    //------------------------------------------------------------------------------
    // emConfigModel.h
    //
    // Copyright (C) 2006-2008,2010 Oliver Hamann.
    //
    // Homepage: http://eaglemode.sourceforge.net/
    //
    // This program is free software: you can redistribute it and/or modify it under
    // the terms of the GNU General Public License version 3 as published by the
    // Free Software Foundation.
    //
    // This program 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 General Public License version 3 for
    // more details.
    //
    // You should have received a copy of the GNU General Public License version 3
    // along with this program. If not, see <http://www.gnu.org/licenses/>.
    //------------------------------------------------------------------------------

    #ifndef emConfigModel_h
    #define emConfigModel_h

    #ifndef emRec_h
    #include <emCore/emRec.h>
    #endif

    #ifndef emModel_h
    #include <emCore/emModel.h>
    #endif

    //==============================================================================
    //=============================== emConfigModel ================================
    //==============================================================================

    class emConfigModel : public emModel {

    public:

            // Base class for a configuration model where the data is stored in an
            // emRec. This class is a little bit similar to emRecFileModel, but it
            // is not an emFileModel. The idea here is to have a loaded state
            // always.

            const emString & GetInstallPath() const;
                    // Get the installation path/name of the configuration file.

            bool IsUnsaved() const;
                    // Ask whether the record data is currently not saved to the
                    // file.

            const emSignal & GetChangeSignal() const;
                    // Signaled on every modification of the record and even on
                    // change of IsUnsaved.

            void TrySave() throw(emString);
            void Save();
                    // Save the record to the install path. On error, the first
                    // version throws the error message, and the second version
                    // calls emFatalError.

            //??? An auto-save mechanism should be implemented, so that saving is
            //??? performed automatically after each change, best with a small time
            //??? delay (a second or so). Maybe that auto-save mechanism should be
            //??? enabled by default.

    protected:

            emConfigModel(emContext & context, const emString & name);
                    // Do not forget to call PostConstruct from an overloaded
                    // constructor.

            void PostConstruct(emRec & rec, const emString & installPath);
                    // Must be called by the constructor of the derived class after
                    // the record has been constructed.
                    // Arguments:
                    //   rec         - The record making up the configuration.
                    //   installPath - Path/name of the configuration file, usually
                    //                 a result of calling the global function
                    //                 emGetInstallPath.

            virtual ~emConfigModel();
                    // Destructor.

            void TryLoad() throw(emString);
            void Load();
                    // Load the record from the install path. On error, the first
                    // version throws the error message, the second version calls
                    // emFatalError. This is typically called by the constructor of
                    // the derived class or by a TryAcquire function. Hint:
                    // Derivatives of emFilePanel may easily report an error with
                    // its SetCustomError method, this is better than calling
                    // emFatalError.

            void TryLoadOrInstall(const char * insSrcPath=NULL) throw(emString);
            void LoadOrInstall(const char * insSrcPath=NULL);
                    // Like above, but if the file does not yet exist, an
                    // installation is performed: If insSrcPath is not NULL, that
                    // file is copied to the install path and loaded. Otherwise the
                    // record is set to its default state and saved to the install
                    // path. Any non existing parent directories of the install path
                    // are created automatically.

            emRec & GetRec();
                    // Not valid before PostConstruct has been called.

    private:

            class RecLink : public emRecListener {
            public:
                    RecLink(emConfigModel & model);
            protected:
                    virtual void OnRecChanged();
            private:
                    emConfigModel & Model;
            };
            friend class RecLink;

            emSignal ChangeSignal;
            RecLink Link;
            emString InstallPath;
            bool Unsaved;
    };

    inline const emString & emConfigModel::GetInstallPath() const
    {
            return InstallPath;
    }

    inline bool emConfigModel::IsUnsaved() const
    {
            return Unsaved;
    }

    inline const emSignal & emConfigModel::GetChangeSignal() const
    {
            return ChangeSignal;
    }

    inline emRec & emConfigModel::GetRec()
    {
            return *Link.GetListenedRec();
    }

    #endif