File indexing completed on 2024-05-12 15:56:39

 /*
  *  SPDX-FileCopyrightText: 2016 Dmitry Kazakov <dimula73@gmail.com>
  *
  *  SPDX-License-Identifier: GPL-2.0-or-later
  */
 
 #ifndef __KO_DERIVED_RESOURCE_CONVERTER_H
 #define __KO_DERIVED_RESOURCE_CONVERTER_H
 
 #include <QScopedPointer>
 #include <QSharedPointer>
 #include "kritaflake_export.h"
 
 class QVariant;
 
 /**
  * \class KoDerivedResourceConverter
  *
  * Defines the abstraction of a derived resource. It should be
  * uploaded to the KoResourceManager during the loading phase.
  * The manager will use it to convert values to/from the source
  * resource.
  *
  *  "Derived" resources are the resources that do not exist temselves.
  *  Instead they are contained in some other resources and are updated
  *  synchronously with the parent resources as well.
  *
  *  E.g. we store opacity and composite op and opacity in the current
  *  paintop preset, which is also a resource. So composite op and opacity
  *  are "derived" resources.
  *
  *  The main goal of this class is to make our resources comply with
  *  a general Model-View-Controller architecture:
  *
  *  Model: KisPaintOpPreset. It stores opacity, composite op, eraser mode
  *         and other "global" properties.
  *
  *  Controller: KoCanvasResourceManager. It controls access to the resources
  *              and emits notification signals when they are changed.
  *
  *  View: KisPaintOpBox and other classes that show the resources on screen
  *
  *  Please take into account that according to the MVC design all the access
  *  to the model resources should be performed through the controller.
  *
  */
  class KRITAFLAKE_EXPORT KoDerivedResourceConverter
 {
 public:
     /**
      * \param key the unique id of the resource defined by this
      *            converter
      *
      * \param sourceKey the id of the parent resource, i.e. where the
      *                  values are really loaded/saved.
      */
     KoDerivedResourceConverter(int key, int sourceKey);
     virtual ~KoDerivedResourceConverter();
 
     int key() const;
     int sourceKey() const;
 
     QVariant readFromSource(const QVariant &value);
     QVariant writeToSource(const QVariant &value,
                            const QVariant &sourceValue,
                            bool *changed);
 
     virtual bool notifySourceChanged(const QVariant &sourceValue);
 
 protected:
     /**
      * Converts the \p value of the source resource into the space of
      * the "derived" resource. E.g. preset -> opacity.
      */
     virtual QVariant fromSource(const QVariant &value) = 0;
 
     /**
      * Converts the value of the "derived" resource into the space of the
      * original ("source") resource. E.g. opacity -> preset.
      */
     virtual QVariant toSource(const QVariant &value, const QVariant &sourceValue) = 0;
 
 private:
     struct Private;
     const QScopedPointer<Private> m_d;
 };
 
 typedef QSharedPointer<KoDerivedResourceConverter> KoDerivedResourceConverterSP;
 
 #endif /* __KO_DERIVED_RESOURCE_CONVERTER_H */