QGCMapPolygon.h

/****************************************************************************
 *
 *   (c) 2009-2016 QGROUNDCONTROL PROJECT <http://www.qgroundcontrol.org>
 *
 * QGroundControl is licensed according to the terms in the file
 * COPYING.md in the root of the source code directory.
 *
 ****************************************************************************/

#ifndef QGCMapPolygon_H
#define QGCMapPolygon_H

#include <QGeoCoordinate>
#include <QObject>
#include <QPolygon>
#include <QVariantList>

#include "QmlObjectListModel.h"

/// The QGCMapPolygon class provides a polygon which can be displayed on a map
/// using a map visuals control. It maintains a representation of the polygon on
/// QVariantList and QmlObjectListModel format.
class QGCMapPolygon : public QObject {
  Q_OBJECT

public:
  QGCMapPolygon(QObject *parent = nullptr);
  QGCMapPolygon(const QGCMapPolygon &other, QObject *parent = nullptr);

  const QGCMapPolygon &operator=(const QGCMapPolygon &other);

  Q_PROPERTY(int count READ count NOTIFY countChanged)
  Q_PROPERTY(QVariantList path READ path NOTIFY pathChanged)
  Q_PROPERTY(QmlObjectListModel *pathModel READ qmlPathModel CONSTANT)
  Q_PROPERTY(bool dirty READ dirty WRITE setDirty NOTIFY dirtyChanged)
  Q_PROPERTY(
      QGeoCoordinate center READ center WRITE setCenter NOTIFY centerChanged)
  Q_PROPERTY(bool centerDrag READ centerDrag WRITE setCenterDrag NOTIFY
                 centerDragChanged)
  Q_PROPERTY(bool interactive READ interactive WRITE setInteractive NOTIFY
                 interactiveChanged)
  Q_PROPERTY(double area READ area NOTIFY areaChanged)

  Q_INVOKABLE void clear(void);
  Q_INVOKABLE void appendVertex(const QGeoCoordinate &coordinate);
  Q_INVOKABLE void removeVertex(int vertexIndex);
  Q_INVOKABLE void appendVertices(const QList<QGeoCoordinate> &coordinates);

  /// Adjust the value for the specified coordinate
  ///     @param vertexIndex Polygon point index to modify (0-based)
  ///     @param coordinate New coordinate for point
  Q_INVOKABLE void adjustVertex(int vertexIndex,
                                const QGeoCoordinate coordinate);

  /// Splits the segment comprised of vertextIndex -> vertexIndex + 1
  Q_INVOKABLE void splitPolygonSegment(int vertexIndex);

  /// Returns true if the specified coordinate is within the polygon
  Q_INVOKABLE bool containsCoordinate(const QGeoCoordinate &coordinate) const;

  /// Offsets the current polygon edges by the specified distance in meters
  Q_INVOKABLE void offset(double distance);

  /// Loads a polygon from a KML/SH{ file
  /// @return true: success
  Q_INVOKABLE bool loadKMLOrSHPFile(const QString &file);

  /// Returns the path in a list of QGeoCoordinate's format
  QList<QGeoCoordinate> coordinateList(void) const;

  /// Returns the QGeoCoordinate for the vertex specified
  Q_INVOKABLE QGeoCoordinate vertexCoordinate(int vertex) const;

  /// Adjust polygon winding order to be clockwise (if needed)
  Q_INVOKABLE void verifyClockwiseWinding(void);

  /// Saves the polygon to the json object.
  ///     @param json Json object to save to
  void saveToJson(QJsonObject &json);

  /// Load a polygon from json
  ///     @param json Json object to load from
  ///     @param required true: no polygon in object will generate error
  ///     @param errorString Error string if return is false
  /// @return true: success, false: failure (errorString set)
  bool loadFromJson(const QJsonObject &json, bool required,
                    QString &errorString);

  /// Convert polygon to NED and return (D is ignored)
  QList<QPointF> nedPolygon(void) const;

  /// Returns the area of the polygon in meters squared
  double area(void) const;

  // Property methods

  int count(void) const { return _polygonPath.count(); }
  bool dirty(void) const { return _dirty; }
  void setDirty(bool dirty);
  QGeoCoordinate center(void) const { return _center; }
  bool centerDrag(void) const { return _centerDrag; }
  bool interactive(void) const { return _interactive; }

  QVariantList path(void) const { return _polygonPath; }
  const QVariantList &pathReference(void) const { return _polygonPath; }
  QmlObjectListModel *qmlPathModel(void) { return &_polygonModel; }
  QmlObjectListModel &pathModel(void) { return _polygonModel; }

  // Friends
  friend void print(const QGCMapPolygon &poly, QString &outputString);
  friend void print(const QGCMapPolygon &poly);

  // static Variables
  static const char *jsonPolygonKey;

signals:
  void countChanged(int count);
  void pathChanged(void);
  void dirtyChanged(bool dirty);
  void cleared(void);
  void centerChanged(QGeoCoordinate center);
  void centerDragChanged(bool centerDrag);
  void interactiveChanged(bool interactive);
  void areaChanged(void);

public slots:
  void setPath(const QList<QGeoCoordinate> &path);
  void setPath(const QVector<QGeoCoordinate> &path);
  void setPath(const QVariantList &path);
  void setCenter(QGeoCoordinate newCenter);
  void setCenterDrag(bool centerDrag);
  void setInteractive(bool interactive);

private slots:
  void _polygonModelCountChanged(int count);
  void _polygonModelDirtyChanged(bool dirty);
  void _updateCenter(void);

private:
  void _init(void);
  QPolygonF _toPolygonF(void) const;
  QGeoCoordinate _coordFromPointF(const QPointF &point) const;
  QPointF _pointFFromCoord(const QGeoCoordinate &coordinate) const;

  QVariantList _polygonPath;
  QmlObjectListModel _polygonModel;
  bool _dirty;
  QGeoCoordinate _center;
  bool _centerDrag;
  bool _ignoreCenterUpdates;
  bool _interactive;
};

#endif