UI: Avoid unnecessary redraws of unrelated editors on space changes

When adding a notifier, `reference` data can be passed. The notifier system
uses this to filter out listeners, for example if data of a scene changes,
windows showing a different scene won't get the notifiers sent to their
listeners.

For the `NC_SPACE` notifiers, a number of places also passed the space as
`reference`, but that wasn't used at all. The notifier would still be sent to
all listeners in all windows (and the listeners didn't use it either). Causing
some unnecessary updates (e.g. see ed2c4825d3e2344).
With this commit, passing a space will make sure the notifier is only sent to
that exact space. Some code seems to already have expected that to be the case.

However there were some cases that passed the space as `reference` without
reason, which would break with this commit (meaning they wouldn't redraw or
update correctly).
Corrected these so they don't pass the space anymore.

8 files changed, 16 insertions, 11 deletions

diff --git a/source/blender/editors/gpencil/gpencil_edit.c b/source/blender/editors/gpencil/gpencil_edit.c
index b03d2c6e795..4bbd475dd2c 100644
--- a/source/blender/editors/gpencil/gpencil_edit.c
+++ b/source/blender/editors/gpencil/gpencil_edit.c
@@ -3095,7 +3095,6 @@ static int gpencil_snap_cursor_to_sel(bContext *C, wmOperator *op)
   const bool is_curve_edit = (bool)GPENCIL_CURVE_EDIT_SESSIONS_ON(gpd);
 
   Scene *scene = CTX_data_scene(C);
-  View3D *v3d = CTX_wm_view3d(C);
 
   float *cursor = scene->cursor.location;
   float centroid[3] = {0.0f};
@@ -3125,7 +3124,7 @@ static int gpencil_snap_cursor_to_sel(bContext *C, wmOperator *op)
     }
 
     DEG_id_tag_update(&scene->id, ID_RECALC_COPY_ON_WRITE);
-    WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, v3d);
+    WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, NULL);
   }
 
   return OPERATOR_FINISHED;
diff --git a/source/blender/editors/object/object_relations.c b/source/blender/editors/object/object_relations.c
index e74d04ab17f..0aa739c2fc8 100644
--- a/source/blender/editors/object/object_relations.c
+++ b/source/blender/editors/object/object_relations.c
@@ -1756,7 +1756,7 @@ static int make_links_data_exec(bContext *C, wmOperator *op)
   }
 
   DEG_relations_tag_update(bmain);
-  WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, CTX_wm_view3d(C));
+  WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, NULL);
   WM_event_add_notifier(C, NC_ANIMATION | ND_NLA_ACTCHANGE, CTX_wm_view3d(C));
   WM_event_add_notifier(C, NC_OBJECT, NULL);
 
@@ -2712,7 +2712,7 @@ static int drop_named_material_invoke(bContext *C, wmOperator *op, const wmEvent
   DEG_id_tag_update(&base->object->id, ID_RECALC_TRANSFORM);
 
   WM_event_add_notifier(C, NC_OBJECT | ND_OB_SHADING, base->object);
-  WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, CTX_wm_view3d(C));
+  WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, NULL);
   WM_event_add_notifier(C, NC_MATERIAL | ND_SHADING_LINKS, ma);
 
   return OPERATOR_FINISHED;
diff --git a/source/blender/editors/space_outliner/outliner_dragdrop.c b/source/blender/editors/space_outliner/outliner_dragdrop.c
index 01fb0fc6f78..b55720c3d01 100644
--- a/source/blender/editors/space_outliner/outliner_dragdrop.c
+++ b/source/blender/editors/space_outliner/outliner_dragdrop.c
@@ -647,7 +647,7 @@ static int material_drop_invoke(bContext *C, wmOperator *UNUSED(op), const wmEve
   BKE_object_material_assign(bmain, ob, ma, ob->totcol + 1, BKE_MAT_ASSIGN_USERPREF);
 
   WM_event_add_notifier(C, NC_OBJECT | ND_OB_SHADING, ob);
-  WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, CTX_wm_view3d(C));
+  WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, NULL);
   WM_event_add_notifier(C, NC_MATERIAL | ND_SHADING_LINKS, ma);
 
   return OPERATOR_FINISHED;
diff --git a/source/blender/editors/space_view3d/view3d_buttons.c b/source/blender/editors/space_view3d/view3d_buttons.c
index 36da0791c4f..17f60dfc210 100644
--- a/source/blender/editors/space_view3d/view3d_buttons.c
+++ b/source/blender/editors/space_view3d/view3d_buttons.c
@@ -1575,7 +1575,7 @@ static void do_view3d_region_buttons(bContext *C, void *UNUSED(index), int event
   }
 
