qgsmaprenderercache.h

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/***************************************************************************
  qgsmaprenderercache.h
  --------------------------------------
  Date                 : December 2013
  Copyright            : (C) 2013 by Martin Dobias
  Email                : wonder dot sk at gmail dot com
 ***************************************************************************
 *                                                                         *
 *   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 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
 
#ifndef QGSMAPRENDERERCACHE_H
#define QGSMAPRENDERERCACHE_H
 
#include "qgis_core.h"
#include <QMap>
#include <QImage>
#include <QMutex>
 
#include "qgsrectangle.h"
#include "qgsmaplayer.h"
 
 
class CORE_EXPORT QgsMapRendererCache : public QObject
{
    Q_OBJECT
  public:
 
    QgsMapRendererCache();
 
    void clear();
 
    bool init( const QgsRectangle &extent, double scale );
 
    void setCacheImage( const QString &cacheKey, const QImage &image, const QList< QgsMapLayer * > &dependentLayers = QList< QgsMapLayer * >() );
 
    bool hasCacheImage( const QString &cacheKey ) const;
 
    QImage cacheImage( const QString &cacheKey ) const;
 
    QList< QgsMapLayer * > dependentLayers( const QString &cacheKey ) const;
 
    void clearCacheImage( const QString &cacheKey );
 
    void invalidateCacheForLayer( QgsMapLayer *layer );
 
  private slots:
    void layerRequestedRepaint();
 
  private:
 
    struct CacheParameters
    {
      QImage cachedImage;
      QgsWeakMapLayerPointerList dependentLayers;
    };
 
    void clearInternal();
 
    void dropUnusedConnections();
 
    QSet< QgsWeakMapLayerPointer > dependentLayers() const;
 
    mutable QMutex mMutex;
    QgsRectangle mExtent;
    double mScale = 0;
 
    QMap<QString, CacheParameters> mCachedImages;
    QSet< QgsWeakMapLayerPointer > mConnectedLayers;
};
 
 
#endif // QGSMAPRENDERERCACHE_H