Cleanup: Rename ARegion variables from ar to region

The old convention was easy to confuse with ScrArea.
Part of https://developer.blender.org/T74432.

This is mostly a batch rename with some manual fixing. Only single word
variable names are changed, no prefixed/suffixed names.

Brecht van Lommel and Campbell Barton both gave me a green light for
this convention change.

Also ran clan clang format on affected files.

5 files changed, 128 insertions, 123 deletions

diff --git a/source/blender/editors/space_action/action_draw.c b/source/blender/editors/space_action/action_draw.c
index 0c57113956d..54308553343 100644
--- a/source/blender/editors/space_action/action_draw.c
+++ b/source/blender/editors/space_action/action_draw.c
@@ -64,13 +64,13 @@
 /* Channel List */
 
 /* left hand part */
-void draw_channel_names(bContext *C, bAnimContext *ac, ARegion *ar)
+void draw_channel_names(bContext *C, bAnimContext *ac, ARegion *region)
 {
   ListBase anim_data = {NULL, NULL};
   bAnimListElem *ale;
   int filter;
 
-  View2D *v2d = &ar->v2d;
+  View2D *v2d = &region->v2d;
   size_t items;
 
   /* build list of channels to draw */
@@ -100,7 +100,7 @@ void draw_channel_names(bContext *C, bAnimContext *ac, ARegion *ar)
     }
   }
   { /* second pass: widgets */
-    uiBlock *block = UI_block_begin(C, ar, __func__, UI_EMBOSS);
+    uiBlock *block = UI_block_begin(C, region, __func__, UI_EMBOSS);
     size_t channel_index = 0;
     float ymax = ACHANNEL_FIRST_TOP(ac);
 
@@ -132,12 +132,12 @@ void draw_channel_names(bContext *C, bAnimContext *ac, ARegion *ar)
 #define EXTRA_SCROLL_PAD 100.0f
 
 /* draw keyframes in each channel */
-void draw_channel_strips(bAnimContext *ac, SpaceAction *saction, ARegion *ar)
+void draw_channel_strips(bAnimContext *ac, SpaceAction *saction, ARegion *region)
 {
   ListBase anim_data = {NULL, NULL};
   bAnimListElem *ale;
 
-  View2D *v2d = &ar->v2d;
+  View2D *v2d = &region->v2d;
   bDopeSheet *ads = &saction->ads;
   AnimData *adt = NULL;
 
diff --git a/source/blender/editors/space_action/action_edit.c b/source/blender/editors/space_action/action_edit.c
index a1d8b9d0b2e..e01986181bc 100644
--- a/source/blender/editors/space_action/action_edit.c
+++ b/source/blender/editors/space_action/action_edit.c
@@ -372,7 +372,7 @@ static int actkeys_viewall(bContext *C, const bool only_sel)
   if (ANIM_animdata_get_context(C, &ac) == 0) {
     return OPERATOR_CANCELLED;
   }
-  v2d = &ac.ar->v2d;
+  v2d = &ac.region->v2d;
 
   /* set the horizontal range, with an extra offset so that the extreme keys will be in view */
   found = get_keyframe_extents(&ac, &min, &max, only_sel);
diff --git a/source/blender/editors/space_action/action_intern.h b/source/blender/editors/space_action/action_intern.h
index c227b794ae7..006ba86a50a 100644
--- a/source/blender/editors/space_action/action_intern.h
+++ b/source/blender/editors/space_action/action_intern.h
@@ -42,8 +42,10 @@ void action_buttons_register(struct ARegionType *art);
 
