Expose proxy model for QgsLegendRenderer to allow filtering rendered content

python/PyQt6/core/auto_generated/layertree/qgslayertreefilterproxymodel.sip.in

@@ -78,6 +78,13 @@ If the list is empty, all types are shown.
     virtual QVariant data( const QModelIndex &index, int role ) const;
     virtual bool setData( const QModelIndex &index, const QVariant &value, int role );
 
+    bool nodeShown( QgsLayerTreeNode *node ) const;
+%Docstring
+Returns ``True`` if the specified ``node`` will be shown in the model.
+
+.. versionadded:: 3.40
+%End
+
   public slots:
     virtual void setFilterText( const QString &filterText = QString() );
 %Docstring

python/PyQt6/core/auto_generated/qgslegendrenderer.sip.in

@@ -31,6 +31,18 @@ All spacing and sizes are in millimeters.
 %Docstring
 Constructor for QgsLegendRenderer. The ownership of the legend model is not changed,
 and the model must exist for the lifetime of this renderer.
+%End
+    ~QgsLegendRenderer();
+
+
+    QgsLayerTreeFilterProxyModel *proxyModel();
+%Docstring
+Returns the filter proxy model used for filtering the legend model content during
+rendering.
+
+Filters can be set on the proxy model to filter rendered legend content.
+
+.. versionadded:: 3.40
 %End
 
     QSizeF minimumSize( QgsRenderContext *renderContext = 0 );
@@ -101,6 +113,8 @@ Returns the style for the given ``node``, within the specified ``model``.
 .. seealso:: :py:func:`setNodeLegendStyle`
 %End
 
+  private:
+    QgsLegendRenderer( const QgsLegendRenderer &other );
 };
 
 /************************************************************************

python/core/auto_generated/layertree/qgslayertreefilterproxymodel.sip.in

@@ -78,6 +78,13 @@ If the list is empty, all types are shown.
     virtual QVariant data( const QModelIndex &index, int role ) const;
     virtual bool setData( const QModelIndex &index, const QVariant &value, int role );
 
+    bool nodeShown( QgsLayerTreeNode *node ) const;
+%Docstring
+Returns ``True`` if the specified ``node`` will be shown in the model.
+
+.. versionadded:: 3.40
+%End
+
   public slots:
     virtual void setFilterText( const QString &filterText = QString() );
 %Docstring

python/core/auto_generated/qgslegendrenderer.sip.in

@@ -31,6 +31,18 @@ All spacing and sizes are in millimeters.
 %Docstring
 Constructor for QgsLegendRenderer. The ownership of the legend model is not changed,
 and the model must exist for the lifetime of this renderer.
+%End
+    ~QgsLegendRenderer();
+
+
+    QgsLayerTreeFilterProxyModel *proxyModel();
+%Docstring
+Returns the filter proxy model used for filtering the legend model content during
+rendering.
+
+Filters can be set on the proxy model to filter rendered legend content.
+
+.. versionadded:: 3.40
 %End
 
     QSizeF minimumSize( QgsRenderContext *renderContext = 0 );
@@ -101,6 +113,8 @@ Returns the style for the given ``node``, within the specified ``model``.
 .. seealso:: :py:func:`setNodeLegendStyle`
 %End
 
+  private:
+    QgsLegendRenderer( const QgsLegendRenderer &other );
 };
 
 /************************************************************************

src/core/layertree/qgslayertreefilterproxymodel.h

@@ -76,6 +76,13 @@ class CORE_EXPORT QgsLayerTreeFilterProxyModel : public QSortFilterProxyModel
     virtual QVariant data( const QModelIndex &index, int role ) const override;
     virtual bool setData( const QModelIndex &index, const QVariant &value, int role ) override;
 
+    /**
+     * Returns TRUE if the specified \a node will be shown in the model.
+     *
+     * \since QGIS 3.40
+     */
+    bool nodeShown( QgsLayerTreeNode *node ) const;
+
   public slots:
     //! Sets the filter text to search for a layer in the tree
     virtual void setFilterText( const QString &filterText = QString() );
@@ -97,8 +104,6 @@ class CORE_EXPORT QgsLayerTreeFilterProxyModel : public QSortFilterProxyModel
      */
     virtual bool layerShown( QgsMapLayer *layer ) const;
 
