Add a priority field for mail formatter and parser extensions.

Add a priority field to EMailFormatterExtension and EMailParserExtension
class structs.  Extension classes can then explicitly specify a priority
with respect to other extension classes with the same MIME type, so that
the order of extension registration doesn't matter.

Priority field defaults to G_PRIORITY_DEFAULT.  Built-in formatters and
extensions will use G_PRIORITY_LOW.  We can get more sophisticated with
priority values if we need to, but this should suffice for now.

1 files changed, 4 insertions, 0 deletions

diff --git a/em-format/e-mail-parser-extension.h b/em-format/e-mail-parser-extension.h
index 2b486a6dda..c011df62ab 100644
--- a/em-format/e-mail-parser-extension.h
+++ b/em-format/e-mail-parser-extension.h
@@ -81,6 +81,10 @@ struct _EMailParserExtensionClass {
 	 * wildcard (e.g. "text/ *"). */
 	const gchar **mime_types;
 
+	/* This is used to prioritize extensions with identical MIME
+	 * types.  Lower values win.  Defaults to G_PRIORITY_DEFAULT. */
+	gint priority;
+
 	/* See the flag descriptions above. */
 	EMailParserExtensionFlags flags;