 /* ***************************************** */
 /* action_draw.c */
-void draw_channel_names(struct bContext *C, struct bAnimContext *ac, struct ARegion *ar);
-void draw_channel_strips(struct bAnimContext *ac, struct SpaceAction *saction, struct ARegion *ar);
+void draw_channel_names(struct bContext *C, struct bAnimContext *ac, struct ARegion *region);
+void draw_channel_strips(struct bAnimContext *ac,
+                         struct SpaceAction *saction,
+                         struct ARegion *region);
 
 void timeline_draw_cache(struct SpaceAction *saction, struct Object *ob, struct Scene *scene);
 
diff --git a/source/blender/editors/space_action/action_select.c b/source/blender/editors/space_action/action_select.c
index 095b30aa57b..458c8690e3c 100644
--- a/source/blender/editors/space_action/action_select.c
+++ b/source/blender/editors/space_action/action_select.c
@@ -71,7 +71,7 @@ static bAnimListElem *actkeys_find_list_element_at_position(bAnimContext *ac,
                                                             float region_x,
                                                             float region_y)
 {
-  View2D *v2d = &ac->ar->v2d;
+  View2D *v2d = &ac->region->v2d;
 
   float view_x, view_y;
   int channel_index;
@@ -158,7 +158,7 @@ static void actkeys_find_key_in_list_element(bAnimContext *ac,
 {
   *r_found = false;
 
-  View2D *v2d = &ac->ar->v2d;
+  View2D *v2d = &ac->region->v2d;
 
   DLRBT_Tree anim_keys;
   BLI_dlrbTree_init(&anim_keys);
@@ -458,7 +458,7 @@ static void box_select_action(bAnimContext *ac, const rcti rect, short mode, sho
   int filter;
 
   BoxSelectData sel_data = {.ac = ac, .selectmode = selectmode};
-  View2D *v2d = &ac->ar->v2d;
+  View2D *v2d = &ac->region->v2d;
   rctf rectf;
 
   /* Convert mouse coordinates to frame ranges and channel
@@ -697,7 +697,7 @@ static void region_select_action_keys(
   int filter;
 
   RegionSelectData sel_data = {.ac = ac, .mode = mode, .selectmode = selectmode};
-  View2D *v2d = &ac->ar->v2d;
+  View2D *v2d = &ac->region->v2d;
   rctf rectf, scaled_rectf;
 
   /* Convert mouse coordinates to frame ranges and channel
@@ -1470,8 +1470,8 @@ static int actkeys_select_leftright_invoke(bContext *C, wmOperator *op, const wm
   /* handle mode-based testing */
   if (leftright == ACTKEYS_LRSEL_TEST) {
     Scene *scene = ac.scene;
-    ARegion *ar = ac.ar;
-    View2D *v2d = &ar->v2d;
+    ARegion *region = ac.region;
+    View2D *v2d = &region->v2d;
     float x;
 
     /* determine which side of the current frame mouse is on */
@@ -1825,7 +1825,7 @@ static int actkeys_clickselect_exec(bContext *C, wmOperator *op)
   }
 
   /* get useful pointers from animation context data */
-  /* ar = ac.ar; */ /* UNUSED */
+  /* region = ac.region; */ /* UNUSED */
 
   /* select mode is either replace (deselect all, then add) or add/extend */
   const short selectmode = RNA_boolean_get(op->ptr, "extend") ? SELECT_INVERT : SELECT_REPLACE;
diff --git a/source/blender/editors/space_action/space_action.c b/source/blender/editors/space_action/space_action.c
index f06b1a02675..af59b56065c 100644
--- a/source/blender/editors/space_action/space_action.c
+++ b/source/blender/editors/space_action/space_action.c
@@ -63,7 +63,7 @@
 static SpaceLink *action_new(const ScrArea *sa, const Scene *scene)
 {
   SpaceAction *saction;
-  ARegion *ar;
+  ARegion *region;
 
   saction = MEM_callocN(sizeof(SpaceAction), "initaction");
   saction->spacetype = SPACE_ACTION;
@@ -82,57 +82,57 @@ static SpaceLink *action_new(const ScrArea *sa, const Scene *scene)
   saction->cache_display |= TIME_CACHE_RIGIDBODY;
 
   /* header */
-  ar = MEM_callocN(sizeof(ARegion), "header for action");
+  region = MEM_callocN(sizeof(ARegion), "header for action");
 
