kgame.h

/*
    This file is part of the KDE games library
    SPDX-FileCopyrightText: 2001 Martin Heni <kde at heni-online.de>
    SPDX-FileCopyrightText: 2001 Andreas Beckermann <[email protected]>
 
    SPDX-License-Identifier: LGPL-2.0-only
*/
 
#ifndef __KGAME_H_
#define __KGAME_H_
 
// own
#include "kgamenetwork.h"
#include "libkdegamesprivate_export.h"
// KF
#include <kcoreaddons_export.h> // for KCOREADDONS_ENABLE_DEPRECATED_SINCE
// Qt
#include <QDataStream>
#include <QList>
#include <QLoggingCategory>
#include <QString>
 
Q_DECLARE_LOGGING_CATEGORY(GAMES_PRIVATE_KGAME)
 
#if KDEGAMESPRIVATE_ENABLE_DEPRECATED_SINCE(7, 3)
class KRandomSequence;
#endif
 
class KPlayer;
class KGamePropertyBase;
class KGamePropertyHandler;
class KGameSequence;
 
class KGamePrivate;
 
/**
 * \class KGame kgame.h <KGame/KGame>
 *
 * @short The main KDE game object
 *
 * The KGame class is the central game object. A game basically
 * consists of following features:
 * - Player handling (add, remove,...)
 * - Game status (end,start,pause,...)
 * - load/save
 * - Move (and message) handling
 * - nextPlayer and gameOver()
 * - Network connection (for KGameNetwork)
 *
 * Example:
 * \code
 * KGame *game=new KGame;
 * \endcode
 */
class KDEGAMESPRIVATE_EXPORT KGame : public KGameNetwork
{
    Q_OBJECT
 
public:
    typedef QList<KPlayer *> KGamePlayerList;
 
    /**
     * The policy of the property. This can be PolicyClean (setVale uses
     * send), PolicyDirty (setValue uses changeValue) or
     * PolicyLocal (setValue uses setLocal).
     *
     * A "clean" policy means that the property is always the same on every
     * client. This is achieved by calling send which actually changes
     * the value only when the message from the MessageServer is received.
     *
     * A "dirty" policy means that as soon as setValue is called the
     * property is changed immediately. And additionally sent over network.
     * This can sometimes lead to bugs as the other clients do not
     * immediately have the same value. For more information see
     * changeValue.
     *
     * PolicyLocal means that a KGameProperty behaves like ever
     * "normal" variable. Whenever setValue is called (e.g. using "=")
     * the value of the property is changes immediately without sending it
     * over network. You might want to use this if you are sure that all
     * clients set the property at the same time.
     */
    enum GamePolicy { PolicyUndefined = 0, PolicyClean = 1, PolicyDirty = 2, PolicyLocal = 3 };
 
    /**
     * Create a KGame object. The cookie is used to identify your
     * game in load/save and network operations. Change this between
     * games.
     */
    explicit KGame(int cookie = 42, QObject *parent = nullptr);
 
    /**
     * Destructs the game
     */
    ~KGame() override;
 
    /**
     * Gives debug output of the game status
     */
    void Debug() override;
 
    /**
     * Game status - Use this to Control the game flow.
     * The KGame e.g. sets the status to Pause when you have
     * less player than the minimum amount
     */
    enum GameStatus { Init = 0, Run = 1, Pause = 2, End = 3, Abort = 4, SystemPause = 5, Intro = 6, UserStatus = 7 };
 
    // Properties
    /**
     * Returns a list of all active players
     *
     * @return the list of players
     */
    KGamePlayerList *playerList();
 
    /**
     * The same as @ref playerList but returns a const pointer.
     */
    const KGamePlayerList *playerList() const;
 
    /**
     * Returns a list of all inactive players
     * @return the list of players
     */
    KGamePlayerList *inactivePlayerList();
 
    /**
     * The same as @ref inactivePlayerList but returns a const pointer.
     */
    const KGamePlayerList *inactivePlayerList() const;
 
