1 /* GTK - The GIMP Toolkit
2  * Copyright (C) 2014 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 "gtkcssunsetvalueprivate.h"
21 
22 #include "gtkcssinheritvalueprivate.h"
23 #include "gtkcssinitialvalueprivate.h"
24 #include "gtkcssstylepropertyprivate.h"
25 
26 struct _GtkCssValue {
27   GTK_CSS_VALUE_BASE
28 };
29 
30 static void
gtk_css_value_unset_free(GtkCssValue * value)31 gtk_css_value_unset_free (GtkCssValue *value)
32 {
33   /* Can only happen if the unique value gets unreffed too often */
34   g_assert_not_reached ();
35 }
36 
37 static GtkCssValue *
gtk_css_value_unset_compute(GtkCssValue * value,guint property_id,GtkStyleProviderPrivate * provider,GtkCssStyle * style,GtkCssStyle * parent_style)38 gtk_css_value_unset_compute (GtkCssValue             *value,
39                              guint                    property_id,
40                              GtkStyleProviderPrivate *provider,
41                              GtkCssStyle             *style,
42                              GtkCssStyle             *parent_style)
43 {
44   GtkCssStyleProperty *property;
45   GtkCssValue *unset_value;
46 
47   property = _gtk_css_style_property_lookup_by_id (property_id);
48 
49   if (_gtk_css_style_property_is_inherit (property))
50     unset_value = _gtk_css_inherit_value_get ();
51   else
52     unset_value = _gtk_css_initial_value_get ();
53 
54   return _gtk_css_value_compute (unset_value,
55                                  property_id,
56                                  provider,
57                                  style,
58                                  parent_style);
59 }
60 
61 static gboolean
gtk_css_value_unset_equal(const GtkCssValue * value1,const GtkCssValue * value2)62 gtk_css_value_unset_equal (const GtkCssValue *value1,
63                            const GtkCssValue *value2)
64 {
65   return TRUE;
66 }
67 
68 static GtkCssValue *
gtk_css_value_unset_transition(GtkCssValue * start,GtkCssValue * end,guint property_id,double progress)69 gtk_css_value_unset_transition (GtkCssValue *start,
70                                 GtkCssValue *end,
71                                 guint        property_id,
72                                 double       progress)
73 {
74   return NULL;
75 }
76 
77 static void
gtk_css_value_unset_print(const GtkCssValue * value,GString * string)78 gtk_css_value_unset_print (const GtkCssValue *value,
79                              GString           *string)
80 {
81   g_string_append (string, "unset");
82 }
83 
84 static const GtkCssValueClass GTK_CSS_VALUE_UNSET = {
85   gtk_css_value_unset_free,
86   gtk_css_value_unset_compute,
87   gtk_css_value_unset_equal,
88   gtk_css_value_unset_transition,
89   gtk_css_value_unset_print
90 };
91 
92 static GtkCssValue unset = { &GTK_CSS_VALUE_UNSET, 1 };
93 
94 GtkCssValue *
_gtk_css_unset_value_new(void)95 _gtk_css_unset_value_new (void)
96 {
97   return _gtk_css_value_ref (&unset);
98 }
99