Implement font-feature-settings

This is a missing part of the CSS font level 3 module.

6 files changed, 360 insertions, 0 deletions

diff --git a/gtk/gtkcssfontfeaturesvalue.c b/gtk/gtkcssfontfeaturesvalue.c
new file mode 100644
index 0000000000..29a389ae70
--- /dev/null
+++ b/gtk/gtkcssfontfeaturesvalue.c
@@ -0,0 +1,296 @@
+/* GTK - The GIMP Toolkit
+ * Copyright (C) 2017 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Matthias Clasen
+ */
+
+#include "config.h"
+
+#include "gtkcsstypesprivate.h"
+#include "gtkcssparserprivate.h"
+#include "gtkcssnumbervalueprivate.h"
+#include "gtkcssfontfeaturesvalueprivate.h"
+
+struct _GtkCssValue {
+  GTK_CSS_VALUE_BASE
+  GHashTable *features;
+};
+
+static GtkCssValue *default_font_features;
+
+static GtkCssValue *gtk_css_font_features_value_new_empty (void);
+
+static void
+gtk_css_font_features_value_add_feature (GtkCssValue *value,
+                                      const char  *name,
+                                      GtkCssValue *val)
+{
+  g_hash_table_insert (value->features, g_strdup (name), val);
+}
+
+
+static void
+gtk_css_value_font_features_free (GtkCssValue *value)
+{
+  g_hash_table_unref (value->features);
+
+  g_slice_free (GtkCssValue, value);
+}
+
+static GtkCssValue *
+gtk_css_value_font_features_compute (GtkCssValue      *specified,
+                                     guint             property_id,
+                                     GtkStyleProvider *provider,
+                                     GtkCssStyle      *style,
+                                     GtkCssStyle      *parent_style)
+{
+  GHashTableIter iter;
+  gpointer name, val;
+  GtkCssValue *computed_val;
+  GtkCssValue *result;
+  gboolean changes = FALSE;
+
+  result = gtk_css_font_features_value_new_empty ();
+
+  g_hash_table_iter_init (&iter, specified->features);
+  while (g_hash_table_iter_next (&iter, &name, &val))
+    {
+      computed_val = _gtk_css_value_compute (val, property_id, provider, style, parent_style);
+      changes |= computed_val != val;
+      gtk_css_font_features_value_add_feature (result, name, computed_val);
+    }
+
+  if (!changes)
+    {
+      _gtk_css_value_unref (result);
+      result = _gtk_css_value_ref (specified);
+    }
+
+  return result;
+}
+
+static gboolean
+gtk_css_value_font_features_equal (const GtkCssValue *value1,
+                                   const GtkCssValue *value2)
+{
+  gpointer name, val1, val2;
+  GHashTableIter iter;
+
+  if (g_hash_table_size (value1->features) != g_hash_table_size (value2->features))
+    return FALSE;
+
+  g_hash_table_iter_init (&iter, value1->features);
+  while (g_hash_table_iter_next (&iter, &name, &val1))
+    {
+      val2 = g_hash_table_lookup (value2->features, name);
+      if (val2 == NULL)
+        return FALSE;
+
+      if (!_gtk_css_value_equal (val1, val2))
+        return FALSE;
+    }
+
+  return TRUE;
+}
+
+static GtkCssValue *
+gtk_css_value_font_features_transition (GtkCssValue *start,
+                                        GtkCssValue *end,
+                                        guint        property_id,
+                                        double       progress)
+{
+  const char *name;
+  GtkCssValue *start_val, *end_val;
+  GHashTableIter iter;
+  GtkCssValue *result, *transition;
+
+  /* XXX: For value that are only in start or end but not both,
+   * we don't transition but just keep the value.
+   * That causes an abrupt transition to the new value at the end.
+   */
+
+  result = gtk_css_font_features_value_new_empty ();
+
+  g_hash_table_iter_init (&iter, start->features);
+  while (g_hash_table_iter_next (&iter, (gpointer *)&name, (gpointer *)&start_val))
+    {
+      end_val = g_hash_table_lookup (end->features, name);
+      if (end_val == NULL)
+        transition = _gtk_css_value_ref (start_val);
+      else
+        transition = _gtk_css_value_transition (start_val, end_val, property_id, progress);
+
+      gtk_css_font_features_value_add_feature (result, name, transition);
+    }
+
+  g_hash_table_iter_init (&iter, end->features);
+  while (g_hash_table_iter_next (&iter, (gpointer *)&name, (gpointer *)&end_val))
+    {
+      start_val = g_hash_table_lookup (start->features, name);
+      if (start_val != NULL)
+        continue;
+
+      gtk_css_font_features_value_add_feature (result, name, _gtk_css_value_ref (end_val));
+    }
+
+  return result;
+}
+
+static void
+gtk_css_value_font_features_print (const GtkCssValue *value,
+                                   GString           *string)
+{
+  GHashTableIter iter;
+  const char *name;
+  GtkCssValue *val;
+  gboolean first = TRUE;
+
+  if (value == default_font_features)
+    {
+      g_string_append (string, "normal");
+      return;
+    }
+
+  g_hash_table_iter_init (&iter, value->features);
+  while (g_hash_table_iter_next (&iter, (gpointer *)&name, (gpointer *)&val))
+    {
