QGIS API Documentation 3.43.0-Master (8fc5848dca1)
qgsmultilinestring.cpp
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1/***************************************************************************
2 qgsmultilinestring.cpp
3 -------------------------------------------------------------------
4Date : 28 Oct 2014
5Copyright : (C) 2014 by Marco Hugentobler
6email : marco.hugentobler at sourcepole dot com
7 ***************************************************************************
8 * *
9 * This program is free software; you can redistribute it and/or modify *
10 * it under the terms of the GNU General Public License as published by *
11 * the Free Software Foundation; either version 2 of the License, or *
12 * (at your option) any later version. *
13 * *
14 ***************************************************************************/
15
16#include "qgsmultilinestring.h"
17#include "qgsabstractgeometry.h"
18#include "qgscurve.h"
19#include "qgsgeometryutils.h"
20#include "qgslinestring.h"
21#include "qgsmulticurve.h"
22
23#include <nlohmann/json.hpp>
24#include <QJsonObject>
25
30
31QgsMultiLineString::QgsMultiLineString( const QList<QgsLineString> &linestrings )
32{
33 if ( linestrings.empty() )
34 return;
35
36 mGeometries.reserve( linestrings.size() );
37 for ( const QgsLineString &line : linestrings )
38 {
39 mGeometries.append( line.clone() );
40 }
41
43}
44
45QgsMultiLineString::QgsMultiLineString( const QList<QgsLineString *> &linestrings )
46{
47 if ( linestrings.empty() )
48 return;
49
50 mGeometries.reserve( linestrings.size() );
51 for ( QgsLineString *line : linestrings )
52 {
53 mGeometries.append( line );
54 }
55
57}
58
60{
61 return qgsgeometry_cast< QgsLineString * >( geometryN( index ) );
62}
63
65{
66 return qgsgeometry_cast< const QgsLineString * >( geometryN( index ) );
67}
68
70{
71 return QStringLiteral( "MultiLineString" );
72}
73
75{
76 auto result = std::make_unique< QgsMultiLineString >();
77 result->mWkbType = mWkbType;
78 return result.release();
79}
80
82{
83 return new QgsMultiLineString( *this );
84}
85
91
92bool QgsMultiLineString::fromWkt( const QString &wkt )
93{
94 return fromCollectionWkt( wkt, {Qgis::WkbType::LineString }, QStringLiteral( "LineString" ) );
95}
96
97QDomElement QgsMultiLineString::asGml2( QDomDocument &doc, int precision, const QString &ns, const AxisOrder axisOrder ) const
98{
99 QDomElement elemMultiLineString = doc.createElementNS( ns, QStringLiteral( "MultiLineString" ) );
100
101 if ( isEmpty() )
102 return elemMultiLineString;
103
104 for ( const QgsAbstractGeometry *geom : mGeometries )
105 {
106 if ( const QgsLineString *lineString = qgsgeometry_cast<const QgsLineString *>( geom ) )
107 {
108 QDomElement elemLineStringMember = doc.createElementNS( ns, QStringLiteral( "lineStringMember" ) );
109 elemLineStringMember.appendChild( lineString->asGml2( doc, precision, ns, axisOrder ) );
110 elemMultiLineString.appendChild( elemLineStringMember );
111 }
112 }
113
114 return elemMultiLineString;
115}
116
117QDomElement QgsMultiLineString::asGml3( QDomDocument &doc, int precision, const QString &ns, const QgsAbstractGeometry::AxisOrder axisOrder ) const
118{
119 QDomElement elemMultiCurve = doc.createElementNS( ns, QStringLiteral( "MultiCurve" ) );
120
121 if ( isEmpty() )
122 return elemMultiCurve;
123
124 for ( const QgsAbstractGeometry *geom : mGeometries )
125 {
126 if ( const QgsLineString *lineString = qgsgeometry_cast<const QgsLineString *>( geom ) )
127 {
128 QDomElement elemCurveMember = doc.createElementNS( ns, QStringLiteral( "curveMember" ) );
129 elemCurveMember.appendChild( lineString->asGml3( doc, precision, ns, axisOrder ) );
130 elemMultiCurve.appendChild( elemCurveMember );
131 }
132 }
133
134 return elemMultiCurve;
135}
136
138{
139 json coordinates( json::array( ) );
140 for ( const QgsAbstractGeometry *geom : mGeometries )