#if KDEGAMESPRIVATE_ENABLE_DEPRECATED_SINCE(7, 3)
#if KCOREADDONS_ENABLE_DEPRECATED_SINCE(5, 75)
    /**
     * Returns a pointer to the game's KRandomSequence. This sequence is
     * identical for all network players!
     * @return KRandomSequence pointer
     * @deprecated Since 7.3, no known users. Any replacement should use QRandomGenerator.
     */
    KDEGAMESPRIVATE_DEPRECATED_VERSION(7, 3, "No known users. Any replacement should use QRandomGenerator.")
    KRandomSequence *random() const;
#endif
#endif
 
    /**
     * @return The KGameSequence object that is currently in use.
     * @see setGameSequence
     */
    KGameSequence *gameSequence() const;
 
    /**
     * Is the game running
     * @return true/false
     */
    bool isRunning() const;
 
    // Player handling
    /**
     * Returns the player object for a given player id
     * @param id Player id
     * @return player object
     */
    KPlayer *findPlayer(quint32 id) const;
 
    /**
     * Set a new @ref KGameSequence to control player management. By default
     * KGame uses a normal @ref KGameSequence object. You might want to subclass
     * that and provide your own object.
     *
     * The previous sequence will get deleted.
     * @param sequence The new game sequence object. KGame takes ownership and
     * will delete it on destruction!
     */
    void setGameSequence(KGameSequence *sequence);
 
    /**
     * Note that KPlayer::save must be implemented properly, as well as
     * KPlayer::rtti
     * This will only send a message to all clients. The player is _not_ added
     * directly!
     * See also playerInput which will be called as soon as the
     * player really has been added.
     *
     * Note that an added player will first get into a "queue" and won't be in
     * the game. It will be added to the game as soon as systemAddPlayer is
     * called what will happen as soon as IdAddPlayer is received.
     *
     * Note: you probably want to connect to signalPlayerJoinedGame for
     * further initialization!
     * @param newplayer The player you want to add. KGame will send a message to
     * all clients and add the player using systemAddPlayer
     */
    bool addPlayer(KPlayer *newplayer);
 
    /**
     * Sends a message over the network, msgid=IdRemovePlayer.
     *
     * As soon as this message is received by networkTransmission
     * systemRemovePlayer is called and the player is removed.
     */
    // AB: TODO: make sendMessage to return if the message will be able to be
    // sent, eg if a socket is connected, etc. If sendMessage returns false
    // remove the player directly using systemRemovePlayer
    bool removePlayer(KPlayer *player)
    {
        return removePlayer(player, 0);
    }
 
    /**
     * Called by the destructor of KPlayer to remove itself from the game
     *
     */
    void playerDeleted(KPlayer *player);
 
    /**
     * sends activate player: internal use only?
     */
    bool activatePlayer(KPlayer *player);
 
    /**
     * sends inactivate player: internal use only?
     */
    bool inactivatePlayer(KPlayer *player);
 
    /**
     * Set the maximal number of players. After this is
     * reached no more players can be added. You must be ADMIN to call this (@see
     * isAdmin).
     * @param maxnumber maximal number of players
     */
    void setMaxPlayers(uint maxnumber);
 
    /**
     * What is the maximal number of players?
     * @return maximal number of players
     */
    int maxPlayers() const;
 
    /**
     * Set the minimal number of players. A game can not be started
     * with less player resp. is paused when already running. You must be ADMIN
     * to call this (see @ref isAdmin)!
     * @param minnumber minimal number of players
     */
    void setMinPlayers(uint minnumber);
 
    /**
     * What is the minimal number of players?
     * @return minimal number of players
     */
    uint minPlayers() const;
 
    /**
     * Returns how many players are plugged into the game
     * @return number of players
     */
    uint playerCount() const;
 
#if KDEGAMESPRIVATE_BUILD_DEPRECATED_SINCE(3, 2)
    /**
     * @deprecated Since 3.2, use KGameSequence::nextPlayer() instead
     */
    KDEGAMESPRIVATE_DEPRECATED_VERSION(3, 2, "Use KGameSequence::nextPlayer()")
    virtual KPlayer *nextPlayer(KPlayer *last, bool exclusive = true);
#endif
 
    // Input events
    /**
     * Called by KPlayer to send a player input to the
     * KMessageServer.
     */
    virtual bool sendPlayerInput(QDataStream &msg, KPlayer *player, quint32 sender = 0);
 
