QGIS API Documentation 3.27.0-Master (a46f227e17)
qgsvectorwarper.cpp
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1/***************************************************************************
2 qgsgcptransformer.cpp
3 --------------------------------------
4 Date : February 2022
5 Copyright : (C) 2022 by Nyall Dawson
6 Email : nyall dot dawson at gmail 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 "qgsvectorwarper.h"
17#include "qgsfeaturesink.h"
18#include "qgsfeedback.h"
20#include "qgsfeaturesource.h"
21#include "qgsvectorlayer.h"
22
23#include <QObject>
24#include <QFileInfo>
25
27 : mMethod( method )
28 , mPoints( points )
29 , mDestinationCrs( destinationCrs )
30{
31
32}
33
35{
36 if ( !sink )
37 return false;
38
39 QVector<QgsPointXY> sourcePoints;
40 sourcePoints.reserve( mPoints.size() );
41 QVector<QgsPointXY> destinationPoints;
42 destinationPoints.reserve( mPoints.size() );
43 for ( const QgsGcpPoint &gcpPoint : mPoints )
44 {
45 sourcePoints << gcpPoint.sourcePoint();
46 destinationPoints << gcpPoint.transformedDestinationPoint( mDestinationCrs, context );
47 }
48
49 if ( feedback && feedback->isCanceled() )
50 return false;
51
52 QgsGcpGeometryTransformer transformer( mMethod, sourcePoints, destinationPoints );
53
54 QgsFeature f;
55
56 long long i = 0;
57 while ( iterator.nextFeature( f ) )
58 {
59 if ( feedback )
60 {
61 if ( feedback->isCanceled() )
62 break;
63
64 feedback->setProcessedCount( i );
65 }
66 i++;
67
68 QgsFeature outputFeature = f;
69 bool ok = false;
70 const QgsGeometry transformed = transformer.transform( f.geometry(), ok, feedback );
71 if ( ok )
72 {
73 outputFeature.setGeometry( transformed );
74 if ( !sink->addFeature( outputFeature, QgsFeatureSink::FastInsert ) )
75 {
76 mError = sink->lastError();
77 return false;
78 }
79 }
80 else
81 {
82 mError = QObject::tr( "An error occurred while transforming a feature" );
83 return false;
84 }
85 }
86 return true;
87}
88
89
90
91//
92// QgsVectorWarperTask
93//
94
96 const QgsCoordinateReferenceSystem &destinationCrs,
97 QgsVectorLayer *layer, const QString &fileName )
98 : QgsTask( tr( "Warping %1" ).arg( fileName ), QgsTask::CanCancel )
99 , mMethod( method )
100 , mPoints( points )
101 , mDestinationCrs( destinationCrs )
102 , mDestFileName( fileName )
103{
104 if ( layer )
105 {
106 mTransformContext = layer->transformContext();
107 mSource.reset( new QgsVectorLayerFeatureSource( layer ) );
108 mFeatureCount = layer->featureCount();
109 mFields = layer->fields();
110 mWkbType = layer->wkbType();
111 }
112}
113
115{
116 if ( mFeedback )
117 mFeedback->cancel();
118
120}
121
123{
124 mFeedback = std::make_unique< QgsFeedback >();
125
127
128 const QString fileExtension = QFileInfo( mDestFileName ).completeSuffix();
129 saveOptions.driverName = QgsVectorFileWriter::driverForExtension( fileExtension );
130
131 std::unique_ptr< QgsVectorFileWriter > exporter( QgsVectorFileWriter::create( mDestFileName, mFields, mWkbType, mDestinationCrs, mTransformContext, saveOptions ) );
132 if ( exporter->hasError() )
133 {
134 mErrorMessage = exporter->errorMessage();
135 mResult = Result::Error;
136 return false;
137 }
138
139 QgsVectorWarper warper( mMethod, mPoints, mDestinationCrs );
140
141 connect( mFeedback.get(), &QgsFeedback::processedCountChanged, this, [ = ]( long long count )
142 {
143 const double newProgress = 100.0 * count / mFeatureCount;
144 // avoid flooding with too many events
145 if ( static_cast< int >( newProgress * 10 ) != static_cast< int >( mLastProgress * 10 ) )
146 {
147 mLastProgress = newProgress;
148 emit progressChanged( newProgress );
149 }
150 } );
151
152 QgsFeatureIterator iterator = mSource->getFeatures();
153 const bool res = warper.transformFeatures( iterator, exporter.get(), mTransformContext, mFeedback.get() );
154 if ( !res )
155 {
156 mErrorMessage = warper.error();
157 mResult = Result::Error;
158 }
159
160 mResult = mFeedback->isCanceled() ? Result::Canceled : Result::Success;
161 mFeedback.reset();
162 return mResult == Result::Success;
163}
164
This class represents a coordinate reference system (CRS).
