Handle legend node in parent gracefully with embedded widgets

src/core/layertree/qgslayertreemodel.cpp

@@ -1196,7 +1196,7 @@ void QgsLayerTreeModel::addLegendToLayer( QgsLayerTreeLayer* nodeL )
 
   QList<QgsLayerTreeModelLegendNode*> filteredLstNew = filterLegendNodes( lstNew );
 
-  bool isEmbedded = filteredLstNew.count() == 1 && filteredLstNew[0]->isEmbeddedInParent();
+  bool hasOnlyEmbedded = filteredLstNew.count() == 1 && filteredLstNew[0]->isEmbeddedInParent();
 
   Q_FOREACH ( QgsLayerTreeModelLegendNode* n, lstNew )
   {
@@ -1215,11 +1215,11 @@ void QgsLayerTreeModel::addLegendToLayer( QgsLayerTreeLayer* nodeL )
 
   int count = data.tree ? data.tree->children[nullptr].count() : filteredLstNew.count();
 
-  if ( ! isEmbedded ) beginInsertRows( node2index( nodeL ), 0, count - 1 );
+  if ( ! hasOnlyEmbedded ) beginInsertRows( node2index( nodeL ), 0, count - 1 );
 
   mLegend[nodeL] = data;
 
-  if ( ! isEmbedded ) endInsertRows();
+  if ( ! hasOnlyEmbedded ) endInsertRows();
 
   if ( hasStyleOverride )
     ml->styleManager()->restoreOverrideStyle();
@@ -1316,17 +1316,19 @@ int QgsLayerTreeModel::legendNodeRowCount( QgsLayerTreeModelLegendNode* node ) c
 
 int QgsLayerTreeModel::legendRootRowCount( QgsLayerTreeLayer* nL ) const
 {
-  if ( legendEmbeddedInParent( nL ) )
-    return 0;
-
   if ( !mLegend.contains( nL ) )
     return 0;
 
   const LayerLegendData& data = mLegend[nL];
   if ( data.tree )
     return data.tree->children[nullptr].count();
 
-  return data.activeNodes.count();
+  int count = data.activeNodes.count();
+
+  if ( legendEmbeddedInParent( nL ) )
+    count--;  // one item less -- it is embedded in parent
+
+  return count;
 }
 
 
@@ -1390,14 +1392,29 @@ Qt::ItemFlags QgsLayerTreeModel::legendNodeFlags( QgsLayerTreeModelLegendNode* n
 
 bool QgsLayerTreeModel::legendEmbeddedInParent( QgsLayerTreeLayer* nodeLayer ) const
 {
+  return legendNodeEmbeddedInParent( nodeLayer );
+}
+
+QgsLayerTreeModelLegendNode* QgsLayerTreeModel::legendNodeEmbeddedInParent( QgsLayerTreeLayer* nodeLayer ) const
+{
+  // legend node embedded in parent does not have to be the first one...
+  // there could be extra legend nodes generated for embedded widgets
   const LayerLegendData& data = mLegend[nodeLayer];
-  return data.activeNodes.count() == 1 && data.activeNodes[0]->isEmbeddedInParent();
+  Q_FOREACH ( QgsLayerTreeModelLegendNode* legendNode, data.activeNodes )
+  {
+    if ( legendNode->isEmbeddedInParent() )
+      return legendNode;
+  }
+  return nullptr;
 }
 
 
 QIcon QgsLayerTreeModel::legendIconEmbeddedInParent( QgsLayerTreeLayer* nodeLayer ) const
 {
-  return QIcon( qvariant_cast<QPixmap>( mLegend[nodeLayer].activeNodes[0]->data( Qt::DecorationRole ) ) );
+  QgsLayerTreeModelLegendNode* legendNode = legendNodeEmbeddedInParent( nodeLayer );
+  if ( !legendNode )
+    return QIcon();
+  return QIcon( qvariant_cast<QPixmap>( legendNode->data( Qt::DecorationRole ) ) );
 }
 
 

src/core/layertree/qgslayertreemodel.h

@@ -277,6 +277,7 @@ class CORE_EXPORT QgsLayerTreeModel : public QAbstractItemModel
     QVariant legendNodeData( QgsLayerTreeModelLegendNode* node, int role ) const;
     Qt::ItemFlags legendNodeFlags( QgsLayerTreeModelLegendNode* node ) const;
     bool legendEmbeddedInParent( QgsLayerTreeLayer* nodeLayer ) const;
+    QgsLayerTreeModelLegendNode* legendNodeEmbeddedInParent( QgsLayerTreeLayer* nodeLayer ) const;
     QIcon legendIconEmbeddedInParent( QgsLayerTreeLayer* nodeLayer ) const;
     void legendCleanup();
     void legendInvalidateMapBasedData();