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

   1 /*
   2  * Copyright © 2012 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 2.1 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  * Authors: Benjamin Otte <otte@gnome.org>
  18  */
  19
  20 #include "config.h"
  21
  22 #include "gtkcsscomputedvaluesprivate.h"
  23
  24 #include "gtkcssstylepropertyprivate.h"
  25 #include "gtkcsstypesprivate.h"
  26 #include "gtkprivatetypebuiltins.h"
  27
  28 G_DEFINE_TYPE (GtkCssComputedValues, _gtk_css_computed_values, G_TYPE_OBJECT)
  29
  30 static void
  31 gtk_css_computed_values_dispose (GObject *object)
  32 {
  33   GtkCssComputedValues *values = GTK_CSS_COMPUTED_VALUES (object);
  34
  35   if (values->values)
  36     {
  37       g_ptr_array_unref (values->values);
  38       values->values = NULL;
  39     }
  40   if (values->sections)
  41     {
  42       g_ptr_array_unref (values->sections);
  43       values->sections = NULL;
  44     }
  45
  46   G_OBJECT_CLASS (_gtk_css_computed_values_parent_class)->dispose (object);
  47 }
  48
  49 static void
  50 _gtk_css_computed_values_class_init (GtkCssComputedValuesClass *klass)
  51 {
  52   GObjectClass *object_class = G_OBJECT_CLASS (klass);
  53
  54   object_class->dispose = gtk_css_computed_values_dispose;
  55 }
  56
  57 static void
  58 _gtk_css_computed_values_init (GtkCssComputedValues *computed_values)
  59 {
  60
  61 }
  62
  63 GtkCssComputedValues *
  64 _gtk_css_computed_values_new (void)
  65 {
  66   return g_object_new (GTK_TYPE_CSS_COMPUTED_VALUES, NULL);
  67 }
  68
  69 static void
  70 maybe_unref_section (gpointer section)
  71 {
  72   if (section)
  73     gtk_css_section_unref (section);
  74 }
  75
  76 void
  77 _gtk_css_computed_values_compute_value (GtkCssComputedValues *values,
  78                                         GtkStyleContext      *context,
  79                                         guint                 id,
  80                                         GtkCssValue          *specified,
  81                                         GtkCssSection        *section)
  82 {
  83   GtkCssStyleProperty *prop;
  84   GtkStyleContext *parent;
  85
  86   g_return_if_fail (GTK_IS_CSS_COMPUTED_VALUES (values));
  87   g_return_if_fail (GTK_IS_STYLE_CONTEXT (context));
  88
  89   prop = _gtk_css_style_property_lookup_by_id (id);
  90   parent = gtk_style_context_get_parent (context);
  91
  92   if (values->values == NULL)
  93     values->values = g_ptr_array_new_with_free_func ((GDestroyNotify)_gtk_css_value_unref);
  94   if (id <= values->values->len)
  95    g_ptr_array_set_size (values->values, id + 1);
  96
  97   /* http://www.w3.org/TR/css3-cascade/#cascade
  98    * Then, for every element, the value for each property can be found
  99    * by following this pseudo-algorithm:
 100    * 1) Identify all declarations that apply to the element
 101    */
 102   if (specified != NULL)
 103     {
 104       if (_gtk_css_value_is_special (specified))
 105         {
 106           switch (_gtk_css_value_get_special_kind (specified))
 107             {
 108             case GTK_CSS_INHERIT:
 109               /* 3) if the value of the winning declaration is ‘inherit’,
 110                * the inherited value (see below) becomes the specified value.
 111                */
 112               specified = NULL;
 113               break;
 114             case GTK_CSS_INITIAL:
 115               /* if the value of the winning declaration is ‘initial’,
 116                * the initial value (see below) becomes the specified value.
 117                */
 118               specified = _gtk_css_style_property_get_initial_value (prop);
 119               break;
 120             default:
 121               /* This is part of (2) above */
 122               break;
 123             }
 124         }
 125
 126       /* 2) If the cascading process (described below) yields a winning
 127        * declaration and the value of the winning declaration is not
 128        * ‘initial’ or ‘inherit’, the value of the winning declaration
 129        * becomes the specified value.
 130        */
 131     }
 132   else
 133     {
 134       if (_gtk_css_style_property_is_inherit (prop))
 135         {
 136           /* 4) if the property is inherited, the inherited value becomes
 137            * the specified value.
