHostAddress	resolveHostName (const QString &hostname)
Static Public Member Functions inherited from QObject
QMetaObject::Connection	connect (const QObject *sender, const char *signal, const QObject *receiver, const char *method, Qt::ConnectionType type)
QMetaObject::Connection	connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type)
QMetaObject::Connection	connect (const QObject *sender, PointerToMemberFunction signal, const QObject *context, Functor functor, Qt::ConnectionType type)
QMetaObject::Connection	connect (const QObject *sender, PointerToMemberFunction signal, const QObject *receiver, PointerToMemberFunction method, Qt::ConnectionType type)
QMetaObject::Connection	connect (const QObject *sender, PointerToMemberFunction signal, Functor functor)
bool	disconnect (const QMetaObject::Connection &connection)
bool	disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *method)
bool	disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method)
bool	disconnect (const QObject *sender, PointerToMemberFunction signal, const QObject *receiver, PointerToMemberFunction method)
QString	tr (const char *sourceText, const char *disambiguation, int n)

Protected Member Functions
virtual void	virtual_hook (int, void *)
Protected Member Functions inherited from QObject
virtual void	childEvent (QChildEvent *event)
virtual void	connectNotify (const QMetaMethod &signal)
virtual void	customEvent (QEvent *event)
virtual void	disconnectNotify (const QMetaMethod &signal)
bool	isSignalConnected (const QMetaMethod &signal) const const
int	receivers (const char *signal) const const
QObject *	sender () const const
int	senderSignalIndex () const const
virtual void	timerEvent (QTimerEvent *event)

Additional Inherited Members
Properties inherited from QObject
	objectName
Public Attributes inherited from QObject
typedef	QObjectList

Detailed Description

Browses for network services advertised over DNS-SD.

This is the central class in the KDNSSD library for applications that want to discover services on network.

Suppose that you need list of web servers running. Then you might do something like

KDNSSD::ServiceBrowser *browser = new KDNSSD::ServiceBrowser(QStringLiteral("_http._tcp"));
connect(browser, &KDNSSD::ServiceBrowser::serviceAdded,
        this, [](KDNSSD::RemoteService::Ptr service) {
        });
connect(browser, &KDNSSD::ServiceBrowser::serviceRemoved,
        this, [](KDNSSD::RemoteService::Ptr service) {
        });
browser->startBrowse();

In above example addService() will be called for every web server already running and for every web service that subsequently appears on the network and delService() will be called when a server previously advertised is stopped.

Because no domain was passed to constructor, the default domain will be searched. To find other domains to browse for services on, use DomainBrowser.

Author

Jakub Stachowski

Definition at line 54 of file servicebrowser.h.

Member Enumeration Documentation

State

enum KDNSSD::ServiceBrowser::State

Availability of DNS-SD services.

Enumerator
Working	the service is available
Stopped	not available because mDnsd or Avahi daemon is not running
Unsupported	not available because KDE was compiled without DNS-SD support

Definition at line 62 of file servicebrowser.h.

Constructor & Destructor Documentation

ServiceBrowser()

KDNSSD::ServiceBrowser::ServiceBrowser ( const QString & type, bool autoResolve = false, const QString & domain = QString(), const QString & subtype = QString() )

explicit

Create a ServiceBrowser for a particular service type.

DomainBrowser can be used to find other domains to browse on. If no domain is given, the default domain is used.

The service type is the high-level protocol type, followed by a dot, followed by the transport protocol type (_tcp or _udp). The DNS-SD website maintains a full list of service types.

The subtype parameter allows you to do more fine-grained filtering on the services you are interested in. So you might request only FTP servers that allow anonymous access by passing "_ftp._tcp" as the type and "_anon" as the subtype. Subtypes are particularly important for types like _soap and _upnp, which are far too generic for most applications. In these cases, the subtype can be used to specify the particular SOAP or UPnP protocol they want.

Warning

Enabling autoResolve will increase network usage by resolving all services, so this feature should be used only when necessary.

Parameters

type	service types to browse for (example: "_http._tcp")
autoResolve	discovered services will be resolved before being reported with the serviceAdded() signal
domain	a domain to search on instead of the default one
subtype	only browse for a specific subtype

See also

startBrowse() and isAvailable()

Definition at line 20 of file avahi-servicebrowser.cpp.

~ServiceBrowser()

KDNSSD::ServiceBrowser::~ServiceBrowser ( )

overridedefault

Definition at line 34 of file dummy-servicebrowser.cpp.

Member Function Documentation

finished

void KDNSSD::ServiceBrowser::finished ( )

signal

Emitted when the list of published services has settled.

This signal is emitted once after startBrowse() is called when all the services of the requested type that are currently published have been reported (even if none are available or the DNS-SD service is not available). It is emitted again when a new batch of services become available or disappear.

For example, if a new host is connected to network and announces some services watched for by this ServiceBrowser, they will be reported by one or more serviceAdded() signals and the whole batch will be concluded by finished().

