gdb/ui-style.h

   1 /* Styling for ui_file
   2    Copyright (C) 2018-2020 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef UI_STYLE_H
  20 #define UI_STYLE_H
  21
  22 /* Styles that can be applied to a ui_file.  */
  23 struct ui_file_style
  24 {
  25   /* One of the basic colors that can be handled by ANSI
  26      terminals.  */
  27   enum basic_color
  28   {
  29     NONE = -1,
  30     BLACK,
  31     RED,
  32     GREEN,
  33     YELLOW,
  34     BLUE,
  35     MAGENTA,
  36     CYAN,
  37     WHITE
  38   };
  39
  40   /* Representation of a terminal color.  */
  41   class color
  42   {
  43   public:
  44
  45     color (basic_color c)
  46       : m_simple (true),
  47         m_value (c)
  48     {
  49     }
  50
  51     color (int c)
  52       : m_simple (true),
  53         m_value (c)
  54     {
  55       gdb_assert (c >= -1 && c <= 255);
  56     }
  57
  58     color (uint8_t r, uint8_t g, uint8_t b)
  59       : m_simple (false),
  60         m_red (r),
  61         m_green (g),
  62         m_blue (b)
  63     {
  64     }
  65
  66     bool operator== (const color &other) const
  67     {
  68       if (m_simple != other.m_simple)
  69         return false;
  70       if (m_simple)
  71         return m_value == other.m_value;
  72       return (m_red == other.m_red && m_green == other.m_green
  73               && m_blue == other.m_blue);
  74     }
  75
  76     bool operator< (const color &other) const
  77     {
  78       if (m_simple != other.m_simple)
  79         return m_simple < other.m_simple;
  80       if (m_simple)
  81         return m_value < other.m_value;
  82       if (m_red < other.m_red)
  83         return true;
  84       if (m_red == other.m_red)
  85         {
  86           if (m_green < other.m_green)
  87             return true;
  88           if (m_green == other.m_green)
  89             return m_blue < other.m_blue;
  90         }
  91       return false;
  92     }
  93
  94     /* Return true if this is the "NONE" color, false otherwise.  */
  95     bool is_none () const
  96     {
  97       return m_simple && m_value == NONE;
  98     }
  99
 100     /* Return true if this is one of the basic colors, false
 101        otherwise.  */
 102     bool is_basic () const
 103     {
 104       return m_simple && m_value >= BLACK && m_value <= WHITE;
 105     }
 106
 107     /* Return the value of a basic color.  */
 108     int get_value () const
 109     {
 110       gdb_assert (is_basic ());
 111       return m_value;
 112     }
 113
 114     /* Fill in RGB with the red/green/blue values for this color.
 115        This may not be called for basic colors or for the "NONE"
 116        color.  */
 117     void get_rgb (uint8_t *rgb) const;
 118
 119     /* Append the ANSI terminal escape sequence for this color to STR.
 120        IS_FG indicates whether this is a foreground or background
 121        color.  Returns true if any characters were written; returns
 122        false otherwise (which can only happen for the "NONE"
 123        color).  */
 124     bool append_ansi (bool is_fg, std::string *str) const;
 125
 126   private:
 127
 128     bool m_simple;
 129     int m_value;
 130     uint8_t m_red, m_green, m_blue;
 131   };
 132
 133   /* Intensity settings that are available.  */
 134   enum intensity
 135   {
 136     NORMAL = 0,
 137     BOLD,
 138     DIM
 139   };
 140
 141   ui_file_style () = default;
 142
 143   ui_file_style (color f, color b, intensity i = NORMAL)
 144     : m_foreground (f),
 145       m_background (b),
 146       m_intensity (i)
 147   {
 148   }
 149
 150   bool operator== (const ui_file_style &other) const
 151   {
 152     return (m_foreground == other.m_foreground
 153             && m_background == other.m_background
 154             && m_intensity == other.m_intensity
 155             && m_reverse == other.m_reverse);
 156   }
 157
 158   bool operator!= (const ui_file_style &other) const
 159   {
 160     return !(*this == other);
 161   }
 162
 163   /* Return the ANSI escape sequence for this style.  */
 164   std::string to_ansi () const;
 165
 166   /* Return true if this style is the default style; false
 167      otherwise.  */
 168   bool is_default () const
 169   {
 170     return (m_foreground == NONE
 171             && m_background == NONE
 172             && m_intensity == NORMAL
 173             && !m_reverse);
 174   }
 175
 176   /* Return true if this style specified reverse display; false
 177      otherwise.  */
 178   bool is_reverse () const
 179   {
 180     return m_reverse;
 181   }
 182
 183   /* Set/clear the reverse display flag.  */
 184   void set_reverse (bool reverse)
 185   {
 186     m_reverse = reverse;
 187   }
 188
 189   /* Return the foreground color of this style.  */
 190   const color &get_foreground () const
 191   {
 192     return m_foreground;
 193   }
 194
 195   /* Set the foreground color of this style.  */
 196   void set_fg (color c)
 197   {
 198     m_foreground = c;
 199   }
 200
 201   /* Return the background color of this style.  */
 202   const color &get_background () const
 203   {
 204     return m_background;
 205   }
 206
 207   /* Set the background color of this style.  */
 208   void set_bg (color c)
 209   {
 210     m_background = c;
 211   }
 212
 213   /* Return the intensity of this style.  */
 214   intensity get_intensity () const
 215   {
 216     return m_intensity;
 217   }
 218
 219   /* Parse an ANSI escape sequence in BUF, modifying this style.  BUF
 220      must begin with an ESC character.  Return true if an escape
 221      sequence was successfully parsed; false otherwise.  In either
 222      case, N_READ is updated to reflect the number of chars read from
 223      BUF.  */
 224   bool parse (const char *buf, size_t *n_read);
 225
 226   /* We need this because we can't pass a reference via va_args.  */
 227   const ui_file_style *ptr () const
 228   {
 229     return this;
 230   }
 231
 232 private:
 233
 234   color m_foreground = NONE;
 235   color m_background = NONE;
 236   intensity m_intensity = NORMAL;
 237   bool m_reverse = false;
 238 };
 239
 240 /* Skip an ANSI escape sequence in BUF.  BUF must begin with an ESC
 241    character.  Return true if an escape sequence was successfully
 242    skipped; false otherwise.  If an escape sequence was skipped,
 243    N_READ is updated to reflect the number of chars read from BUF.  */
 244
 245 extern bool skip_ansi_escape (const char *buf, int *n_read);
 246
 247 #endif /* UI_STYLE_H */