source/blender/blenkernel/BKE_screen.h

@@ -163,7 +163,8 @@ typedef struct RegionPollParams {
   const struct ScrArea *area;
   const struct ARegion *region;
 
-  /* For now only WM context members here, could add the scene or even #bContext if needed. */
+  /* Full context, if WM context above is not enough. */
+  const struct bContext *context;
 } RegionPollParams;
 
 typedef struct ARegionType {

source/blender/editors/asset/ED_asset_shelf.h

@@ -17,10 +17,13 @@ struct bContextDataResult;
 struct BlendDataReader;
 struct BlendWriter;
 struct wmWindowManager;
+struct RegionPollParams;
 
 /* -------------------------------------------------------------------- */
 /* Asset Shelf Regions */
 
+bool ED_asset_shelf_poll(const struct RegionPollParams *params);
+
 /** Only needed for #RGN_TYPE_ASSET_SHELF (not #RGN_TYPE_ASSET_SHELF_FOOTER). */
 void ED_asset_shelf_region_listen(const struct wmRegionListenerParams *params);
 void ED_asset_shelf_region_draw(const bContext *C, struct ARegion *region);

source/blender/editors/asset/intern/asset_shelf.cc

@@ -46,6 +46,26 @@ void send_redraw_notifier(const bContext &C)
 /** \name Asset Shelf Regions
  * \{ */
 
+static bool asset_shelf_poll(const bContext *C, const SpaceLink *space_link)
+{
+  const SpaceType *space_type = BKE_spacetype_from_id(space_link->spacetype);
+
+  /* Is there any asset shelf type registered that returns true for it's poll? */
+  LISTBASE_FOREACH (AssetShelfType *, shelf_type, &space_type->asset_shelf_types) {
+    if (shelf_type->poll && shelf_type->poll(C, shelf_type)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+bool ED_asset_shelf_poll(const RegionPollParams *params)
+{
+  return asset_shelf_poll(params->context,
+                          static_cast<SpaceLink *>(params->area->spacedata.first));
+}
+
 static void asset_shelf_region_listen(const wmRegionListenerParams *params)
 {
   ARegion *region = params->region;
@@ -83,17 +103,7 @@ void ED_asset_shelf_region_listen(const wmRegionListenerParams *params)
  */
 static bool asset_shelf_region_header_type_poll(const bContext *C, HeaderType * /*header_type*/)
 {
-  const SpaceLink *space_link = CTX_wm_space_data(C);
+  return asset_shelf_poll(C, CTX_wm_space_data(C));
-  const SpaceType *space_type = BKE_spacetype_from_id(space_link->spacetype);
-
-  /* Is there any asset shelf type registered that returns true for it's poll? */
-  LISTBASE_FOREACH (AssetShelfType *, shelf_type, &space_type->asset_shelf_types) {
-    if (shelf_type->poll && shelf_type->poll(C, shelf_type)) {
-      return true;
-    }
-  }
-
-  return false;
 }
 
 void ED_asset_shelf_region_draw(const bContext *C, ARegion *region)

source/blender/editors/screen/screen_edit.c

@@ -713,7 +713,10 @@ void ED_screens_init(Main *bmain, wmWindowManager *wm)
   }
 }
 
-static bool region_poll(const bScreen *screen, const ScrArea *area, const ARegion *region)
+static bool region_poll(const bContext *C,
+                        const bScreen *screen,
+                        const ScrArea *area,
+                        const ARegion *region)
 {
   if (!region->type || !region->type->poll) {
     /* Show region by default. */
@@ -724,20 +727,27 @@ static bool region_poll(const bScreen *screen, const ScrArea *area, const ARegio
   params.screen = screen;
   params.area = area;
   params.region = region;
+  params.context = C;
 
   return region->type->poll(&params);
 }
 
 static void screen_regions_poll(bContext *C, const wmWindow *win, bScreen *screen)
 {
+  ScrArea *prev_area = CTX_wm_area(C);
+  ARegion *prev_region = CTX_wm_region(C);
+
   bool any_changed = false;
   ED_screen_areas_iter (win, screen, area) {
+    CTX_wm_area_set(C, area);
+
     LISTBASE_FOREACH (ARegion *, region, &area->regionbase) {
       const int old_region_flag = region->flag;
 
       region->flag &= ~RGN_FLAG_POLL_FAILED;
 
-      if (region_poll(screen, area, region) == false) {
+      CTX_wm_region_set(C, region);
+      if (region_poll(C, screen, area, region) == false) {
         region->flag |= RGN_FLAG_POLL_FAILED;
       }
 
@@ -754,6 +764,8 @@ static void screen_regions_poll(bContext *C, const wmWindow *win, bScreen *scree
   if (any_changed) {
     screen->do_refresh = true;
   }
+  CTX_wm_area_set(C, prev_area);
+  CTX_wm_region_set(C, prev_region);
 }
 
 void ED_screen_ensure_updated(bContext *C, wmWindowManager *wm, wmWindow *win, bScreen *screen)

source/blender/editors/space_view3d/space_view3d.cc

@@ -2244,6 +2244,7 @@ void ED_spacetype_view3d()
   art->keymapflag = ED_KEYMAP_UI | ED_KEYMAP_ASSET_SHELF | ED_KEYMAP_VIEW2D | ED_KEYMAP_FRAMES |
                     ED_KEYMAP_HEADER;
   art->listener = ED_asset_shelf_region_listen;
+  art->poll = ED_asset_shelf_poll;
   art->context = view3d_asset_shelf_context;
   art->init = view3d_header_region_init;
   art->draw = ED_asset_shelf_region_draw;
@@ -2256,6 +2257,7 @@ void ED_spacetype_view3d()
   art->prefsizey = HEADERY;
   art->keymapflag = ED_KEYMAP_UI | ED_KEYMAP_ASSET_SHELF | ED_KEYMAP_VIEW2D | ED_KEYMAP_FOOTER;
   art->init = ED_asset_shelf_footer_region_init;
+  art->poll = ED_asset_shelf_poll;
   art->draw = ED_asset_shelf_footer_region;
   art->listener = ED_asset_shelf_footer_region_listen;
   art->context = view3d_asset_shelf_context;