qgsmaprendererjob.h

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/***************************************************************************
  qgsmaprendererjob.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 QGSMAPRENDERERJOB_H
#define QGSMAPRENDERERJOB_H

#include <QtConcurrentRun>
#include <QFutureWatcher>
#include <QImage>
#include <QPainter>
#include <QObject>
#include <QTime>

#include "qgsrendercontext.h"

#include "qgsmapsettings.h"

#include "qgsgeometrycache.h"

class QgsLabelingResults;
class QgsMapLayerRenderer;
class QgsMapRendererCache;
class QgsPalLabeling;


struct LayerRenderJob
{
  QgsRenderContext context;
  QImage* img; // may be null if it is not necessary to draw to separate image (e.g. sequential rendering)
  QgsMapLayerRenderer* renderer; // must be deleted
  QPainter::CompositionMode blendMode;
  bool cached; // if true, img already contains cached image from previous rendering
  QString layerId;
};

typedef QList<LayerRenderJob> LayerRenderJobs;


class CORE_EXPORT QgsMapRendererJob : public QObject
{
    Q_OBJECT
  public:

    QgsMapRendererJob( const QgsMapSettings& settings );

    virtual ~QgsMapRendererJob() {}

    virtual void start() = 0;

    virtual void cancel() = 0;

    virtual void waitForFinished() = 0;

    virtual bool isActive() const = 0;

    virtual QgsLabelingResults* takeLabelingResults() = 0;

    struct Error
    {
      Error( const QString& lid, const QString& msg ) : layerID( lid ), message( msg ) {}

      QString layerID;
      QString message;
    };

    typedef QList<Error> Errors;

    Errors errors() const;


    void setCache( QgsMapRendererCache* cache );

    void setRequestedGeometryCacheForLayers( const QStringList& layerIds ) { mRequestedGeomCacheForLayers = layerIds; }

    int renderingTime() const { return mRenderingTime; }

  signals:

    void finished();

  protected:

    static bool reprojectToLayerExtent( const QgsCoordinateTransform* ct, bool layerCrsGeographic, QgsRectangle& extent, QgsRectangle& r2 );

    LayerRenderJobs prepareJobs( QPainter* painter, QgsPalLabeling* labelingEngine );

    void cleanupJobs( LayerRenderJobs& jobs );

    static QImage composeImage( const QgsMapSettings& settings, const LayerRenderJobs& jobs );

    bool needTemporaryImage( QgsMapLayer* ml );

    static void drawLabeling( const QgsMapSettings& settings, QgsRenderContext& renderContext, QgsPalLabeling* labelingEngine, QPainter* painter );
    static void drawOldLabeling( const QgsMapSettings& settings, QgsRenderContext& renderContext );
    static void drawNewLabeling( const QgsMapSettings& settings, QgsRenderContext& renderContext, QgsPalLabeling* labelingEngine );

    void updateLayerGeometryCaches();

    QgsMapSettings mSettings;
    Errors mErrors;

    QgsMapRendererCache* mCache;

    QStringList mRequestedGeomCacheForLayers;
    QMap<QString, QgsGeometryCache> mGeometryCaches;

    QTime mRenderingStart;
    int mRenderingTime;
};


class CORE_EXPORT QgsMapRendererQImageJob : public QgsMapRendererJob
{
  public:
    QgsMapRendererQImageJob( const QgsMapSettings& settings );

    virtual QImage renderedImage() = 0;
};


#endif // QGSMAPRENDERERJOB_H