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, 29 insertions, 0 deletions

diff --git a/source/blender/editors/space_file/space_file.c b/source/blender/editors/space_file/space_file.c
index 780c2ec5a47..3f26604c23a 100644
--- a/source/blender/editors/space_file/space_file.c
+++ b/source/blender/editors/space_file/space_file.c
@@ -49,6 +49,7 @@
 
 #include "WM_api.h"
 #include "WM_types.h"
+#include "WM_message.h"
 
 #include "ED_space_api.h"
 #include "ED_screen.h"
@@ -354,6 +355,33 @@ static void file_main_region_listener(
 	}
 }
 
+static void file_main_region_message_subscribe(
+        const struct bContext *UNUSED(C),
+        struct WorkSpace *UNUSED(workspace), struct Scene *UNUSED(scene),
+        struct bScreen *screen, struct ScrArea *sa, struct ARegion *ar,
+        struct wmMsgBus *mbus)
+{
+	SpaceFile *sfile = sa->spacedata.first;
+	FileSelectParams *params = ED_fileselect_get_params(sfile);
+	/* This is a bit odd that a region owns the subscriber for an area,
+	 * keep for now since all subscribers for WM are regions.
+	 * May be worth re-visiting later. */
+	wmMsgSubscribeValue msg_sub_value_area_tag_refresh = {
+		.owner = ar,
+		.user_data = sa,
+		.notify = ED_area_do_msg_notify_tag_refresh,
+	};
+
+	/* FileSelectParams */
+	{
+		PointerRNA ptr;
+		RNA_pointer_create(&screen->id, &RNA_FileSelectParams, params, &ptr);
+
+		/* All properties for this space type. */
+		WM_msg_subscribe_rna(mbus, &ptr, NULL, &msg_sub_value_area_tag_refresh, __func__);
+	}
+}
+
 static void file_main_region_draw(const bContext *C, ARegion *ar)
 {
 	/* draw entirely, view changes should be handled here */
@@ -731,6 +759,7 @@ void ED_spacetype_file(void)
 	art->init = file_main_region_init;
 	art->draw = file_main_region_draw;
 	art->listener = file_main_region_listener;
+	art->message_subscribe = file_main_region_message_subscribe;
 	art->keymapflag = ED_KEYMAP_UI | ED_KEYMAP_VIEW2D;
 	BLI_addhead(&st->regiontypes, art);