-    bool nodeShown( QgsLayerTreeNode *node ) const;
-
     //! This will call the virtual method and takes care of emitting dataChanged signal
     void setLayerCheckedPrivate( QgsMapLayer *layer, bool checked );
 

src/core/qgslegendrenderer.cpp

@@ -22,6 +22,8 @@
 #include "qgsrendercontext.h"
 #include "qgsexpressioncontextutils.h"
 #include "qgstextrenderer.h"
+#include "qgslayertreefilterproxymodel.h"
+
 #include <QJsonObject>
 #include <QPainter>
 
@@ -29,10 +31,14 @@
 
 QgsLegendRenderer::QgsLegendRenderer( QgsLayerTreeModel *legendModel, const QgsLegendSettings &settings )
   : mLegendModel( legendModel )
+  , mProxyModel( std::make_unique< QgsLayerTreeFilterProxyModel >() )
   , mSettings( settings )
 {
+  mProxyModel->setLayerTreeModel( mLegendModel );
 }
 
+QgsLegendRenderer::~QgsLegendRenderer() = default;
+
 QSizeF QgsLegendRenderer::minimumSize( QgsRenderContext *renderContext )
 {
   std::unique_ptr< QgsRenderContext > tmpContext;
@@ -86,6 +92,9 @@ QJsonObject QgsLegendRenderer::exportLegendToJson( const QgsRenderContext &conte
   const QList<QgsLayerTreeNode *> childNodes = nodeGroup->children();
   for ( QgsLayerTreeNode *node : childNodes )
   {
+    if ( !mProxyModel->nodeShown( node ) )
+      continue;
+
     if ( QgsLayerTree::isGroup( node ) )
     {
       QgsLayerTreeGroup *nodeGroup = QgsLayerTree::toGroup( node );
@@ -316,6 +325,9 @@ QList<QgsLegendRenderer::LegendComponentGroup> QgsLegendRenderer::createComponen
   const QList<QgsLayerTreeNode *> childNodes = parentGroup->children();
   for ( QgsLayerTreeNode *node : childNodes )
   {
+    if ( !mProxyModel->nodeShown( node ) )
+      continue;
+
     if ( QgsLayerTree::isGroup( node ) )
     {
       QgsLayerTreeGroup *nodeGroup = QgsLayerTree::toGroup( node );
@@ -1087,6 +1099,11 @@ QgsLegendStyle::Style QgsLegendRenderer::nodeLegendStyle( QgsLayerTreeNode *node
   return nodeLegendStyle( node, mLegendModel );
 }
 
+QgsLayerTreeFilterProxyModel *QgsLegendRenderer::proxyModel()
+{
+  return mProxyModel.get();
+}
+
 void QgsLegendRenderer::setNodeLegendStyle( QgsLayerTreeNode *node, QgsLegendStyle::Style style )
 {
   QString str;

src/core/qgslegendrenderer.h

@@ -30,6 +30,7 @@ class QgsLayerTreeModelLegendNode;
 class QgsLayerTreeNode;
 class QgsSymbol;
 class QgsRenderContext;
+class QgsLayerTreeFilterProxyModel;
 
 #include "qgslegendsettings.h"
 
@@ -52,6 +53,22 @@ class CORE_EXPORT QgsLegendRenderer
      * and the model must exist for the lifetime of this renderer.
      */
     QgsLegendRenderer( QgsLayerTreeModel *legendModel, const QgsLegendSettings &settings );
+    ~QgsLegendRenderer();
+
+#ifndef SIP_RUN
+    QgsLegendRenderer( const QgsLegendRenderer &other ) = delete;
+    QgsLegendRenderer &operator=( const QgsLegendRenderer &other ) = delete;
+#endif
+
+    /**
+     * Returns the filter proxy model used for filtering the legend model content during
+     * rendering.
+     *
+     * Filters can be set on the proxy model to filter rendered legend content.
+     *
+     * \since QGIS 3.40
+     */
+    QgsLayerTreeFilterProxyModel *proxyModel();
 
     /**
      * Runs the layout algorithm and returns the minimum size required for the legend.
@@ -296,6 +313,7 @@ class CORE_EXPORT QgsLegendRenderer
     QgsLegendStyle::Style nodeLegendStyle( QgsLayerTreeNode *node );
 
