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     /* [GTK_CSS_S] = */ "s",
  80     /* [GTK_CSS_MS] = */ "ms",
  81   };
  82
  83   g_ascii_dtostr (buf, sizeof (buf), number->value);
  84   g_string_append (string, buf);
  85   if (number->value != 0.0)
  86     g_string_append (string, names[number->unit]);
  87 }
  88
  89 static const GtkCssValueClass GTK_CSS_VALUE_NUMBER = {
  90   gtk_css_value_number_free,
  91   gtk_css_value_number_equal,
  92   gtk_css_value_number_transition,
  93   gtk_css_value_number_print
  94 };
  95
  96 GtkCssValue *
  97 _gtk_css_number_value_new (double     value,
  98                            GtkCssUnit unit)
  99 {
 100   static GtkCssValue zero_singleton = { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_NUMBER, 0 };
 101   static GtkCssValue px_singletons[] = {
 102     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 0 },
 103     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 1 },
 104     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 2 },
 105     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 3 },
 106     { &GTK_CSS_VALUE_NUMBER, 1, GTK_CSS_PX, 4 },
 107   };
 108   GtkCssValue *result;
 109
 110   if (unit == GTK_CSS_NUMBER && value == 0)
 111     return _gtk_css_value_ref (&zero_singleton);
 112
 113   if (unit == GTK_CSS_PX &&
 114       (value == 0 ||
 115        value == 1 ||
 116        value == 2 ||
 117        value == 3 ||
 118        value == 4))
 119     {
 120       return _gtk_css_value_ref (&px_singletons[(int) value]);
 121     }
 122
 123   result = _gtk_css_value_new (GtkCssValue, &GTK_CSS_VALUE_NUMBER);
 124   result->unit = unit;
 125   result->value = value;
 126
 127   return result;
 128 }
 129
 130 GtkCssUnit
 131 _gtk_css_number_value_get_unit (const GtkCssValue *value)
 132 {
 133   g_return_val_if_fail (value->class == &GTK_CSS_VALUE_NUMBER, GTK_CSS_NUMBER);
 134
 135   return value->unit;
 136 }
 137
 138 double
 139 _gtk_css_number_value_get (const GtkCssValue *number,
 140                            double             one_hundred_percent)
 141 {
 142   g_return_val_if_fail (number != NULL, 0.0);
 143   g_return_val_if_fail (number->class == &GTK_CSS_VALUE_NUMBER, 0.0);
 144
 145   if (number->unit == GTK_CSS_PERCENT)
 146     return number->value * one_hundred_percent / 100;
 147   else
 148     return number->value;
 149 }
 150
 151 GtkCssValue *
 152 _gtk_css_number_value_compute (GtkCssValue     *number,
 153                                GtkStyleContext *context)
 154 {
 155   g_return_val_if_fail (number->class == &GTK_CSS_VALUE_NUMBER, NULL);
 156
 157   switch (number->unit)
 158     {
 159     default:
 160       g_assert_not_reached();
 161       /* fall through */
 162     case GTK_CSS_PERCENT:
 163     case GTK_CSS_NUMBER:
 164     case GTK_CSS_PX:
 165     case GTK_CSS_DEG:
 166     case GTK_CSS_S:
 167       return _gtk_css_value_ref (number);
 168     case GTK_CSS_PT:
 169       return _gtk_css_number_value_new (number->value * 96.0 / 72.0,
 170                                         GTK_CSS_PX);
 171     case GTK_CSS_PC:
 172       return _gtk_css_number_value_new (number->value * 96.0 / 72.0 * 12.0,
 173                                         GTK_CSS_PX);
 174       break;
 175     case GTK_CSS_IN:
 176       return _gtk_css_number_value_new (number->value * 96.0,
 177                                         GTK_CSS_PX);
 178       break;
 179     case GTK_CSS_CM:
 180       return _gtk_css_number_value_new (number->value * 96.0 * 0.39370078740157477,
 181                                         GTK_CSS_PX);
 182       break;
 183     case GTK_CSS_MM:
 184       return _gtk_css_number_value_new (number->value * 96.0 * 0.039370078740157477,
 185                                         GTK_CSS_PX);
 186       break;
 187     case GTK_CSS_EM:
 188       return _gtk_css_number_value_new (number->value *
 189                                         _gtk_css_number_value_get (_gtk_style_context_peek_property (context, GTK_CSS_PROPERTY_FONT_SIZE), 100),
 190                                         GTK_CSS_PX);
 191       break;
 192     case GTK_CSS_EX:
 193       /* for now we pretend ex is half of em */
 194       return _gtk_css_number_value_new (number->value * 0.5 *
 195                                         _gtk_css_number_value_get (_gtk_style_context_peek_property (context, GTK_CSS_PROPERTY_FONT_SIZE), 100),
 196                                         GTK_CSS_PX);
 197     case GTK_CSS_RAD:
 198       return _gtk_css_number_value_new (number->value * 360.0 / (2 * G_PI),
 199                                         GTK_CSS_DEG);
 200     case GTK_CSS_GRAD:
 201       return _gtk_css_number_value_new (number->value * 360.0 / 400.0,
 202                                         GTK_CSS_DEG);
 203     case GTK_CSS_TURN:
 204       return _gtk_css_number_value_new (number->value * 360.0,
 205                                         GTK_CSS_DEG);
 206     case GTK_CSS_MS:
 207       return _gtk_css_number_value_new (number->value / 1000.0,
 208                                         GTK_CSS_S);
 209     }
 210 }
 211