[Geometry checker] Add dangle check

src/plugins/geometry_checker/CMakeLists.txt

@@ -8,6 +8,7 @@ SET (geometrychecker_SRCS
     qgsgeometrycheckfactory.cpp
     checks/qgsgeometryanglecheck.cpp
     checks/qgsgeometryareacheck.cpp
+    checks/qgsgeometrydanglecheck.cpp
     checks/qgsgeometrydegeneratepolygoncheck.cpp
     checks/qgsgeometryduplicatecheck.cpp
     checks/qgsgeometryduplicatenodescheck.cpp
@@ -45,6 +46,7 @@ SET (geometrychecker_MOC_HDRS
     checks/qgsgeometryanglecheck.h
     checks/qgsgeometryareacheck.h
     checks/qgsgeometrycheck.h
+    checks/qgsgeometrydanglecheck.h
     checks/qgsgeometrydegeneratepolygoncheck.h
     checks/qgsgeometryduplicatecheck.h
     checks/qgsgeometryduplicatenodescheck.h

src/plugins/geometry_checker/checks/qgsgeometrydanglecheck.cpp

@@ -0,0 +1,109 @@
+/***************************************************************************
+    qgsgeometrydanglecheck.cpp
+    ---------------------
+    begin                : June 2017
+    copyright            : (C) 2017 by Sandro Mani / Sourcepole AG
+    email                : smani at sourcepole dot ch
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#include "qgsgeometrydanglecheck.h"
+#include "qgslinestring.h"
+
+void QgsGeometryDangleCheck::collectErrors( QList<QgsGeometryCheckError *> &errors, QStringList &/*messages*/, QAtomicInt *progressCounter, const QMap<QString, QgsFeatureIds> &ids ) const
+{
+  QMap<QString, QgsFeatureIds> featureIds = ids.isEmpty() ? allLayerFeatureIds() : ids;
+  QgsGeometryCheckerUtils::LayerFeatures layerFeatures( mContext->featurePools, featureIds, mCompatibleGeometryTypes, progressCounter );
+  for ( const QgsGeometryCheckerUtils::LayerFeature &layerFeature : layerFeatures )
+  {
+    const QgsAbstractGeometry *geom = layerFeature.geometry();
+    for ( int iPart = 0, nParts = geom->partCount(); iPart < nParts; ++iPart )
+    {
+      const QgsLineString *line = dynamic_cast<const QgsLineString *>( QgsGeometryCheckerUtils::getGeomPart( geom, iPart ) );
+      if ( !line )
+      {
+        // Should not happen
+        continue;
+      }
+      // Check that start and end node lie on a line
+      int nVerts = geom->vertexCount( iPart, 0 );
+      const QgsPoint &p1 = geom->vertexAt( QgsVertexId( iPart, 0, 0 ) );
+      const QgsPoint &p2 = geom->vertexAt( QgsVertexId( iPart, 0, nVerts - 1 ) );
+
+      bool p1touches = QgsGeometryCheckerUtils::pointOnLine( p1, line, mContext->tolerance, true );
+      bool p2touches = QgsGeometryCheckerUtils::pointOnLine( p2, line, mContext->tolerance, true );
+
+      if ( p1touches && p2touches )
+      {
+        // Both endpoints lie on line itself
+        continue;
+      }
+
+      // Check whether endpoints line on another line in the layer
+      QgsGeometryCheckerUtils::LayerFeatures checkFeatures( mContext->featurePools, QList<QString>() << layerFeature.layer().id(), line->boundingBox(), {QgsWkbTypes::LineGeometry} );
+      for ( const QgsGeometryCheckerUtils::LayerFeature &checkFeature : checkFeatures )
+      {
+        if ( checkFeature.feature().id() == layerFeature.feature().id() )
+        {
+          // Skip current feature, it was already checked above
+          continue;
+        }
+        const QgsAbstractGeometry *testGeom = checkFeature.geometry();
+        for ( int jPart = 0, mParts = testGeom->partCount(); jPart < mParts; ++jPart )
+        {
+          const QgsLineString *testLine = dynamic_cast<const QgsLineString *>( QgsGeometryCheckerUtils::getGeomPart( testGeom, jPart ) );
+          if ( !testLine )
+          {
+            continue;
+          }
+          p1touches = p1touches || QgsGeometryCheckerUtils::pointOnLine( p1, testLine, mContext->tolerance );
+          p2touches = p2touches || QgsGeometryCheckerUtils::pointOnLine( p2, testLine, mContext->tolerance );
+          if ( p1touches && p2touches )
+          {
+            break;
+          }
+        }
+        if ( p1touches && p2touches )
+        {
+          break;
+        }
+      }
+      if ( p1touches && p2touches )
+      {
+        continue;
+      }
+      if ( !p1touches )
+      {
+        errors.append( new QgsGeometryCheckError( this, layerFeature, p1, QgsVertexId( iPart, 0, 0 ) ) );
+      }
+      if ( !p2touches )
+      {
+        errors.append( new QgsGeometryCheckError( this, layerFeature, p2, QgsVertexId( iPart, 0, nVerts - 1 ) ) );
+      }
+    }
+  }
+}
+
+void QgsGeometryDangleCheck::fixError( QgsGeometryCheckError *error, int method, const QMap<QString, int> & /*mergeAttributeIndices*/, Changes & /*changes*/ ) const
+{
+  if ( method == NoChange )
+  {
+    error->setFixed( method );
+  }
+  else
+  {
+    error->setFixFailed( tr( "Unknown method" ) );
+  }
+}
+
+QStringList QgsGeometryDangleCheck::getResolutionMethods() const
+{
+  static QStringList methods = QStringList() << tr( "No action" );
+  return methods;
+}

