/* This file is part of the KDE project
 *
 * Copyright (C) 2004 Jakub Stachowski <qbast@go2.pl>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#ifndef KDNSSDSERVICETYPEBROWSER_H
#define KDNSSDSERVICETYPEBROWSER_H

#include <QtCore/QObject>
#include <dnssd/remoteservice.h>

class QStringList;
namespace KDNSSD
{
class ServiceTypeBrowserPrivate;

/**
 * @class ServiceBrowser servicebrowser.h KDNSSD/ServiceBrowser
 * @short Browses the service types being published on a domain
 *
 * This class is mostly useful for generic utilities for
 * browsing all the published services on a local network.
 * Applications that wish to find out about available services
 * of a particular type (such as web servers) should use
 * ServiceBrowser.
 *
 * ServiceTypeBrowser provides a list of all the service types
 * published by at least one service on a given domain.
 *
 * @author Jakub Stachowski
 */
class KDNSSD_EXPORT ServiceTypeBrowser : public QObject
{
    Q_OBJECT

public:
    /**
     * Create a ServiceTypeBrowser for a domain
     *
     * The link-local domain (the LAN subnet for this computer) will
     * be used if no @p domain is given.  DomainBrowser can be used
     * to get a list of browsing domains.
     *
     * Note that WAN domains may not support service type browsing.
     *
     * @param domain a browsing domain to search
     * @param parent the parent object (see QObject documentation)
     *
     * @see startBrowse() and ServiceBrowser::isAvailable()
     */
    explicit ServiceTypeBrowser(const QString &domain = QString(),
                                QObject *parent = 0);

    ~ServiceTypeBrowser();

    /**
     * All the service types currently being published
     *
     * @return a list of service types, in the form _type._tcp or _type._udp
     */
    QStringList serviceTypes() const;

    /**
     * Starts browsing
     *
     * Only the first call to this function will have any effect.
     *
     * Browsing stops when the ServiceBrowser object is destroyed.
     *
     * @warning The serviceTypeAdded() signal may be emitted before this
     *          function returns.
     *
     * @see serviceTypeAdded(), serviceTypeRemoved() and finished()
     */
    void startBrowse();

#ifndef KDNSSD_NO_DEPRECATED
    /**
     * This method is unnecessary, since it is safe to call startBrowse()
     * multiple times.
     * @deprecated since 4.0, just call startBrowse() again.
     */
    KDNSSD_DEPRECATED bool isRunning() const
    {
        return false;
    }
#endif

Q_SIGNALS:
    /**
     * Emitted when there are no more services of this type
     *
     * @warning
     * This signal is not reliable: it is possible that it will not be
     * emitted even after last service of this type disappeared
     *
     * @param type the service type
     *
     * @see serviceTypeAdded() and finished()
     */
    void serviceTypeRemoved(const QString &type);

    /**
     * A new type of service has been found
     *
     * @param type the service type
     *
     * @see serviceTypeAdded() and finished()
     */
    void serviceTypeAdded(const QString &type);

    /**
     * Emitted when the list of published service types has settled
     *
     * This signal is emitted once after startBrowse() is called
     * when the types of all the services that are
     * currently published have been reported (even if no services
     * are available or the DNS-SD service is not available).
     * It is emitted again when a new batch of service types become
     * available or disappear.
     *
     * For example, if a new host is connected to network and
     * announces services of several new types,
     * they will be reported by several serviceTypeAdded() 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 service types
     * (similar to a directory listing) and do not care about
     * adding or removing service types that appear or disappear later.
     *
     * @see serviceTypeAdded() and serviceTypeRemoved()
     */
    void finished();

private:
    friend class ServiceTypeBrowserPrivate;
    ServiceTypeBrowserPrivate *const d;
};

}

#endif
