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diff --git a/include/drawinglayer/primitive2d/groupprimitive2d.hxx b/include/drawinglayer/primitive2d/groupprimitive2d.hxx
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+++ b/include/drawinglayer/primitive2d/groupprimitive2d.hxx
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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#pragma once
+
+#include <drawinglayer/drawinglayerdllapi.h>
+
+#include <drawinglayer/primitive2d/baseprimitive2d.hxx>
+#include <drawinglayer/primitive2d/Primitive2DContainer.hxx>
+
+// GroupPrimitive2D class
+
+namespace drawinglayer::primitive2d
+{
+        /** GroupPrimitive2D class
+
+            Baseclass for all grouping 2D primitives
+
+            The grouping primitive in its basic form is capable of holding
+            a child primitive content and returns it on decomposition on default.
+            It is used for two main purposes, but more may apply:
+
+            - to transport extended information, e.g. for text classification,
+              see e.g. TextHierarchy*Primitive2D implementations. Since they
+              decompose to their child content, renderers not aware/interested
+              in that extra information will just ignore these primitives
+
+            - to encapsulate common geometry, e.g. the ShadowPrimitive2D implements
+              applying a generic shadow to a child sequence by adding the needed
+              offset and color stuff in the decomposition
+
+            In most cases the decomposition is straightforward, so by default
+            this primitive will not buffer the result and is not derived from
+            BufferedDecompositionPrimitive2D, but from BasePrimitive2D.
+
+            A renderer has to take GroupPrimitive2D derivations into account which
+            are used to hold a state.
+
+            Current Basic 2D StatePrimitives are:
+
+            - TransparencePrimitive2D (objects with freely defined transparence)
+            - InvertPrimitive2D (for XOR)
+            - MaskPrimitive2D (for masking)
+            - ModifiedColorPrimitive2D (for a stack of color modifications)
+            - TransformPrimitive2D (for a transformation stack)
+         */
+        class DRAWINGLAYER_DLLPUBLIC GroupPrimitive2D : public BasePrimitive2D
+        {
+        private:
+            /// the children. Declared private since this shall never be changed at all after construction
+            Primitive2DContainer                             maChildren;
+
+        public:
+            /// constructor
+            explicit GroupPrimitive2D(Primitive2DContainer&& aChildren);
+
+            /// data read access
+            const Primitive2DContainer& getChildren() const { return maChildren; }
+
+            void getChildren(Primitive2DDecompositionVisitor& rVisitor) const { rVisitor.visit(maChildren); }
+
+            /// compare operator
+            virtual bool operator==( const BasePrimitive2D& rPrimitive ) const override;
+
+            /// local decomposition. Implementation will just return children
+            virtual void get2DDecomposition(Primitive2DDecompositionVisitor& rVisitor, const geometry::ViewInformation2D& rViewInformation) const override;
+
+            /// provide unique ID
+            virtual sal_uInt32 getPrimitive2DID() const override;
+
+            // XAccounting
+            virtual sal_Int64 estimateUsage() override;
+        };
+} // end of namespace drawinglayer::primitive2d
+
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */