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

#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* newCoordParent, QObject* parent = NULL);

    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_INVOKABLE void clear(void);
    Q_INVOKABLE void appendVertex(const QGeoCoordinate& coordinate);
    Q_INVOKABLE void removeVertex(int vertexIndex);

    /// 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 the center point coordinate for the polygon
    Q_INVOKABLE QGeoCoordinate center(void) const;

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

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

    /// 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);

    // Property methods

    int     count   (void) const { return _polygonPath.count(); }
    bool    dirty   (void) const { return _dirty; }
    void    setDirty(bool dirty);

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

    void setPath(const QList<QGeoCoordinate>& path);
    void setPath(const QVariantList& path);

signals:
    void countChanged(int count);
    void pathChanged(void);
    void dirtyChanged(bool dirty);

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

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

    QObject*            _newCoordParent;
    QVariantList        _polygonPath;
    QmlObjectListModel  _polygonModel;
    bool                _dirty;

    static const char* _jsonPolygonKey;
};

#endif