141 {
142 if ( qgsgeometry_cast<const QgsCurve *>( geom ) )
143 {
144 const QgsLineString *lineString = static_cast<const QgsLineString *>( geom );
146 lineString->points( pts );
147 coordinates.push_back( QgsGeometryUtils::pointsToJson( pts, precision ) );
148 }
149 }
150 return
151 {
152 { "type", "MultiLineString" },
153 { "coordinates", coordinates }
154 };
155}
156
158{
159 if ( !dynamic_cast<QgsLineString *>( g ) )
160 {
161 delete g;
162 return false;
163 }
164
165 if ( mGeometries.empty() )
166 {
168 }
169 if ( is3D() && !g->is3D() )
170 g->addZValue();
171 else if ( !is3D() && g->is3D() )
172 g->dropZValue();
173 if ( isMeasure() && !g->isMeasure() )
174 g->addMValue();
175 else if ( !isMeasure() && g->isMeasure() )
176 g->dropMValue();
177 return QgsGeometryCollection::addGeometry( g ); // NOLINT(bugprone-parent-virtual-call) clazy:exclude=skipped-base-method
178}
179
180bool QgsMultiLineString::addGeometries( const QVector<QgsAbstractGeometry *> &geometries )
181{
182 for ( QgsAbstractGeometry *g : geometries )
183 {
184 if ( !qgsgeometry_cast<QgsLineString *>( g ) )
185 {
186 qDeleteAll( geometries );
187 return false;
188 }
189 }
190
191 if ( mGeometries.empty() && !geometries.empty() )
192 {
194 }
195 mGeometries.reserve( mGeometries.size() + geometries.size() );
196 for ( QgsAbstractGeometry *g : geometries )
197 {
198 if ( is3D() && !g->is3D() )
199 g->addZValue();
200 else if ( !is3D() && g->is3D() )
201 g->dropZValue();
202 if ( isMeasure() && !g->isMeasure() )
203 g->addMValue();
204 else if ( !isMeasure() && g->isMeasure() )
205 g->dropMValue();
206 mGeometries.append( g );
207 }
208
209 clearCache();
210 return true;
211}
212
214{
216 {
217 delete g;
218 return false;
219 }
220
221 return QgsMultiCurve::insertGeometry( g, index );
222}
223
225{
226 auto result = std::make_unique< QgsMultiLineString >();
227 result->reserve( mGeometries.size() );
228 for ( int i = 0; i < mGeometries.size(); ++i )
229 {
230 result->addGeometry( mGeometries.at( i )->simplifyByDistance( tolerance ) );
231 }
232 return result.release();
233}
234
236{
237 QgsMultiCurve *multiCurve = new QgsMultiCurve();
238 multiCurve->reserve( mGeometries.size() );
239 for ( int i = 0; i < mGeometries.size(); ++i )
240 {
241 multiCurve->addGeometry( mGeometries.at( i )->toCurveType() );
242 }
243 return multiCurve;
244}
245
247{
248 return true;
249}
250
251QgsMultiLineString *QgsMultiLineString::measuredLine( double start, double end ) const
252{
253 auto result = std::make_unique< QgsMultiLineString >();
254 if ( isEmpty() )
255 {
256 result->convertTo( QgsWkbTypes::addM( mWkbType ) );
257 return result.release();
258 }
259
260 /* Calculate the total length of the line */
261 const double length{this->length()};
262 const double range{end - start};
263 double lengthSoFar{0.0};
264
265 result->reserve( numGeometries() );
266 for ( int i = 0; i < numGeometries(); i++ )
267 {
268 const double subLength{geometryN( i )->length()};
269
270 const double subStart{ ( start + range *lengthSoFar / length ) };
271 const double subEnd{ ( start + range * ( lengthSoFar + subLength ) / length ) };
272
273 std::unique_ptr< QgsLineString > measuredLine = qgsgeometry_cast<const QgsLineString *>( geometryN( i ) )->measuredLine( subStart, subEnd );
274 result->addGeometry( measuredLine.release() );
275
276 lengthSoFar += subLength;
277 }
278
279 return result.release();
280}
@ LineString
LineString.
@ MultiLineString
MultiLineString.
Abstract base class for all geometries.
virtual bool addZValue(double zValue=0)=0
Adds a z-dimension to the geometry, initialized to a preset value.
virtual bool dropMValue()=0
Drops any measure values which exist in the geometry.
bool isMeasure() const
Returns true if the geometry contains m values.
bool is3D() const
Returns true if the geometry is 3D and contains a z-value.
