optimize feature model sorting

app/CMakeLists.txt

@@ -52,7 +52,6 @@ set(MM_SRCS
     compass.cpp
     featurelayerpair.cpp
     featuresmodel.cpp
-    featuresproxymodel.cpp
     fieldsmodel.cpp
     guidelinecontroller.cpp
     identifykit.cpp
@@ -136,7 +135,6 @@ set(MM_HDRS
     enumhelper.h
     featurelayerpair.h
     featuresmodel.h
-    featuresproxymodel.h
     fieldsmodel.h
     guidelinecontroller.h
     identifykit.h

app/featuresmodel.cpp

@@ -141,7 +141,6 @@ QVariant FeaturesModel::data( const QModelIndex &index, int role ) const
     case LayerName: return pair.layer() ? pair.layer()->name() : QString();
     case LayerIcon: return pair.layer() ? InputUtils::loadIconFromLayer( pair.layer() ) : QString();
     case Qt::DisplayRole: return featureTitle( pair );
-    case SortValue: return sortValue( pair );
   }
 
   return QVariant();
@@ -178,15 +177,6 @@ QVariant FeaturesModel::featureTitle( const FeatureLayerPair &featurePair ) cons
   return title;
 }
 
-QVariant FeaturesModel::sortValue( const FeatureLayerPair &featurePair ) const
-{
-  QgsExpressionContext context( QgsExpressionContextUtils::globalProjectLayerScopes( featurePair.layer() ) );
-  context.setFeature( featurePair.feature() );
-  QgsExpression expr( mSortExpression );
-  QVariant result = expr.evaluate( &context );
-  return result;
-}
-
 QString FeaturesModel::searchResultPair( const FeatureLayerPair &pair ) const
 {
   if ( mSearchExpression.isEmpty() )
@@ -261,6 +251,20 @@ void FeaturesModel::setupFeatureRequest( QgsFeatureRequest &request )
     request.setFilterExpression( buildSearchExpression() );
   }
 
+  if ( mUseAttributeTableSortOrder && mLayer && !mLayer->attributeTableConfig().sortExpression().isEmpty() )
+  {
+    // get a context with global, project and layer scopes
+    // QGIS docs are not very clear, but this context is also used for evaluation of the request's 'order by' expressions too
+    QgsExpressionContext context = mLayer->createExpressionContext();
+    request.setExpressionContext( context );
+    request.setOrderBy( QgsFeatureRequest::OrderBy(
+    {
+      QgsFeatureRequest::OrderByClause(
+      mLayer->attributeTableConfig().sortExpression(),
+      mLayer->attributeTableConfig().sortOrder() == Qt::AscendingOrder )
+    } ) );
+  }
+
   request.setLimit( FEATURES_LIMIT );
 }
 
@@ -290,7 +294,6 @@ QHash<int, QByteArray> FeaturesModel::roleNames() const
   roleNames[SearchResult] = QStringLiteral( "SearchResult" ).toLatin1();
   roleNames[LayerName] = QStringLiteral( "LayerName" ).toLatin1();
   roleNames[LayerIcon] = QStringLiteral( "LayerIcon" ).toLatin1();
-  roleNames[SortValue] = QStringLiteral( "SortValue" ).toLatin1();
   return roleNames;
 }
 
@@ -363,7 +366,6 @@ void FeaturesModel::setLayer( QgsVectorLayer *newLayer )
     }
 
     mLayer = newLayer;
-    setupSorting();
     emit layerChanged( mLayer );
 
     if ( mLayer )
@@ -384,19 +386,3 @@ QgsVectorLayer *FeaturesModel::layer() const
 {
   return mLayer;
 }
-
-void FeaturesModel::setupSorting()
-{
-  mSortExpression = mLayer ? mLayer->attributeTableConfig().sortExpression() : QString();
-  mSortOrder = mLayer ? mLayer->attributeTableConfig().sortOrder() : Qt::AscendingOrder;
-}
-
-bool FeaturesModel::sortingEnabled() const
-{
-  return !mSortExpression.isEmpty();
-}
-
-Qt::SortOrder FeaturesModel::sortOrder() const
-{
-  return mSortOrder;
-}

app/featuresmodel.h

@@ -52,6 +52,9 @@ class FeaturesModel : public QAbstractListModel
     // Name of the property is intentionally `count` so that it matches ListModel's count property
     Q_PROPERTY( int count READ count NOTIFY countChanged )
 
