qgsscalebarrenderer.h

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/***************************************************************************
                            qgsscalebarrenderer.h
                            ---------------------
    begin                : June 2008
    copyright            : (C) 2008 by Marco Hugentobler
    email                : [email protected]
 ***************************************************************************/
/***************************************************************************
 *                                                                         *
 *   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 QGSSCALEBARRENDERER_H
#define QGSSCALEBARRENDERER_H

#include "qgis_core.h"
#include <QRectF>
#include <QList>

class QgsRenderContext;
class QgsScaleBarSettings;

class CORE_EXPORT QgsScaleBarRenderer
{
  public:

    struct ScaleBarContext
    {
      double segmentWidth { 0.0 };

      QSizeF size;

      double scale { 1.0 };

    };

    QgsScaleBarRenderer() = default;
    virtual ~QgsScaleBarRenderer() = default;

    virtual QString name() const = 0;

    virtual void draw( QgsRenderContext &context,
                       const QgsScaleBarSettings &settings,
                       const QgsScaleBarRenderer::ScaleBarContext &scaleContext ) const = 0;

    virtual QSizeF calculateBoxSize( const QgsScaleBarSettings &settings,
                                     const QgsScaleBarRenderer::ScaleBarContext &scaleContext ) const;

  protected:

    void drawDefaultLabels( QgsRenderContext &context,
                            const QgsScaleBarSettings &settings,
                            const QgsScaleBarRenderer::ScaleBarContext &scaleContext ) const;

    QString firstLabelString( const QgsScaleBarSettings &settings ) const;

    double firstLabelXOffset( const QgsScaleBarSettings &settings ) const;

    QList<double> segmentPositions( const QgsScaleBarRenderer::ScaleBarContext &scaleContext, const QgsScaleBarSettings &settings ) const;

    QList<double> segmentWidths( const QgsScaleBarRenderer::ScaleBarContext &scaleContext, const QgsScaleBarSettings &settings ) const;

};

#endif //QGSSCALEBARRENDERER_H