QGIS/python/core/geometry/qgslinestring.sip

/** \ingroup core
 * \class QgsLineString
 * \brief Line string geometry type, with support for z-dimension and m-values.
 * \note added in QGIS 2.10
 */
class QgsLineString: public QgsCurve
{
%TypeHeaderCode
#include <qgslinestring.h>
%End

  public:
    QgsLineString();
    ~QgsLineString();

    bool operator==( const QgsCurve& other ) const;
    bool operator!=( const QgsCurve& other ) const;

    /** Returns the specified point from inside the line string.
     * @param i index of point, starting at 0 for the first point
     */
    QgsPointV2 pointN( int i ) const;

    /** Returns the z-coordinate of the specified node in the line string.
     * @param index index of node, where the first node in the line is 0
     * @returns z-coordinate of node, or 0.0 if index is out of bounds or the line
     * does not have a z dimension
     * @see setZAt()
     */
    double zAt( int index ) const;

    /** Returns the m value of the specified node in the line string.
     * @param index index of node, where the first node in the line is 0
     * @returns m value of node, or 0.0 if index is out of bounds or the line
     * does not have m values
     * @see setMAt()
     */
    double mAt( int index ) const;

    /** Sets the x-coordinate of the specified node in the line string.
     * @param index index of node, where the first node in the line is 0. Corresponding
     * node must already exist in line string.
     * @param x x-coordinate of node
     * @see xAt()
     */
    void setXAt( int index, double x );

    /** Sets the y-coordinate of the specified node in the line string.
     * @param index index of node, where the first node in the line is 0. Corresponding
     * node must already exist in line string.
     * @param y y-coordinate of node
     * @see yAt()
     */
    void setYAt( int index, double y );

    /** Sets the z-coordinate of the specified node in the line string.
     * @param index index of node, where the first node in the line is 0. Corresponding
     * node must already exist in line string, and the line string must have z-dimension.
     * @param z z-coordinate of node
     * @see zAt()
     */
    void setZAt( int index, double z );

    /** Sets the m value of the specified node in the line string.
     * @param index index of node, where the first node in the line is 0. Corresponding
     * node must already exist in line string, and the line string must have m values.
     * @param m m value of node
     * @see mAt()
     */
    void setMAt( int index, double m );

    /** Resets the line string to match the specified list of points. The line string will
     * inherit the dimensionality of the first point in the list.
     * @param points new points for line string. If empty, line string will be cleared.
     */
    void setPoints( const QList<QgsPointV2>& points );

    /** Appends the contents of another line string to the end of this line string.
     * @param line line to append. Ownership is not transferred.
     */
    void append( const QgsLineString* line );

    /** Adds a new vertex to the end of the line string.
     * @param pt vertex to add
     */
    void addVertex( const QgsPointV2& pt );

    /** Closes the line string by appending the first point to the end of the line, if it is not already closed.*/
    void close();

    /** Returns the geometry converted to the more generic curve type QgsCompoundCurve
        @return the converted geometry. Caller takes ownership*/
    QgsAbstractGeometry* toCurveType() const /Factory/;

    /**
     * Extends the line geometry by extrapolating out the start or end of the line
     * by a specified distance. Lines are extended using the bearing of the first or last
     * segment in the line.
     * @note added in QGIS 3.0
     */
    void extend( double startDistance, double endDistance );

    //reimplemented methods

    virtual QString geometryType() const;
    virtual int dimension() const;
    virtual QgsLineString* clone() const /Factory/;
    virtual void clear();

    virtual bool fromWkb( QgsConstWkbPtr& wkb );
    virtual bool fromWkt( const QString& wkt );

    QByteArray asWkb() const;
    QString asWkt( int precision = 17 ) const;
    QDomElement asGML2( QDomDocument& doc, int precision = 17, const QString& ns = "gml" ) const;
    QDomElement asGML3( QDomDocument& doc, int precision = 17, const QString& ns = "gml" ) const;
    QString asJSON( int precision = 17 ) const;

    //curve interface
    virtual double length() const;
    virtual QgsPointV2 startPoint() const;
    virtual QgsPointV2 endPoint() const;
    /** Returns a new line string geometry corresponding to a segmentized approximation
     * of the curve.
     * @param tolerance segmentation tolerance
     * @param toleranceType maximum segmentation angle or maximum difference between approximation and curve*/
    virtual QgsLineString* curveToLine( double tolerance = M_PI_2 / 90, SegmentationToleranceType toleranceType = MaximumAngle ) const /Factory/;

    int numPoints() const;
    virtual int nCoordinates() const;
    void points( QList<QgsPointV2>& pt ) const;

    void draw( QPainter& p ) const;
    void transform( const QgsCoordinateTransform& ct, QgsCoordinateTransform::TransformDirection d = QgsCoordinateTransform::ForwardTransform,
                    bool transformZ = false );
    void transform( const QTransform& t );

    void addToPainterPath( QPainterPath& path ) const;
    void drawAsPolygon( QPainter& p ) const;

    virtual bool insertVertex( QgsVertexId position, const QgsPointV2& vertex );
    virtual bool moveVertex( QgsVertexId position, const QgsPointV2& newPos );
    virtual bool deleteVertex( QgsVertexId position );

    virtual QgsLineString* reversed() const /Factory/;

    double closestSegment( const QgsPointV2& pt, QgsPointV2& segmentPt,  QgsVertexId& vertexAfter, bool* leftOf, double epsilon ) const;
    bool pointAt( int i, QgsPointV2& vertex, QgsVertexId::VertexType& type ) const;

    virtual QgsPointV2 centroid() const;

    void sumUpArea( double& sum ) const;
    double vertexAngle( QgsVertexId vertex ) const;

    virtual bool addZValue( double zValue = 0 );
    virtual bool addMValue( double mValue = 0 );

    virtual bool dropZValue();
    virtual bool dropMValue();

    virtual bool convertTo( QgsWkbTypes::Type type );

    virtual double xAt( int index ) const;
    virtual double yAt( int index ) const;

  protected:

    virtual QgsRectangle calculateBoundingBox() const;

};