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 "color.h"
  24 #include "globalconf.h"
  25
  26 #include <ctype.h>
  27
  28 /* 0xFFFF / 0xFF == 0x101 (257) */
  29 #define RGB_8TO16(i) (((i) & 0xff)   * 0x101)
  30 #define RGB_16TO8(i) (((i) & 0xffff) / 0x101)
  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  * \return True if everything alright.
  39  */
  40 static bool
  41 color_parse(const char *colstr, ssize_t len,
  42             uint8_t *red, uint8_t *green, uint8_t *blue)
  43 {
  44     unsigned long colnum;
  45     char *p;
  46
  47     colnum = strtoul(colstr + 1, &p, 16);
  48     if(len == 9 && (p - colstr) == 9)
  49     {
  50         /* We ignore the alpha component */
  51         colnum >>= 8;
  52         len -= 2;
  53         p -= 2;
  54     }
  55     if(len != 7 || colstr[0] != '#' || (p - colstr) != 7)
  56     {
  57         warn("awesome: error, invalid color '%s'", colstr);
  58         return false;
  59     }
  60
  61     *red   = (colnum >> 16) & 0xff;
  62     *green = (colnum >> 8) & 0xff;
  63     *blue  = colnum & 0xff;
  64
  65     return true;
  66 }
  67
  68 /** Send a request to initialize a X color.
  69  * If you are only interested in the rgba values and don't need the color's
  70  * pixel value, you should use color_init_unchecked() instead.
  71  * \param color color_t struct to store color into.
  72  * \param colstr Color specification.
  73  * \param len The length of colstr (which still MUST be NULL terminated).
  74  * \return request informations.
  75  */
  76 color_init_request_t
  77 color_init_unchecked(color_t *color, const char *colstr, ssize_t len)
  78 {
  79     color_init_request_t req;
  80     uint8_t red, green, blue;
  81
  82     p_clear(&req, 1);
  83
  84     if(!len)
  85     {
  86         req.has_error = true;
  87         return req;
  88     }
  89
  90     req.color = color;
  91
  92     /* The color is given in RGB value */
  93     if(!color_parse(colstr, len, &red, &green, &blue))
  94     {
  95         warn("awesome: error, invalid color '%s'", colstr);
  96         req.has_error = true;
  97         return req;
  98     }
  99
 100     req.cookie_hexa = xcb_alloc_color_unchecked(globalconf.connection,
 101                                                 globalconf.default_cmap,
 102                                                 RGB_8TO16(red),
 103                                                 RGB_8TO16(green),
 104                                                 RGB_8TO16(blue));
 105
 106     req.has_error = false;
 107     req.colstr = colstr;
 108
 109     return req;
 110 }
 111
 112 /** Initialize a X color.
 113  * \param req color_init request.
 114  * \return True if color allocation was successful.
 115  */
 116 bool
 117 color_init_reply(color_init_request_t req)
 118 {
 119     if(req.has_error)
 120         return false;
 121
 122     xcb_alloc_color_reply_t *hexa_color;
 123
 124     if((hexa_color = xcb_alloc_color_reply(globalconf.connection,
 125                                            req.cookie_hexa, NULL)))
 126     {
 127         req.color->pixel = hexa_color->pixel;
 128         req.color->red   = hexa_color->red;
 129         req.color->green = hexa_color->green;
 130         req.color->blue  = hexa_color->blue;
 131         req.color->initialized = true;
 132         p_delete(&hexa_color);
 133         return true;
 134     }
 135
 136     warn("awesome: error, cannot allocate color '%s'", req.colstr);
 137     return false;
 138 }
 139
 140 /** Push a color as a string onto the stack
 141  * \param L The Lua VM state.
 142  * \param c The color to push.
 143  * \return The number of elements pushed on stack.
 144  */
 145 int
 146 luaA_pushcolor(lua_State *L, const color_t c)
 147 {
 148     uint8_t r = RGB_16TO8(c.red);
 149     uint8_t g = RGB_16TO8(c.green);
 150     uint8_t b = RGB_16TO8(c.blue);
 151
 152     char s[10];
 153     int len = snprintf(s, sizeof(s), "#%02x%02x%02x", r, g, b);
 154     lua_pushlstring(L, s, len);
 155     return 1;
 156 }
 157
 158 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80