qgsmaplayerrenderer.h

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/***************************************************************************
  qgsmaplayerrenderer.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 QGSMAPLAYERRENDERER_H
#define QGSMAPLAYERRENDERER_H
 
#include "qgis.h"
#include "qgis_core.h"
#include "qgis_sip.h"
 
#include <QStringList>
 
class QgsFeedback;
class QgsRenderContext;
class QgsRenderedItemDetails;

class CORE_EXPORT QgsMapLayerRenderer
{
  public:

    QgsMapLayerRenderer( const QString &layerID, QgsRenderContext *context = nullptr )
      : mLayerID( layerID )
      , mContext( context )
    {}
 
    virtual ~QgsMapLayerRenderer();

    virtual bool render() = 0;

    virtual bool forceRasterRender() const;

    virtual Qgis::MapLayerRendererFlags flags() const;

    virtual QgsFeedback *feedback() const;

    QStringList errors() const { return mErrors; }

    QString layerId() const { return mLayerID; }

    QgsRenderContext *renderContext() { return mContext; }

    const QgsRenderContext *renderContext() const SIP_SKIP { return mContext; }

    bool isReadyToCompose() const { return mReadyToCompose; }

    virtual void setLayerRenderingTimeHint( int time ) SIP_SKIP { Q_UNUSED( time ) }

    QList< QgsRenderedItemDetails * > takeRenderedItemDetails() SIP_TRANSFERBACK;
 
  protected:
    QStringList mErrors;
    QString mLayerID;
 
    // TODO QGIS 4.0 - make false as default

    bool mReadyToCompose = true;

    static constexpr int MAX_TIME_TO_USE_CACHED_PREVIEW_IMAGE = 3000 SIP_SKIP;

    void appendRenderedItemDetails( QgsRenderedItemDetails *details SIP_TRANSFER );
 
  private:
 
    // TODO QGIS 4.0 - make reference instead of pointer!

    QgsRenderContext *mContext = nullptr;
 
    QList<QgsRenderedItemDetails *> mRenderedItemDetails;
};
 
#endif // QGSMAPLAYERRENDERER_H