QGIS API Documentation  3.8.0-Zanzibar (11aff65)
qgsgeometrysegmentlengthcheck.cpp
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1 /***************************************************************************
2  qgsgeometrysegmentlengthcheck.cpp
3  ---------------------
4  begin : September 2015
5  copyright : (C) 2014 by Sandro Mani / Sourcepole AG
6  email : smani at sourcepole dot ch
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 
18 #include "qgsgeometryutils.h"
19 #include "qgsfeaturepool.h"
20 #include "qgsgeometrycheckerror.h"
21 
22 void QgsGeometrySegmentLengthCheck::collectErrors( const QMap<QString, QgsFeaturePool *> &featurePools, QList<QgsGeometryCheckError *> &errors, QStringList &messages, QgsFeedback *feedback, const LayerFeatureIds &ids ) const
23 {
24  Q_UNUSED( messages )
25 
26  QMap<QString, QgsFeatureIds> featureIds = ids.isEmpty() ? allLayerFeatureIds( featurePools ) : ids.toMap();
27  QgsGeometryCheckerUtils::LayerFeatures layerFeatures( featurePools, featureIds, compatibleGeometryTypes(), feedback, mContext );
28  for ( const QgsGeometryCheckerUtils::LayerFeature &layerFeature : layerFeatures )
29  {
30  double layerToMapUnits = scaleFactor( layerFeature.layer() );
31  double minLength = mMinLengthMapUnits / layerToMapUnits;
32 
33  const QgsAbstractGeometry *geom = layerFeature.geometry().constGet();
34  for ( int iPart = 0, nParts = geom->partCount(); iPart < nParts; ++iPart )
35  {
36  for ( int iRing = 0, nRings = geom->ringCount( iPart ); iRing < nRings; ++iRing )
37  {
38  bool isClosed = false;
39  int nVerts = QgsGeometryCheckerUtils::polyLineSize( geom, iPart, iRing, &isClosed );
40  if ( nVerts < 2 )
41  {
42  continue;
43  }
44  for ( int iVert = isClosed ? 0 : 1, jVert = isClosed ? nVerts - 1 : 0; iVert < nVerts; jVert = iVert++ )
45  {
46  QgsPoint pi = geom->vertexAt( QgsVertexId( iPart, iRing, iVert ) );
47  QgsPoint pj = geom->vertexAt( QgsVertexId( iPart, iRing, jVert ) );
48  double dist = pi.distance( pj );
49  // Don't report very small lengths, they are either duplicate nodes or degenerate geometries
50  if ( dist < minLength && dist > mContext->tolerance )
51  {
52  QgsPointXY pos( 0.5 * ( pi.x() + pj.x() ), 0.5 * ( pi.y() + pj.y() ) );
53  errors.append( new QgsGeometryCheckError( this, layerFeature, pos, QgsVertexId( iPart, iRing, iVert ), dist * layerToMapUnits, QgsGeometryCheckError::ValueLength ) );
54  }
55  }
56  }
57  }
58  }
59 }
60 
61 void QgsGeometrySegmentLengthCheck::fixError( const QMap<QString, QgsFeaturePool *> &featurePools, QgsGeometryCheckError *error, int method, const QMap<QString, int> & /*mergeAttributeIndices*/, Changes &/*changes*/ ) const
62 {
63  QgsFeaturePool *featurePool = featurePools[ error->layerId() ];
64  QgsFeature feature;
65  if ( !featurePool->getFeature( error->featureId(), feature ) )
66  {
67  error->setObsolete();
68  return;
69  }
70 
71  QgsGeometry featureGeom = feature.geometry();
72  const QgsAbstractGeometry *geom = featureGeom.constGet();
73  QgsVertexId vidx = error->vidx();
74 
75  // Check if point still exists
76  if ( !vidx.isValid( geom ) )
77  {
78  error->setObsolete();
79  return;
80  }
81 
82  // Check if error still applies
83  int nVerts = QgsGeometryCheckerUtils::polyLineSize( geom, vidx.part, vidx.ring );
84  if ( nVerts == 0 )
85  {
86  error->setObsolete();
87  return;
88  }
89 
90  QgsPoint pi = geom->vertexAt( error->vidx() );
91  QgsPoint pj = geom->vertexAt( QgsVertexId( vidx.part, vidx.ring, ( vidx.vertex - 1 + nVerts ) % nVerts ) );
92  double dist = pi.distance( pj );
93  double layerToMapUnits = scaleFactor( featurePool->layer() );
94  double minLength = mMinLengthMapUnits / layerToMapUnits;
95  if ( dist >= minLength )
96  {
97  error->setObsolete();
98  return;
99  }
100 
101  // Fix error
102  if ( method == NoChange )
103  {
104  error->setFixed( method );
105  }
106  else
107  {
108  error->setFixFailed( tr( "Unknown method" ) );
109  }
110 }
111 
113 {
114  static QStringList methods = QStringList() << tr( "No action" );
115  return methods;
116 }
117 
119 {
121 }
double y
Definition: qgspoint.h:42
double scaleFactor(const QPointer< QgsVectorLayer > &layer) const
Determines the scale factor of a layer to the map coordinate reference system.
bool isValid() const
Returns true if the vertex id is valid.
double distance(double x, double y) const
Returns the distance between this point and a specified x, y coordinate.
Definition: qgspoint.h:276
A class to represent a 2D point.
Definition: qgspointxy.h:43
QMap< QString, QgsFeatureIds > toMap() const
static QgsGeometryCheck::CheckType factoryCheckType()
Contains a set of layers and feature ids in those layers to pass to a geometry check.
CheckType
The type of a check.
static int polyLineSize(const QgsAbstractGeometry *geom, int iPart, int iRing, bool *isClosed=nullptr)
Returns the number of points in a polyline, accounting for duplicate start and end point if the polyl...
QStringList resolutionMethods() const override
Returns a list of descriptions for available resolutions for errors.
A geometry is the spatial representation of a feature.
Definition: qgsgeometry.h:111
void setObsolete()
Set the error status to obsolete.
The feature class encapsulates a single feature including its id, geometry and a list of field/values...
Definition: qgsfeature.h:55
void setFixFailed(const QString &reason)
Set the error status to failed and specify the reason for failure.
Base class for feedback objects to be used for cancellation of something running in a worker thread...
Definition: qgsfeedback.h:44
QgsVectorLayer * layer() const
Gets a pointer to the underlying layer.
Utility class for identifying a unique vertex within a geometry.
bool getFeature(QgsFeatureId id, QgsFeature &feature)
Retrieves the feature with the specified id into feature.
A layer feature combination to uniquely identify and access a feature in a set of layers...
QList< QgsWkbTypes::GeometryType > compatibleGeometryTypes() const override
A list of geometry types for which this check can be performed.
virtual int ringCount(int part=0) const =0
Returns the number of rings of which this geometry is built.
Abstract base class for all geometries.
QMap< QString, QgsFeatureIds > allLayerFeatureIds(const QMap< QString, QgsFeaturePool *> &featurePools) const
Returns all layers and feature ids.
const QString & layerId() const
The id of the layer on which this error has been detected.
const double tolerance
The tolerance to allow for in geometry checks.
const QgsGeometryCheckContext * mContext
Point geometry type, with support for z-dimension and m-values.
Definition: qgspoint.h:37
A list of layers and feature ids for each of these layers.
void fixError(const QMap< QString, QgsFeaturePool *> &featurePools, QgsGeometryCheckError *error, int method, const QMap< QString, int > &mergeAttributeIndices, Changes &changes) const override
Fix the error error with the specified method.
const QgsAbstractGeometry * constGet() const
Returns a non-modifiable (const) reference to the underlying abstract geometry primitive.
QMap< QString, QMap< QgsFeatureId, QList< QgsGeometryCheck::Change > > > Changes
A collection of changes.
A feature pool is based on a vector layer and caches features.
void setFixed(int method)
Set the status to fixed and specify the method that has been used to fix the error.
QgsFeatureId featureId() const
The id of the feature on which this error has been detected.
QgsGeometry geometry
Definition: qgsfeature.h:67
This represents an error reported by a geometry check.
virtual QgsPoint vertexAt(QgsVertexId id) const =0
Returns the point corresponding to a specified vertex id.
void collectErrors(const QMap< QString, QgsFeaturePool *> &featurePools, QList< QgsGeometryCheckError *> &errors, QStringList &messages, QgsFeedback *feedback, const LayerFeatureIds &ids=LayerFeatureIds()) const override
The main worker method.
const QgsVertexId & vidx() const
The id of the affected vertex.
virtual int partCount() const =0
Returns count of parts contained in the geometry.
The check controls individual nodes.
double x
Definition: qgspoint.h:41