qgslabelingenginev2.h

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/***************************************************************************
  qgslabelingenginev2.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 QGSLABELINGENGINEV2_H
#define QGSLABELINGENGINEV2_H

#include "qgsgeometry.h"

#include "qgsmapsettings.h"

#include "qgspallabeling.h"

#include <QFlags>


class QgsLabelingEngineV2;


class CORE_EXPORT QgsAbstractLabelProvider
{

  public:
    QgsAbstractLabelProvider( const QString& layerId = QString() );
    virtual ~QgsAbstractLabelProvider() {}

    void setEngine( const QgsLabelingEngineV2* engine ) { mEngine = engine; }

    enum Flag
    {
      DrawLabels              = 1 << 1,  
      DrawAllLabels           = 1 << 2,  
      MergeConnectedLines     = 1 << 3,  
      CentroidMustBeInside    = 1 << 4,  
      FitInPolygonOnly        = 1 << 5,  
      LabelPerFeaturePart     = 1 << 6,  
    };
    Q_DECLARE_FLAGS( Flags, Flag )

    
    virtual QList<QgsLabelFeature*> labelFeatures( QgsRenderContext& context ) = 0;

    virtual void drawLabel( QgsRenderContext& context, pal::LabelPosition* label ) const = 0;

    virtual QList<QgsAbstractLabelProvider*> subProviders() { return QList<QgsAbstractLabelProvider*>(); }

    QString name() const { return mName; }

    QString layerId() const { return mLayerId; }

    Flags flags() const { return mFlags; }

    QgsPalLayerSettings::Placement placement() const { return mPlacement; }

    unsigned int linePlacementFlags() const { return mLinePlacementFlags; }

    double priority() const { return mPriority; }

    QgsPalLayerSettings::ObstacleType obstacleType() const { return mObstacleType; }

    QgsPalLayerSettings::UpsideDownLabels upsidedownLabels() const { return mUpsidedownLabels; }

  protected:
    const QgsLabelingEngineV2* mEngine;

    QString mName;
    QString mLayerId;
    Flags mFlags;
    QgsPalLayerSettings::Placement mPlacement;
    unsigned int mLinePlacementFlags;
    double mPriority;
    QgsPalLayerSettings::ObstacleType mObstacleType;
    QgsPalLayerSettings::UpsideDownLabels mUpsidedownLabels;
};

Q_DECLARE_OPERATORS_FOR_FLAGS( QgsAbstractLabelProvider::Flags )




class CORE_EXPORT QgsLabelingEngineV2
{
  public:
    QgsLabelingEngineV2();
    ~QgsLabelingEngineV2();

    enum Flag
    {
      UseAllLabels          = 1 << 1,  
      UsePartialCandidates  = 1 << 2,  
      RenderOutlineLabels   = 1 << 3,  
      DrawLabelRectOnly     = 1 << 4,  
      DrawCandidates        = 1 << 5,  
      DrawShadowRects       = 1 << 6,  
    };
    Q_DECLARE_FLAGS( Flags, Flag )

    
    void setMapSettings( const QgsMapSettings& mapSettings ) { mMapSettings = mapSettings; }
    const QgsMapSettings& mapSettings() const { return mMapSettings; }

    void addProvider( QgsAbstractLabelProvider* provider );

    void removeProvider( QgsAbstractLabelProvider* provider );

    void run( QgsRenderContext& context );

    QgsLabelingResults* takeResults();

    QgsLabelingResults* results() const { return mResults; }

    void setFlags( const Flags& flags ) { mFlags = flags; }
    Flags flags() const { return mFlags; }
    bool testFlag( Flag f ) const { return mFlags.testFlag( f ); }
    void setFlag( Flag f, bool enabled = true ) { if ( enabled ) mFlags |= f; else mFlags &= ~f; }

    void numCandidatePositions( int& candPoint, int& candLine, int& candPolygon ) { candPoint = mCandPoint; candLine = mCandLine; candPolygon = mCandPolygon; }
    void setNumCandidatePositions( int candPoint, int candLine, int candPolygon ) { mCandPoint = candPoint; mCandLine = candLine; mCandPolygon = candPolygon; }

    void setSearchMethod( QgsPalLabeling::Search s ) { mSearchMethod = s; }
    QgsPalLabeling::Search searchMethod() const { return mSearchMethod; }

    void readSettingsFromProject();
    void writeSettingsToProject();

  protected:
    void processProvider( QgsAbstractLabelProvider* provider, QgsRenderContext& context, pal::Pal& p );

  protected:
    QgsMapSettings mMapSettings;
    QList<QgsAbstractLabelProvider*> mProviders;
    QList<QgsAbstractLabelProvider*> mSubProviders;
    Flags mFlags;
    QgsPalLabeling::Search mSearchMethod;
    int mCandPoint, mCandLine, mCandPolygon;

    QgsLabelingResults* mResults;

  private:

    QgsLabelingEngineV2( const QgsLabelingEngineV2& rh );
    QgsLabelingEngineV2& operator=( const QgsLabelingEngineV2& rh );
};

Q_DECLARE_OPERATORS_FOR_FLAGS( QgsLabelingEngineV2::Flags )



class CORE_EXPORT QgsLabelingUtils
{
  public:

    static QString encodePredefinedPositionOrder( const QVector< QgsPalLayerSettings::PredefinedPointPosition >& positions );

    static QVector< QgsPalLayerSettings::PredefinedPointPosition > decodePredefinedPositionOrder( const QString& positionString );

};

#endif // QGSLABELINGENGINEV2_H