    /**
     * Called when a player input arrives from KMessageServer.
     *
     * Calls prepareNext (using QTimer::singleShot) if gameOver()
     * returns 0. This function should normally not be used outside KGame.
     * It could be made non-virtual,protected in a later version. At the
     * moment it is a virtual function to give you more control over KGame.
     *
     * For documentation see playerInput.
     */
    virtual bool systemPlayerInput(QDataStream &msg, KPlayer *player, quint32 sender = 0);
 
    /**
     * This virtual function is called if the KGame needs to create a new player.
     * This happens only over a network and with load/save. Doing nothing
     * will create a default KPlayer. If you want to have your own player
     * you have to create one with the given rtti here.
     * Note: If your game uses a player class derived from KPlayer you MUST
     * override this function and create your player here. Otherwise the
     * game will crash.
     * Example:
     * \code
     *  KPlayer *MyGame::createPlayer(int rtti,int io,bool isvirtual)
     *  {
     *    KPlayer *player=new MyPlayer;
     *    if (!isvirtual) // network player ?
     *    {
     *      // Define something like this to add the IO modules
     *      createIO(player,(KGameIO::IOMode)io);
     *    }
     *    return player;
     *    }
     * \endcode
     *
     * @param rtti is the type of the player (0 means default KPlayer)
     * @param io is the 'or'ed rtti of the KGameIO's
     * @param isvirtual true if player is virtual
     */
    virtual KPlayer *createPlayer(int rtti, int io, bool isvirtual);
 
    // load/save
    /**
     * Load a saved game, from file OR network. This function has
     * to be overwritten or you need to connect to the load signal
     * if you have game data other than KGameProperty.
     * For file load you should reset() the game before any load attempt
     * to make sure you load into an clear state.
     *
     * @param stream a data stream where you can stream the game from
     * @param reset - shall the game be reset before loading
     *
     * @return true?
     */
    virtual bool load(QDataStream &stream, bool reset = true);
 
    /**
     * Same as above function but with different parameters
     *
     * @param filename - the filename of the file to be opened
     * @param reset - shall the game be reset before loading
     *
     * @return true?
     */
    virtual bool load(const QString &filename, bool reset = true);
 
    /**
     * Save a game to a file OR to network. Otherwise the same as
     * the load function
     *
     * @param stream a data stream to load the game from
     * @param saveplayers If true then all players wil be saved too
     *
     * @return true?
     */
    virtual bool save(QDataStream &stream, bool saveplayers = true);
 
    /**
     * Same as above function but with different parameters
     *
     * @param filename the filename of the file to be saved
     * @param saveplayers If true then all players wil be saved too
     *
     * @return true?
     */
    virtual bool save(const QString &filename, bool saveplayers = true);
 
    /**
     * Resets the game, i.e. puts it into a state where everything
     * can be started from, e.g. a load game
     * Right now it does only need to delete all players
     *
     * @return true on success
     */
    virtual bool reset();
 
    // Game sequence
    /**
     * returns the game status, ie running,pause,ended,...
     *
     * @return game status
     */
    int gameStatus() const;
 
    /**
     * sets the game status
     *
     * @param status the new status
     */
    void setGameStatus(int status);
 
    /**
     *  docu: see KPlayer
     */
    bool addProperty(KGamePropertyBase *data);
 
    /**
     * This is called by KPlayer::sendProperty only! Internal function!
     */
    bool sendPlayerProperty(int msgid, QDataStream &s, quint32 playerId);
 
    /**
     * This function allows to find the pointer to a player
     * property when you know its id
     */
    KGamePropertyBase *findProperty(int id) const;
 
    /**
     * Changes the consistency policy of a property. The
     * GamePolicy is one of PolicyClean (default), PolicyDirty or PolicyLocal.
     *
     * It is up to you to decide how you want to work.
     */
    void setPolicy(GamePolicy p, bool recursive = true);
 
    /**
     * @return The default policy of the property
     */
    GamePolicy policy() const;
 
    /**
     * See KGameNetwork::sendMessage
     *
     * Send a network message msg with a given message ID msgid to all players of
     * a given group (see KPlayer::group)
     * @param msg the message which will be send. See messages.txt for contents
     * @param msgid an id for this message
     * @param sender the id of the sender
     * @param group the group of the receivers
     * @return true if worked
     */
    bool sendGroupMessage(const QByteArray &msg, int msgid, quint32 sender, const QString &group);
    bool sendGroupMessage(const QDataStream &msg, int msgid, quint32 sender, const QString &group);
    bool sendGroupMessage(int msg, int msgid, quint32 sender, const QString &group);
    bool sendGroupMessage(const QString &msg, int msgid, quint32 sender, const QString &group);
 
