qgstextrendererutils.h

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/***************************************************************************
  qgstextrendererutils.h
  -----------------
   begin                : May 2020
   copyright            : (C) Nyall Dawson
   email                : nyall dot dawson 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 QGSTEXTRENDERERUTILS_H
#define QGSTEXTRENDERERUTILS_H
 
#include "qgis_sip.h"
#include "qgis_core.h"
#include "qgstextbackgroundsettings.h"
#include "qgstextshadowsettings.h"
#include "qgstextmetrics.h"
 
class CORE_EXPORT QgsTextRendererUtils
{
  public:
 
    static QgsTextBackgroundSettings::ShapeType decodeShapeType( const QString &string );
 
    static QgsTextBackgroundSettings::SizeType decodeBackgroundSizeType( const QString &string );
 
    static QgsTextBackgroundSettings::RotationType decodeBackgroundRotationType( const QString &string );
 
    static QgsTextShadowSettings::ShadowPlacement decodeShadowPlacementType( const QString &string );
 
    static QString encodeTextOrientation( Qgis::TextOrientation orientation );
 
    static Qgis::TextOrientation decodeTextOrientation( const QString &name, bool *ok = nullptr );
 
    static Qgis::RenderUnit convertFromOldLabelUnit( int val ) SIP_SKIP;
 
    static QColor readColor( QgsVectorLayer *layer, const QString &property, const QColor &defaultColor = Qt::black, bool withAlpha = true ) SIP_SKIP;
 
#ifndef SIP_RUN
 
    class CurvedGraphemePlacement
    {
      public:
 
        double x = 0;
        double y = 0;
        double width = 0;
        double height = 0;
        double angle = 0;
        int graphemeIndex = 0;
    };
 
    class CurvePlacementProperties
    {
      public:
 
        QVector< QgsTextRendererUtils::CurvedGraphemePlacement > graphemePlacement;
        int upsideDownCharCount = 0;
        bool labeledLineSegmentIsRightToLeft = false;
        bool flippedCharacterPlacementToGetUprightLabels = false;
    };
 
    enum LabelLineDirection
    {
      RespectPainterOrientation, 
      FollowLineDirection 
    };
 
#if 0
    // TODO - refine API when used. We probably want to use QPolygonF here instead of QgsLineString!
    static CurvePlacementProperties *generateCurvedTextPlacement( const QgsPrecalculatedTextMetrics &metrics, const QgsLineString *line, double offsetAlongLine, LabelLineDirection direction = RespectPainterOrientation, double maxConcaveAngle = -1, double maxConvexAngle = -1, bool uprightOnly = true ) SIP_FACTORY;
#endif
 
    static CurvePlacementProperties *generateCurvedTextPlacement( const QgsPrecalculatedTextMetrics &metrics, const double *x, const double *y, int numPoints, const std::vector< double> &pathDistances, double offsetAlongLine, LabelLineDirection direction = RespectPainterOrientation, double maxConcaveAngle = -1, double maxConvexAngle = -1, bool uprightOnly = true ) SIP_SKIP;
#endif
 
  private:
 
    static CurvePlacementProperties *generateCurvedTextPlacementPrivate( const QgsPrecalculatedTextMetrics &metrics, const double *x, const double *y, int numPoints, const std::vector< double> &pathDistances, double offsetAlongLine, LabelLineDirection direction, double maxConcaveAngle = -1, double maxConvexAngle = -1, bool uprightOnly = true, bool isSecondAttempt = false ) SIP_SKIP;
 
    static bool nextCharPosition( double charWidth, double segmentLength, const double *x, const double *y, int numPoints, int &index, double &currentDistanceAlongSegment,
                                  double &characterStartX, double &characterStartY, double &characterEndX, double &characterEndY );
 
    static void findLineCircleIntersection( double cx, double cy, double radius,
                                            double x1, double y1, double x2, double y2,
                                            double &xRes, double &yRes );
};
 
 
#endif // QGSTEXTRENDERERUTILS_H