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 "gtkstylepropertyprivate.h"
  24
  25 struct _GtkCssValue {
  26   GTK_CSS_VALUE_BASE
  27   GtkCssUnit unit;
  28   double value;
  29 };
  30
  31 static void
  32 gtk_css_value_number_free (GtkCssValue *value)
  33 {
  34   g_slice_free (GtkCssValue, value);
  35 }
  36
  37 static GtkCssValue *
  38 gtk_css_value_number_compute (GtkCssValue             *number,
  39                               guint                    property_id,
  40                               GtkStyleProviderPrivate *provider,
  41                               GtkCssComputedValues    *values,
  42                               GtkCssComputedValues    *parent_values,
  43                               GtkCssDependencies      *dependencies)
  44 {
  45   switch (number->unit)
  46     {
  47     default:
  48       g_assert_not_reached();
  49       /* fall through */
  50     case GTK_CSS_PERCENT:
  51     case GTK_CSS_NUMBER:
  52     case GTK_CSS_PX:
  53     case GTK_CSS_DEG:
  54     case GTK_CSS_S:
  55       return _gtk_css_value_ref (number);
  56     case GTK_CSS_PT:
  57       return _gtk_css_number_value_new (number->value * 96.0 / 72.0,
  58                                         GTK_CSS_PX);
  59     case GTK_CSS_PC:
  60       return _gtk_css_number_value_new (number->value * 96.0 / 72.0 * 12.0,
  61                                         GTK_CSS_PX);
  62       break;
  63     case GTK_CSS_IN:
  64       return _gtk_css_number_value_new (number->value * 96.0,
  65                                         GTK_CSS_PX);
  66       break;
  67     case GTK_CSS_CM:
  68       return _gtk_css_number_value_new (number->value * 96.0 * 0.39370078740157477,
  69                                         GTK_CSS_PX);
  70       break;
  71     case GTK_CSS_MM:
  72       return _gtk_css_number_value_new (number->value * 96.0 * 0.039370078740157477,
  73                                         GTK_CSS_PX);
  74       break;
  75     case GTK_CSS_EM:
  76       *dependencies = GTK_CSS_DEPENDS_ON_FONT_SIZE;
  77       return _gtk_css_number_value_new (number->value *
  78                                         _gtk_css_number_value_get (_gtk_css_computed_values_get_value (values, GTK_CSS_PROPERTY_FONT_SIZE), 100),
  79                                         GTK_CSS_PX);
  80       break;
  81     case GTK_CSS_EX:
  82       /* for now we pretend ex is half of em */
  83       *dependencies = GTK_CSS_DEPENDS_ON_FONT_SIZE;
  84       return _gtk_css_number_value_new (number->value * 0.5 *
  85                                         _gtk_css_number_value_get (_gtk_css_computed_values_get_value (values, GTK_CSS_PROPERTY_FONT_SIZE), 100),
  86                                         GTK_CSS_PX);
  87     case GTK_CSS_RAD:
  88       return _gtk_css_number_value_new (number->value * 360.0 / (2 * G_PI),
  89                                         GTK_CSS_DEG);
  90     case GTK_CSS_GRAD:
  91       return _gtk_css_number_value_new (number->value * 360.0 / 400.0,
  92                                         GTK_CSS_DEG);
  93     case GTK_CSS_TURN:
  94       return _gtk_css_number_value_new (number->value * 360.0,
  95                                         GTK_CSS_DEG);
  96     case GTK_CSS_MS:
  97       return _gtk_css_number_value_new (number->value / 1000.0,
  98                                         GTK_CSS_S);
  99     }
 100 }
 101
 102 static gboolean
 103 gtk_css_value_number_equal (const GtkCssValue *number1,
 104                             const GtkCssValue *number2)
 105 {
 106   return number1->unit == number2->unit &&
 107          number1->value == number2->value;
 108 }
 109
 110 static GtkCssValue *
