include/drawinglayer/primitive2d/groupprimitive2d.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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  19
  20 #pragma once
  21
  22 #include <drawinglayer/drawinglayerdllapi.h>
  23
  24 #include <drawinglayer/primitive2d/baseprimitive2d.hxx>
  25 #include <drawinglayer/primitive2d/Primitive2DContainer.hxx>
  26
  27 // GroupPrimitive2D class
  28
  29 namespace drawinglayer::primitive2d
  30 {
  31         /** GroupPrimitive2D class
  32
  33             Baseclass for all grouping 2D primitives
  34
  35             The grouping primitive in its basic form is capable of holding
  36             a child primitive content and returns it on decomposition on default.
  37             It is used for two main purposes, but more may apply:
  38
  39             - to transport extended information, e.g. for text classification,
  40               see e.g. TextHierarchy*Primitive2D implementations. Since they
  41               decompose to their child content, renderers not aware/interested
  42               in that extra information will just ignore these primitives
  43
  44             - to encapsulate common geometry, e.g. the ShadowPrimitive2D implements
  45               applying a generic shadow to a child sequence by adding the needed
  46               offset and color stuff in the decomposition
  47
  48             In most cases the decomposition is straightforward, so by default
  49             this primitive will not buffer the result and is not derived from
  50             BufferedDecompositionPrimitive2D, but from BasePrimitive2D.
  51
  52             A renderer has to take GroupPrimitive2D derivations into account which
  53             are used to hold a state.
  54
  55             Current Basic 2D StatePrimitives are:
  56
  57             - TransparencePrimitive2D (objects with freely defined transparence)
  58             - InvertPrimitive2D (for XOR)
  59             - MaskPrimitive2D (for masking)
  60             - ModifiedColorPrimitive2D (for a stack of color modifications)
  61             - TransformPrimitive2D (for a transformation stack)
  62          */
  63         class DRAWINGLAYER_DLLPUBLIC GroupPrimitive2D : public BasePrimitive2D
  64         {
  65         private:
  66             /// the children. Declared private since this shall never be changed at all after construction
  67             Primitive2DContainer                             maChildren;
  68
  69         public:
  70             /// constructor
  71             explicit GroupPrimitive2D(Primitive2DContainer&& aChildren);
  72
  73             /// data read access
  74             const Primitive2DContainer& getChildren() const { return maChildren; }
  75
  76             void getChildren(Primitive2DDecompositionVisitor& rVisitor) const { rVisitor.visit(maChildren); }
  77
  78             /// compare operator
  79             virtual bool operator==( const BasePrimitive2D& rPrimitive ) const override;
  80
  81             /// local decomposition. Implementation will just return children
  82             virtual void get2DDecomposition(Primitive2DDecompositionVisitor& rVisitor, const geometry::ViewInformation2D& rViewInformation) const override;
  83
  84             /// provide unique ID
  85             virtual sal_uInt32 getPrimitive2DID() const override;
  86
  87             // XAccounting
  88             virtual sal_Int64 estimateUsage() override;
  89         };
  90 } // end of namespace drawinglayer::primitive2d
  91
  92
  93 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */