Source: kconfig.h

# Source: kconfig.h |
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    /*
       This file is part of the KDE libraries
       Copyright (c) 1999 Preston Brown <pbrown@kde.org>
       Copyright (C) 1997 Matthias Kalle Dalheimer <kalle@kde.org>

       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., 59 Temple Place - Suite 330,
       Boston, MA 02111-1307, USA.
    */

    // $Id: kconfig.h,v 1.34 2000/09/25 03:53:04 waba Exp $

    #ifndef _KCONFIG_H
    #define _KCONFIG_H

    class QTimer;

    #include "kconfigbase.h"

    class KConfigPrivate;

    /**
    * Access KDE Configuration entries.
    *
    * This class implements KDE's default configuration system.
    *
    * @author Kalle Dalheimer <kalle@kde.org>, Preston Brown <pbrown@kde.org>
    * @version $Id: kconfig.h,v 1.34 2000/09/25 03:53:04 waba Exp $
    * @see KGlobal::config KConfigBase KSimpleConfig
    * @short KDE Configuration Management class
    */
    class KConfig : public KConfigBase
    {
      Q_OBJECT

    public:
      /**
       * Construct a KConfig object.
       *
       * @param fileName A file to parse in addition to the
       *        system-wide file(s).  If it is not provided, only global
       *        KDE configuration data will be read (depending on the value of
       *        @p bUseKDEGlobals).
       * @param bReadOnly Set the config object's read-only status.
       * @param bUseKDEGlobals Toggle reading the global KDE configuration file.
       * @param resType the place to look in (config, data, etc) See @ref KStandardDirs
       */
      KConfig( const QString& fileName = QString::null,
              bool bReadOnly = false, bool bUseKDEGlobals = true, const char *resType="config");

      /**
       * Destructor.
       *
       * Writes back any dirty configuration entries, and destroys
       * dynamically created objects.
       */
      virtual ~KConfig();

      /**
       * Clears all entries out of the @p dirtyEntryMap, so the
       * values will not be written to disk on a later call to
       * @ref sync().
       *
       * @param bDeep If true, the dirty map is actually emptied.
       *        otherwise, the config object's global dirty flag is set to
       *        false, but the dirty entries remain in the dirty entry
       *        map.
       *
       * @see KConfigBase::rollback
       */
      virtual void rollback(bool bDeep = true);

      /**
       * @return @p true if the specified group is known.
       *
       * @param _pGroup The group to search for.
       * @returns @p true if the group exists.
       */
      virtual bool hasGroup(const QString &_pGroup) const;

      /**
       * Retrieve a list of groups that are known.
       * @returns The list of groups.
       */
      virtual QStringList groupList() const;

      /*
       * Check if the key has an entry in the currently active group. Use
       * this to determine if a key is not specified for the current group
       * (@p hasKey returns @p false). Keys with null data are considered
       * nonexistent.
       *
       * @param pKey The key to search for.
       */
      virtual bool hasKey(const QString &pKey) const;

      /**
       * Retrieve a map (tree) of entries for all entries in a particular
       * group.
       *
       *  Only the actual entry string is returned, none of the
       * other internal data should be included.
       *
       * @param pGroup A group to get keys from.
       * @return A map of entries in the group specified, indexed by key.
       *         The returned map may be empty if the group is not found.
       */
      virtual QMap<QString, QString> entryMap(const QString &pGroup) const;

      /**
       * Clear all internal data structures and then reread
       * configuration information from disk.
       */
      virtual void reparseConfiguration();

    protected:

      /**
       * Retrieve a map (tree) of the entries in the specified group.
       *
       * Do not use this function, the implementation / return type are
       * subject to change.
       *
       * @param pGroup the group to provide a KEntryMap for.
       * @return The map of the entries in the group.
       * @internal
       */
      virtual KEntryMap internalEntryMap(const QString &pGroup) const;

      /**
       * Returns a copy of the internal map used to hold all entries.
       *
       * Do not use this function, the implementation / return type are
       * subject to change.
       *
       * @param pGroup the group to provide a KEntryMap for.
       * @return The map of the entries in the group.
       * @internal
       */
       virtual KEntryMap internalEntryMap() const { return aEntryMap; }

      /**
       * Insert a key,value pair into the internal storage mechanism of
       * the configuration object.
       *
       * @param _key The key to insert.  It contains information both on
       *        the group of the key and the key itself. If the key already
       *        exists, the old value will be replaced.
       * @param _data the KEntry that is to be stored.
       */
      virtual void putData(const KEntryKey &_key, const KEntry &_data);

      /**
       * Look up an entry in the config object's internal structure.
       *
       * @param _key The key to look up  It contains information both on
       *        the group of the key and the entry's key itself.
       * @return the KEntry value (data) found for the key.  KEntry.aValue
       * will be the null string if nothing was located.
       */
      virtual KEntry lookupData(const KEntryKey &_key) const;

      /**
       * Contains all key,value entries, as well as some "special"
       * keys which indicate the start of a group of entries.
       *
       * These
       * special keys will have the .key portion of their @ref KEntryKey
       * set to @ref QString::null.
       */
      KEntryMap aEntryMap;

    public:
      /**
       * Overloaded public functions.
       */
      virtual bool hasGroup(const QCString &_pGroup) const;
      virtual bool hasGroup(const char *_pGroup) const;
      virtual bool hasKey(const char *pKey) const;

    private:
      /**
       * indicates whether the internal data cache is full or empty.
       * If it is empty, the config files on disk will need to be
       * reopened and read before any reading can take place.
       */
      bool isCached;

      /**
       * timer which is periodically triggered to flush out the
       * data cache.
       */
      QTimer *cacheTimer;

      /**
       * The last time a value was either read or written.  Used to
       * determine a cache time threshold.  Because lookupData() is
       * called for reads and writes, we only need to update the time
       * there; we can ignore putData().
       *
       * @see #lookupData, #putData
       */
      QTime lastIoOp;

      /**
       * time between flush attempts.  We initialize this to 30 seconds.
       */
      int flushInterval;

      /**
       * @internal
       * copy-construction and assignment are not allowed
       */
      KConfig( const KConfig& );
      /**
       * @internal
       * copy-construction and assignment are not allowed
       */
      KConfig& operator= ( const KConfig& rConfig );

      /**
       * Checks whether the cache is loaded from disk, and loads it if
       * needed.  Not actually a const function, so we need to do some
       * internal funny business to get around constness, but needed to be
       * const because of where it is called from (functions that really
       * *should* remain const).
       */
      void cacheCheck() const;

    private slots:
      /**
       * attempts to flush the entry cache. Will set isCached
       * variable to the appropriate value upon completion.
       */
      void flushCache();

    private:
      KConfigPrivate *d;
    };

    #endif