src/plugins/geometry_checker/checks/qgsgeometrydanglecheck.h

@@ -0,0 +1,38 @@
+/***************************************************************************
+    qgsgeometrydanglecheck.h
+    ---------------------
+    begin                : June 2017
+    copyright            : (C) 2017 by Sandro Mani / Sourcepole AG
+    email                : smani at sourcepole dot ch
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#ifndef QGSGEOMETRYDANGLECHECK_H
+#define QGSGEOMETRYDANGLECHECK_H
+
+#include "qgsgeometrycheck.h"
+
+class QgsGeometryDangleCheck : public QgsGeometryCheck
+{
+    Q_OBJECT
+
+  public:
+    QgsGeometryDangleCheck( QgsGeometryCheckerContext *context )
+      : QgsGeometryCheck( FeatureNodeCheck, {QgsWkbTypes::LineGeometry}, context )
+    {}
+    void collectErrors( QList<QgsGeometryCheckError *> &errors, QStringList &messages, QAtomicInt *progressCounter = nullptr, const QMap<QString, QgsFeatureIds> &ids = QMap<QString, QgsFeatureIds>() ) const override;
+    void fixError( QgsGeometryCheckError *error, int method, const QMap<QString, int> &mergeAttributeIndices, Changes &changes ) const override;
+    QStringList getResolutionMethods() const override;
+    QString errorDescription() const override { return tr( "Dangle" ); }
+    QString errorName() const override { return QStringLiteral( "QgsGeometryDangleCheck" ); }
+  private:
+    enum ResolutionMethod { NoChange };
+};
+
+#endif // QGSGEOMETRYDANGLECHECK_H

src/plugins/geometry_checker/qgsgeometrycheckfactory.cpp

@@ -19,6 +19,7 @@
 #include "checks/qgsgeometryanglecheck.h"
 #include "checks/qgsgeometryareacheck.h"
 #include "checks/qgsgeometrycontainedcheck.h"
+#include "checks/qgsgeometrydanglecheck.h"
 #include "checks/qgsgeometrydegeneratepolygoncheck.h"
 #include "checks/qgsgeometryduplicatecheck.h"
 #include "checks/qgsgeometryduplicatenodescheck.h"
@@ -126,6 +127,34 @@ REGISTER_QGS_GEOMETRY_CHECK_FACTORY( QgsGeometryCheckFactoryT<QgsGeometryContain
 