   /* default for now */
-  WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, v3d);
+  WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, NULL);
 }
 
 static bool view3d_panel_transform_poll(const bContext *C, PanelType *UNUSED(pt))
diff --git a/source/blender/editors/space_view3d/view3d_snap.c b/source/blender/editors/space_view3d/view3d_snap.c
index cce9287679c..61eeafbe7c7 100644
--- a/source/blender/editors/space_view3d/view3d_snap.c
+++ b/source/blender/editors/space_view3d/view3d_snap.c
@@ -667,7 +667,7 @@ static int snap_curs_to_grid_exec(bContext *C, wmOperator *UNUSED(op))
   curs[1] = gridf * floorf(0.5f + curs[1] / gridf);
   curs[2] = gridf * floorf(0.5f + curs[2] / gridf);
 
-  WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, v3d); /* hrm */
+  WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, NULL); /* hrm */
   DEG_id_tag_update(&scene->id, ID_RECALC_COPY_ON_WRITE);
 
   return OPERATOR_FINISHED;
@@ -913,7 +913,7 @@ static int snap_curs_to_active_exec(bContext *C, wmOperator *UNUSED(op))
   View3D *v3d = CTX_wm_view3d(C);
 
   if (snap_calc_active_center(C, false, scene->cursor.location)) {
-    WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, v3d);
+    WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, NULL);
     DEG_id_tag_update(&scene->id, ID_RECALC_COPY_ON_WRITE);
 
     return OPERATOR_FINISHED;
diff --git a/source/blender/editors/transform/transform_ops.c b/source/blender/editors/transform/transform_ops.c
index 01c00247a7a..9b5f15a2574 100644
--- a/source/blender/editors/transform/transform_ops.c
+++ b/source/blender/editors/transform/transform_ops.c
@@ -163,14 +163,13 @@ const EnumPropertyItem rna_enum_transform_mode_types[] = {
 static int select_orientation_exec(bContext *C, wmOperator *op)
 {
   Scene *scene = CTX_data_scene(C);
-  View3D *v3d = CTX_wm_view3d(C);
 
   int orientation = RNA_enum_get(op->ptr, "orientation");
 
   BKE_scene_orientation_slot_set_index(&scene->orientation_slots[SCE_ORIENT_DEFAULT], orientation);
 
   WM_event_add_notifier(C, NC_SCENE | ND_TOOLSETTINGS, NULL);
-  WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, v3d);
+  WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, NULL);
 
   struct wmMsgBus *mbus = CTX_wm_message_bus(C);
   WM_msg_publish_rna_prop(mbus, &scene->id, scene, TransformOrientationSlot, type);
@@ -286,7 +285,7 @@ static int create_orientation_exec(bContext *C, wmOperator *op)
     WM_event_add_notifier(C, NC_SCENE | NA_EDITED, scene);
   }
 
-  WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, v3d);
+  WM_event_add_notifier(C, NC_SPACE | ND_SPACE_VIEW3D, NULL);
 
   return OPERATOR_FINISHED;
 }
diff --git a/source/blender/windowmanager/WM_types.h b/source/blender/windowmanager/WM_types.h
index b46a354c7ae..385a572ab85 100644
--- a/source/blender/windowmanager/WM_types.h
+++ b/source/blender/windowmanager/WM_types.h
@@ -287,6 +287,9 @@ typedef struct wmNotifier {
 #define NC_TEXT (12 << 24)
 #define NC_WORLD (13 << 24)
 #define NC_ANIMATION (14 << 24)
+/* When passing a space as reference data with this (e.g. `WM_event_add_notifier(..., space)`),
+ * the notifier will only be sent to this space. That avoids unnecessary updates for unrelated
+ * spaces. */
 #define NC_SPACE (15 << 24)
 #define NC_GEOM (16 << 24)
 #define NC_NODE (17 << 24)
diff --git a/source/blender/windowmanager/intern/wm_event_system.c b/source/blender/windowmanager/intern/wm_event_system.c
index a39200537d5..33ba27c849c 100644
--- a/source/blender/windowmanager/intern/wm_event_system.c
+++ b/source/blender/windowmanager/intern/wm_event_system.c
@@ -577,6 +577,10 @@ void wm_event_do_notifiers(bContext *C)
         }
 
         ED_screen_areas_iter (win, screen, area) {
+          if ((note->category == NC_SPACE) && note->reference &&
+              (note->reference != area->spacedata.first)) {
+            continue;
+          }
           wmSpaceTypeListenerParams area_params = {
               .window = win,
               .area = area,