When rendering layout legends, respect exclude-by-default flag

python/PyQt6/core/auto_generated/layout/qgslayoutitemlegend.sip.in

@@ -59,7 +59,6 @@ Emitted to refresh the legend.
 };
 
 
-
 class QgsLayoutItemLegend : QgsLayoutItem
 {
 %Docstring(signature="appended")

python/core/auto_generated/layout/qgslayoutitemlegend.sip.in

@@ -59,7 +59,6 @@ Emitted to refresh the legend.
 };
 
 
-
 class QgsLayoutItemLegend : QgsLayoutItem
 {
 %Docstring(signature="appended")

src/core/layout/qgslayoutitemlegend.cpp

@@ -40,12 +40,50 @@
 #include "qgslayoutreportcontext.h"
 #include "qgslayertreefiltersettings.h"
 #include "qgsreferencedgeometry.h"
+#include "qgsmaplayerlegend.h"
 
 #include <QDomDocument>
 #include <QDomElement>
 #include <QPainter>
 #include "qgsexpressioncontext.h"
 
+//
+// QgsLegendFilterProxyModel
+//
+
+QgsLegendFilterProxyModel::QgsLegendFilterProxyModel( QObject *parent )
+  : QgsLayerTreeFilterProxyModel( parent )
+{
+  setIsDefaultLegend( true );
+}
+
+void QgsLegendFilterProxyModel::setIsDefaultLegend( bool isDefault )
+{
+  mIsDefaultLegend = isDefault;
+
+  // only show private layers when not in default mode
+  setShowPrivateLayers( !mIsDefaultLegend );
+
+  invalidateFilter();
+}
+
+bool QgsLegendFilterProxyModel::layerShown( QgsMapLayer *layer ) const
+{
+  if ( !layer )
+    return true;
+
+  if ( QgsMapLayerLegend *layerLegend = layer->legend(); mIsDefaultLegend && layerLegend->flags().testFlag( Qgis::MapLayerLegendFlag::ExcludeByDefault ) )
+  {
+    return false;
+  }
+
+  return true;
+}
+
+//
+// QgsLayoutItemLegend
+//
+
 QgsLayoutItemLegend::QgsLayoutItemLegend( QgsLayout *layout )
   : QgsLayoutItem( layout )
   , mLegendModel( new QgsLegendModel( nullptr, this ) )
@@ -330,9 +368,8 @@ QgsLegendRenderer QgsLayoutItemLegend::createRenderer() const
 {
   QgsLegendRenderer res( mLegendModel.get(), mSettings );
 
-  // only show private layers when not in auto update mode
-  QgsLayerTreeFilterProxyModel *proxy = new QgsLayerTreeFilterProxyModel();
-  proxy->setShowPrivateLayers( static_cast< bool >( mCustomLayerTree ) );
+  QgsLegendFilterProxyModel *proxy = new QgsLegendFilterProxyModel();
+  proxy->setIsDefaultLegend( !static_cast< bool >( mCustomLayerTree ) );
   res.setProxyModel( proxy );
 
   return res;

src/core/layout/qgslayoutitemlegend.h

@@ -22,6 +22,7 @@
 #include "qgis_sip.h"
 #include "qgslayoutitem.h"
 #include "qgslayertreemodel.h"
+#include "qgslayertreefilterproxymodel.h"
 #include "qgslegendsettings.h"
 #include "qgslayertree.h"
 #include "qgsexpressioncontext.h"
@@ -102,7 +103,37 @@ class CORE_EXPORT QgsLegendModel : public QgsLayerTreeModel
 
 };
 
+#ifndef SIP_RUN
+/**
+ * \ingroup core
+ * \brief A layout item subclass for map legend filtering.
+ * \note Not available in Python bindings
+ * \since QGIS 4.0
+ */
+class CORE_EXPORT QgsLegendFilterProxyModel : public QgsLayerTreeFilterProxyModel
+{
+    Q_OBJECT
+  public:
 
+    /**
+     * Constructor for QgsLegendFilterProxyModel, with the specified \a parent object.
+     */
+    QgsLegendFilterProxyModel( QObject *parent SIP_TRANSFERTHIS = nullptr );
+
+    /**
+     * Sets whether the legend is showing the default legend for a project (as opposed
+     * to a customised legend).
+     */
+    void setIsDefaultLegend( bool isDefault );
+
+  private:
+
+    bool layerShown( QgsMapLayer *layer ) const override;
+
+    bool mIsDefaultLegend = true;
+
+};
+#endif
 
 /**
  * \ingroup core

tests/src/python/test_qgslayoutlegend.py

@@ -2046,6 +2046,70 @@ class TestQgsLayoutItemLegend(QgisTestCase, LayoutItemTestCase):
 
         self.assertTrue(self.render_layout_check("composer_legend_auto_wrap", layout))
 
+    def test_exclude_from_default_legend(self):
+        """
+        Test layer legend setting for excluding from default legends
+        """
+        point_path = os.path.join(TEST_DATA_DIR, "points.shp")
+        point_layer1 = QgsVectorLayer(point_path, "layer 1", "ogr")
+        point_layer2 = QgsVectorLayer(point_path, "layer 2", "ogr")
+        point_layer3 = QgsVectorLayer(point_path, "layer 3", "ogr")
+        p = QgsProject()
+        p.addMapLayers([point_layer1, point_layer2, point_layer3])
+
+        point_layer2.legend().setFlag(Qgis.MapLayerLegendFlag.ExcludeByDefault, True)
+
+        marker_symbol = QgsMarkerSymbol.createSimple(
+            {
+                "color": "#ff0000",
+                "outline_style": "no",
+                "size": "5",
+                "size_unit": "MapUnit",
+            }
+        )
+
+        point_layer1.setRenderer(QgsSingleSymbolRenderer(marker_symbol.clone()))
+        point_layer2.setRenderer(QgsSingleSymbolRenderer(marker_symbol.clone()))
+        point_layer3.setRenderer(QgsSingleSymbolRenderer(marker_symbol.clone()))
+
+        layout = QgsLayout(p)
+        layout.initializeDefaults()
+
+        legend = QgsLayoutItemLegend(layout)
+        legend.setTitle("Legend")
+        legend.attemptSetSceneRect(QRectF(120, 20, 80, 80))
+        legend.setFrameEnabled(True)
+        legend.setFrameStrokeWidth(QgsLayoutMeasurement(2))
+        legend.setBackgroundColor(QColor(200, 200, 200))
+        legend.setTitle("")
+        layout.addLayoutItem(legend)
+        legend.setResizeToContents(True)
+
+        legend.setStyleFont(
+            QgsLegendStyle.Style.Title, QgsFontUtils.getStandardTestFont("Bold", 16)
+        )
+        legend.setStyleFont(
+            QgsLegendStyle.Style.Group, QgsFontUtils.getStandardTestFont("Bold", 16)
+        )
+        legend.setStyleFont(
+            QgsLegendStyle.Style.Subgroup, QgsFontUtils.getStandardTestFont("Bold", 16)
+        )
+        legend.setStyleFont(
+            QgsLegendStyle.Style.Symbol, QgsFontUtils.getStandardTestFont("Bold", 16)
+        )
+        legend.setStyleFont(
+            QgsLegendStyle.Style.SymbolLabel,
+            QgsFontUtils.getStandardTestFont("Bold", 16),
+        )
+
+        legend.refresh()
+        legend.setResizeToContents(True)
+        legend.updateLegend()
+
+        self.assertTrue(
+            self.render_layout_check("composer_legend_exclude_by_default", layout)
+        )
+
 
 if __name__ == "__main__":
     unittest.main()