AxisOrder
Axis order for GML generation.
virtual bool addMValue(double mValue=0)=0
Adds a measure to the geometry, initialized to a preset value.
Qgis::WkbType wkbType() const
Returns the WKB type of the geometry.
void setZMTypeFromSubGeometry(const QgsAbstractGeometry *subggeom, Qgis::WkbType baseGeomType)
Updates the geometry type based on whether sub geometries contain z or m values.
virtual double length() const
Returns the planar, 2-dimensional length of the geometry.
virtual bool dropZValue()=0
Drops any z-dimensions which exist in the geometry.
QVector< QgsAbstractGeometry * > mGeometries
bool fromCollectionWkt(const QString &wkt, const QVector< Qgis::WkbType > &subtypes, const QString &defaultChildWkbType=QString())
Reads a collection from a WKT string.
void reserve(int size)
Attempts to allocate memory for at least size geometries.
void clearCache() const override
Clears any cached parameters associated with the geometry, e.g., bounding boxes.
bool isEmpty() const override
Returns true if the geometry is empty.
double length() const override
Returns the planar, 2-dimensional length of the geometry.
virtual bool addGeometry(QgsAbstractGeometry *g)
Adds a geometry and takes ownership. Returns true in case of success.
int numGeometries() const
Returns the number of geometries within the collection.
const QgsAbstractGeometry * geometryN(int n) const
Returns a const reference to a geometry from within the collection.
static json pointsToJson(const QgsPointSequence &points, int precision)
Returns coordinates as json object.
Line string geometry type, with support for z-dimension and m-values.
void points(QgsPointSequence &pt) const override
Returns a list of points within the curve.
Multi curve geometry collection.
bool insertGeometry(QgsAbstractGeometry *g, int index) override
Inserts a geometry before a specified index and takes ownership.
bool addGeometry(QgsAbstractGeometry *g) override
Adds a geometry and takes ownership. Returns true in case of success.
void clear() override
Clears the geometry, ie reset it to a null geometry.
Multi line string geometry collection.
void clear() override
Clears the geometry, ie reset it to a null geometry.
QString geometryType() const override
Returns a unique string representing the geometry type.
bool addGeometries(const QVector< QgsAbstractGeometry * > &geometries) final
Adds a list of geometries to the collection, transferring ownership to the collection.
QgsMultiCurve * toCurveType() const override
Returns the geometry converted to the more generic curve type QgsMultiCurve.
bool wktOmitChildType() const override
Returns whether child type names are omitted from Wkt representations of the collection.
bool fromWkt(const QString &wkt) override
Sets the geometry from a WKT string.
bool insertGeometry(QgsAbstractGeometry *g, int index) override
Inserts a geometry before a specified index and takes ownership.
json asJsonObject(int precision=17) const override
Returns a json object representation of the geometry.
QDomElement asGml3(QDomDocument &doc, int precision=17, const QString &ns="gml", QgsAbstractGeometry::AxisOrder axisOrder=QgsAbstractGeometry::AxisOrder::XY) const override
Returns a GML3 representation of the geometry.
QgsMultiLineString * measuredLine(double start, double end) const
Re-write the measure ordinate (or add one, if it isn't already there) interpolating the measure betwe...
QgsMultiLineString * clone() const override
Clones the geometry by performing a deep copy.
QgsMultiLineString * createEmptyWithSameType() const override
Creates a new geometry with the same class and same WKB type as the original and transfers ownership.
QgsMultiLineString()
Constructor for an empty multilinestring geometry.
bool addGeometry(QgsAbstractGeometry *g) override
Adds a geometry and takes ownership. Returns true in case of success.
QgsMultiLineString * simplifyByDistance(double tolerance) const override
Simplifies the geometry by applying the Douglas Peucker simplification by distance algorithm.
QDomElement asGml2(QDomDocument &doc, int precision=17, const QString &ns="gml", QgsAbstractGeometry::AxisOrder axisOrder=QgsAbstractGeometry::AxisOrder::XY) const override
Returns a GML2 representation of the geometry.
QgsLineString * lineStringN(int index)
Returns the line string with the specified index.
static Qgis::WkbType addM(Qgis::WkbType type)
Adds the m dimension to a WKB type and returns the new type.
static Qgis::WkbType flatType(Qgis::WkbType type)
Returns the flat type for a WKB type.
QVector< QgsPoint > QgsPointSequence
int precision