This signal can be used by applications that just want to get a list of the currently available services (similar to a directory listing) and do not care about adding or removing services that appear or disappear later.

Warning

There is no guarantee any RemoteService pointers received by serviceAdded() will be valid by the time this signal is emitted, so you should either do all your work involving them in the slot receiving the serviceAdded() signal, or you should listen to serviceRemoved() as well.

See also

serviceAdded() and serviceRemoved()

getLocalHostName()

QString KDNSSD::ServiceBrowser::getLocalHostName ( )

static

The mDNS hostname of the local machine.

Usually this will return the same as QHostInfo::localHostName(), but it may be changed to something different in the Avahi configuration file (if using the Avahi backend).

Returns

the hostname, or an empty string on failure

Since

4.2

Definition at line 244 of file avahi-servicebrowser.cpp.

isAutoResolving()

bool KDNSSD::ServiceBrowser::isAutoResolving

(

)

const

Whether discovered services are resolved before being reported.

Returns

the value of the autoResolve parameter passed to the constructor

Since

4.1

Definition at line 40 of file avahi-servicebrowser.cpp.

isAvailable()

ServiceBrowser::State KDNSSD::ServiceBrowser::isAvailable ( )

static

Checks availability of DNS-SD services.

Although this method is part of ServiceBrowser, none of the classes in this library will be able to perform their intended function if this method does not return Working.

If this method does not return Working, it is still safe to call any of the methods in this library. However, no services will be found or published and no domains will be found.

If you use this function to report an error to the user, below is a suggestion on how to word the errors when publishing a service. The first line of each error message can also be used for reporting errors when browsing for services.

switch(KDNSSD::ServiceBrowser::isAvailable()) {
case KDNSSD::ServiceBrowser::Working:
    return "";
case KDNSSD::ServiceBrowser::Stopped:
    return i18n("<p>The Zeroconf daemon is not running. See the Service"
                " Discovery Handbook for more information.<br/>"
                "Other users will not see the services provided by this
                " system when browsing the network via zeroconf, but "
                " normal access will still work.</p>");
case KDNSSD::ServiceBrowser::Unsupported:
    return i18n("<p>Zeroconf support is not available in this version of KDE."
                " See the Service Discovery Handbook for more information.<br/>"
                "Other users will not see the services provided by this
                " application when browsing the network via zeroconf, but "
                " normal access will still work.</p>");
default:
    return i18n("<p>Unknown error with Zeroconf.<br/>"
                "Other users will not see the services provided by this
                " application when browsing the network via zeroconf, but "
                " normal access will still work.</p>");
}

Definition at line 31 of file avahi-servicebrowser.cpp.

resolveHostName()

QHostAddress KDNSSD::ServiceBrowser::resolveHostName ( const QString & hostname )

static

Resolves an mDNS hostname into an IP address.

This function is very rarely useful, since a properly configured system is able to resolve an mDNS-based host name using the system resolver (ie: you can just pass the mDNS hostname to KIO or other library).

Parameters

hostname

the hostname to be resolved

Returns

a QHostAddress containing the IP address, or QHostAddress() if resolution failed

Since

4.2

Definition at line 225 of file avahi-servicebrowser.cpp.

serviceAdded

void KDNSSD::ServiceBrowser::serviceAdded ( KDNSSD::RemoteService::Ptr service )

signal

Emitted when new service is discovered.

If isAutoResolving() returns true, this will not be emitted until the service has been resolved.

Parameters

service

a RemoteService object describing the service

See also

serviceRemoved() and finished()

serviceRemoved

void KDNSSD::ServiceBrowser::serviceRemoved ( KDNSSD::RemoteService::Ptr service )

signal

Emitted when a service is no longer published over DNS-SD.

The RemoteService object is removed from the services() list and deleted immediately after this signal returns.

Warning

Do not use a delayed connection with this signal

Parameters

service

a RemoteService object describing the service

See also

serviceAdded() and finished()

services()

QList< RemoteService::Ptr > KDNSSD::ServiceBrowser::services

(

)

const

The currently known services of the specified type.

Returns

a list of RemoteService pointers

See also

serviceAdded() and serviceRemoved()

Definition at line 215 of file avahi-servicebrowser.cpp.

startBrowse()

void KDNSSD::ServiceBrowser::startBrowse ( )

virtual

Starts browsing for services.

Only the first call to this function will have any effect.

Browsing stops when the ServiceBrowser object is destroyed.

Warning

The serviceAdded() signal may be emitted before this function returns.

See also

serviceAdded(), serviceRemoved() and finished()

Definition at line 46 of file avahi-servicebrowser.cpp.

virtual_hook()

void KDNSSD::ServiceBrowser::virtual_hook ( int , void *  )

protectedvirtual

Definition at line 221 of file avahi-servicebrowser.cpp.

---

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

• servicebrowser.h
• avahi-servicebrowser.cpp
• dummy-servicebrowser.cpp
• mdnsd-servicebrowser.cpp