Better UX in geometry validation panel

src/app/qgsgeometryvalidationdock.cpp

@@ -37,6 +37,7 @@ QgsGeometryValidationDock::QgsGeometryValidationDock( const QString &title, QgsM
   connect( mMapCanvas, &QgsMapCanvas::currentLayerChanged, this, &QgsGeometryValidationDock::updateLayerTransform );
   connect( mMapCanvas, &QgsMapCanvas::destinationCrsChanged, this, &QgsGeometryValidationDock::updateLayerTransform );
   connect( mMapCanvas, &QgsMapCanvas::transformContextChanged, this, &QgsGeometryValidationDock::updateLayerTransform );
+  connect( mTopologyChecksPendingButton, &QToolButton::clicked, this, &QgsGeometryValidationDock::triggerTopologyChecks );
 
   mFeatureRubberband = new QgsRubberBand( mMapCanvas );
   mErrorRubberband = new QgsRubberBand( mMapCanvas );
@@ -54,6 +55,8 @@ QgsGeometryValidationDock::QgsGeometryValidationDock( const QString &title, QgsM
   mErrorLocationRubberband->setWidth( scaleFactor );
   mErrorLocationRubberband->setIconSize( scaleFactor * 5 );
   mErrorLocationRubberband->setColor( QColor( 50, 255, 50, 255 ) );
+
+  mProblemDetailWidget->setVisible( false );
 }
 
 
@@ -104,6 +107,13 @@ void QgsGeometryValidationDock::zoomToFeature()
   mMapCanvas->zoomToFeatureExtent( mapExtent );
 }
 
+void QgsGeometryValidationDock::triggerTopologyChecks()
+{
+  QgsVectorLayer *layer = qobject_cast<QgsVectorLayer *>( mMapCanvas->currentLayer() );
+  if ( layer )
+    mGeometryValidationService->triggerTopologyChecks( layer );
+}
+
 void QgsGeometryValidationDock::updateLayerTransform()
 {
   if ( !mMapCanvas->currentLayer() )
@@ -130,13 +140,18 @@ QModelIndex QgsGeometryValidationDock::currentIndex() const
 void QgsGeometryValidationDock::onCurrentErrorChanged( const QModelIndex &current, const QModelIndex &previous )
 {
   Q_UNUSED( previous )
+
+  mProblemDetailWidget->setVisible( current.isValid() );
+
   mNextButton->setEnabled( current.isValid() && current.row() < mGeometryValidationModel->rowCount() - 1 );
   mPreviousButton->setEnabled( current.isValid() && current.row() > 0 );
 
   mProblemDetailWidget->setVisible( current.isValid() );
-  mProblemDescriptionLabel->setText( current.data().toString() );
+  mProblemDescriptionLabel->setText( current.data( QgsGeometryValidationModel::DetailsRole ).toString() );
+
+  QgsGeometryCheckError *error = current.data( QgsGeometryValidationModel::GeometryCheckErrorRole ).value<QgsGeometryCheckError *>();
+  if ( error )
   {
-    QgsGeometryCheckError *error = current.data( QgsGeometryValidationModel::GeometryCheckErrorRole ).value<QgsGeometryCheckError *>();
     while ( QPushButton *btn =  mResolutionWidget->findChild<QPushButton *>() )
       delete btn;
     const QStringList resolutionMethods = error->check()->resolutionMethods();

src/app/qgsgeometryvalidationdock.h

@@ -47,6 +47,7 @@ class QgsGeometryValidationDock : public QgsDockWidget, public Ui_QgsGeometryVal
     void gotoPreviousError();
     void zoomToProblem();
     void zoomToFeature();
+    void triggerTopologyChecks();
     void updateLayerTransform();
 
   private:

src/app/qgsgeometryvalidationmodel.cpp

@@ -52,6 +52,8 @@ QVariant QgsGeometryValidationModel::data( const QModelIndex &index, int role )
     switch ( role )
     {
       case Qt::DisplayRole:
+        FALLTHROUGH;
+      case DetailsRole:
       {
         const QgsFeatureId fid = topologyError->featureId();
         const QgsFeature feature = mCurrentLayer->getFeature( fid ); // TODO: this should be cached!
@@ -135,6 +137,40 @@ QVariant QgsGeometryValidationModel::data( const QModelIndex &index, int role )
           return QVariant();
       }
 
+      case GeometryCheckErrorRole:
+      {
+        // Not (yet?) used
+        break;
+      }
+
+      case FeatureExtentRole:
+      {
+        return mCurrentLayer->getFeature( featureItem.fid ).geometry().boundingBox();
+      }
+
+      case ErrorLocationGeometryRole:
+      {
+        QgsSingleGeometryCheckError *error = featureItem.errors.first().get();
+        return error->errorLocation();
+      }
+
+      case ProblemExtentRole:
+      {
+        QgsSingleGeometryCheckError *error = featureItem.errors.first().get();
+        return error->errorLocation().boundingBox();
+      }
+
+      case DetailsRole:
+      {
+        QStringList details;
+        for ( const std::shared_ptr<QgsSingleGeometryCheckError> &error : qgis::as_const( featureItem.errors ) )
+        {
+          details << error->description();
+        }
+
+        return details.join( '\n' );
+      }
+
       default:
         return QVariant();
     }

src/app/qgsgeometryvalidationmodel.h

@@ -20,7 +20,8 @@ class QgsGeometryValidationModel : public QAbstractItemModel
       ErrorGeometryRole,
       FeatureGeometryRole,
       ErrorLocationGeometryRole,
-      GeometryCheckErrorRole
+      GeometryCheckErrorRole,
+      DetailsRole
     };
 
     QgsGeometryValidationModel( QgsGeometryValidationService *geometryValidationService, QObject *parent = nullptr );

src/app/qgsgeometryvalidationservice.h

@@ -67,6 +67,8 @@ class QgsGeometryValidationService : public QObject
 
     void fixError( const QgsGeometryCheckError *error, int method );
 
+    void triggerTopologyChecks( QgsVectorLayer *layer );
+
   signals:
     void geometryCheckStarted( QgsVectorLayer *layer, QgsFeatureId fid );
     void geometryCheckCompleted( QgsVectorLayer *layer, QgsFeatureId fid, const QList<std::shared_ptr<QgsSingleGeometryCheckError>> &errors );
@@ -89,8 +91,6 @@ class QgsGeometryValidationService : public QObject
 
     void processFeature( QgsVectorLayer *layer, QgsFeatureId fid );
 
-    void triggerTopologyChecks( QgsVectorLayer *layer );
-
     QgsProject *mProject = nullptr;
 
     struct VectorCheckState