+      if (first)
+        first = FALSE;
+      else
+        g_string_append (string, ", ");
+      g_string_append_printf (string, "\"%s\" ", name);
+      _gtk_css_value_print (val, string);
+    }
+}
+
+static const GtkCssValueClass GTK_CSS_VALUE_FONT_FEATURES = {
+  gtk_css_value_font_features_free,
+  gtk_css_value_font_features_compute,
+  gtk_css_value_font_features_equal,
+  gtk_css_value_font_features_transition,
+  gtk_css_value_font_features_print
+};
+
+static GtkCssValue *
+gtk_css_font_features_value_new_empty (void)
+{
+  GtkCssValue *result;
+
+  result = _gtk_css_value_new (GtkCssValue, &GTK_CSS_VALUE_FONT_FEATURES);
+  result->features = g_hash_table_new_full (g_str_hash, g_str_equal,
+                                        g_free,
+                                        (GDestroyNotify) _gtk_css_value_unref);
+
+  return result;
+}
+
+GtkCssValue *
+gtk_css_font_features_value_new_default (void)
+{
+  if (default_font_features == NULL)
+    default_font_features = gtk_css_font_features_value_new_empty ();
+
+  return _gtk_css_value_ref (default_font_features);
+}
+
+static gboolean
+is_valid_opentype_tag (const char *s)
+{
+  if (strlen (s) != 4)
+    return FALSE;
+
+  if (s[0] < 0x20 || s[0] > 0x7e ||
+      s[1] < 0x20 || s[1] > 0x7e ||
+      s[2] < 0x20 || s[2] > 0x7e ||
+      s[3] < 0x20 || s[3] > 0x7e)
+    return FALSE;
+
+  return TRUE;
+}
+
+GtkCssValue *
+gtk_css_font_features_value_parse (GtkCssParser *parser)
+{
+  GtkCssValue *result, *val;
+  char *name;
+  int num;
+
+  if (_gtk_css_parser_try (parser, "normal", TRUE))
+    return gtk_css_font_features_value_new_default ();
+
+  result = gtk_css_font_features_value_new_empty ();
+
+  do {
+    _gtk_css_parser_skip_whitespace (parser);
+    name = _gtk_css_parser_read_string (parser);
+    if (name == NULL)
+      {
+        _gtk_css_value_unref (result);
+        return NULL;
+      }
+
+    if (!is_valid_opentype_tag (name))
+      {
+        _gtk_css_parser_error (parser, "Not a valid OpenType tag.");
+        g_free (name);
+        _gtk_css_value_unref (result);
+        return NULL;
+      }
+
+    if (_gtk_css_parser_try (parser, "on", TRUE))
+      val = _gtk_css_number_value_new (1.0, GTK_CSS_NUMBER);
+    else if (_gtk_css_parser_try (parser, "off", TRUE))
+      val = _gtk_css_number_value_new (0.0, GTK_CSS_NUMBER);
+    else if (_gtk_css_parser_try_int (parser, &num))
+      val = _gtk_css_number_value_new ((double)num, GTK_CSS_NUMBER);
+    else
+      val = _gtk_css_number_value_new (1.0, GTK_CSS_NUMBER);
+
+    gtk_css_font_features_value_add_feature (result, name, val);
+    g_free (name);
+  } while (_gtk_css_parser_try (parser, ",", TRUE));
+
+  return result;
+}
+
+char *
+gtk_css_font_features_value_get_features (GtkCssValue *value)
+{
+  GtkCssValue *val;
+  GHashTableIter iter;
+  gboolean first = TRUE;
+  const char *name;
+  GString *string;
+
+  g_return_val_if_fail (value->class == &GTK_CSS_VALUE_FONT_FEATURES, NULL);
+
+  if (value == default_font_features)
+    return NULL;
+
+  string = g_string_new ("");
+
+  g_hash_table_iter_init (&iter, value->features);
+  while (g_hash_table_iter_next (&iter, (gpointer *)&name, (gpointer *)&val))
+    {
+      if (first)
+        first = FALSE;
+      else
+        g_string_append (string, ", ");
+      g_string_append_printf (string, "%s %d", name, (int)_gtk_css_number_value_get (val, 100));
+    }
+
+  return g_string_free (string, FALSE);
+}
diff --git a/gtk/gtkcssfontfeaturesvalueprivate.h b/gtk/gtkcssfontfeaturesvalueprivate.h
new file mode 100644
index 0000000000..834a9a09bd
--- /dev/null
+++ b/gtk/gtkcssfontfeaturesvalueprivate.h
@@ -0,0 +1,36 @@
+/*
+ * Copyright © 2017 Red Hat Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen
+ */
+
+#ifndef __GTK_CSS_FONT_FEATURES_VALUE_PRIVATE_H__
+#define __GTK_CSS_FONT_FEATURES_PRIVATE_H__
+
+#include "gtkcssparserprivate.h"
+#include "gtkcssvalueprivate.h"
+
+G_BEGIN_DECLS
+
+GtkCssValue *   gtk_css_font_features_value_new_default  (void);
+
+GtkCssValue *   gtk_css_font_features_value_parse        (GtkCssParser *parser);
+
+char *          gtk_css_font_features_value_get_features (GtkCssValue  *value);
+
+G_END_DECLS
+
+#endif /* __GTK_CSS_FONT_FEATURES_VALUE_PRIVATE_H__ */
diff --git a/gtk/gtkcssstyle.c b/gtk/gtkcssstyle.c
index 670a87d7b0..78af3ae9d4 100644
--- a/gtk/gtkcssstyle.c
+++ b/gtk/gtkcssstyle.c
@@ -32,6 +32,7 @@
 #include "gtkcsssectionprivate.h"
 #include "gtkcssshorthandpropertyprivate.h"
 #include "gtkcssstringvalueprivate.h"
+#include "gtkcssfontfeaturesvalueprivate.h"
 #include "gtkcssstylepropertyprivate.h"
 #include "gtkcsstransitionprivate.h"
 #include "gtkstyleanimationprivate.h"
@@ -238,6 +239,7 @@ gtk_css_style_get_pango_attributes (GtkCssStyle *style)
   GtkCssFontVariantNumeric numeric;
   GtkCssFontVariantEastAsian east_asian;
   GString *s;
+  char *settings;
 