-  BLI_addtail(&saction->regionbase, ar);
-  ar->regiontype = RGN_TYPE_HEADER;
-  ar->alignment = (U.uiflag & USER_HEADER_BOTTOM) ? RGN_ALIGN_BOTTOM : RGN_ALIGN_TOP;
+  BLI_addtail(&saction->regionbase, region);
+  region->regiontype = RGN_TYPE_HEADER;
+  region->alignment = (U.uiflag & USER_HEADER_BOTTOM) ? RGN_ALIGN_BOTTOM : RGN_ALIGN_TOP;
 
   /* channel list region */
-  ar = MEM_callocN(sizeof(ARegion), "channel region for action");
-  BLI_addtail(&saction->regionbase, ar);
-  ar->regiontype = RGN_TYPE_CHANNELS;
-  ar->alignment = RGN_ALIGN_LEFT;
+  region = MEM_callocN(sizeof(ARegion), "channel region for action");
+  BLI_addtail(&saction->regionbase, region);
+  region->regiontype = RGN_TYPE_CHANNELS;
+  region->alignment = RGN_ALIGN_LEFT;
 
   /* only need to set scroll settings, as this will use 'listview' v2d configuration */
-  ar->v2d.scroll = V2D_SCROLL_BOTTOM;
-  ar->v2d.flag = V2D_VIEWSYNC_AREA_VERTICAL;
+  region->v2d.scroll = V2D_SCROLL_BOTTOM;
+  region->v2d.flag = V2D_VIEWSYNC_AREA_VERTICAL;
 
   /* ui buttons */
-  ar = MEM_callocN(sizeof(ARegion), "buttons region for action");
+  region = MEM_callocN(sizeof(ARegion), "buttons region for action");
 
-  BLI_addtail(&saction->regionbase, ar);
-  ar->regiontype = RGN_TYPE_UI;
-  ar->alignment = RGN_ALIGN_RIGHT;
-  ar->flag = RGN_FLAG_HIDDEN;
+  BLI_addtail(&saction->regionbase, region);
+  region->regiontype = RGN_TYPE_UI;
+  region->alignment = RGN_ALIGN_RIGHT;
+  region->flag = RGN_FLAG_HIDDEN;
 
   /* main region */
-  ar = MEM_callocN(sizeof(ARegion), "main region for action");
+  region = MEM_callocN(sizeof(ARegion), "main region for action");
 
-  BLI_addtail(&saction->regionbase, ar);
-  ar->regiontype = RGN_TYPE_WINDOW;
+  BLI_addtail(&saction->regionbase, region);
+  region->regiontype = RGN_TYPE_WINDOW;
 
-  ar->v2d.tot.xmin = (float)(SFRA - 10);
-  ar->v2d.tot.ymin = (float)(-sa->winy) / 3.0f;
-  ar->v2d.tot.xmax = (float)(EFRA + 10);
-  ar->v2d.tot.ymax = 0.0f;
+  region->v2d.tot.xmin = (float)(SFRA - 10);
+  region->v2d.tot.ymin = (float)(-sa->winy) / 3.0f;
+  region->v2d.tot.xmax = (float)(EFRA + 10);
+  region->v2d.tot.ymax = 0.0f;
 
-  ar->v2d.cur = ar->v2d.tot;
+  region->v2d.cur = region->v2d.tot;
 
-  ar->v2d.min[0] = 0.0f;
-  ar->v2d.min[1] = 0.0f;
+  region->v2d.min[0] = 0.0f;
+  region->v2d.min[1] = 0.0f;
 
-  ar->v2d.max[0] = MAXFRAMEF;
-  ar->v2d.max[1] = FLT_MAX;
+  region->v2d.max[0] = MAXFRAMEF;
+  region->v2d.max[1] = FLT_MAX;
 