 111 gtk_css_value_number_transition (GtkCssValue *start,
 112                                  GtkCssValue *end,
 113                                  guint        property_id,
 114                                  double       progress)
 115 {
 116   /* FIXME: This needs to be supported at least for percentages,
 117    * but for that we kinda need to support calc(5px + 50%) */
 118   if (start->unit != end->unit)
 119     return NULL;
 120
 121   return _gtk_css_number_value_new (start->value + (end->value - start->value) * progress,
 122                                     start->unit);
 123 }
 124
 125 static void
 126 gtk_css_value_number_print (const GtkCssValue *number,
 127                             GString           *string)
 128 {
 129   char buf[G_ASCII_DTOSTR_BUF_SIZE];
 130
 131   const char *names[] = {
 132     /* [GTK_CSS_NUMBER] = */ "",
 133     /* [GTK_CSS_PERCENT] = */ "%",
 134     /* [GTK_CSS_PX] = */ "px",
 135     /* [GTK_CSS_PT] = */ "pt",
 136     /* [GTK_CSS_EM] = */ "em",
 137     /* [GTK_CSS_EX] = */ "ex",
 138     /* [GTK_CSS_PC] = */ "pc",
 139     /* [GTK_CSS_IN] = */ "in",
 140     /* [GTK_CSS_CM] = */ "cm",
 141     /* [GTK_CSS_MM] = */ "mm",
 142     /* [GTK_CSS_RAD] = */ "rad",
 143     /* [GTK_CSS_DEG] = */ "deg",
 144     /* [GTK_CSS_GRAD] = */ "grad",
 145     /* [GTK_CSS_TURN] = */ "turn",
 146     /* [GTK_CSS_S] = */ "s",
 147     /* [GTK_CSS_MS] = */ "ms",
 148   };
 149
 150   g_ascii_dtostr (buf, sizeof (buf), number->value);
 151   g_string_append (string, buf);
 152   if (number->value != 0.0)
 153     g_string_append (string, names[number->unit]);
 154 }
 155
 156 static const GtkCssValueClass GTK_CSS_VALUE_NUMBER = {
 157   gtk_css_value_number_free,
 158   gtk_css_value_number_compute,
 159   gtk_css_value_number_equal,
 160   gtk_css_value_number_transition,
 161   gtk_css_value_number_print
 162 };
 163
 164 GtkCssValue *
 165 _gtk_css_number_value_new (double     value,
 166                            GtkCssUnit unit)
 167 {
 168   static GtkCssValue zero_singleton = { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_NUMBER, 0 };
 169   static GtkCssValue px_singletons[] = {
 170     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 0 },
 171     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 1 },
 172     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 2 },
 173     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 3 },
 174     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 4 },
 175   };
 176   GtkCssValue *result;
 177
 178   if (unit == GTK_CSS_NUMBER && value == 0)
 179     return _gtk_css_value_ref (&zero_singleton);
 180
 181   if (unit == GTK_CSS_PX &&
 182       (value == 0 ||
 183        value == 1 ||
 184        value == 2 ||
 185        value == 3 ||
 186        value == 4))
 187     {
 188       return _gtk_css_value_ref (&px_singletons[(int) value]);
 189     }
 190
 191   result = _gtk_css_value_new (GtkCssValue, &GTK_CSS_VALUE_NUMBER);
 192   result->unit = unit;
 193   result->value = value;
 194
 195   return result;
 196 }
 197
 198 GtkCssUnit
 199 _gtk_css_number_value_get_unit (const GtkCssValue *value)
 200 {
 201   g_return_val_if_fail (value->class == &GTK_CSS_VALUE_NUMBER, GTK_CSS_NUMBER);
 202
 203   return value->unit;
 204 }
 205
 206 double
 207 _gtk_css_number_value_get (const GtkCssValue *number,
 208                            double             one_hundred_percent)
 209 {
 210   g_return_val_if_fail (number != NULL, 0.0);
 211   g_return_val_if_fail (number->class == &GTK_CSS_VALUE_NUMBER, 0.0);
 212
 213   if (number->unit == GTK_CSS_PERCENT)
 214     return number->value * one_hundred_percent / 100;
 215   else
 216     return number->value;
 217 }
 218