   /* text-decoration */
   decoration_line = _gtk_css_text_decoration_line_value_get (gtk_css_style_get_value (style, GTK_CSS_PROPERTY_TEXT_DECORATION_LINE));
@@ -424,6 +426,16 @@ gtk_css_style_get_pango_attributes (GtkCssStyle *style)
         append_separated (s, "ruby 1");
     }
 
+g_print ("before: %s\n", s->str);
+  value = gtk_css_style_get_value (style, GTK_CSS_PROPERTY_FONT_FEATURE_SETTINGS);
+  settings = gtk_css_font_features_value_get_features (value);
+  if (settings)
+    {
+      append_separated (s, settings);
+      g_free (settings);
+    }
+g_print ("after: %s\n", s->str);
+
   attrs = add_pango_attr (attrs, pango_attr_font_features_new (s->str));
   g_string_free (s, TRUE);
 
diff --git a/gtk/gtkcssstylepropertyimpl.c b/gtk/gtkcssstylepropertyimpl.c
index eacf945ab0..65c27d8ca5 100644
--- a/gtk/gtkcssstylepropertyimpl.c
+++ b/gtk/gtkcssstylepropertyimpl.c
@@ -657,6 +657,12 @@ parse_font_variant_east_asian (GtkCssStyleProperty *property,
 }
 
 static GtkCssValue *
+parse_font_feature_settings (GtkCssStyleProperty *property,
+                             GtkCssParser        *parser)
+{
+  return gtk_css_font_features_value_parse (parser);
+}
+
 box_shadow_value_parse (GtkCssStyleProperty *property,
                         GtkCssParser        *parser)
 {
@@ -1800,4 +1806,12 @@ _gtk_css_style_property_init_properties (void)
                                           color_parse,
                                           color_query,
                                           _gtk_css_color_value_new_current_color ());
+  gtk_css_style_property_register        ("font-feature-settings",
+                                          GTK_CSS_PROPERTY_FONT_FEATURE_SETTINGS,
+                                          G_TYPE_NONE,
+                                          GTK_STYLE_PROPERTY_INHERIT | GTK_STYLE_PROPERTY_ANIMATED,
+                                          GTK_CSS_AFFECTS_TEXT_ATTRS | GTK_CSS_AFFECTS_TEXT_SIZE,
+                                          parse_font_feature_settings,
+                                          NULL,
+                                          gtk_css_font_features_value_new_default ());
 }
diff --git a/gtk/gtkcsstypesprivate.h b/gtk/gtkcsstypesprivate.h
index 0b73d106dd..f7b68ee445 100644
--- a/gtk/gtkcsstypesprivate.h
+++ b/gtk/gtkcsstypesprivate.h
@@ -244,6 +244,7 @@ enum { /*< skip >*/
   GTK_CSS_PROPERTY_GTK_KEY_BINDINGS,
   GTK_CSS_PROPERTY_CARET_COLOR,
   GTK_CSS_PROPERTY_SECONDARY_CARET_COLOR,
+  GTK_CSS_PROPERTY_FONT_FEATURE_SETTINGS,
   /* add more */
   GTK_CSS_PROPERTY_N_PROPERTIES
 };
diff --git a/gtk/meson.build b/gtk/meson.build
index be8cc45df3..4b18f532fa 100644
--- a/gtk/meson.build
+++ b/gtk/meson.build
@@ -85,6 +85,7 @@ gtk_public_sources = files([
   'gtkcsseasevalue.c',
   'gtkcssenumvalue.c',
   'gtkcssfiltervalue.c',
+  'gtkcssfontfeaturesvalue.c',
   'gtkcssiconthemevalue.c',
   'gtkcssimage.c',
   'gtkcssimagebuiltin.c',