File indexing completed on 2024-04-28 04:41:47

 /***************************************************************************
  *   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_CONTEXTADAPTER_H
 #define KQUICKITEMVIEWS_CONTEXTADAPTER_H
 
 // Qt
 #include <QtCore/QModelIndex>
 class QQmlContext;
 
 // KQuickItemViews
 class AbstractItemAdapter;
 class ContextAdapterFactory;
 class DynamicContext;
 class ContextExtension;
 
 /**
  * Calling `context()` on an instance of this object will create a
  * QQmlContext reflecting the model roles (and other property groups).
  *
  * One instance needs exists per context. It is possible to replace the
  * QModelIndex later on as needs suit. The two main use cases are to
  * either track multiple QModelIndex at once and display them or use a
  * single instance along with some QQmlExpression to add "just-in-time"
  * properties to objects (like QItemDelegate or
  * QSortFilterProxyModel::acceptRow)
  *
  * These objects MUST BE CREATED AFTER the last call to addContextExtension
  * has been made and the model(index) has been set.
  */
 class ContextAdapter
 {
     friend class AbstractItemAdapter;
     friend class ContextAdapterFactory; //factory
 public:
     virtual ~ContextAdapter();
 
     bool isCacheEnabled() const;
     void setCacheEnabled(bool v);
 
     bool isActive() const;
 
     virtual QModelIndex index() const;
     void setModelIndex(const QModelIndex& index);
 
     virtual QQmlContext* context() const final;
     virtual AbstractItemAdapter* item() const;
 
     /**
      * Clear the cache entry and send the notify signal on the property `id`
      * from the extension `e`.
      */
     void dismissCache(ContextExtension* e, int id);
 
     /**
      * Notify the adapter some QModelIndex roles changed.
      *
      * @return True when the updated roles affect the adapter, false otherwise.
      */
     bool updateRoles(const QVector<int> &modified) const;
 
     /**
      * Clear the cache of role values.
      *
      * To improve performance, QAbstractItemModel::data is only called once
      * unless dataChanged() is called. The value is then stored in the QML
      * context. Call this to manually invalidate the cache and for roles to be
      * reloaded.
      */
     void flushCache();
 
     QObject *contextObject() const;
 
 protected:
     explicit ContextAdapter(QQmlContext *parentContext = nullptr);
 
 private:
     DynamicContext* d_ptr {nullptr};
 };
 
 Q_DECLARE_METATYPE(ContextAdapter*)
 
 #endif