    /**
     * This will either forward an incoming message to a specified player
     * (see KPlayer::networkTransmission) or
     * handle the message directly (e.g. if msgif==IdRemovePlayer it will remove
     * the (in the stream) specified player). If both is not possible (i.e. the
     * message is user specified data) the signal signalNetworkData is
     * emitted.
     *
     * This emits signalMessageUpdate <em>before</em> doing anything with
     * the message. You can use this signal when you want to be notified about
     * an update/change.
     * @param msgid Specifies the kind of the message. See messages.txt for
     * further information
     * @param stream The message that is being sent
     * @param receiver The is of the player this message is for. 0 For broadcast.
     * @param sender
     * @param clientID the client from which we received the transmission - hardly used
     */
    void networkTransmission(QDataStream &stream, int msgid, quint32 receiver, quint32 sender, quint32 clientID) override;
 
    /**
     * Returns a pointer to the KGame property handler
     */
    KGamePropertyHandler *dataHandler() const;
 
protected Q_SLOTS:
    /**
     * Called by KGamePropertyHandler only! Internal function!
     */
    void sendProperty(int msgid, QDataStream &stream, bool *sent);
 
    /**
     * Called by KGamePropertyHandler only! Internal function!
     */
    void emitSignal(KGamePropertyBase *me);
 
#if KDEGAMESPRIVATE_BUILD_DEPRECATED_SINCE(3, 2)
    /**
     * @deprecated Since 3.2, use KGameSequence::nextPlayer() & KGameSequence::currentPlayer() instead
     */
    KDEGAMESPRIVATE_DEPRECATED_VERSION(3, 2, "Use KGameSequence::nextPlayer() & KGameSequence::currentPlayer()")
    virtual void prepareNext();
#endif
 
    /**
     * Calls negotiateNetworkGame()
     * See KGameNetwork::signalClientConnected
     */
    void slotClientConnected(quint32 clientId);
 
    /**
     * This slot is called whenever the connection to a client is lost (ie the
     * signal KGameNetwork::signalClientDisconnected is emitted) and will remove
     * the players from that client.
     * @param clientId The client the connection has been lost to
     * @param broken (ignore this - not used)
     */
    void slotClientDisconnected(quint32 clientId, bool broken);
 
    /**
     * This slot is called whenever the connection to the server is lost (ie the
     * signal KGameNetwork::signalConnectionBroken is emitted) and will
     * switch to local game mode
     */
    void slotServerDisconnected();
 
Q_SIGNALS:
    /**
     * When a client disconnects from the game usually all players from that
     * client are removed. But if you use completely the KGame structure you
     * probably don't want this. You just want to replace the KGameIO of the
     * (human) player by a computer KGameIO. So this player continues game but
     * is from this point on controlled by the computer.
     *
     * You achieve this by connecting to this signal. It is emitted as soon as a
     * client disconnects on <em>all</em> other clients. Make sure to add a new
     * KGameIO only once! you might want to use @ref isAdmin for this. If you
     * added a new KGameIO set *remove=false otherwise the player is completely
     * removed.
     * @param player The player that is about to be removed. Add your new
     * KGameIO here - but only on <em>one</em> client!
     * @param remove Set this to FALSE if you don't want this player to be
     * removed completely.
     */
    void signalReplacePlayerIO(KPlayer *player, bool *remove);
 
    /**
     * The game will be loaded from the given stream. Load from here
     * the data which is NOT a game or player property.
     * It is not necessary to use this signal for a full property game.
     *
     * This signal is emitted <em>before</em> the players are loaded by
     * KGame. See also signalLoad
     *
     * You must load <em>exactly</em> the same data from the stream that you have saved
     * in signalSavePrePlayers. Otherwise player loading will not work
     * anymore.
     *
     * @param stream the load stream
     */
    void signalLoadPrePlayers(QDataStream &stream);
 
    /**
     * The game will be loaded from the given stream. Load from here
     * the data which is NOT a game or player property.
     * It is not necessary to use this signal for a full property game.
     *
     * @param stream the load stream
     */
    void signalLoad(QDataStream &stream);
 
