kolourpaint/imagelib/kpColor.h

   1
   2 /*
   3    Copyright (c) 2003-2007 Clarence Dang <dang@kde.org>
   4    All rights reserved.
   5
   6    Redistribution and use in source and binary forms, with or without
   7    modification, are permitted provided that the following conditions
   8    are met:
   9
  10    1. Redistributions of source code must retain the above copyright
  11       notice, this list of conditions and the following disclaimer.
  12    2. Redistributions in binary form must reproduce the above copyright
  13       notice, this list of conditions and the following disclaimer in the
  14       documentation and/or other materials provided with the distribution.
  15
  16    THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  17    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  18    OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  19    IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  20    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  21    NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  22    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  23    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  25    THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26 */
  27
  28
  29 #ifndef KP_COLOR_H
  30 #define KP_COLOR_H
  31
  32
  33 #include <qcolor.h>
  34
  35
  36 class QDataStream;
  37
  38
  39 //
  40 // kpColor is an object-oriented abstraction of QRgb, for document image data,
  41 // with the additional restriction of enforcing the KolourPaint convention of
  42 // only supporting totally transparent and totally opaque colors.  Eventually,
  43 // this restriction will be dropped.  In the future, other color models such as
  44 // 8-bit indexed will be supported.  It also provides better error handling,
  45 // reporting (noisy kError()'s) and recovery compared to Qt.  This abstraction
  46 // will allow us to eventually dump the Qt paint routines.
  47 //
  48 // In general, you should pass around kpColor objects instead of QRgb
  49 // and QColor.  Only convert an opaque kpColor to a QColor (using toQColor())
  50 // if you need to draw something on-screen.
  51 //
  52 // Constructing a kpColor object from QColor is usually wrong since QColor's
  53 // come from on-screen pixels, which may lack the full color resolution of
  54 // kpColor, due to the limited color range on e.g. a 16-bit screen.
  55 //
  56 class kpColor
  57 {
  58 public:
  59     kpColor ();
  60     kpColor (int red, int green, int blue, bool isTransparent = false);
  61     kpColor (const QRgb &rgba);
  62     kpColor (const kpColor &rhs);
  63     friend QDataStream &operator<< (QDataStream &stream, const kpColor &color);
  64     friend QDataStream &operator>> (QDataStream &stream, kpColor &color);
  65     kpColor &operator= (const kpColor &rhs);
  66     bool operator== (const kpColor &rhs) const;
  67     bool operator!= (const kpColor &rhs) const;
  68
  69
  70 //
  71 // Constants
  72 //
  73 public:
  74     // "lhs.isSimilarTo (rhs, kpColor::Exact)" is exactly the same as calling
  75     // "lhs == rhs".
  76     static const int Exact;
  77
  78     static const kpColor Invalid;
  79     static const kpColor Transparent;
  80
  81
  82     //
  83     // Primary Colors + B&W
  84     //
  85
  86     static const kpColor Red, Green, Blue;
  87     static const kpColor Black, White;
  88
  89
  90     //
  91     // Full-brightness Colors
  92     //
  93
  94     static const kpColor Yellow, Purple, Aqua;
  95
  96
  97     //
  98     // Mixed Colors
  99     //
 100
 101     static const kpColor Gray, LightGray, Orange;
 102
 103
 104     //
 105     // Pastel Colors
 106     //
 107
 108     static const kpColor Pink, LightGreen, LightBlue, Tan;
 109
 110
 111     //
 112     // Dark Colors
 113     //
 114
 115     static const kpColor DarkRed;
 116
 117     // (identical)
 118     static const kpColor DarkOrange, Brown;
 119
 120     static const kpColor DarkYellow, DarkGreen, DarkAqua, DarkBlue,
 121         DarkPurple, DarkGray;
 122
 123
 124 public:
 125     static int processSimilarity (double colorSimilarity);
 126     // Usage: isSimilarTo (rhs, kpColor::processSimilarity (.1)) checks for
 127     //        Color Similarity within 10%
 128     bool isSimilarTo (const kpColor &rhs, int processedSimilarity) const;
 129     ~kpColor ();
 130
 131     bool isValid () const;
 132
 133     int red () const;
 134     int green () const;
 135     int blue () const;
 136     int alpha () const;
 137     bool isTransparent () const;
 138     bool isOpaque () const;
 139
 140     // Cast operators will most likely result in careless conversions so
 141     // use explicit functions instead:
 142     QRgb toQRgb () const;
 143
 144     // (only valid if isOpaque())
 145     QColor toQColor () const;
 146
 147     QColor maskColor () const;
 148
 149 private:
 150     // Catch accidental call to "const QRgb &rgba" (unsigned int) ctor
 151     // by e.g. "kpColor(Qt::black)" (Qt::black is an enum element that can cast
 152     // to "unsigned int").
 153     kpColor (Qt::GlobalColor color);
 154
 155     bool m_rgbaIsValid;
 156     QRgb m_rgba;
 157
 158     mutable bool m_colorCacheIsValid;
 159     mutable QColor m_colorCache;
 160 };
 161
 162
 163 #endif  // KP_COLOR_H