-  ar->v2d.minzoom = 0.01f;
-  ar->v2d.maxzoom = 50;
-  ar->v2d.scroll = (V2D_SCROLL_BOTTOM | V2D_SCROLL_HORIZONTAL_HANDLES);
-  ar->v2d.scroll |= (V2D_SCROLL_RIGHT);
-  ar->v2d.keepzoom = V2D_LOCKZOOM_Y;
-  ar->v2d.keepofs = V2D_KEEPOFS_Y;
-  ar->v2d.align = V2D_ALIGN_NO_POS_Y;
-  ar->v2d.flag = V2D_VIEWSYNC_AREA_VERTICAL;
+  region->v2d.minzoom = 0.01f;
+  region->v2d.maxzoom = 50;
+  region->v2d.scroll = (V2D_SCROLL_BOTTOM | V2D_SCROLL_HORIZONTAL_HANDLES);
+  region->v2d.scroll |= (V2D_SCROLL_RIGHT);
+  region->v2d.keepzoom = V2D_LOCKZOOM_Y;
+  region->v2d.keepofs = V2D_KEEPOFS_Y;
+  region->v2d.align = V2D_ALIGN_NO_POS_Y;
+  region->v2d.flag = V2D_VIEWSYNC_AREA_VERTICAL;
 
   return (SpaceLink *)saction;
 }
@@ -160,27 +160,27 @@ static SpaceLink *action_duplicate(SpaceLink *sl)
 }
 
 /* add handlers, stuff you only do once or on area/region changes */
-static void action_main_region_init(wmWindowManager *wm, ARegion *ar)
+static void action_main_region_init(wmWindowManager *wm, ARegion *region)
 {
   wmKeyMap *keymap;
 
-  UI_view2d_region_reinit(&ar->v2d, V2D_COMMONVIEW_CUSTOM, ar->winx, ar->winy);
+  UI_view2d_region_reinit(&region->v2d, V2D_COMMONVIEW_CUSTOM, region->winx, region->winy);
 
   /* own keymap */
   keymap = WM_keymap_ensure(wm->defaultconf, "Dopesheet", SPACE_ACTION, 0);
-  WM_event_add_keymap_handler_v2d_mask(&ar->handlers, keymap);
+  WM_event_add_keymap_handler_v2d_mask(&region->handlers, keymap);
   keymap = WM_keymap_ensure(wm->defaultconf, "Dopesheet Generic", SPACE_ACTION, 0);
-  WM_event_add_keymap_handler(&ar->handlers, keymap);
+  WM_event_add_keymap_handler(&region->handlers, keymap);
 }
 
-static void action_main_region_draw(const bContext *C, ARegion *ar)
+static void action_main_region_draw(const bContext *C, ARegion *region)
 {
   /* draw entirely, view changes should be handled here */
   SpaceAction *saction = CTX_wm_space_action(C);
   Scene *scene = CTX_data_scene(C);
   Object *obact = CTX_data_active_object(C);
   bAnimContext ac;
-  View2D *v2d = &ar->v2d;
+  View2D *v2d = &region->v2d;
   View2DScrollers *scrollers;
   short marker_flag = 0;
   short cfra_flag = 0;
@@ -194,14 +194,14 @@ static void action_main_region_draw(const bContext *C, ARegion *ar)
   /* time grid */
   UI_view2d_draw_lines_x__discrete_frames_or_seconds(v2d, scene, saction->flag & SACTION_DRAWTIME);
 
-  ED_region_draw_cb_draw(C, ar, REGION_DRAW_PRE_VIEW);
+  ED_region_draw_cb_draw(C, region, REGION_DRAW_PRE_VIEW);
 
   /* start and end frame */
   ANIM_draw_framerange(scene, v2d);
 
   /* data */
   if (ANIM_animdata_get_context(C, &ac)) {
-    draw_channel_strips(&ac, saction, ar);
+    draw_channel_strips(&ac, saction, region);
   }
 
   /* current frame */
@@ -211,7 +211,7 @@ static void action_main_region_draw(const bContext *C, ARegion *ar)
   ANIM_draw_cfra(C, v2d, cfra_flag);
 
