[layout] Added template method to retrieve QgsLayoutObjects

python/core/layout/qgslayout.sip

@@ -87,6 +87,7 @@ Returns the items model attached to the layout.
 %End
 
 
+
     QList<QgsLayoutItem *> selectedLayoutItems( const bool includeLockedItems = true );
 %Docstring
 Returns list of selected layout items.

src/core/layout/qgslayout.h

@@ -133,6 +133,33 @@ class CORE_EXPORT QgsLayout : public QGraphicsScene, public QgsExpressionContext
       }
     }
 
+    /**
+     * Returns a list of layout objects (items and multiframes) of a specific type.
+     * \note not available in Python bindings
+     */
+    template<class T> void layoutObjects( QList<T *> &objectList ) const SIP_SKIP
+    {
+      objectList.clear();
+      const QList<QGraphicsItem *> itemList( items() );
+      const QList<QgsLayoutMultiFrame *> frameList( multiFrames() );
+      for ( const auto &obj :  itemList )
+      {
+        T *item = dynamic_cast<T *>( obj );
+        if ( item )
+        {
+          objectList.push_back( item );
+        }
+      }
+      for ( const auto &obj :  frameList )
+      {
+        T *item = dynamic_cast<T *>( obj );
+        if ( item )
+        {
+          objectList.push_back( item );
+        }
+      }
+    }
+
     /**
      * Returns list of selected layout items.
      *