cppcanvas/source/inc/action.hxx

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  19
  20 #pragma once
  21
  22 #include <sal/types.h>
  23
  24 namespace basegfx
  25 {
  26     class B2DHomMatrix;
  27     class B2DRange;
  28 }
  29
  30
  31 /* Definition of Action interface */
  32
  33 namespace cppcanvas::internal
  34     {
  35         /** Interface for internal render actions
  36
  37             This interface is implemented by all objects generated
  38             from the metafile renderer, and corresponds roughly to the
  39             VCL meta action.
  40          */
  41         class Action
  42         {
  43         public:
  44             /** Used for rendering action subsets
  45
  46                 There are several cases where an Action might have
  47                 subsettable content, e.g. text, or referenced
  48                 metafiles, like the transparent action.
  49
  50                 Generally, at the metafile renderer, all actions are
  51                 'flattened' out, i.e. a meta action rendering the
  52                 string "Hello" counts five indices, and a transparent
  53                 action containing a metafile with 100 actions counts
  54                 at least 100 indices (contained transparency or text
  55                 actions recursively add to this value). From the
  56                 outside, the subset to render is referenced via this
  57                 flat index range
  58              */
  59             struct Subset
  60             {
  61                 /** Denotes start of the subset.
  62
  63                     The index given here specifies the first subaction
  64                     to render.
  65                  */
  66                 sal_Int32   mnSubsetBegin;
  67
  68                 /** Denotes end of the subset
  69
  70                     The index given here specifies the first subaction
  71                     <em>not<em> to render, i.e. one action behind the
  72                     subset to be rendered
  73                  */
  74                 sal_Int32   mnSubsetEnd;
  75             };
  76
  77             virtual ~Action() {}
  78
  79             /** Render this action to the associated canvas
  80
  81                 @param rTransformation
  82                 Transformation matrix to apply before rendering
  83
  84                 @return true, if rendering was successful. If
  85                 rendering failed, false is returned.
  86              */
  87             virtual bool render( const ::basegfx::B2DHomMatrix& rTransformation ) const = 0;
  88
  89             /** Render the given part of the action to the associated
  90                 canvas.
  91
  92                 @param rTransformation
  93                 Transformation matrix to apply before rendering
  94
  95                 @param rSubset
  96                 Subset of the action to render. See Subset description
  97                 for index semantics.
  98
  99                 @return true, if rendering was successful. If the
 100                 specified subset is invalid for this action, or if
 101                 rendering failed for other reasons, false is returned.
 102              */
 103             virtual bool renderSubset( const ::basegfx::B2DHomMatrix& rTransformation,
 104                                        const Subset&                  rSubset ) const = 0;
 105
 106             /** Query bounds of this action on the associated canvas
 107
 108                 @param rTransformation
 109                 Transformation matrix to apply
 110
 111                 @return the bounds for this action in device
 112                 coordinate space.
 113              */
 114             virtual ::basegfx::B2DRange getBounds( const ::basegfx::B2DHomMatrix& rTransformation ) const = 0;
 115
 116             /** Query bounds for the given part of the action on the
 117                 associated canvas.
 118
 119                 @param rTransformation
 120                 Transformation matrix to apply.
 121
 122                 @param rSubset
 123                 Subset of the action to query. See Subset description
 124                 for index semantics.
 125
 126                 @return the bounds for the given subset in device
 127                 coordinate space.
 128              */
 129             virtual ::basegfx::B2DRange getBounds( const ::basegfx::B2DHomMatrix&   rTransformation,
 130                                                    const Subset&                    rSubset ) const = 0;
 131
 132             /** Query action count.
 133
 134                 This method returns the number of subset actions
 135                 contained in this action. The render( Subset ) method
 136                 must accept subset ranges up to the value returned
 137                 here.
 138
 139                 @return the number of subset actions
 140              */
 141             virtual sal_Int32 getActionCount() const = 0;
 142         };
 143 }
 144
 145 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */