cppcanvas/source/inc/action.hxx

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  19
  20 #ifndef INCLUDED_CPPCANVAS_SOURCE_INC_ACTION_HXX
  21 #define INCLUDED_CPPCANVAS_SOURCE_INC_ACTION_HXX
  22
  23 #include <sal/types.h>
  24 #include <memory>
  25
  26 namespace basegfx
  27 {
  28     class B2DHomMatrix;
  29     class B2DRange;
  30 }
  31
  32
  33 /* Definition of Action interface */
  34
  35 namespace cppcanvas
  36 {
  37     namespace internal
  38     {
  39         /** Interface for internal render actions
  40
  41             This interface is implemented by all objects generated
  42             from the metafile renderer, and corresponds roughly to the
  43             VCL meta action.
  44          */
  45         class Action
  46         {
  47         public:
  48             /** Used for rendering action subsets
  49
  50                 There are several cases where an Action might have
  51                 subsettable content, e.g. text, or referenced
  52                 metafiles, like the transparent action.
  53
  54                 Generally, at the metafile renderer, all actions are
  55                 'flattened' out, i.e. a meta action rendering the
  56                 string "Hello" counts five indices, and a transparent
  57                 action containing a metafile with 100 actions counts
  58                 at least 100 indices (contained transparency or text
  59                 actions recursively add to this value). From the
  60                 outside, the subset to render is referenced via this
  61                 flat index range
  62              */
  63             struct Subset
  64             {
  65                 /** Denotes start of the subset.
  66
  67                     The index given here specifies the first subaction
  68                     to render.
  69                  */
  70                 sal_Int32   mnSubsetBegin;
  71
  72                 /** Denotes end of the subset
  73
  74                     The index given here specifies the first subaction
  75                     <em>not<em> to render, i.e. one action behind the
  76                     subset to be rendered
  77                  */
  78                 sal_Int32   mnSubsetEnd;
  79             };
  80
  81             virtual ~Action() {}
  82
  83             /** Render this action to the associated canvas
  84
  85                 @param rTransformation
  86                 Transformation matrix to apply before rendering
  87
  88                 @return true, if rendering was successful. If
  89                 rendering failed, false is returned.
  90              */
  91             virtual bool render( const ::basegfx::B2DHomMatrix& rTransformation ) const = 0;
  92
  93             /** Render the given part of the action to the associated
  94                 canvas.
  95
  96                 @param rTransformation
  97                 Transformation matrix to apply before rendering
  98
  99                 @param rSubset
 100                 Subset of the action to render. See Subset description
 101                 for index semantics.
 102
 103                 @return true, if rendering was successful. If the
 104                 specified subset is invalid for this action, or if
 105                 rendering failed for other reasons, false is returned.
 106              */
 107             virtual bool renderSubset( const ::basegfx::B2DHomMatrix& rTransformation,
 108                                        const Subset&                  rSubset ) const = 0;
 109
 110             /** Query bounds of this action on the associated canvas
 111
 112                 @param rTransformation
 113                 Transformation matrix to apply
 114
 115                 @return the bounds for this action in device
 116                 coordinate space.
 117              */
 118             virtual ::basegfx::B2DRange getBounds( const ::basegfx::B2DHomMatrix& rTransformation ) const = 0;
 119
 120             /** Query bounds for the given part of the action on the
 121                 associated canvas.
 122
 123                 @param rTransformation
 124                 Transformation matrix to apply.
 125
 126                 @param rSubset
 127                 Subset of the action to query. See Subset description
 128                 for index semantics.
 129
 130                 @return the bounds for the given subset in device
 131                 coordinate space.
 132              */
 133             virtual ::basegfx::B2DRange getBounds( const ::basegfx::B2DHomMatrix&   rTransformation,
 134                                                    const Subset&                    rSubset ) const = 0;
 135
 136             /** Query action count.
 137
 138                 This method returns the number of subset actions
 139                 contained in this action. The render( Subset ) method
 140                 must accept subset ranges up to the value returned
 141                 here.
 142
 143                 @return the number of subset actions
 144              */
 145             virtual sal_Int32 getActionCount() const = 0;
 146         };
 147
 148         typedef std::shared_ptr< Action > ActionSharedPtr;
 149
 150     }
 151 }
 152
 153 #endif // INCLUDED_CPPCANVAS_SOURCE_INC_ACTION_HXX
 154
 155 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */