[gnome-builder] buffer: make warning underline color check dynamic

[Christian Hergert <chergert src gnome org>]

commit 13c233e83de893836940e17805540755bc2a3448
Author: Christian Hergert <christian hergert me>
Date:   Fri Mar 27 01:08:03 2015 -0700

    buffer: make warning underline color check dynamic

 libide/ide-buffer.c |   46 +++++++++++++++++++++++++++++++++-------------
 1 files changed, 33 insertions(+), 13 deletions(-)
---
diff --git a/libide/ide-buffer.c b/libide/ide-buffer.c
index de0484c..2382a1f 100644
--- a/libide/ide-buffer.c
+++ b/libide/ide-buffer.c
@@ -715,34 +715,54 @@ ide_buffer_mark_set (GtkTextBuffer     *buffer,
     ide_buffer_emit_cursor_moved (IDE_BUFFER (buffer));
 }
 
+static gboolean
+ide_buffer_check_underline_rgba (void)
+{
+  static gboolean did_check;
+  static gboolean has_underline_rgba;
+
+  if (!did_check)
+    {
+      GObjectClass *type_class;
+      GParamSpec *pspec;
+
+      type_class = g_type_class_ref (GTK_TYPE_TEXT_TAG);
+      pspec = g_object_class_find_property (type_class, "underline-rgba");
+      has_underline_rgba = (pspec != NULL) && (pspec->value_type == GDK_TYPE_RGBA);
+      g_type_class_unref (type_class);
+      did_check = TRUE;
+    }
+
+  return has_underline_rgba;
+}
+
 static void
 ide_buffer_constructed (GObject *object)
 {
   IdeBuffer *self = (IdeBuffer *)object;
   IdeBufferPrivate *priv = ide_buffer_get_instance_private (self);
-#if GTK_CHECK_VERSION(3, 16, 1)
-  GdkRGBA warning_rgba;
-#endif
+  GtkTextTag *warning_tag;
 
   G_OBJECT_CLASS (ide_buffer_parent_class)->constructed (object);
 
-#if GTK_CHECK_VERSION(3, 16, 1)
-  gdk_rgba_parse (&warning_rgba, "#fcaf3e");
-#endif
-
   gtk_text_buffer_create_tag (GTK_TEXT_BUFFER (self), TAG_ERROR,
                               "underline", PANGO_UNDERLINE_ERROR,
                               NULL);
-  gtk_text_buffer_create_tag (GTK_TEXT_BUFFER (self), TAG_WARNING,
-                              "underline", PANGO_UNDERLINE_ERROR,
-#if GTK_CHECK_VERSION (3, 16, 1)
-                              "underline-rgba", &warning_rgba,
-#endif
-                              NULL);
   gtk_text_buffer_create_tag (GTK_TEXT_BUFFER (self), TAG_NOTE,
                               "underline", PANGO_UNDERLINE_SINGLE,
                               NULL);
 
+  warning_tag = gtk_text_buffer_create_tag (GTK_TEXT_BUFFER (self), TAG_WARNING,
+                                            "underline", PANGO_UNDERLINE_ERROR,
+                                            NULL);
+  if (ide_buffer_check_underline_rgba ())
+    {
+      GdkRGBA warning_rgba;
+
+      gdk_rgba_parse (&warning_rgba, "#fcaf3e");
+      g_object_set (warning_tag, "underline-rgba", &warning_rgba, NULL);
+    }
+
   priv->highlight_engine = ide_highlight_engine_new (self);
 
   ide_buffer_reload_highlighter (self);