[gnome-text-editor] spellcheck: use def:misspelled-word style

[Christian Hergert <chergert src gnome org>]

commit f3bf8fe22aaff45989da5bb5c62e13a62c7e8330
Author: Christian Hergert <chergert redhat com>
Date:   Thu Dec 30 12:32:59 2021 -0800

    spellcheck: use def:misspelled-word style
    
    This will allow style schemes to override the styling a bit for misspelled
    words.

 src/editor-text-buffer-spell-adapter.c | 36 ++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)
---
diff --git a/src/editor-text-buffer-spell-adapter.c b/src/editor-text-buffer-spell-adapter.c
index 2933370..e2cde23 100644
--- a/src/editor-text-buffer-spell-adapter.c
+++ b/src/editor-text-buffer-spell-adapter.c
@@ -379,6 +379,35 @@ invalidate_tag_region_cb (EditorTextBufferSpellAdapter *self,
     }
 }
 
+static void
+apply_error_style_cb (GtkSourceBuffer *buffer,
+                      GParamSpec      *pspec,
+                      GtkTextTag      *tag)
+{
+  GtkSourceStyleScheme *scheme;
+  GtkSourceStyle *style;
+
+  g_assert (GTK_SOURCE_IS_BUFFER (buffer));
+  g_assert (GTK_IS_TEXT_TAG (tag));
+
+  g_object_set (tag,
+                "underline", PANGO_UNDERLINE_ERROR,
+                "background-set", FALSE,
+                "foreground-set", FALSE,
+                "weight-set", FALSE,
+                "variant-set", FALSE,
+                "style-set", FALSE,
+                "indent-set", FALSE,
+                "size-set", FALSE,
+                NULL);
+
+  if ((scheme = gtk_source_buffer_get_style_scheme (buffer)))
+    {
+      if ((style = gtk_source_style_scheme_get_style (scheme, "def:misspelled-word")))
+        gtk_source_style_apply (style, tag);
+    }
+}
+
 static void
 editor_text_buffer_spell_adapter_set_buffer (EditorTextBufferSpellAdapter *self,
                                              GtkTextBuffer                *buffer)
@@ -404,6 +433,13 @@ editor_text_buffer_spell_adapter_set_buffer (EditorTextBufferSpellAdapter *self,
                                               "underline", PANGO_UNDERLINE_ERROR,
                                               NULL);
 
+      g_signal_connect_object (buffer,
+                               "notify::style-scheme",
+                               G_CALLBACK (apply_error_style_cb),
+                               self->tag,
+                               0);
+      apply_error_style_cb (GTK_SOURCE_BUFFER (buffer), NULL, self->tag);
+
       /* Track tag changes from the tag table and extract "no-spell-check"
        * tag from GtkSourceView so that we can avoid words with that tag.
        */