+    // Returns if the model should be sorted according to the layer's attribute table configuration sort order
+    Q_PROPERTY( bool useAttributeTableSortOrder MEMBER mUseAttributeTableSortOrder )
+
   public:
 
     enum ModelRoles
@@ -64,7 +67,6 @@ class FeaturesModel : public QAbstractListModel
       SearchResult, // pair of attribute and its value by which the feature was found, empty if search expression is empty
       LayerName,
       LayerIcon,
-      SortValue,
     };
     Q_ENUM( ModelRoles );
 
@@ -118,15 +120,6 @@ class FeaturesModel : public QAbstractListModel
 
     int layerFeaturesCount() const;
 
-    //! Populates the sort expression and sort order for the model
-    virtual void setupSorting();
-
-    //! Returns true if there is a sort expression set for the model
-    bool sortingEnabled() const;
-
-    //! Returns the order in witch the model should be sorted
-    Qt::SortOrder sortOrder() const;
-
   signals:
 
     void featuresLimitChanged( int featuresLimit );
@@ -149,9 +142,6 @@ class FeaturesModel : public QAbstractListModel
 
     virtual QVariant featureTitle( const FeatureLayerPair &featurePair ) const;
 
-    QString mSortExpression;
-    Qt::SortOrder mSortOrder = Qt::AscendingOrder;
-
   private slots:
     void onFutureFinished();
 
@@ -164,9 +154,6 @@ class FeaturesModel : public QAbstractListModel
     //! Returns found attribute and its value from search expression for feature
     QString searchResultPair( const FeatureLayerPair &feat ) const;
 
-    //! Evaluates the sort expression and returns the value used for this feature when sorting the model
-    QVariant sortValue( const FeatureLayerPair &featurePair ) const;
-
     const int FEATURES_LIMIT = 10000; //!< Number of maximum features loaded from layer
 
     FeatureLayerPairs mFeatures;
@@ -176,6 +163,9 @@ class FeaturesModel : public QAbstractListModel
     QAtomicInt mNextSearchId = 0;
     QFutureWatcher<QgsFeatureList> mSearchResultWatcher;
     bool mFetchingResults = false;
+    bool mUseAttributeTableSortOrder = false;
+
+    friend class TestModels;
 };
 
 #endif // FEATURESMODEL_H

app/main.cpp

@@ -91,7 +91,6 @@
 #include "position/positionkit.h"
 #include "scalebarkit.h"
 #include "featuresmodel.h"
-#include "featuresproxymodel.h"
 #include "relationfeaturesmodel.h"
 #include "relationreferencefeaturesmodel.h"
 #include "fieldvalidator.h"
@@ -327,7 +326,6 @@ void initDeclarative()
   qmlRegisterType< MapThemesModel >( "mm", 1, 0, "MapThemesModel" );
   qmlRegisterType< GuidelineController >( "mm", 1, 0, "GuidelineController" );
   qmlRegisterType< FeaturesModel >( "mm", 1, 0, "FeaturesModel" );
-  qmlRegisterType< FeaturesProxyModel >( "mm", 1, 0, "FeaturesProxyModel" );
   qmlRegisterType< RelationFeaturesModel >( "mm", 1, 0, "RelationFeaturesModel" );
   qmlRegisterType< ValueRelationFeaturesModel >( "mm", 1, 0, "ValueRelationFeaturesModel" );
   qmlRegisterType< RelationReferenceFeaturesModel >( "mm", 1, 0, "RelationReferenceFeaturesModel" );

app/qml/form/editors/MMFormValueRelationEditor.qml

@@ -76,15 +76,11 @@ MMFormComboboxBaseEditor {
       valueRole: "FeatureId"
       textRole: "FeatureTitle"
 
-      list.model: MM.FeaturesProxyModel {
-        id: vrDropdownProxyModel
+      list.model: MM.ValueRelationFeaturesModel {
+        id: vrDropdownModel
 
-        featuresSourceModel: MM.ValueRelationFeaturesModel {
-          id: vrDropdownModel
-
-          config: root._fieldConfig
-          pair: root._fieldFeatureLayerPair
-        }
+        config: root._fieldConfig
+        pair: root._fieldFeatureLayerPair
       }
 
       onSearchTextChanged: ( searchText ) => vrDropdownModel.searchExpression = searchText

app/qml/layers/MMFeaturesListPage.qml

@@ -55,14 +55,11 @@ MMComponents.MMPage {
         topMargin: __style.spacing20
       }
 
-      model: MM.FeaturesProxyModel {
-        id: featuresProxyModel
+      model: MM.FeaturesModel {
+        id: featuresModel
 
-        featuresSourceModel: MM.FeaturesModel {
-          id: featuresModel
-
-          layer: root.selectedLayer
-        }
+        useAttributeTableSortOrder: true
+        layer: root.selectedLayer
       }
 
       clip: true