   /* markers */
-  UI_view2d_view_orthoSpecial(ar, v2d, 1);
+  UI_view2d_view_orthoSpecial(region, v2d, 1);
 
   marker_flag = ((ac.markers && (ac.markers != &ac.scene->markers)) ? DRAW_MARKERS_LOCAL : 0) |
                 DRAW_MARKERS_MARGIN;
@@ -231,13 +231,13 @@ static void action_main_region_draw(const bContext *C, ARegion *ar)
 
   /* callback */
   UI_view2d_view_ortho(v2d);
-  ED_region_draw_cb_draw(C, ar, REGION_DRAW_POST_VIEW);
+  ED_region_draw_cb_draw(C, region, REGION_DRAW_POST_VIEW);
 
   /* reset view matrix */
   UI_view2d_view_restore(C);
 
   /* scrubbing region */
-  ED_time_scrub_draw(ar, scene, saction->flag & SACTION_DRAWTIME, true);
+  ED_time_scrub_draw(region, scene, saction->flag & SACTION_DRAWTIME, true);
 
   /* scrollers */
   scrollers = UI_view2d_scrollers_calc(v2d, NULL);
@@ -246,28 +246,28 @@ static void action_main_region_draw(const bContext *C, ARegion *ar)
 }
 
 /* add handlers, stuff you only do once or on area/region changes */
-static void action_channel_region_init(wmWindowManager *wm, ARegion *ar)
+static void action_channel_region_init(wmWindowManager *wm, ARegion *region)
 {
   wmKeyMap *keymap;
 
   /* ensure the 2d view sync works - main region has bottom scroller */
-  ar->v2d.scroll = V2D_SCROLL_BOTTOM;
+  region->v2d.scroll = V2D_SCROLL_BOTTOM;
 
-  UI_view2d_region_reinit(&ar->v2d, V2D_COMMONVIEW_LIST, ar->winx, ar->winy);
+  UI_view2d_region_reinit(&region->v2d, V2D_COMMONVIEW_LIST, region->winx, region->winy);
 
   /* own keymap */
   keymap = WM_keymap_ensure(wm->defaultconf, "Animation Channels", 0, 0);
-  WM_event_add_keymap_handler_v2d_mask(&ar->handlers, keymap);
+  WM_event_add_keymap_handler_v2d_mask(&region->handlers, keymap);
 
   keymap = WM_keymap_ensure(wm->defaultconf, "Dopesheet Generic", SPACE_ACTION, 0);
-  WM_event_add_keymap_handler(&ar->handlers, keymap);
+  WM_event_add_keymap_handler(&region->handlers, keymap);
 }
 
-static void action_channel_region_draw(const bContext *C, ARegion *ar)
+static void action_channel_region_draw(const bContext *C, ARegion *region)
 {
   /* draw entirely, view changes should be handled here */
   bAnimContext ac;
-  View2D *v2d = &ar->v2d;
+  View2D *v2d = &region->v2d;
 
   /* clear and setup matrix */
   UI_ThemeClearColor(TH_BACK);
@@ -277,11 +277,11 @@ static void action_channel_region_draw(const bContext *C, ARegion *ar)
 
   /* data */
   if (ANIM_animdata_get_context(C, &ac)) {
-    draw_channel_names((bContext *)C, &ac, ar);
+    draw_channel_names((bContext *)C, &ac, region);
   }
 
   /* channel filter next to scrubbing area */
-  ED_time_scrub_channel_search_draw(C, ar, ac.ads);
+  ED_time_scrub_channel_search_draw(C, region, ac.ads);
 
   /* reset view matrix */
   UI_view2d_view_restore(C);
@@ -290,32 +290,32 @@ static void action_channel_region_draw(const bContext *C, ARegion *ar)
 }
 