    /**
     * The game will be saved to the given stream. Fill this with data
     * which is NOT a game or player property.
     * It is not necessary to use this signal for a full property game.
     *
     * This signal is emitted <em>before</em> the players are saved by
     * KGame. See also signalSave
     *
     * If you can choose between signalSavePrePlayers and signalSave then
     * better use signalSave
     *
     * @param stream the save stream
     */
    void signalSavePrePlayers(QDataStream &stream);
 
    /**
     * The game will be saved to the given stream. Fill this with data
     * which is NOT a game or player property.
     * It is not necessary to use this signal for a full property game.
     *
     * @param stream the save stream
     */
    void signalSave(QDataStream &stream);
 
    /**
     * Is emitted if a game with a different version cookie is loaded.
     * Normally this should result in an error. But maybe you do support
     * loading of older game versions. Here would be a good place to do a
     * conversion.
     *
     * @param stream - the load stream
     * @param network - true if this is a network connect. False for load game
     * @param cookie - the saved cookie. It differs from KGame::cookie()
     * @param result - set this to true if you managed to load the game
     */
    void signalLoadError(QDataStream &stream, bool network, int cookie, bool &result);
 
    /**
     * We got an user defined update message. This is usually done
     * by a sendData in a inherited KGame Object which defines its
     * own methods and has to synchronize them over the network.
     * Reaction to this is usually a call to a KGame function.
     */
    void signalNetworkData(int msgid, const QByteArray &buffer, quint32 receiver, quint32 sender);
 
    /**
     * We got an network message. this can be used to notify us that something
     * changed. What changed can be seen in the message id. Whether this is
     * the best possible method to do this is unclear...
     */
    void signalMessageUpdate(int msgid, quint32 receiver, quint32 sender);
 
    /**
     * a player left the game because of a broken connection or so!
     *
     * Note that when this signal is emitted the player is not part of @ref
     * playerList anymore but the pointer is still valid. You should do some
     * final cleanups here since the player is usually deleted after the signal
     * is emitted.
     *
     * @param player the player who left the game
     */
    void signalPlayerLeftGame(KPlayer *player);
 
    /**
     * a player joined the game
     *
     * @param player the player who joined the game
     */
    void signalPlayerJoinedGame(KPlayer *player);
 
    /**
     * This signal is emitted if a player property changes its value and
     * the property is set to notify this change
     */
    void signalPropertyChanged(KGamePropertyBase *property, KGame *me);
 
    /**
     * Is emitted after a call to gameOver() returns a non zero
     * return code. This code is forwarded to this signal as 'status'.
     *
     * @param status the return code of gameOver()
     * @param current the player who did the last move
     * @param me a pointer to the KGame object
     */
    void signalGameOver(int status, KPlayer *current, KGame *me);
 
    /**
     * Is emitted after a client is successfully connected to the game.
     * The client id is the id of the new game client. An easy way to
     * check whether that's us is
     * \code
     *   if (clientid==gameid()) .. // we joined
     *   else ... // someone joined the game
     * \endcode
     * @param clientid - The id of the new client
     * @param me - our game pointer
     */
    void signalClientJoinedGame(quint32 clientid, KGame *me);
 
    /**
     * This signal is emitted after a network partner left the
     * game (either by a broken connection or voluntarily).
     * All changes to the network players have already be done.
     * If there are not enough players left, the game might have
     * been paused. To check this you get the old gamestatus
     * before the disconnection as argument here. The id of the
     * client who left the game allows to distinguish who left the
     * game. If it is 0, the server disconnected and you were a client
     * which has been switched back to local play.
     * You can use this signal to, e.g. set some menus back to local
     * player when they were network before.
     *
     * @param clientID - 0:server left, otherwise the client who left
     * @param oldgamestatus - the gamestatus before the loss
     * @param me - our game pointer
     */
    void signalClientLeftGame(int clientID, int oldgamestatus, KGame *me);
 
