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 GtkCssValue *
  45 gtk_css_value_number_transition (GtkCssValue *start,
  46                                  GtkCssValue *end,
  47                                  double       progress)
  48 {
  49   /* FIXME: This needs to be supported at least for percentages,
  50    * but for that we kinda need to support calc(5px + 50%) */
  51   if (start->unit != end->unit)
  52     return NULL;
  53
  54   return _gtk_css_number_value_new (start->value + (end->value - start->value) * progress,
  55                                     start->unit);
  56 }
  57
  58 static void
  59 gtk_css_value_number_print (const GtkCssValue *number,
  60                             GString           *string)
  61 {
  62   char buf[G_ASCII_DTOSTR_BUF_SIZE];
  63
  64   const char *names[] = {
  65     /* [GTK_CSS_NUMBER] = */ "",
  66     /* [GTK_CSS_PERCENT] = */ "%",
  67     /* [GTK_CSS_PX] = */ "px",
  68     /* [GTK_CSS_PT] = */ "pt",
  69     /* [GTK_CSS_EM] = */ "em",
  70     /* [GTK_CSS_EX] = */ "ex",
  71     /* [GTK_CSS_PC] = */ "pc",
  72     /* [GTK_CSS_IN] = */ "in",
  73     /* [GTK_CSS_CM] = */ "cm",
  74     /* [GTK_CSS_MM] = */ "mm",
  75     /* [GTK_CSS_RAD] = */ "rad",
  76     /* [GTK_CSS_DEG] = */ "deg",
  77     /* [GTK_CSS_GRAD] = */ "grad",
  78     /* [GTK_CSS_TURN] = */ "turn",
  79   };
  80
  81   g_ascii_dtostr (buf, sizeof (buf), number->value);
  82   g_string_append (string, buf);
  83   if (number->value != 0.0)
  84     g_string_append (string, names[number->unit]);
  85 }
  86
  87 static const GtkCssValueClass GTK_CSS_VALUE_NUMBER = {
  88   gtk_css_value_number_free,
  89   gtk_css_value_number_equal,
  90   gtk_css_value_number_transition,
  91   gtk_css_value_number_print
  92 };
  93
  94 GtkCssValue *
  95 _gtk_css_number_value_new (double     value,
  96                            GtkCssUnit unit)
  97 {
  98   static GtkCssValue zero_singleton = { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_NUMBER, 0 };
  99   static GtkCssValue px_singletons[] = {
 100     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 0 },
 101     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 1 },
 102     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 2 },
 103     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 3 },
 104     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 4 },
 105   };
 106   GtkCssValue *result;
 107
 108   if (unit == GTK_CSS_NUMBER && value == 0)
 109     return _gtk_css_value_ref (&zero_singleton);
 110
 111   if (unit == GTK_CSS_PX &&
 112       (value == 0 ||
 113        value == 1 ||
 114        value == 2 ||
 115        value == 3 ||
 116        value == 4))
 117     {
 118       return _gtk_css_value_ref (&px_singletons[(int) value]);
 119     }
 120
 121   result = _gtk_css_value_new (GtkCssValue, &GTK_CSS_VALUE_NUMBER);
 122   result->unit = unit;
 123   result->value = value;
 124
 125   return result;
 126 }
 127
 128 GtkCssValue *
 129 _gtk_css_number_value_parse (GtkCssParser           *parser,
 130                              GtkCssNumberParseFlags  flags)
 131 {
 132   GtkCssNumber number;
 133
 134   g_return_val_if_fail (parser != NULL, NULL);
 135
 136   if (!_gtk_css_parser_read_number (parser, &number, flags))
 137     return NULL;
 138
 139   return _gtk_css_number_value_new (number.value, number.unit);
 140 }
 141
 142 double
 143 _gtk_css_number_value_get (const GtkCssValue *number,
 144                            double             one_hundred_percent)
 145 {
 146   g_return_val_if_fail (number != NULL, 0.0);
 147   g_return_val_if_fail (number->class == &GTK_CSS_VALUE_NUMBER, 0.0);
 148
 149   if (number->unit == GTK_CSS_PERCENT)
 150     return number->value * one_hundred_percent / 100;
 151   else
 152     return number->value;
 153 }
 154
 155 GtkCssValue *
 156 _gtk_css_number_value_compute (GtkCssValue     *number,
 157                                GtkStyleContext *context)
 158 {
 159   g_return_val_if_fail (number->class == &GTK_CSS_VALUE_NUMBER, NULL);
 160
 161   switch (number->unit)
 162     {
 163     default:
 164       g_assert_not_reached();
 165       /* fall through */
 166     case GTK_CSS_PERCENT:
 167     case GTK_CSS_NUMBER:
 168     case GTK_CSS_PX:
 169     case GTK_CSS_DEG:
 170       return _gtk_css_value_ref (number);
 171     case GTK_CSS_PT:
 172       return _gtk_css_number_value_new (number->value * 96.0 / 72.0,
 173                                         GTK_CSS_PX);
 174     case GTK_CSS_PC:
 175       return _gtk_css_number_value_new (number->value * 96.0 / 72.0 * 12.0,
 176                                         GTK_CSS_PX);
 177       break;
 178     case GTK_CSS_IN:
 179       return _gtk_css_number_value_new (number->value * 96.0,
 180                                         GTK_CSS_PX);
 181       break;
 182     case GTK_CSS_CM:
 183       return _gtk_css_number_value_new (number->value * 96.0 * 0.39370078740157477,
 184                                         GTK_CSS_PX);
 185       break;
 186     case GTK_CSS_MM:
 187       return _gtk_css_number_value_new (number->value * 96.0 * 0.039370078740157477,
 188                                         GTK_CSS_PX);
 189       break;
 190     case GTK_CSS_EM:
 191       return _gtk_css_number_value_new (number->value *
 192                                         _gtk_css_number_value_get (_gtk_style_context_peek_property (context, "font-size"), 100),
 193                                         GTK_CSS_PX);
 194       break;
 195     case GTK_CSS_EX:
 196       /* for now we pretend ex is half of em */
 197       return _gtk_css_number_value_new (number->value * 0.5 *
 198                                         _gtk_css_number_value_get (_gtk_style_context_peek_property (context, "font-size"), 100),
 199                                         GTK_CSS_PX);
 200     case GTK_CSS_RAD:
 201       return _gtk_css_number_value_new (number->value * 360.0 / (2 * G_PI),
 202                                         GTK_CSS_DEG);
 203     case GTK_CSS_GRAD:
 204       return _gtk_css_number_value_new (number->value * 360.0 / 400.0,
 205                                         GTK_CSS_DEG);
 206     case GTK_CSS_TURN:
 207       return _gtk_css_number_value_new (number->value * 360.0,
 208                                         GTK_CSS_DEG);
 209     }
 210 }
 211