qgsvectorlayerlabelprovider.h

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/***************************************************************************
  qgsvectorlayerlabelprovider.h
  --------------------------------------
  Date                 : September 2015
  Copyright            : (C) 2015 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 QGSVECTORLAYERLABELPROVIDER_H
#define QGSVECTORLAYERLABELPROVIDER_H

#include "qgslabelingenginev2.h"
#include "qgsrendererv2.h"

class QgsAbstractFeatureSource;
class QgsFeatureRendererV2;
class QgsSymbolV2;

class CORE_EXPORT QgsVectorLayerLabelProvider : public QgsAbstractLabelProvider
{
  public:

    explicit QgsVectorLayerLabelProvider( QgsVectorLayer* layer, bool withFeatureLoop = true, const QgsPalLayerSettings* settings = nullptr, const QString& layerName = QString() );

    QgsVectorLayerLabelProvider( const QgsPalLayerSettings& settings,
                                 const QString& layerId,
                                 const QgsFields& fields,
                                 const QgsCoordinateReferenceSystem& crs,
                                 QgsAbstractFeatureSource* source,
                                 bool ownsSource,
                                 QgsFeatureRendererV2* renderer = nullptr );

    ~QgsVectorLayerLabelProvider();

    virtual QList<QgsLabelFeature*> labelFeatures( QgsRenderContext& context ) override;

    virtual void drawLabel( QgsRenderContext& context, pal::LabelPosition* label ) const override;

    // new virtual methods

    virtual bool prepare( const QgsRenderContext& context, QStringList& attributeNames );

    virtual void registerFeature( QgsFeature& feature, QgsRenderContext &context, QgsGeometry* obstacleGeometry = nullptr );

    static QgsGeometry* getPointObstacleGeometry( QgsFeature& fet, QgsRenderContext& context, const QgsSymbolV2List& symbols );

  protected:
    void init();
    void drawLabelPrivate( pal::LabelPosition* label, QgsRenderContext& context, QgsPalLayerSettings& tmpLyr, QgsPalLabeling::DrawLabelType drawType, double dpiRatio = 1.0 ) const;

  protected:
    QgsPalLayerSettings mSettings;
    QGis::GeometryType mLayerGeometryType;

    QgsFeatureRendererV2* mRenderer;

    // these are needed only if using own renderer loop

    QgsFields mFields;
    QgsCoordinateReferenceSystem mCrs;
    QgsAbstractFeatureSource* mSource;
    bool mOwnsSource;

    QList<QgsLabelFeature*> mLabels;

    friend class TestQgsLabelingEngineV2;
};

#endif // QGSVECTORLAYERLABELPROVIDER_H