protected:
    /**
     * A player input occurred. This is the most important function
     * as the given message will contain the current move made by
     * the given player.
     * Note that you HAVE to overwrite this function. Otherwise your
     * game makes no sense at all.
     * Generally you have to return TRUE in this function. Only then
     * the game sequence is proceeded by calling @ref playerInputFinished
     * which in turn will check for game over or the next player
     * However, if you have a delayed move, because you e.g. move a
     * card or a piece you want to return FALSE to pause the game sequence
     * and then manually call @ref playerInputFinished to resume it.
     * Example:
     * \code
     * bool MyClass::playerInput(QDataStream &msg,KPlayer *player)
     * {
     *   qint32 move;
     *   msg >>  move;
     *   qDebug() << "  Player" << player->id() << "moved to" << move;
     *   return true;
     * }
     * \endcode
     *
     * @param msg the move message
     * @param player the player who did the move
     * @return true - input ready, false: input manual
     */
    virtual bool playerInput(QDataStream &msg, KPlayer *player) = 0;
 
    /**
     * Called after the player input is processed by the game. Here the
     * checks for game over and nextPlayer (in the case of turn base games)
     * are processed.
     * Call this manually if you have a delayed move, i.e. your playerInput
     * function returns FALSE. If it returns true you need not do anything
     * here.
     *
     * @return the current player
     *
     */
    KPlayer *playerInputFinished(KPlayer *player);
 
    /**
     * This virtual function can be overwritten for your own player management.
     * It is called when a new game connects to an existing network game or
     * to the network master. In case you do not want all players of both games
     * to be present in the new network game, you can deactivate players here.
     * This is of particular importance if you have a game with fixed number of
     * player like e.g. chess. A network connect needs to disable one player of
     * each game to make sense.
     *
     * Not overwriting this function will activate a default behaviour which
     * will deactivate players until the @ref maxPlayers() number is reached
     * according to the KPlayer::networkPriority() value. Players with a low
     * value will be kicked out first. With equal priority players of the new
     * client will leave first. This means, not setting this value and not
     * overwriting this function will never allow a chess game to add client
     * players!!!
     * On the other hand setting one player of each game to a networkPriorty of
     * say 10, already does most of the work for you.
     *
     * The parameters of this function are the playerlist of the network game,
     * which is @ref playerList(). The second argument is the player list of
     * the new client who wants to join and the third argument serves as return
     * parameter. All <em>player ID's</em> which are written into this list
     * will be <em>removed</em> from the created game. You do this by an
     * \code
     * inactivate.append(player->id());
     * \endcode
     *
     * @param oldplayer - the list of the network players
     * @param newplayer - the list of the client players
     * @param inactivate - the value list of ids to be deactivated
     *
     */
    virtual void newPlayersJoin(KGamePlayerList *oldplayer, KGamePlayerList *newplayer, QList<int> &inactivate)
    {
        Q_UNUSED(oldplayer);
        Q_UNUSED(newplayer);
        Q_UNUSED(inactivate);
    }
 
    /**
     * Save the player list to a stream. Used for network game and load/save.
     * Can be overwritten if you know what you are doing
     *
     * @param stream is the stream to save the player ot
     * @param list the optional list is the player list to be saved, default is playerList()
     *
     */
    void savePlayers(QDataStream &stream, KGamePlayerList *list = nullptr);
 
    /**
     * Prepare a player for being added. Put all data about a player into the
     * stream so that it can be sent to the KGameCommunicationServer using
     * addPlayer (e.g.)
     *
     * This function ensures that the code for adding a player is the same in
     * addPlayer as well as in negotiateNetworkGame
     * @param stream is the stream to add the player
     * @param player The player to add
     */
    void savePlayer(QDataStream &stream, KPlayer *player);
 
    /**
     * Load the player list from a stream. Used for network game and load/save.
     * Can be overwritten if you know what you are doing
     *
     * @param stream is the stream to save the player to
     * @param isvirtual will set the virtual flag true/false
     *
     */
    KPlayer *loadPlayer(QDataStream &stream, bool isvirtual = false);
 
    /**
     * inactivates player. Use @ref inactivatePlayer instead!
     */
    bool systemInactivatePlayer(KPlayer *player);
 
    /**
     * activates player. Use @ref activatePlayer instead!
     */
    bool systemActivatePlayer(KPlayer *player);
 
