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 "gtkcssenumvalueprivate.h"
  23 #include "gtkcssinitialvalueprivate.h"
  24 #include "gtkstylepropertyprivate.h"
  25
  26 struct _GtkCssValue {
  27   GTK_CSS_VALUE_BASE
  28   GtkCssUnit unit;
  29   double value;
  30 };
  31
  32 static void
  33 gtk_css_value_number_free (GtkCssValue *value)
  34 {
  35   g_slice_free (GtkCssValue, value);
  36 }
  37
  38 static double
  39 get_base_font_size (guint                    property_id,
  40                     GtkStyleProviderPrivate *provider,
  41                     GtkCssComputedValues    *values,
  42                     GtkCssComputedValues    *parent_values,
  43                     GtkCssDependencies      *dependencies)
  44 {
  45   if (property_id == GTK_CSS_PROPERTY_FONT_SIZE)
  46     {
  47       *dependencies = GTK_CSS_DEPENDS_ON_PARENT;
  48       if (parent_values)
  49         return _gtk_css_number_value_get (_gtk_css_computed_values_get_value (parent_values, GTK_CSS_PROPERTY_FONT_SIZE), 100);
  50       else
  51         return _gtk_css_font_size_get_default (provider);
  52     }
  53
  54   *dependencies = GTK_CSS_DEPENDS_ON_FONT_SIZE;
  55   return _gtk_css_number_value_get (_gtk_css_computed_values_get_value (values, GTK_CSS_PROPERTY_FONT_SIZE), 100);
  56 }
  57
  58 static GtkCssValue *
  59 gtk_css_value_number_compute (GtkCssValue             *number,
  60                               guint                    property_id,
  61                               GtkStyleProviderPrivate *provider,
  62                               GtkCssComputedValues    *values,
  63                               GtkCssComputedValues    *parent_values,
  64                               GtkCssDependencies      *dependencies)
  65 {
  66   switch (number->unit)
  67     {
  68     default:
  69       g_assert_not_reached();
  70       /* fall through */
  71     case GTK_CSS_PERCENT:
  72       /* percentages for font sizes are computed, other percentages aren't */
  73       if (property_id == GTK_CSS_PROPERTY_FONT_SIZE)
  74         return _gtk_css_number_value_new (number->value / 100.0 *
  75                                           get_base_font_size (property_id, provider, values, parent_values, dependencies),
  76                                           GTK_CSS_PX);
  77     case GTK_CSS_NUMBER:
  78     case GTK_CSS_PX:
  79     case GTK_CSS_DEG:
  80     case GTK_CSS_S:
  81       return _gtk_css_value_ref (number);
  82     case GTK_CSS_PT:
  83       return _gtk_css_number_value_new (number->value * 96.0 / 72.0,
  84                                         GTK_CSS_PX);
  85     case GTK_CSS_PC:
  86       return _gtk_css_number_value_new (number->value * 96.0 / 72.0 * 12.0,
  87                                         GTK_CSS_PX);
  88       break;
  89     case GTK_CSS_IN:
  90       return _gtk_css_number_value_new (number->value * 96.0,
  91                                         GTK_CSS_PX);
  92       break;
  93     case GTK_CSS_CM:
  94       return _gtk_css_number_value_new (number->value * 96.0 * 0.39370078740157477,
  95                                         GTK_CSS_PX);
  96       break;
  97     case GTK_CSS_MM:
  98       return _gtk_css_number_value_new (number->value * 96.0 * 0.039370078740157477,
  99                                         GTK_CSS_PX);
 100       break;
 101     case GTK_CSS_EM:
 102       return _gtk_css_number_value_new (number->value *
 103                                         get_base_font_size (property_id, provider, values, parent_values, dependencies),
 104                                         GTK_CSS_PX);
 105       break;
 106     case GTK_CSS_EX:
 107       /* for now we pretend ex is half of em */
 108       return _gtk_css_number_value_new (number->value * 0.5 *
 109                                         get_base_font_size (property_id, provider, values, parent_values, dependencies),
 110                                         GTK_CSS_PX);
 111     case GTK_CSS_RAD:
 112       return _gtk_css_number_value_new (number->value * 360.0 / (2 * G_PI),
 113                                         GTK_CSS_DEG);
 114     case GTK_CSS_GRAD:
 115       return _gtk_css_number_value_new (number->value * 360.0 / 400.0,
 116                                         GTK_CSS_DEG);
 117     case GTK_CSS_TURN:
 118       return _gtk_css_number_value_new (number->value * 360.0,
