File indexing completed on 2024-05-19 05:28:14

 /*
     This file is part of Konsole, KDE's terminal.
 
     SPDX-FileCopyrightText: 2007-2008 Robert Knight <robertknight@gmail.com>
     SPDX-FileCopyrightText: 1997, 1998 Lars Doelle <lars.doelle@on-line.de>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 
     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
 
     You should have received a copy of the GNU General Public License
     along with this program; if not, write to the Free Software
     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
     02110-1301  USA.
 */
 
 #ifndef CHARACTERCOLOR_H
 #define CHARACTERCOLOR_H
 
 // Qt
 #include <QColor>
 #include <span>
 
 // #include <kdemacros.h>
 #define KDE_NO_EXPORT
 
 namespace Konsole
 {
 
 /**
  * An entry in a terminal display's color palette.
  *
  * A color palette is an array of 16 ColorEntry instances which map
  * system color indexes (from 0 to 15) into actual colors.
  *
  * Each entry can be set as bold, in which case any text
  * drawn using the color should be drawn in bold.
  *
  * Each entry can also be transparent, in which case the terminal
  * display should avoid drawing the background for any characters
  * using the entry as a background.
  */
 class ColorEntry
 {
 public:
     /** Specifies the weight to use when drawing text with this color. */
     enum FontWeight {
         /** Always draw text in this color with a bold weight. */
         Bold,
         /** Always draw text in this color with a normal weight. */
         Normal,
         /**
          * Use the current font weight set by the terminal application.
          * This is the default behavior.
          */
         UseCurrentFormat
     };
 
     /**
      * Constructs a new color palette entry.
      *
      * @param c The color value for this entry.
      * @param tr Specifies that the color should be transparent when used as a background color.
      * @param weight Specifies the font weight to use when drawing text with this color.
      */
     constexpr ColorEntry(QColor c, bool tr, FontWeight weight = UseCurrentFormat)
         : color(c)
         , transparent(tr)
         , fontWeight(weight)
     {
     }
 
     /**
      * Constructs a new color palette entry with an undefined color, and
      * with the transparent and bold flags set to false.
      */
     ColorEntry()
         : transparent(false)
         , fontWeight(UseCurrentFormat)
     {
     }
 
     /** The color value of this entry for display. */
     QColor color;
 
     /**
      * If true character backgrounds using this color should be transparent.
      * This is not applicable when the color is used to render text.
      */
     bool transparent;
     /**
      * Specifies the font weight to use when drawing text with this color.
      * This is not applicable when the color is used to draw a character's background.
      */
     FontWeight fontWeight;
 };
 
 // Attributed Character Representations ///////////////////////////////
 
 // Colors
 
 constexpr auto BASE_COLORS = (2 + 8);
 constexpr auto INTENSITIES = 2;
 constexpr auto TABLE_COLORS = (INTENSITIES * BASE_COLORS);
 
 constexpr auto DEFAULT_FORE_COLOR = 0;
 constexpr auto DEFAULT_BACK_COLOR = 1;
 
 // a standard set of colors using black text on a white background.
 // defined in TerminalDisplay.cpp
 
 /* CharacterColor is a union of the various color spaces.
 
    Assignment is as follows:
 
    Type  - Space        - Values
 
    0     - Undefined   - u:  0,      v:0        w:0
    1     - Default     - u:  0..1    v:intense  w:0
    2     - System      - u:  0..7    v:intense  w:0
    3     - Index(256)  - u: 16..255  v:0        w:0
    4     - RGB         - u:  0..255  v:0..256   w:0..256
 
    Default colour space has two separate colours, namely
    default foreground and default background colour.
 */
 
 #define COLOR_SPACE_UNDEFINED 0
 #define COLOR_SPACE_DEFAULT 1
 #define COLOR_SPACE_SYSTEM 2
 #define COLOR_SPACE_256 3
 #define COLOR_SPACE_RGB 4
 
 /**
  * Describes the color of a single character in the terminal.
  */
 class CharacterColor
 {
     friend class Character;
 
 public:
     /** Constructs a new CharacterColor whoose color and color space are undefined. */
     constexpr CharacterColor()
         : _colorSpace(COLOR_SPACE_UNDEFINED)
         , _u(0)
         , _v(0)
         , _w(0)
     {
     }
 
