Only filter legend nodes that are checked.

Keep unchecked legend items when filtered by expression

Author: Hugo Mercier

src/app/qgisapp.cpp

@@ -4938,13 +4938,13 @@ void QgisApp::toggleFilterLegendByExpression( bool checked )
 
 void QgisApp::updateFilterLegend()
 {
-  if ( mActionFilterLegend->isChecked() )
+  bool hasExpressions = mLegendExpressionFilterButton->isChecked() && QgsLayerTreeUtils::hasLegendFilterExpression( *mLayerTreeView->layerTreeModel()->rootGroup() );
+  if ( mActionFilterLegend->isChecked() || hasExpressions )
   {
-    layerTreeView()->layerTreeModel()->setLegendFilterByMap( &mMapCanvas->mapSettings() );
-  }
-  else if ( QgsLayerTreeUtils::hasLegendFilterExpression( *mLayerTreeView->layerTreeModel()->rootGroup() ) )
-  {
-    layerTreeView()->layerTreeModel()->setLegendFilter( &mMapCanvas->mapSettings(), /* useExtent */ false );
+    layerTreeView()->layerTreeModel()->setLegendFilter( &mMapCanvas->mapSettings(),
+        /* useExtent */ mActionFilterLegend->isChecked(),
+        /* polygon */ QgsGeometry(),
+        hasExpressions );
   }
   else
   {

src/core/layertree/qgslayertreemodel.cpp

@@ -39,6 +39,7 @@ QgsLayerTreeModel::QgsLayerTreeModel( QgsLayerTreeGroup* rootNode, QObject *pare
     , mFlags( ShowLegend | AllowLegendChangeState | DeferredLegendInvalidation )
     , mAutoCollapseLegendNodesCount( -1 )
     , mLegendFilterByScale( 0 )
+    , mLegendFilterUsesExtent( false )
     , mLegendMapViewMupp( 0 )
     , mLegendMapViewDpi( 0 )
     , mLegendMapViewScale( 0 )
@@ -590,6 +591,7 @@ void QgsLayerTreeModel::setLegendFilter( const QgsMapSettings* settings, bool us
     mLegendFilterMapSettings.reset( new QgsMapSettings( *settings ) );
     mLegendFilterMapSettings->setLayerStyleOverrides( mLayerStyleOverrides );
     QgsMapHitTest::LayerFilterExpression exprs;
+    mLegendFilterUsesExtent = useExtent;
     // collect expression filters
     if ( useExpressions )
     {
@@ -1098,8 +1100,9 @@ QList<QgsLayerTreeModelLegendNode*> QgsLayerTreeModel::filterLegendNodes( const
   {
     Q_FOREACH ( QgsLayerTreeModelLegendNode* node, nodes )
     {
-      QgsSymbolV2* symbolKey = reinterpret_cast< QgsSymbolV2* >( node->data( QgsSymbolV2LegendNode::SymbolV2LegacyRuleKeyRole ).value<void*>() );
-      if ( symbolKey )
+      QgsSymbolV2* ruleKey = reinterpret_cast< QgsSymbolV2* >( node->data( QgsSymbolV2LegendNode::SymbolV2LegacyRuleKeyRole ).value<void*>() );
+      bool checked = mLegendFilterUsesExtent || node->data( Qt::CheckStateRole ).toInt() == Qt::Checked;
+      if ( ruleKey && checked )
       {
         QString ruleKey = node->data( QgsSymbolV2LegendNode::RuleKeyRole ).toString();
         if ( QgsVectorLayer* vl = qobject_cast<QgsVectorLayer*>( node->layerNode()->layer() ) )
@@ -1108,7 +1111,7 @@ QList<QgsLayerTreeModelLegendNode*> QgsLayerTreeModel::filterLegendNodes( const
             filtered << node;
         }
       }
-      else  // unknown node type
+      else  // unknown node type or unchecked
         filtered << node;
     }
   }

src/core/layertree/qgslayertreemodel.h

@@ -337,6 +337,9 @@ class CORE_EXPORT QgsLayerTreeModel : public QAbstractItemModel
     QScopedPointer<QgsMapSettings> mLegendFilterMapSettings;
     QScopedPointer<QgsMapHitTest> mLegendFilterHitTest;
 
+    //! whether to use map filtering
+    bool mLegendFilterUsesExtent;
+
     double mLegendMapViewMupp;
     int mLegendMapViewDpi;
     double mLegendMapViewScale;

tests/src/core/testqgslegendrenderer.cpp

@@ -458,9 +458,11 @@ void TestQgsLegendRenderer::testFilterByPolygon()
   // again with useExtent to true
   legendModel.setLegendFilter( &mapSettings, /*useExtent*/ true, *geom.data() );
 
+  QString testName2 = testName + "2";
+  QString report2 = mReport + "2";
   _setStandardTestFont( settings );
-  _renderLegend( testName, &legendModel, settings );
-  QVERIFY( _verifyImage( testName, mReport ) );
+  _renderLegend( testName2, &legendModel, settings );
+  QVERIFY( _verifyImage( testName2, report2 ) );
 }
 
 void TestQgsLegendRenderer::testFilterByExpression()
@@ -497,9 +499,11 @@ void TestQgsLegendRenderer::testFilterByExpression()
   legendModel.setLegendFilterByMap( 0 );
   legendModel.setLegendFilter( &mapSettings, /*useExtent*/ false );
 
+  QString testName2 = testName + "2";
+  QString report2 = mReport + "2";
   _setStandardTestFont( settings );
-  _renderLegend( testName, &legendModel, settings );
-  QVERIFY( _verifyImage( testName, mReport ) );
+  _renderLegend( testName2, &legendModel, settings );
+  QVERIFY( _verifyImage( testName2, report2 ) );
 }
 
 QTEST_MAIN( TestQgsLegendRenderer )