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 /* 0xFFFF / 0xFF == 0x101 (257) */
  30 #define RGB_8TO16(i) (((i) & 0xff)   * 0x101)
  31 #define RGB_16TO8(i) (((i) & 0xffff) / 0x101)
  32
  33 /** Parse an hexadecimal color string to its component.
  34  * \param colstr The color string.
  35  * \param len The color string length.
  36  * \param red A pointer to the red color to fill.
  37  * \param green A pointer to the green color to fill.
  38  * \param blue A pointer to the blue 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)
  44 {
  45     unsigned long colnum;
  46     char *p;
  47
  48     colnum = strtoul(colstr + 1, &p, 16);
  49     if(len == 9 && (p - colstr) == 9)
  50     {
  51         /* We ignore the alpha component */
  52         colnum >>= 8;
  53         len -= 2;
  54         p -= 2;
  55     }
  56     if(len != 7 || colstr[0] != '#' || (p - colstr) != 7)
  57     {
  58         warn("awesome: error, invalid color '%s'", colstr);
  59         return false;
  60     }
  61
  62     *red   = (colnum >> 16) & 0xff;
  63     *green = (colnum >> 8) & 0xff;
  64     *blue  = colnum & 0xff;
  65
  66     return true;
  67 }
  68
  69 /** Send a request to initialize a X color.
  70  * If you are only interested in the rgba values and don't need the color's
  71  * pixel value, you should use color_init_unchecked() instead.
  72  * \param color color_t struct to store color into.
  73  * \param colstr Color specification.
  74  * \param len The length of colstr (which still MUST be NULL terminated).
  75  * \return request informations.
  76  */
  77 color_init_request_t
  78 color_init_unchecked(color_t *color, const char *colstr, ssize_t len)
  79 {
  80     color_init_request_t req;
  81     uint8_t red, green, blue;
  82
  83     p_clear(&req, 1);
  84
  85     if(!len)
  86     {
  87         req.has_error = true;
  88         return req;
  89     }
  90
  91     req.color = color;
  92
  93     /* The color is given in RGB value */
  94     if(!color_parse(colstr, len, &red, &green, &blue))
  95     {
  96         warn("awesome: error, invalid color '%s'", colstr);
  97         req.has_error = true;
  98         return req;
  99     }
 100
 101     req.cookie_hexa = xcb_alloc_color_unchecked(globalconf.connection,
 102                                                 globalconf.default_cmap,
 103                                                 RGB_8TO16(red),
 104                                                 RGB_8TO16(green),
 105                                                 RGB_8TO16(blue));
 106
 107     req.has_error = false;
 108     req.colstr = colstr;
 109
 110     return req;
 111 }
 112
 113 /** Initialize a X color.
 114  * \param req color_init request.
 115  * \return True if color allocation was successful.
 116  */
 117 bool
 118 color_init_reply(color_init_request_t req)
 119 {
 120     if(req.has_error)
 121         return false;
 122
 123     xcb_alloc_color_reply_t *hexa_color;
 124
 125     if((hexa_color = xcb_alloc_color_reply(globalconf.connection,
 126                                            req.cookie_hexa, NULL)))
 127     {
 128         req.color->pixel = hexa_color->pixel;
 129         req.color->red   = hexa_color->red;
 130         req.color->green = hexa_color->green;
 131         req.color->blue  = hexa_color->blue;
 132         req.color->initialized = true;
 133         p_delete(&hexa_color);
 134         return true;
 135     }
 136
 137     warn("awesome: error, cannot allocate color '%s'", req.colstr);
 138     return false;
 139 }
 140
 141 /** Push a color as a string onto the stack
 142  * \param L The Lua VM state.
 143  * \param c The color to push.
 144  * \return The number of elements pushed on stack.
 145  */
 146 int
 147 luaA_pushcolor(lua_State *L, const color_t c)
 148 {
 149     uint8_t r = RGB_16TO8(c.red);
 150     uint8_t g = RGB_16TO8(c.green);
 151     uint8_t b = RGB_16TO8(c.blue);
 152
 153     char s[10];
 154     int len = snprintf(s, sizeof(s), "#%02x%02x%02x", r, g, b);
 155     lua_pushlstring(L, s, len);
 156     return 1;
 157 }
 158
 159 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80