 /* add handlers, stuff you only do once or on area/region changes */
-static void action_header_region_init(wmWindowManager *UNUSED(wm), ARegion *ar)
+static void action_header_region_init(wmWindowManager *UNUSED(wm), ARegion *region)
 {
-  ED_region_header_init(ar);
+  ED_region_header_init(region);
 }
 
-static void action_header_region_draw(const bContext *C, ARegion *ar)
+static void action_header_region_draw(const bContext *C, ARegion *region)
 {
-  ED_region_header(C, ar);
+  ED_region_header(C, region);
 }
 
 static void action_channel_region_listener(wmWindow *UNUSED(win),
                                            ScrArea *UNUSED(sa),
-                                           ARegion *ar,
+                                           ARegion *region,
                                            wmNotifier *wmn,
                                            const Scene *UNUSED(scene))
 {
   /* context changes */
   switch (wmn->category) {
     case NC_ANIMATION:
-      ED_region_tag_redraw(ar);
+      ED_region_tag_redraw(region);
       break;
     case NC_SCENE:
       switch (wmn->data) {
         case ND_OB_ACTIVE:
         case ND_FRAME:
-          ED_region_tag_redraw(ar);
+          ED_region_tag_redraw(region);
           break;
       }
       break;
@@ -324,28 +324,28 @@ static void action_channel_region_listener(wmWindow *UNUSED(win),
         case ND_BONE_ACTIVE:
         case ND_BONE_SELECT:
         case ND_KEYS:
-          ED_region_tag_redraw(ar);
+          ED_region_tag_redraw(region);
           break;
         case ND_MODIFIER:
           if (wmn->action == NA_RENAME) {
-            ED_region_tag_redraw(ar);
+            ED_region_tag_redraw(region);
           }
           break;
       }
       break;
     case NC_GPENCIL:
       if (ELEM(wmn->action, NA_RENAME, NA_SELECTED)) {
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
       }
       break;
     case NC_ID:
       if (wmn->action == NA_RENAME) {
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
       }
       break;
     default:
       if (wmn->data == ND_KEYS) {
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
       }
       break;
   }
@@ -356,15 +356,15 @@ static void saction_channel_region_message_subscribe(const struct bContext *UNUS
                                                      struct Scene *UNUSED(scene),
                                                      struct bScreen *screen,
                                                      struct ScrArea *sa,
-                                                     struct ARegion *ar,
+                                                     struct ARegion *region,
                                                      struct wmMsgBus *mbus)
 {
   PointerRNA ptr;
   RNA_pointer_create(&screen->id, &RNA_SpaceDopeSheetEditor, sa->spacedata.first, &ptr);
 
   wmMsgSubscribeValue msg_sub_value_region_tag_redraw = {
-      .owner = ar,
-      .user_data = ar,
+      .owner = region,
+      .user_data = region,
       .notify = ED_region_do_msg_notify_tag_redraw,
   };
 
@@ -398,14 +398,14 @@ static void saction_channel_region_message_subscribe(const struct bContext *UNUS
 
