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21 
22 
23 
24 #ifndef _SVX_ACCESSIBILITY_DG_COLOR_NAME_LOOK_UP_HXX
25 #define _SVX_ACCESSIBILITY_DG_COLOR_NAME_LOOK_UP_HXX
26 
27 #include <rtl/ustrbuf.hxx>
28 #include <hash_map>
29 
30 namespace accessibility {
31 
32 /** This is a color name lookup targeted to be used by the accessibility
33     <type>DescriptionGenerator</type> class (hence the DG prefix).  It
34     encapsulates a <type>com.sun.star.drawing.ColorTable</type> and provides
35     an inverse look up of color names for given a numerical color
36     descriptions--the RGB values encoded as integer.
37 
38     <p>The class itself is designed as singleton so that the
39     <type>com.sun.star.drawing.ColorTable</type> object needs to be created
40     only once.</p>
41 
42     <p>The singleton instance of this class lives at the moment until the
43     application terminates.  However, the color table from which it takes
44     its values may change during this time.  Reacting to these changes
45     remains a task for the future.</p>
46 */
47 class DGColorNameLookUp
48 {
49 public:
50     /** Return the single instance of this class.  Use this to look up
51         color names with the <member>LookUpColor()</member> method.
52     */
53     static DGColorNameLookUp& Instance (void);
54 
55     /** Return the color name of the color expressed by the given integer.
56         @param nColor
57             This integer is the sum of the 8 Bit red value shifted left 16
58             Bits, the green value shifted left 8 Bits, and the unshifted
59             blue value.
60         @return
61             The returned string is either the color name of the specified
62             color or, when no name exists, a string of the form "#RRGGBB"
63             with two hexadecimal digits for each color component.
64     */
65     ::rtl::OUString LookUpColor (long int nColor) const;
66 
67 private:
68     /// Define hash map type to convert numerical color values to names.
69     typedef std::hash_map<long int, ::rtl::OUString>
70         tColorValueToNameMap;
71 
72     /// This ma translates from numerical color values to names.
73     tColorValueToNameMap maColorValueToNameMap;
74 
75     /** The pointer to the only instance of this class.  It is NULL until
76         the <member>Instance</member> is called for the first time.
77     */
78     static DGColorNameLookUp* mpInstance;
79 
80     /// Create a new (the only) instance of this class.
81     DGColorNameLookUp (void);
82 
83     /// The destructor is never called.
84     ~DGColorNameLookUp (void);
85 
86     /// The copy constructor is not implemented.
87     DGColorNameLookUp (const DGColorNameLookUp&);
88 
89     /// The assignment operator is not implemented.
90     DGColorNameLookUp& operator= (const DGColorNameLookUp&);
91 };
92 
93 } // end of namespace accessibility
94 
95 #endif
96