     QgsLayerTreeModel *mLegendModel = nullptr;
+    std::unique_ptr< QgsLayerTreeFilterProxyModel >mProxyModel;
 
     QgsLegendSettings mSettings;
 
@@ -303,6 +321,10 @@ class CORE_EXPORT QgsLegendRenderer
 
 #endif
 
+#ifdef SIP_RUN
+    QgsLegendRenderer( const QgsLegendRenderer &other );
+#endif
+
     void widthAndOffsetForTitleText( const Qt::AlignmentFlag halignment, double legendWidth, double &width, double &offset ) const;
 };
 

tests/src/core/testqgslegendrenderer.cpp

@@ -33,6 +33,7 @@
 #include "qgsmaplayerlegend.h"
 #include "qgspainteffect.h"
 #include "qgsproject.h"
+#include "qgslayertreefilterproxymodel.h"
 #include "qgslegendrenderer.h"
 #include "qgsrasterlayer.h"
 #include "qgsshadoweffect.h"
@@ -73,10 +74,8 @@ static QImage _base64ToImage( const QString &base64 )
   return QImage::fromData( bytearray, "PNG" );
 }
 
-static QImage _renderLegend( QgsLayerTreeModel *legendModel, QgsLegendSettings &settings )
+static QImage _renderLegend( QgsLegendRenderer &legendRenderer )
 {
-  settings.setTitle( QStringLiteral( "Legend" ) );
-  QgsLegendRenderer legendRenderer( legendModel, settings );
   const QSizeF size = legendRenderer.minimumSize();
 
   const int dpi = 96;
@@ -104,6 +103,14 @@ static QImage _renderLegend( QgsLayerTreeModel *legendModel, QgsLegendSettings &
   return img;
 }
 
+static QImage _renderLegend( QgsLayerTreeModel *legendModel, QgsLegendSettings &settings )
+{
+  settings.setTitle( QStringLiteral( "Legend" ) );
+  QgsLegendRenderer legendRenderer( legendModel, settings );
+  return _renderLegend( legendRenderer );
+}
+
+
 static QJsonObject _renderJsonLegend( QgsLayerTreeModel *legendModel, const QgsLegendSettings &settings )
 {
   QgsLegendRenderer legendRenderer( legendModel, settings );
@@ -212,6 +219,9 @@ class TestQgsLegendRenderer : public QgsTest
     void testLabelLegend();
     void testHeatmap();
 
+    void testFilteredVector();
+    void testFilteredRaster();
+
   private:
     QgsLayerTree *mRoot = nullptr;
     QgsVectorLayer *mVL1 =  nullptr ; // line
@@ -2045,6 +2055,38 @@ void TestQgsLegendRenderer::testHeatmap()
   QVERIFY( _verifyImage( res, QStringLiteral( "heatmap" ) ) );
 }
 
+void TestQgsLegendRenderer::testFilteredVector()
+{
+  const QString testName = QStringLiteral( "legend_filtered_vector" );
+
+  QgsLayerTreeModel legendModel( mRoot );
+
+  QgsLegendSettings settings;
+  settings.setTitle( QStringLiteral( "Legend" ) );
+  _setStandardTestFont( settings, QStringLiteral( "Bold" ) );
+  QgsLegendRenderer legendRenderer( &legendModel, settings );
+  legendRenderer.proxyModel()->setFilters( Qgis::LayerFilter::VectorLayer );
+
+  const QImage res = _renderLegend( legendRenderer );
+  QVERIFY( _verifyImage( res, testName ) );
+}
+
+void TestQgsLegendRenderer::testFilteredRaster()
+{
+  const QString testName = QStringLiteral( "legend_filtered_raster" );
+
+  QgsLayerTreeModel legendModel( mRoot );
+
+  QgsLegendSettings settings;
+  settings.setTitle( QStringLiteral( "Legend" ) );
+  _setStandardTestFont( settings, QStringLiteral( "Bold" ) );
+  QgsLegendRenderer legendRenderer( &legendModel, settings );
+  legendRenderer.proxyModel()->setFilters( Qgis::LayerFilter::RasterLayer );
+
+  const QImage res = _renderLegend( legendRenderer );
+  QVERIFY( _verifyImage( res, testName ) );
+}
+
 
 QGSTEST_MAIN( TestQgsLegendRenderer )
 #include "testqgslegendrenderer.moc"