 static void action_main_region_listener(wmWindow *UNUSED(win),
                                         ScrArea *UNUSED(sa),
-                                        ARegion *ar,
+                                        ARegion *region,
                                         wmNotifier *wmn,
                                         const Scene *UNUSED(scene))
 {
   /* context changes */
   switch (wmn->category) {
     case NC_ANIMATION:
-      ED_region_tag_redraw(ar);
+      ED_region_tag_redraw(region);
       break;
     case NC_SCENE:
       switch (wmn->data) {
@@ -414,7 +414,7 @@ static void action_main_region_listener(wmWindow *UNUSED(win),
         case ND_FRAME:
         case ND_FRAME_RANGE:
         case ND_MARKERS:
-          ED_region_tag_redraw(ar);
+          ED_region_tag_redraw(region);
           break;
       }
       break;
@@ -426,30 +426,30 @@ static void action_main_region_listener(wmWindow *UNUSED(win),
         case ND_BONE_ACTIVE:
         case ND_BONE_SELECT:
         case ND_KEYS:
-          ED_region_tag_redraw(ar);
+          ED_region_tag_redraw(region);
           break;
       }
       break;
     case NC_NODE:
       switch (wmn->action) {
         case NA_EDITED:
-          ED_region_tag_redraw(ar);
+          ED_region_tag_redraw(region);
           break;
       }
       break;
     case NC_ID:
       if (wmn->action == NA_RENAME) {
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
       }
       break;
     case NC_SCREEN:
       if (ELEM(wmn->data, ND_LAYER)) {
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
       }
       break;
     default:
       if (wmn->data == ND_KEYS) {
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
       }
       break;
   }
@@ -460,15 +460,15 @@ static void saction_main_region_message_subscribe(const struct bContext *C,
                                                   struct Scene *scene,
                                                   struct bScreen *screen,
                                                   struct ScrArea *sa,
-                                                  struct ARegion *ar,
+                                                  struct ARegion *region,
                                                   struct wmMsgBus *mbus)
 {
   PointerRNA ptr;
   RNA_pointer_create(&screen->id, &RNA_SpaceDopeSheetEditor, sa->spacedata.first, &ptr);
 
   wmMsgSubscribeValue msg_sub_value_region_tag_redraw = {
-      .owner = ar,
-      .user_data = ar,
+      .owner = region,
+      .user_data = region,
       .notify = ED_region_do_msg_notify_tag_redraw,
   };
 
@@ -497,7 +497,7 @@ static void saction_main_region_message_subscribe(const struct bContext *C,
   }
 
   /* Now run the general "channels region" one - since channels and main should be in sync */
-  saction_channel_region_message_subscribe(C, workspace, scene, screen, sa, ar, mbus);
+  saction_channel_region_message_subscribe(C, workspace, scene, screen, sa, region, mbus);
 }
 
 /* editor level listener */
@@ -563,11 +563,11 @@ static void action_listener(wmWindow *UNUSED(win),
           ED_area_tag_redraw(sa);
           break;
         case ND_FRAME_RANGE:
-          for (ARegion *ar = sa->regionbase.first; ar; ar = ar->next) {
-            if (ar->regiontype == RGN_TYPE_WINDOW) {
+          for (ARegion *region = sa->regionbase.first; region; region = region->next) {
+            if (region->regiontype == RGN_TYPE_WINDOW) {
               Scene *scene = wmn->reference;
-              ar->v2d.tot.xmin = (float)(SFRA - 4);
-              ar->v2d.tot.xmax = (float)(EFRA + 4);
+              region->v2d.tot.xmin = (float)(SFRA - 4);
+              region->v2d.tot.xmax = (float)(EFRA + 4);
               break;
             }
           }
@@ -655,8 +655,11 @@ static void action_listener(wmWindow *UNUSED(win),
   }
 }
 
-static void action_header_region_listener(
-    wmWindow *UNUSED(win), ScrArea *sa, ARegion *ar, wmNotifier *wmn, const Scene *UNUSED(scene))
+static void action_header_region_listener(wmWindow *UNUSED(win),
+                                          ScrArea *sa,
+                                          ARegion *region,
+                                          wmNotifier *wmn,
+                                          const Scene *UNUSED(scene))
 {
   SpaceAction *saction = (SpaceAction *)sa->spacedata.first;
 
@@ -665,7 +668,7 @@ static void action_header_region_listener(
     case NC_SCREEN:
       if (saction->mode == SACTCONT_TIMELINE) {
         if (wmn->data == ND_ANIMPLAY) {
-          ED_region_tag_redraw(ar);
+          ED_region_tag_redraw(region);
         }
       }
       break;
@@ -678,21 +681,21 @@ static void action_header_region_listener(
           case ND_FRAME_RANGE:
           case ND_KEYINGSET:
           case ND_RENDER_OPTIONS:
-            ED_region_tag_redraw(ar);
+            ED_region_tag_redraw(region);
             break;
         }
       }
       else {
         switch (wmn->data) {
           case ND_OB_ACTIVE:
-            ED_region_tag_redraw(ar);
+            ED_region_tag_redraw(region);
             break;
         }
       }
       break;
     case NC_ID:
       if (wmn->action == NA_RENAME) {
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
       }
       break;
     case NC_ANIMATION:
@@ -701,12 +704,12 @@ static void action_header_region_listener(
           /* NOTE: for now, this should usually just mean that the filters changed
            *       It may be better if we had a dedicated flag for that though
            */
-          ED_region_tag_redraw(ar);
+          ED_region_tag_redraw(region);
           break;
 
