Move partial responsibility for filtering attribute table to

nyalldawson · nyalldawson · commit 4d8f886b389d · 2017-03-05T12:02:48.000+10:00
dual view master model

This avoids requiring the table to load ALL features when the
table is set to just display selected or visible features

Dramatically improves load time of the attribute table when
working with large layers, so long as the table is set to
display selected features or visible features by default

On behalf of Faunalia, sponsored by ENEL
diff --git a/src/app/qgsattributetabledialog.cpp b/src/app/qgsattributetabledialog.cpp
@@ -134,8 +134,9 @@ QgsAttributeTableDialog::QgsAttributeTableDialog( QgsVectorLayer *layer, QWidget
 
   QgsFeatureRequest r;
   bool needsGeom = false;
+  QgsAttributeTableFilterModel::FilterMode initialMode = static_cast< QgsAttributeTableFilterModel::FilterMode>( settings.value( QStringLiteral( "/qgis/attributeTableBehavior" ), QgsAttributeTableFilterModel::ShowAll ).toInt() );
   if ( mLayer->geometryType() != QgsWkbTypes::NullGeometry &&
-       settings.value( QStringLiteral( "/qgis/attributeTableBehavior" ), QgsAttributeTableFilterModel::ShowAll ).toInt() == QgsAttributeTableFilterModel::ShowVisible )
+       initialMode == QgsAttributeTableFilterModel::ShowVisible )
   {
     QgsMapCanvas *mc = QgisApp::instance()->mapCanvas();
     QgsRectangle extent( mc->mapSettings().mapToLayerCoordinates( layer, mc->extent() ) );
@@ -147,6 +148,11 @@ QgsAttributeTableDialog::QgsAttributeTableDialog( QgsVectorLayer *layer, QWidget
     mActionShowAllFilter->setText( tr( "Show All Features In Initial Canvas Extent" ) );
     needsGeom = true;
   }
+  else if ( initialMode == QgsAttributeTableFilterModel::ShowSelected )
+  {
+    if ( theLayer->selectedFeatureCount() > 0 )
+      r.setFilterFids( theLayer->selectedFeatureIds() );
+  }
   if ( !needsGeom )
     r.setFlags( QgsFeatureRequest::NoGeometry );
 
diff --git a/src/gui/attributetable/qgsdualview.cpp b/src/gui/attributetable/qgsdualview.cpp
@@ -70,6 +70,8 @@ QgsDualView::QgsDualView( QWidget *parent )
 
 void QgsDualView::init( QgsVectorLayer *layer, QgsMapCanvas *mapCanvas, const QgsFeatureRequest &request, const QgsAttributeEditorContext &context )
 {
+  mMapCanvas = mapCanvas;
+
   if ( !layer )
     return;
 
@@ -192,15 +194,66 @@ QgsDualView::ViewMode QgsDualView::view() const
 
 void QgsDualView::setFilterMode( QgsAttributeTableFilterModel::FilterMode filterMode )
 {
-  bool needsGeometry = filterMode == QgsAttributeTableFilterModel::ShowVisible;
+  if ( mFilterModel->filterMode() == filterMode )
+    return;
+
+  // cleanup any existing connections
+  switch ( mFilterModel->filterMode() )
+  {
+    case QgsAttributeTableFilterModel::ShowVisible:
+      disconnect( mMapCanvas, &QgsMapCanvas::extentsChanged, this, &QgsDualView::extentChanged );
+      break;
+
+    case QgsAttributeTableFilterModel::ShowAll:
+    case QgsAttributeTableFilterModel::ShowEdited:
+    case QgsAttributeTableFilterModel::ShowFilteredList:
+      break;
+
+    case QgsAttributeTableFilterModel::ShowSelected:
+      disconnect( masterModel()->layer(), &QgsVectorLayer::selectionChanged, this, &QgsDualView::updateSelectedFeatures );
+      break;
+  }
 
