Pileus Git - ~andy/gtk/blob - gtk/gtkcssnumbervalue.c

   1 /* GTK - The GIMP Toolkit
   2  * Copyright (C) 2011 Red Hat, Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library. If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "config.h"
  19
  20 #include "gtkcssnumbervalueprivate.h"
  21
  22 #include "gtkstylepropertyprivate.h"
  23
  24 struct _GtkCssValue {
  25   GTK_CSS_VALUE_BASE
  26   GtkCssUnit unit;
  27   double value;
  28 };
  29
  30 static void
  31 gtk_css_value_number_free (GtkCssValue *value)
  32 {
  33   g_slice_free (GtkCssValue, value);
  34 }
  35
  36 static gboolean
  37 gtk_css_value_number_equal (const GtkCssValue *number1,
  38                             const GtkCssValue *number2)
  39 {
  40   return number1->unit == number2->unit &&
  41          number1->value == number2->value;
  42 }
  43
  44 static void
  45 gtk_css_value_number_print (const GtkCssValue *number,
  46                             GString           *string)
  47 {
  48   char buf[G_ASCII_DTOSTR_BUF_SIZE];
  49
  50   const char *names[] = {
  51     /* [GTK_CSS_NUMBER] = */ "",
  52     /* [GTK_CSS_PERCENT] = */ "%",
  53     /* [GTK_CSS_PX] = */ "px",
  54     /* [GTK_CSS_PT] = */ "pt",
  55     /* [GTK_CSS_EM] = */ "em",
  56     /* [GTK_CSS_EX] = */ "ex",
  57     /* [GTK_CSS_PC] = */ "pc",
  58     /* [GTK_CSS_IN] = */ "in",
  59     /* [GTK_CSS_CM] = */ "cm",
  60     /* [GTK_CSS_MM] = */ "mm",
  61     /* [GTK_CSS_RAD] = */ "rad",
  62     /* [GTK_CSS_DEG] = */ "deg",
  63     /* [GTK_CSS_GRAD] = */ "grad",
  64     /* [GTK_CSS_TURN] = */ "turn",
  65   };
  66
  67   g_ascii_dtostr (buf, sizeof (buf), number->value);
  68   g_string_append (string, buf);
  69   if (number->value != 0.0)
  70     g_string_append (string, names[number->unit]);
  71 }
  72
  73 static const GtkCssValueClass GTK_CSS_VALUE_NUMBER = {
  74   gtk_css_value_number_free,
  75   gtk_css_value_number_equal,
  76   gtk_css_value_number_print
  77 };
  78
  79 GtkCssValue *
  80 _gtk_css_number_value_new (double     value,
  81                            GtkCssUnit unit)
  82 {
  83   static GtkCssValue zero_singleton = { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_NUMBER, 0 };
  84   static GtkCssValue px_singletons[] = {
  85     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 0 },
  86     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 1 },
  87     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 2 },
  88     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 3 },
  89     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 4 },
  90   };
  91   GtkCssValue *result;
  92
  93   if (unit == GTK_CSS_NUMBER && value == 0)
  94     return _gtk_css_value_ref (&zero_singleton);
  95
  96   if (unit == GTK_CSS_PX &&
  97       (value == 0 ||
  98        value == 1 ||
  99        value == 2 ||
 100        value == 3 ||
 101        value == 4))
 102     {
 103       return _gtk_css_value_ref (&px_singletons[(int) value]);
 104     }
 105
 106   result = _gtk_css_value_new (GtkCssValue, &GTK_CSS_VALUE_NUMBER);
 107   result->unit = unit;
 108   result->value = value;
 109
 110   return result;
 111 }
 112
 113 GtkCssValue *
 114 _gtk_css_number_value_parse (GtkCssParser           *parser,
 115                              GtkCssNumberParseFlags  flags)
 116 {
 117   GtkCssNumber number;
 118
 119   g_return_val_if_fail (parser != NULL, NULL);
 120
 121   if (!_gtk_css_parser_read_number (parser, &number, flags))
 122     return NULL;
 123
 124   return _gtk_css_number_value_new (number.value, number.unit);
 125 }
 126
 127 double
 128 _gtk_css_number_value_get (const GtkCssValue *number,
 129                            double             one_hundred_percent)
 130 {
 131   g_return_val_if_fail (number != NULL, 0.0);
 132   g_return_val_if_fail (number->class == &GTK_CSS_VALUE_NUMBER, 0.0);
 133
 134   if (number->unit == GTK_CSS_PERCENT)
 135     return number->value * one_hundred_percent / 100;
 136   else
 137     return number->value;
 138 }
 139
 140 GtkCssValue *
 141 _gtk_css_number_value_compute (GtkCssValue     *number,
 142                                GtkStyleContext *context)
 143 {
 144   g_return_val_if_fail (number->class == &GTK_CSS_VALUE_NUMBER, NULL);
 145
 146   switch (number->unit)
 147     {
 148     default:
 149       g_assert_not_reached();
 150       /* fall through */
 151     case GTK_CSS_PERCENT:
 152     case GTK_CSS_NUMBER:
 153     case GTK_CSS_PX:
 154     case GTK_CSS_DEG:
 155       return _gtk_css_value_ref (number);
 156     case GTK_CSS_PT:
 157       return _gtk_css_number_value_new (number->value * 96.0 / 72.0,
 158                                         GTK_CSS_PX);
 159     case GTK_CSS_PC:
 160       return _gtk_css_number_value_new (number->value * 96.0 / 72.0 * 12.0,
 161                                         GTK_CSS_PX);
 162       break;
 163     case GTK_CSS_IN:
 164       return _gtk_css_number_value_new (number->value * 96.0,
 165                                         GTK_CSS_PX);
 166       break;
 167     case GTK_CSS_CM:
 168       return _gtk_css_number_value_new (number->value * 96.0 * 0.39370078740157477,
 169                                         GTK_CSS_PX);
 170       break;
 171     case GTK_CSS_MM:
 172       return _gtk_css_number_value_new (number->value * 96.0 * 0.039370078740157477,
 173                                         GTK_CSS_PX);
 174       break;
 175     case GTK_CSS_EM:
 176       return _gtk_css_number_value_new (number->value * _gtk_css_value_get_double (_gtk_style_context_peek_property (context, "font-size")),
 177                                         GTK_CSS_PX);
 178       break;
 179     case GTK_CSS_EX:
 180       /* for now we pretend ex is half of em */
 181       return _gtk_css_number_value_new (number->value * 0.5 * _gtk_css_value_get_double (_gtk_style_context_peek_property (context, "font-size")),
 182                                         GTK_CSS_PX);
 183     case GTK_CSS_RAD:
 184       return _gtk_css_number_value_new (number->value * 360.0 / (2 * G_PI),
 185                                         GTK_CSS_DEG);
 186     case GTK_CSS_GRAD:
 187       return _gtk_css_number_value_new (number->value * 360.0 / 400.0,
 188                                         GTK_CSS_DEG);
 189     case GTK_CSS_TURN:
 190       return _gtk_css_number_value_new (number->value * 360.0,
 191                                         GTK_CSS_DEG);
 192     }
 193 }
 194