    /**
     * Adds a player to the game
     *
     * Use @ref addPlayer to send @ref KGameMessage::IdAddPlayer. As soon as
     * this Id is received this function is called, where the player (see @ref
     * KPlayer::rtti) is added as well as its properties (see @ref KPlayer::save
     * and @ref KPlayer::load)
     *
     * This method calls the overloaded @ref systemAddPlayer with the created
     * player as argument. That method will really add the player.
     * If you need to do some changes to your newly added player just connect to
     * @ref signalPlayerJoinedGame
     */
 
    /**
     * Finally adds a player to the game and therefore to the list.
     */
    bool systemAddPlayer(KPlayer *newplayer);
 
    /**
     * Removes a player from the game
     *
     * Use removePlayer to send KGameMessage::IdRemovePlayer. As soon
     * as this Id is received systemRemovePlayer is called and the player is
     * removed directly.
     */
    void systemRemovePlayer(KPlayer *player, bool deleteit);
 
    /**
     * This member function will transmit e.g. all players to that client, as well as
     * all properties of these players (at least if they have been added by
     * @ref KPlayer::addProperty) so that the client will finally have the same
     * status as the master. You want to overwrite this function if you expand
     * KGame by any properties which have to be known by all clients.
     *
     * Only the ADMIN is allowed to call this.
     * @param clientID The ID of the message client which has connected
     */
    virtual void negotiateNetworkGame(quint32 clientID);
 
#if KDEGAMESPRIVATE_ENABLE_DEPRECATED_SINCE(7, 3)
    /**
     * synchronize the random numbers with all network clients
     * not used by KGame - if it should be kept then as public method
     * @deprecated Since 7.3, no known users.
     */
    KDEGAMESPRIVATE_DEPRECATED_VERSION(7, 3, "No known users")
    void syncRandom();
#endif
 
    void deletePlayers();
    void deleteInactivePlayers();
 
#if KDEGAMESPRIVATE_BUILD_DEPRECATED_SINCE(3, 2)
    /**
     * @param player the player who made the last move
     * @return anything else but 0 is considered as game over
     *
     * @deprecated Since 3.2, use KGameSequence instead.
     */
    KDEGAMESPRIVATE_DEPRECATED_VERSION(3, 2, "Use KGameSequence")
    virtual int checkGameOver(KPlayer *player);
#endif
 
    /**
     * Load a saved game, from file OR network. Internal.
     * Warning: loadgame must not rely that all players all already
     * activated. Actually the network will activate a player AFTER
     * the loadgame only. This is not true anymore. But be careful
     * anyway.
     *
     * @param stream a data stream where you can stream the game from
     * @param network is it a network call -> make players virtual
     * @param reset shall the game be reset before loading
     *
     * @return true?
     */
    virtual bool loadgame(QDataStream &stream, bool network, bool reset);
 
    /**
     * Save a game, to file OR network. Internal.
     *
     * @param stream a data stream where you can stream the game from
     * @param network is it a call from the network or from a file (unused but informative)
     * @param saveplayers shall the players be saved too (should be TRUE)
     *
     * @return true?
     */
    virtual bool savegame(QDataStream &stream, bool network, bool saveplayers);
 
private:
    // AB: this is to hide the "receiver" parameter from the user. It shouldn't be
    // used if possible (except for init).
    /**
     * This is an overloaded function. Id differs from the public one only in
     * its parameters:
     *
     * @param receiver The Client that will receive the message. You will hardly
     * ever need this. It it internally used to initialize a newly connected
     * client.
     */
    // void addPlayer(KPlayer* newplayer, quint32 receiver);
 
    /**
     * Just the same as the public one except receiver:
     * @param receiver 0 for broadcast, otherwise the receiver. Should only be
     * used in special circumstances and not outside KGame.
     */
    bool removePlayer(KPlayer *player, quint32 receiver);
 
    /**
     * Helping function - game negotiation
     */
    void setupGame(quint32 sender);
 
    /**
     * Helping function - game negotiation
     */
    void setupGameContinue(QDataStream &msg, quint32 sender);
 
    /**
     * Removes a player from all lists, removes the @ref KGame pointer from the
     * @ref KPlayer and deletes the player. Used by (e.g.) @ref
     * systemRemovePlayer
     * @return True if the player has been removed, false if the current is not
     * found
     */
    bool systemRemove(KPlayer *player, bool deleteit);
 
private:
    KGamePrivate *const d;
};
 
#endif