         case ND_KEYFRAME: /* new keyframed added -> active action may have changed */
           // saction->flag |= SACTION_TEMP_NEEDCHANSYNC;
-          ED_region_tag_redraw(ar);
+          ED_region_tag_redraw(region);
           break;
       }
       break;
@@ -714,38 +717,38 @@ static void action_header_region_listener(
 }
 
 /* add handlers, stuff you only do once or on area/region changes */
-static void action_buttons_area_init(wmWindowManager *wm, ARegion *ar)
+static void action_buttons_area_init(wmWindowManager *wm, ARegion *region)
 {
   wmKeyMap *keymap;
 
-  ED_region_panels_init(wm, ar);
+  ED_region_panels_init(wm, region);
 
   keymap = WM_keymap_ensure(wm->defaultconf, "Dopesheet Generic", SPACE_ACTION, 0);
-  WM_event_add_keymap_handler(&ar->handlers, keymap);
+  WM_event_add_keymap_handler(&region->handlers, keymap);
 }
 
-static void action_buttons_area_draw(const bContext *C, ARegion *ar)
+static void action_buttons_area_draw(const bContext *C, ARegion *region)
 {
-  ED_region_panels(C, ar);
+  ED_region_panels(C, region);
 }
 
 static void action_region_listener(wmWindow *UNUSED(win),
                                    ScrArea *UNUSED(sa),
-                                   ARegion *ar,
+                                   ARegion *region,
                                    wmNotifier *wmn,
                                    const Scene *UNUSED(scene))
 {
   /* context changes */
   switch (wmn->category) {
     case NC_ANIMATION:
-      ED_region_tag_redraw(ar);
+      ED_region_tag_redraw(region);
       break;
     case NC_SCENE:
       switch (wmn->data) {
         case ND_OB_ACTIVE:
         case ND_FRAME:
         case ND_MARKERS:
-          ED_region_tag_redraw(ar);
+          ED_region_tag_redraw(region);
           break;
       }
       break;
@@ -754,13 +757,13 @@ static void action_region_listener(wmWindow *UNUSED(win),
         case ND_BONE_ACTIVE:
         case ND_BONE_SELECT:
         case ND_KEYS:
-          ED_region_tag_redraw(ar);
+          ED_region_tag_redraw(region);
           break;
       }
       break;
     default:
       if (wmn->data == ND_KEYS) {
-        ED_region_tag_redraw(ar);
+        ED_region_tag_redraw(region);
       }
       break;
   }
@@ -774,7 +777,7 @@ static void action_refresh(const bContext *C, ScrArea *sa)
    * NOTE: the temp flag is used to indicate when this needs to be done,
    * and will be cleared once handled. */
   if (saction->runtime.flag & SACTION_RUNTIME_FLAG_NEED_CHAN_SYNC) {
-    ARegion *ar;
+    ARegion *region;
 
     /* Perform syncing of channel state incl. selection
      * Active action setting also occurs here
@@ -787,8 +790,8 @@ static void action_refresh(const bContext *C, ScrArea *sa)
      *   or else they don't update [#28962]
      */
     ED_area_tag_redraw(sa);
-    for (ar = sa->regionbase.first; ar; ar = ar->next) {
-      ED_region_tag_redraw(ar);
+    for (region = sa->regionbase.first; region; region = region->next) {
+      ED_region_tag_redraw(region);
     }
   }