     /**
      * Constructs a new CharacterColor using the specified @p colorSpace and with
      * color value @p co
      *
      * The meaning of @p co depends on the @p colorSpace used.
      *
      * TODO : Document how @p co relates to @p colorSpace
      *
      * TODO : Add documentation about available color spaces.
      */
     constexpr CharacterColor(quint8 colorSpace, int co)
         : _colorSpace(colorSpace)
         , _u(0)
         , _v(0)
         , _w(0)
     {
         switch (colorSpace) {
         case COLOR_SPACE_DEFAULT:
             _u = co & 1;
             break;
         case COLOR_SPACE_SYSTEM:
             _u = co & 7;
             _v = (co >> 3) & 1;
             break;
         case COLOR_SPACE_256:
             _u = co & 255;
             break;
         case COLOR_SPACE_RGB:
             _u = co >> 16;
             _v = co >> 8;
             _w = co;
             break;
         default:
             _colorSpace = COLOR_SPACE_UNDEFINED;
         }
     }
 
     /**
      * Returns true if this character color entry is valid.
      */
     constexpr bool isValid() const
     {
         return _colorSpace != COLOR_SPACE_UNDEFINED;
     }
 
     /**
      * Set the value of this color from a normal system color to the corresponding intensive
      * system color if it's not already an intensive system color.
      *
      * This is only applicable if the color is using the COLOR_SPACE_DEFAULT or COLOR_SPACE_SYSTEM
      * color spaces.
      */
     void setIntensive();
 
     /**
      * Returns the color within the specified color @p palette
      *
      * The @p palette is only used if this color is one of the 16 system colors, otherwise
      * it is ignored.
      */
     constexpr QColor color(std::span<const ColorEntry> palette) const;
 
     /**
      * Compares two colors and returns true if they represent the same color value and
      * use the same color space.
      */
     constexpr friend bool operator==(const CharacterColor &a, const CharacterColor &b);
     /**
      * Compares two colors and returns true if they represent different color values
      * or use different color spaces.
      */
     constexpr friend bool operator!=(const CharacterColor &a, const CharacterColor &b);
 
 private:
     quint8 _colorSpace;
 
     // bytes storing the character color
     quint8 _u;
     quint8 _v;
     quint8 _w;
 };
 
 constexpr inline bool operator==(const CharacterColor &a, const CharacterColor &b)
 {
     return a._colorSpace == b._colorSpace && a._u == b._u && a._v == b._v && a._w == b._w;
 }
 
 constexpr inline bool operator!=(const CharacterColor &a, const CharacterColor &b)
 {
     return !operator==(a, b);
 }
 
 constexpr inline const QColor color256(quint8 u, std::span<const ColorEntry> base)
 {
     //   0.. 16: system colors
     if (u < 8)
         return base[u + 2].color;
     u -= 8;
     if (u < 8)
         return base[u + 2 + BASE_COLORS].color;
     u -= 8;
 
     //  16..231: 6x6x6 rgb color cube
     if (u < 216)
         return QColor(((u / 36) % 6) ? (40 * ((u / 36) % 6) + 55) : 0,
                       ((u / 6) % 6) ? (40 * ((u / 6) % 6) + 55) : 0,
                       ((u / 1) % 6) ? (40 * ((u / 1) % 6) + 55) : 0);
     u -= 216;
 
     // 232..255: gray, leaving out black and white
     int gray = u * 10 + 8;
     return QColor(gray, gray, gray);
 }
 
 constexpr inline QColor CharacterColor::color(std::span<const ColorEntry> base) const
 {
     switch (_colorSpace) {
     case COLOR_SPACE_DEFAULT:
         return base[_u + 0 + (_v ? BASE_COLORS : 0)].color;
     case COLOR_SPACE_SYSTEM:
         return base[_u + 2 + (_v ? BASE_COLORS : 0)].color;
     case COLOR_SPACE_256:
         return color256(_u, base);
     case COLOR_SPACE_RGB:
         return {_u, _v, _w};
     case COLOR_SPACE_UNDEFINED:
         return QColor();
     }
 
     Q_ASSERT(false); // invalid color space
 
     return QColor();
 }
 
 inline void CharacterColor::setIntensive()
 {
     if (_colorSpace == COLOR_SPACE_SYSTEM || _colorSpace == COLOR_SPACE_DEFAULT) {
         _v = 1;
     }
 }
 }
 
 #endif // CHARACTERCOLOR_H