 ///////////////////////////////////////////////////////////////////////////////
 
+template<> void QgsGeometryCheckFactoryT<QgsGeometryDangleCheck>::restorePrevious( Ui::QgsGeometryCheckerSetupTab &ui ) const
+{
+  ui.checkBoxDangle->setChecked( QgsSettings().value( sSettingsGroup + "checkDangle" ).toBool() );
+}
+
+template<> bool QgsGeometryCheckFactoryT<QgsGeometryDangleCheck>::checkApplicability( Ui::QgsGeometryCheckerSetupTab &ui, int /*nPoint*/, int nLineString, int /*nPolygon*/ ) const
+{
+  ui.checkBoxDangle->setEnabled( nLineString > 0 );
+  return ui.checkBoxDangle->isEnabled();
+}
+
+template<> QgsGeometryCheck *QgsGeometryCheckFactoryT<QgsGeometryDangleCheck>::createInstance( QgsGeometryCheckerContext *context, const Ui::QgsGeometryCheckerSetupTab &ui ) const
+{
+  QgsSettings().setValue( sSettingsGroup + "checkDangle", ui.checkBoxDangle->isChecked() );
+  if ( ui.checkBoxDangle->isEnabled() && ui.checkBoxDangle->isChecked() )
+  {
+    return new QgsGeometryDangleCheck( context );
+  }
+  else
+  {
+    return nullptr;
+  }
+}
+
+REGISTER_QGS_GEOMETRY_CHECK_FACTORY( QgsGeometryCheckFactoryT<QgsGeometryDangleCheck> )
+
+///////////////////////////////////////////////////////////////////////////////
+
 template<> void QgsGeometryCheckFactoryT<QgsGeometryDegeneratePolygonCheck>::restorePrevious( Ui::QgsGeometryCheckerSetupTab &ui ) const
 {
   ui.checkBoxDegeneratePolygon->setChecked( QgsSettings().value( sSettingsGroup + "checkDegeneratePolygon" ).toBool() );

src/plugins/geometry_checker/ui/qgsgeometrycheckersetuptab.ui

@@ -43,7 +43,7 @@
         <x>0</x>
         <y>0</y>
         <width>626</width>
-        <height>820</height>
+        <height>872</height>
        </rect>
       </property>
       <layout class="QGridLayout" name="gridLayout_4">
@@ -280,6 +280,13 @@
                </property>
               </widget>
              </item>
+             <item>
+              <widget class="QCheckBox" name="checkBoxDangle">
+               <property name="text">
+                <string>Lines must not have dangles</string>
+               </property>
+              </widget>
+             </item>
             </layout>
            </widget>
           </item>

src/plugins/geometry_checker/utils/qgsgeometrycheckerutils.cpp

@@ -206,6 +206,22 @@ namespace QgsGeometryCheckerUtils
     return nom / std::sqrt( dx * dx + dy * dy );
   }
 
+  bool pointOnLine( const QgsPoint &p, const QgsLineString *line, double tol, bool excludeExtremities )
+  {
+    int nVerts = line->vertexCount();
+    for ( int i = 0 + excludeExtremities; i < nVerts - 1 - excludeExtremities; ++i )
+    {
+      QgsPoint p1 = line->vertexAt( QgsVertexId( 0, 0, i ) );
+      QgsPoint p2 = line->vertexAt( QgsVertexId( 0, 0, i + 1 ) );
+      double dist = pointLineDist( p1, p2, 1 );
+      if ( dist < tol )
+      {
+        return true;
+      }
+    }
+    return false;
+  }
+
   double sharedEdgeLength( const QgsAbstractGeometry *geom1, const QgsAbstractGeometry *geom2, double tol )
   {
     double len = 0;

src/plugins/geometry_checker/utils/qgsgeometrycheckerutils.h

@@ -126,6 +126,8 @@ namespace QgsGeometryCheckerUtils
     }
   }
 
+  bool pointOnLine( const QgsPoint &p, const QgsLineString *line, double tol, bool excludeExtremities = false );
+
   double sharedEdgeLength( const QgsAbstractGeometry *geom1, const QgsAbstractGeometry *geom2, double tol );
 
   /**