File indexing completed on 2024-04-28 04:41:48

 /***************************************************************************
  *   Copyright (C) 2018 by Emmanuel Lepage Vallee                          *
  *   Author : Emmanuel Lepage Vallee <emmanuel.lepage@kde.org>             *
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU General Public License as published by  *
  *   the Free Software Foundation; either version 3 of the License, or     *
  *   (at your option) any later version.                                   *
  *                                                                         *
  *   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 for more details.                          *
  *                                                                         *
  *   You should have received a copy of the GNU General Public License     *
  *   along with this program.  If not, see <http://www.gnu.org/licenses/>. *
  **************************************************************************/
 #ifndef KQUICKITEMVIEWS_CONTEXTEXTENSION_H
 #define KQUICKITEMVIEWS_CONTEXTEXTENSION_H
 
 // Qt
 #include <QtCore/QVariant>
 #include <QtCore/QByteArray>
 #include <QtCore/QModelIndex>
 
 class ContextExtensionPrivate;
 
 /**
  * Add more properties to the QML context.
  *
  * This allows to add a predefined set of extra properties to the QML
  * context. It does *not* support adding more properties at runtime.
  *
  * The memory ownership is not transferred, do not re-use the instance
  * across many views (it will crash).
  */
 class ContextExtension
 {
 public:
 
     explicit ContextExtension();
     virtual ~ContextExtension() {}
 
     /**
         * Return a list of properties.
         *
         * This **MUST NEVER CHANGE** and needs to always return the same
         * vector. Implementations should use a `static` QVector.
         *
         * The property index is what's passed to getProperty, setProperty
         * and is the argument of changeProperty.
         */
     virtual QVector<QByteArray>& propertyNames() const;
 
     /**
         * The default implementation returns propertyNames().size()
         *
         * Implementing this rather than using `propertyNames` makes sense
         * when the properties contained in an existing data structure or
         * associated with extra metadata.
         */
     virtual uint size() const;
 
     /**
         * The default implementation returns propertyNames()[id];
         *
         * Implementing this rather than using `propertyNames` makes sense
         * when the properties contained in an existing data structure or
         * associated with extra metadata.
         */
     virtual QByteArray getPropertyName(uint id) const;
 
     /**
         * Some variants, like QModelIndex ones, cannot be cached and will
         * most likely point to invalid memory.
         *
         * If the group has such properties, implement this function. Note
         * that the return value cannot change.
         *
         * The default implementation always returns true.
         */
     virtual bool supportCaching(uint id) const;
 
     /**
         * The id comes from propertyNames.
         *
         * It is recommended to use a switch statement or if/else_if for the
         * implementation and avoid QHash (or worst).
         */
     virtual QVariant getProperty(AbstractItemAdapter* item, uint id, const QModelIndex& index) const = 0;
 
     /**
         * Optionally make the property read/write.
         */
     virtual bool setProperty(AbstractItemAdapter* item, uint id, const QVariant& value, const QModelIndex& index) const;
 
     /**
         * Notify that content of this property has changed.
         */
     void changeProperty(AbstractItemAdapter* item, uint id);
 
     ContextExtensionPrivate *d_ptr;
 };
 
 #endif