svx/source/inc/DGColorNameLookUp.hxx

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  30
  31 #ifndef _SVX_ACCESSIBILITY_DG_COLOR_NAME_LOOK_UP_HXX
  32 #define _SVX_ACCESSIBILITY_DG_COLOR_NAME_LOOK_UP_HXX
  33
  34 #include <rtl/ustrbuf.hxx>
  35 #include <hash_map>
  36
  37 namespace accessibility {
  38
  39 /** This is a color name lookup targeted to be used by the accessibility
  40     <type>DescriptionGenerator</type> class (hence the DG prefix).  It
  41     encapsulates a <type>com.sun.star.drawing.ColorTable</type> and provides
  42     an inverse look up of color names for given a numerical color
  43     descriptions--the RGB values encoded as integer.
  44
  45     <p>The class itself is designed as singleton so that the
  46     <type>com.sun.star.drawing.ColorTable</type> object needs to be created
  47     only once.</p>
  48
  49     <p>The singleton instance of this class lives at the moment until the
  50     application terminates.  However, the color table from which it takes
  51     its values may change during this time.  Reacting to these changes
  52     remains a task for the future.</p>
  53 */
  54 class DGColorNameLookUp
  55 {
  56 public:
  57     /** Return the single instance of this class.  Use this to look up
  58         color names with the <member>LookUpColor()</member> method.
  59     */
  60     static DGColorNameLookUp& Instance (void);
  61
  62     /** Return the color name of the color expressed by the given integer.
  63         @param nColor
  64             This integer is the sum of the 8 Bit red value shifted left 16
  65             Bits, the green value shifted left 8 Bits, and the unshifted
  66             blue value.
  67         @return
  68             The returned string is either the color name of the specified
  69             color or, when no name exists, a string of the form "#RRGGBB"
  70             with two hexadecimal digits for each color component.
  71     */
  72     ::rtl::OUString LookUpColor (long int nColor) const;
  73
  74 private:
  75     /// Define hash map type to convert numerical color values to names.
  76     typedef std::hash_map<long int, ::rtl::OUString>
  77         tColorValueToNameMap;
  78
  79     /// This ma translates from numerical color values to names.
  80     tColorValueToNameMap maColorValueToNameMap;
  81
  82     /** The pointer to the only instance of this class.  It is NULL until
  83         the <member>Instance</member> is called for the first time.
  84     */
  85     static DGColorNameLookUp* mpInstance;
  86
  87     /// Create a new (the only) instance of this class.
  88     DGColorNameLookUp (void);
  89
  90     /// The destructor is never called.
  91     ~DGColorNameLookUp (void);
  92
  93     /// The copy constructor is not implemented.
  94     DGColorNameLookUp (const DGColorNameLookUp&);
  95
  96     /// The assignment operator is not implemented.
  97     DGColorNameLookUp& operator= (const DGColorNameLookUp&);
  98 };
  99
 100 } // end of namespace accessibility
 101
 102 #endif