Contains information about the context in which a coordinate transform is executed.
Wrapper for iterator of features from vector data provider or vector layer.
bool nextFeature(QgsFeature &f)
An interface for objects which accept features via addFeature(s) methods.
virtual bool addFeature(QgsFeature &feature, QgsFeatureSink::Flags flags=QgsFeatureSink::Flags())
Adds a single feature to the sink.
@ FastInsert
Use faster inserts, at the cost of updating the passed features to reflect changes made at the provid...
virtual QString lastError() const
Returns the most recent error encountered by the sink, e.g.
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
Definition: qgsfeature.h:56
QgsGeometry geometry
Definition: qgsfeature.h:67
void setGeometry(const QgsGeometry &geometry)
Set the feature's geometry.
Definition: qgsfeature.cpp:170
Base class for feedback objects to be used for cancellation of something running in a worker thread.
Definition: qgsfeedback.h:45
void setProcessedCount(unsigned long long processedCount)
Sets the current processed objects count for the feedback object.
Definition: qgsfeedback.h:99
void processedCountChanged(unsigned long long processedCount)
Emitted when the feedback object reports a change in the number of processed objects.
bool isCanceled() const SIP_HOLDGIL
Tells whether the operation has been canceled already.
Definition: qgsfeedback.h:54
A geometry transformer which uses an underlying Ground Control Points (GCP) based transformation to m...
QgsGeometry transform(const QgsGeometry &geometry, bool &ok, QgsFeedback *feedback=nullptr)
Transforms the specified input geometry using the GCP based transform.
Contains properties of a ground control point (GCP).
Definition: qgsgcppoint.h:31
TransformMethod
Available transformation methods.
A geometry is the spatial representation of a feature.
Definition: qgsgeometry.h:164
QgsCoordinateTransformContext transformContext() const
Returns the layer data provider coordinate transform context or a default transform context if the la...
Abstract base class for long running background tasks.
virtual void cancel()
Notifies the task that it should terminate.
Options to pass to writeAsVectorFormat()
static QgsVectorFileWriter * create(const QString &fileName, const QgsFields &fields, QgsWkbTypes::Type geometryType, const QgsCoordinateReferenceSystem &srs, const QgsCoordinateTransformContext &transformContext, const QgsVectorFileWriter::SaveVectorOptions &options, QgsFeatureSink::SinkFlags sinkFlags=QgsFeatureSink::SinkFlags(), QString *newFilename=nullptr, QString *newLayer=nullptr)
Create a new vector file writer.
static QString driverForExtension(const QString &extension)
Returns the OGR driver name for a specified file extension.
Partial snapshot of vector layer's state (only the members necessary for access to features)
Represents a vector layer which manages a vector based data sets.
Q_INVOKABLE QgsWkbTypes::Type wkbType() const FINAL
Returns the WKBType or WKBUnknown in case of error.
long long featureCount(const QString &legendKey) const
Number of features rendered with specified legend key.
QgsFields fields() const FINAL
Returns the list of fields of this layer.
bool run() override
Performs the task's operation.
@ Error
An error occurred while warping.
void cancel() override
Notifies the task that it should terminate.
QgsVectorWarperTask(QgsGcpTransformerInterface::TransformMethod method, const QList< QgsGcpPoint > &points, const QgsCoordinateReferenceSystem &destinationCrs, QgsVectorLayer *layer, const QString &fileName)
Constructor for QgsVectorWarperTask.
Vector layer warper which warps vector layers based on a list of source and destination GCPs.
bool transformFeatures(QgsFeatureIterator &iterator, QgsFeatureSink *sink, const QgsCoordinateTransformContext &context, QgsFeedback *feedback=nullptr) const
Transforms the features from iterator and adds the results to the specified sink.
QgsVectorWarper(QgsGcpTransformerInterface::TransformMethod method, const QList< QgsGcpPoint > &points, const QgsCoordinateReferenceSystem &destinationCrs)
Constructor for QgsVectorWarper.