color.c

   1 /*
   2  * color.c - color functions
   3  *
   4  * Copyright © 2008-2009 Julien Danjou <julien@danjou.info>
   5  * Copyright © 2009 Uli Schlachter <psychon@znc.in>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  */
  22
  23 #include <ctype.h>
  24
  25 #include "color.h"
  26 #include "globalconf.h"
  27 #include "common/xutil.h"
  28
  29 #define RGB_8TO16(i)   (0xffff * ((i) & 0xff) / 0xff)
  30 #define RGB_16TO8(i)   (0xff * ((i) & 0xffff) / 0xffff)
  31
  32 /** Parse an hexadecimal color string to its component.
  33  * \param colstr The color string.
  34  * \param len The color string length.
  35  * \param red A pointer to the red color to fill.
  36  * \param green A pointer to the green color to fill.
  37  * \param blue A pointer to the blue color to fill.
  38  * \param alpha A pointer to the alpha color to fill.
  39  * \return True if everything alright.
  40  */
  41 static bool
  42 color_parse(const char *colstr, ssize_t len,
  43             uint8_t *red, uint8_t *green, uint8_t *blue, uint8_t *alpha)
  44 {
  45     unsigned long colnum;
  46     char *p;
  47
  48     if(len == 7)
  49     {
  50         colnum = strtoul(colstr + 1, &p, 16);
  51         if(p - colstr != 7)
  52             goto invalid;
  53         *alpha = 0xff;
  54     }
  55     /* we have alpha */
  56     else if(len == 9)
  57     {
  58         colnum = strtoul(colstr + 1, &p, 16);
  59         if(p - colstr != 9)
  60             goto invalid;
  61         *alpha = colnum & 0xff;
  62         colnum >>= 8;
  63     }
  64     else
  65     {
  66       invalid:
  67         warn("awesome: error, invalid color '%s'", colstr);
  68         return false;
  69     }
  70
  71     *red   = (colnum >> 16) & 0xff;
  72     *green = (colnum >> 8) & 0xff;
  73     *blue  = colnum & 0xff;
  74
  75     return true;
  76 }
  77
  78 /** Send a request to initialize a X color.
  79  * If you are only interested in the rgba values and don't need the color's
  80  * pixel value, you should use color_init_unchecked() instead.
  81  * \param color color_t struct to store color into.
  82  * \param colstr Color specification.
  83  * \param len The length of colstr (which still MUST be NULL terminated).
  84  * \return request informations.
  85  */
  86 color_init_request_t
  87 color_init_unchecked(color_t *color, const char *colstr, ssize_t len)
  88 {
  89     color_init_request_t req;
  90     uint8_t red, green, blue, alpha;
  91
  92     p_clear(&req, 1);
  93
  94     if(!len)
  95     {
  96         req.has_error = true;
  97         return req;
  98     }
  99
 100     req.alpha = 0xffff;
 101     req.color = color;
 102
 103     /* The color is given in RGB value */
 104     if(!color_parse(colstr, len, &red, &green, &blue, &alpha))
 105     {
 106         warn("awesome: error, invalid color '%s'", colstr);
 107         req.has_error = true;
 108         return req;
 109     }
 110
 111     req.alpha = RGB_8TO16(alpha);
 112
 113     req.cookie_hexa = xcb_alloc_color_unchecked(globalconf.connection,
 114                                                 globalconf.default_cmap,
 115                                                 RGB_8TO16(red),
 116                                                 RGB_8TO16(green),
 117                                                 RGB_8TO16(blue));
 118
 119     req.has_error = false;
 120     req.colstr = colstr;
 121
 122     return req;
 123 }
 124
 125 /** Initialize a X color.
 126  * \param req color_init request.
 127  * \return True if color allocation was successful.
 128  */
 129 bool
 130 color_init_reply(color_init_request_t req)
 131 {
 132     if(req.has_error)
 133         return false;
 134
 135     xcb_alloc_color_reply_t *hexa_color;
 136
 137     if((hexa_color = xcb_alloc_color_reply(globalconf.connection,
 138                                            req.cookie_hexa, NULL)))
 139     {
 140         req.color->pixel = hexa_color->pixel;
 141         req.color->red   = hexa_color->red;
 142         req.color->green = hexa_color->green;
 143         req.color->blue  = hexa_color->blue;
 144         req.color->alpha = req.alpha;
 145         req.color->initialized = true;
 146         p_delete(&hexa_color);
 147         return true;
 148     }
 149
 150     warn("awesome: error, cannot allocate color '%s'", req.colstr);
 151     return false;
 152 }
 153
 154 /** Push a color as a string onto the stack
 155  * \param L The Lua VM state.
 156  * \param c The color to push.
 157  * \return The number of elements pushed on stack.
 158  */
 159 int
 160 luaA_pushcolor(lua_State *L, const color_t c)
 161 {
 162     uint8_t r = (unsigned) c.red   * 0xff / 0xffff;
 163     uint8_t g = (unsigned) c.green * 0xff / 0xffff;
 164     uint8_t b = (unsigned) c.blue  * 0xff / 0xffff;
 165     uint8_t a = (unsigned) c.alpha * 0xff / 0xffff;
 166     char s[10];
 167     int len;
 168     /* do not print alpha if it's full */
 169     if(a == 0xff)
 170         len = snprintf(s, sizeof(s), "#%02x%02x%02x", r, g, b);
 171     else
 172         len = snprintf(s, sizeof(s), "#%02x%02x%02x%02x", r, g, b, a);
 173     lua_pushlstring(L, s, len);
 174     return 1;
 175 }
 176
 177 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=80