   QgsFeatureRequest r = mMasterModel->request();
+  bool needsGeometry = filterMode == QgsAttributeTableFilterModel::ShowVisible;
+
   if ( !needsGeometry )
     r.setFlags( r.flags() | QgsFeatureRequest::NoGeometry );
   else
     r.setFlags( r.flags() & ~( QgsFeatureRequest::NoGeometry ) );
+
+  switch ( filterMode )
+  {
+    case QgsAttributeTableFilterModel::ShowVisible:
+      connect( mMapCanvas, &QgsMapCanvas::extentsChanged, this, &QgsDualView::extentChanged );
+      r.setFilterFids( QgsFeatureIds() );
+      r.disableFilter();
+      if ( mMapCanvas )
+      {
+        QgsRectangle rect = mMapCanvas->mapSettings().mapToLayerCoordinates( mLayer, mMapCanvas->extent() );
+        r.setFilterRect( rect );
+      }
+      break;
+
+    case QgsAttributeTableFilterModel::ShowAll:
+    case QgsAttributeTableFilterModel::ShowEdited:
+    case QgsAttributeTableFilterModel::ShowFilteredList:
+      r.setFilterFids( QgsFeatureIds() );
+      r.disableFilter();
+      break;
+
+    case QgsAttributeTableFilterModel::ShowSelected:
+      connect( masterModel()->layer(), &QgsVectorLayer::selectionChanged, this, &QgsDualView::updateSelectedFeatures );
+      if ( masterModel()->layer()->selectedFeatureCount() > 0 )
+        r.setFilterFids( masterModel()->layer()->selectedFeatureIds() );
+      else
+        r.disableFilter();
+      break;
+  }
+
   mMasterModel->setRequest( r );
   whileBlocking( mLayerCache )->setCacheGeometry( needsGeometry );
+  mMasterModel->loadLayer();
 
   mFilterModel->setFilterMode( filterMode );
   emit filterChanged();
@@ -649,6 +702,29 @@ void QgsDualView::sortByPreviewExpression()
   setSortExpression( mFeatureList->displayExpression(), sortOrder );
 }
 
+void QgsDualView::updateSelectedFeatures()
+{
+  QgsFeatureRequest r = mMasterModel->request();
+  if ( masterModel()->layer()->selectedFeatureCount() > 0 )
+    r.setFilterFids( masterModel()->layer()->selectedFeatureIds() );
+  else
+    r.disableFilter();
+  mMasterModel->setRequest( r );
+  mMasterModel->loadLayer();
+}
+
+void QgsDualView::extentChanged()
+{
+  QgsFeatureRequest r = mMasterModel->request();
+  if ( mMapCanvas )
+  {
+    QgsRectangle rect = mMapCanvas->mapSettings().mapToLayerCoordinates( mLayer, mMapCanvas->extent() );
+    r.setFilterRect( rect );
+  }
+  mMasterModel->setRequest( r );
+  mMasterModel->loadLayer();
+}
+
 void QgsDualView::featureFormAttributeChanged()
 {
   mFeatureList->setCurrentFeatureEdited( true );
diff --git a/src/gui/attributetable/qgsdualview.h b/src/gui/attributetable/qgsdualview.h
@@ -297,6 +297,10 @@ class GUI_EXPORT QgsDualView : public QStackedWidget, private Ui::QgsDualViewBas
 
     void sortByPreviewExpression();
 
+    void updateSelectedFeatures();
+
+    void extentChanged();
+
     /**
      * Will be called whenever the currently shown feature form changes.
      * Will forward this signal to the feature list to visually represent
@@ -343,6 +347,7 @@ class GUI_EXPORT QgsDualView : public QStackedWidget, private Ui::QgsDualViewBas
     QString mDisplayExpression;
     QgsAttributeTableConfig mConfig;
     QScrollArea *mAttributeEditorScrollArea = nullptr;
+    QgsMapCanvas *mMapCanvas = nullptr;
 
     friend class TestQgsDualView;
 };
