WM: message bus replacement for property notifiers

Use dynamically generated message publish/subscribe
so buttons and manipulators update properly.

This resolves common glitches where manipulators weren't updating
as well as the UI when add-ons exposed properties which
hard coded listeners weren't checking for.

Python can also publish/scribe changes via `bpy.msgbus`.

See D2917

1 files changed, 41 insertions, 0 deletions

diff --git a/source/blender/windowmanager/message_bus/intern/wm_message_bus_intern.h b/source/blender/windowmanager/message_bus/intern/wm_message_bus_intern.h
new file mode 100644
index 00000000000..8d7b9d4ced2
--- /dev/null
+++ b/source/blender/windowmanager/message_bus/intern/wm_message_bus_intern.h
@@ -0,0 +1,41 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/windowmanager/message_bus/intern/wm_message_bus_intern.h
+ *  \ingroup wm
+ */
+
+#ifndef __WM_MESSAGE_BUS_INTERN_H__
+#define __WM_MESSAGE_BUS_INTERN_H__
+
+/* wm_message_bus.h must be included first */
+
+struct wmMsgBus {
+	struct GSet *messages_gset[WM_MSG_TYPE_NUM];
+	/** Messages in order of being added. */
+	ListBase messages;
+	/** Avoid checking messages when no tags exist. */
+	uint     messages_tag_count;
+};
+
+void wm_msg_subscribe_value_free(
+        struct wmMsgSubscribeKey *msg_key, struct wmMsgSubscribeValueLink *msg_lnk);
+
+#endif /* __WM_MESSAGE_BUS_INTERN_H__ */