 138            */
 139           specified = NULL;
 140         }
 141       else
 142         {
 143           /* 5) Otherwise, the initial value becomes the specified value.
 144            */
 145           specified = _gtk_css_style_property_get_initial_value (prop);
 146         }
 147     }
 148
 149   if (specified == NULL && parent == NULL)
 150     {
 151       /* If the ‘inherit’ value is set on the root element, the property is
 152        * assigned its initial value. */
 153       specified = _gtk_css_style_property_get_initial_value (prop);
 154     }
 155
 156   if (specified)
 157     {
 158       g_ptr_array_index (values->values, id) =
 159         _gtk_css_style_property_compute_value (prop,
 160                                                context,
 161                                                specified);
 162     }
 163   else
 164     {
 165       GtkCssValue *parent_value;
 166       /* Set NULL here and do the inheritance upon lookup? */
 167       parent_value = _gtk_style_context_peek_property (parent,
 168                                                        _gtk_style_property_get_name (GTK_STYLE_PROPERTY (prop)));
 169
 170       g_ptr_array_index (values->values, id) = _gtk_css_value_ref (parent_value);
 171     }
 172
 173   if (section)
 174     {
 175       if (values->sections == NULL)
 176         values->sections = g_ptr_array_new_with_free_func (maybe_unref_section);
 177       if (values->sections->len <= id)
 178         g_ptr_array_set_size (values->sections, id + 1);
 179
 180       g_ptr_array_index (values->sections, id) = gtk_css_section_ref (section);
 181     }
 182 }
 183
 184 void
 185 _gtk_css_computed_values_set_value (GtkCssComputedValues *values,
 186                                     guint                 id,
 187                                     GtkCssValue          *value,
 188                                     GtkCssSection        *section)
 189 {
 190   g_return_if_fail (GTK_IS_CSS_COMPUTED_VALUES (values));
 191
 192   if (values->values == NULL)
 193     values->values = g_ptr_array_new_with_free_func ((GDestroyNotify)_gtk_css_value_unref);
 194   if (id <= values->values->len)
 195    g_ptr_array_set_size (values->values, id + 1);
 196
 197   g_ptr_array_index (values->values, id) = _gtk_css_value_ref (value);
 198
 199   if (section)
 200     {
 201       if (values->sections == NULL)
 202         values->sections = g_ptr_array_new_with_free_func (maybe_unref_section);
 203       if (values->sections->len <= id)
 204         g_ptr_array_set_size (values->sections, id + 1);
 205
 206       g_ptr_array_index (values->sections, id) = gtk_css_section_ref (section);
 207     }
 208 }
 209
 210 GtkCssValue *
 211 _gtk_css_computed_values_get_value (GtkCssComputedValues *values,
 212                                     guint                 id)
 213 {
 214   g_return_val_if_fail (GTK_IS_CSS_COMPUTED_VALUES (values), NULL);
 215
 216   if (values->values == NULL ||
 217       id >= values->values->len)
 218     return NULL;
 219
 220   return g_ptr_array_index (values->values, id);
 221 }
 222
 223 GtkCssValue *
 224 _gtk_css_computed_values_get_value_by_name (GtkCssComputedValues *values,
 225                                             const char           *name)
 226 {
 227   GtkStyleProperty *prop;
 228
 229   g_return_val_if_fail (GTK_IS_CSS_COMPUTED_VALUES (values), NULL);
 230   g_return_val_if_fail (name != NULL, NULL);
 231
 232   prop = _gtk_style_property_lookup (name);
 233   g_assert (GTK_IS_CSS_STYLE_PROPERTY (prop));
 234
 235   return _gtk_css_computed_values_get_value (values, _gtk_css_style_property_get_id (GTK_CSS_STYLE_PROPERTY (prop)));
 236 }
 237
 238 GtkCssSection *
 239 _gtk_css_computed_values_get_section (GtkCssComputedValues *values,
 240                                       guint                 id)
 241 {
 242   g_return_val_if_fail (GTK_IS_CSS_COMPUTED_VALUES (values), NULL);
 243
 244   if (values->sections == NULL ||
 245       id >= values->sections->len)
 246     return NULL;
 247
 248   return g_ptr_array_index (values->sections, id);
 249 }
 250