qgslayoutsnapper.h

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/***************************************************************************
                             qgslayoutsnapper.h
                             -------------------
    begin                : July 2017
    copyright            : (C) 2017 by 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 QGSLAYOUTSNAPPER_H
#define QGSLAYOUTSNAPPER_H

#include "qgis_core.h"
#include "qgslayoutmeasurement.h"
#include "qgslayoutpoint.h"
#include "qgslayoutguidecollection.h"
#include "qgslayoutserializableobject.h"
#include <QPen>

class QgsLayout;
class QgsReadWriteContext;

class CORE_EXPORT QgsLayoutSnapper: public QgsLayoutSerializableObject
{

  public:

    QgsLayoutSnapper( QgsLayout *layout );

    QString stringType() const override { return QStringLiteral( "LayoutSnapper" ); }
    QgsLayout *layout() override;

    void setSnapTolerance( const int snapTolerance );

    int snapTolerance() const { return mTolerance; }

    bool snapToGrid() const { return mSnapToGrid; }

    void setSnapToGrid( bool enabled );

    bool snapToGuides() const { return mSnapToGuides; }

    void setSnapToGuides( bool enabled );

    bool snapToItems() const { return mSnapToItems; }

    void setSnapToItems( bool enabled );

    QPointF snapPoint( QPointF point, double scaleFactor, bool &snapped SIP_OUT, QGraphicsLineItem *horizontalSnapLine = nullptr,
                       QGraphicsLineItem *verticalSnapLine = nullptr,
                       const QList< QgsLayoutItem * > *ignoreItems = nullptr ) const;

    QRectF snapRect( const QRectF &rect, double scaleFactor, bool &snapped SIP_OUT, QGraphicsLineItem *horizontalSnapLine = nullptr,
                     QGraphicsLineItem *verticalSnapLine = nullptr,
                     const QList< QgsLayoutItem * > *ignoreItems = nullptr ) const;

    QPointF snapPointToGrid( QPointF point, double scaleFactor, bool &snappedX SIP_OUT, bool &snappedY SIP_OUT ) const;

    QPointF snapPointsToGrid( const QList< QPointF > &points, double scaleFactor, bool &snappedX SIP_OUT, bool &snappedY SIP_OUT ) const;

    double snapPointToGuides( double original, Qt::Orientation orientation, double scaleFactor, bool &snapped SIP_OUT ) const;

    double snapPointsToGuides( const QList< double > &points, Qt::Orientation orientation, double scaleFactor, bool &snapped SIP_OUT ) const;

    double snapPointToItems( double original, Qt::Orientation orientation, double scaleFactor, const QList< QgsLayoutItem * > &ignoreItems, bool &snapped SIP_OUT,
                             QGraphicsLineItem *snapLine = nullptr ) const;

    double snapPointsToItems( const QList< double > &points, Qt::Orientation orientation, double scaleFactor, const QList< QgsLayoutItem * > &ignoreItems, bool &snapped SIP_OUT,
                              QGraphicsLineItem *snapLine = nullptr ) const;

    bool writeXml( QDomElement &parentElement, QDomDocument &document, const QgsReadWriteContext &context ) const override;

    bool readXml( const QDomElement &gridElement, const QDomDocument &document, const QgsReadWriteContext &context ) override;

  private:

    // Used for 'collapsing' undo commands
    enum UndoCommand
    {
      UndoTolerance = 1,
      UndoSnapToGrid,
      UndoSnapToGuides,
    };

    QgsLayout *mLayout = nullptr;

    int mTolerance = 5;
    bool mSnapToGrid = false;
    bool mSnapToGuides = true;
    bool mSnapToItems = true;

    friend class QgsLayoutSnapperUndoCommand;

};

#endif //QGSLAYOUTSNAPPER_H