 119                                         GTK_CSS_DEG);
 120     case GTK_CSS_MS:
 121       return _gtk_css_number_value_new (number->value / 1000.0,
 122                                         GTK_CSS_S);
 123     }
 124 }
 125
 126 static gboolean
 127 gtk_css_value_number_equal (const GtkCssValue *number1,
 128                             const GtkCssValue *number2)
 129 {
 130   return number1->unit == number2->unit &&
 131          number1->value == number2->value;
 132 }
 133
 134 static GtkCssValue *
 135 gtk_css_value_number_transition (GtkCssValue *start,
 136                                  GtkCssValue *end,
 137                                  guint        property_id,
 138                                  double       progress)
 139 {
 140   /* FIXME: This needs to be supported at least for percentages,
 141    * but for that we kinda need to support calc(5px + 50%) */
 142   if (start->unit != end->unit)
 143     return NULL;
 144
 145   return _gtk_css_number_value_new (start->value + (end->value - start->value) * progress,
 146                                     start->unit);
 147 }
 148
 149 static void
 150 gtk_css_value_number_print (const GtkCssValue *number,
 151                             GString           *string)
 152 {
 153   char buf[G_ASCII_DTOSTR_BUF_SIZE];
 154
 155   const char *names[] = {
 156     /* [GTK_CSS_NUMBER] = */ "",
 157     /* [GTK_CSS_PERCENT] = */ "%",
 158     /* [GTK_CSS_PX] = */ "px",
 159     /* [GTK_CSS_PT] = */ "pt",
 160     /* [GTK_CSS_EM] = */ "em",
 161     /* [GTK_CSS_EX] = */ "ex",
 162     /* [GTK_CSS_PC] = */ "pc",
 163     /* [GTK_CSS_IN] = */ "in",
 164     /* [GTK_CSS_CM] = */ "cm",
 165     /* [GTK_CSS_MM] = */ "mm",
 166     /* [GTK_CSS_RAD] = */ "rad",
 167     /* [GTK_CSS_DEG] = */ "deg",
 168     /* [GTK_CSS_GRAD] = */ "grad",
 169     /* [GTK_CSS_TURN] = */ "turn",
 170     /* [GTK_CSS_S] = */ "s",
 171     /* [GTK_CSS_MS] = */ "ms",
 172   };
 173
 174   g_ascii_dtostr (buf, sizeof (buf), number->value);
 175   g_string_append (string, buf);
 176   if (number->value != 0.0)
 177     g_string_append (string, names[number->unit]);
 178 }
 179
 180 static const GtkCssValueClass GTK_CSS_VALUE_NUMBER = {
 181   gtk_css_value_number_free,
 182   gtk_css_value_number_compute,
 183   gtk_css_value_number_equal,
 184   gtk_css_value_number_transition,
 185   gtk_css_value_number_print
 186 };
 187
 188 GtkCssValue *
 189 _gtk_css_number_value_new (double     value,
 190                            GtkCssUnit unit)
 191 {
 192   static GtkCssValue number_singletons[] = {
 193     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_NUMBER, 0 },
 194     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_NUMBER, 1 },
 195   };
 196   static GtkCssValue px_singletons[] = {
 197     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 0 },
 198     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 1 },
 199     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 2 },
 200     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 3 },
 201     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 4 },
 202   };
 203   GtkCssValue *result;
 204
 205   if (unit == GTK_CSS_NUMBER && (value == 0 || value == 1))
 206     return _gtk_css_value_ref (&number_singletons[(int) value]);
 207
 208   if (unit == GTK_CSS_PX &&
 209       (value == 0 ||
 210        value == 1 ||
 211        value == 2 ||
 212        value == 3 ||
 213        value == 4))
 214     {
 215       return _gtk_css_value_ref (&px_singletons[(int) value]);
 216     }
 217
 218   result = _gtk_css_value_new (GtkCssValue, &GTK_CSS_VALUE_NUMBER);
 219   result->unit = unit;
 220   result->value = value;
 221
 222   return result;
 223 }
 224
 225 GtkCssUnit
 226 _gtk_css_number_value_get_unit (const GtkCssValue *value)
 227 {
 228   g_return_val_if_fail (value->class == &GTK_CSS_VALUE_NUMBER, GTK_CSS_NUMBER);
 229
 230   return value->unit;
 231 }
 232
 233 double
 234 _gtk_css_number_value_get (const GtkCssValue *number,
 235                            double             one_hundred_percent)
 236 {
 237   g_return_val_if_fail (number != NULL, 0.0);
 238   g_return_val_if_fail (number->class == &GTK_CSS_VALUE_NUMBER, 0.0);
 239
 240   if (number->unit == GTK_CSS_PERCENT)
 241     return number->value * one_hundred_percent / 100;
 242   else
 243     return number->value;
 244 }
 245