Assets: Expose active asset library in context

For the Asset Browser, this returns the active asset library of the
Asset Browser, otherwise it returns the one active in the workspace.

This gives simple access to the active asset library from UI code and
Python scripts. For example the upcoming Pose Library add-on uses this,
as well as the upcoming asset view template.

source/blender/blenkernel/BKE_context.h

@@ -357,6 +357,8 @@ int CTX_data_visible_gpencil_layers(const bContext *C, ListBase *list);
 int CTX_data_editable_gpencil_layers(const bContext *C, ListBase *list);
 int CTX_data_editable_gpencil_strokes(const bContext *C, ListBase *list);
 
+const struct AssetLibraryReference *CTX_wm_asset_library(const bContext *C);
+
 bool CTX_wm_interface_locked(const bContext *C);
 
 /* Gets pointer to the dependency graph.

source/blender/blenkernel/intern/context.c

@@ -1448,6 +1448,11 @@ int CTX_data_editable_gpencil_strokes(const bContext *C, ListBase *list)
   return ctx_data_collection_get(C, "editable_gpencil_strokes", list);
 }
 
+const AssetLibraryReference *CTX_wm_asset_library(const bContext *C)
+{
+  return ctx_data_pointer_get(C, "asset_library");
+}
+
 Depsgraph *CTX_data_depsgraph_pointer(const bContext *C)
 {
   Main *bmain = CTX_data_main(C);

source/blender/editors/screen/screen_context.c

@@ -36,6 +36,7 @@
 #include "DNA_sequence_types.h"
 #include "DNA_space_types.h"
 #include "DNA_windowmanager_types.h"
+#include "DNA_workspace_types.h"
 
 #include "BLI_ghash.h"
 #include "BLI_listbase.h"
@@ -111,6 +112,7 @@ const char *screen_context_dir[] = {
     "selected_editable_fcurves",
     "active_editable_fcurve",
     "selected_editable_keyframes",
+    "asset_library",
     NULL,
 };
 
@@ -1024,6 +1026,14 @@ static eContextResult screen_ctx_selected_editable_keyframes(const bContext *C,
   return CTX_RESULT_NO_DATA;
 }
 
+static eContextResult screen_ctx_asset_library(const bContext *C, bContextDataResult *result)
+{
+  WorkSpace *workspace = CTX_wm_workspace(C);
+  CTX_data_pointer_set(
+      result, &workspace->id, &RNA_AssetLibraryReference, &workspace->active_asset_library);
+  return CTX_RESULT_OK;
+}
+
 /* Registry of context callback functions. */
 
 typedef eContextResult (*context_callback)(const bContext *C, bContextDataResult *result);
@@ -1098,6 +1108,7 @@ static void ensure_ed_screen_context_functions(void)
   register_context_function("selected_visible_fcurves", screen_ctx_selected_visible_fcurves);
   register_context_function("active_editable_fcurve", screen_ctx_active_editable_fcurve);
   register_context_function("selected_editable_keyframes", screen_ctx_selected_editable_keyframes);
+  register_context_function("asset_library", screen_ctx_asset_library);
 }
 
 /* Entry point for the screen context. */

source/blender/editors/space_file/space_file.c

@@ -868,7 +868,12 @@ static void file_space_subtype_item_extend(bContext *UNUSED(C),
   }
 }
 
-static const char *file_context_dir[] = {"active_file", "id", NULL};
+static const char *file_context_dir[] = {
+    "active_file",
+    "asset_library",
+    "id",
+    NULL,
+};
 
 static int /*eContextResult*/ file_context(const bContext *C,
                                            const char *member,
@@ -899,6 +904,23 @@ static int /*eContextResult*/ file_context(const bContext *C,
     CTX_data_pointer_set(result, &screen->id, &RNA_FileSelectEntry, file);
     return CTX_RESULT_OK;
   }
+  if (CTX_data_equals(member, "asset_library")) {
+    FileAssetSelectParams *asset_params = ED_fileselect_get_asset_params(sfile);
+    if (!asset_params) {
+      return CTX_RESULT_NO_DATA;
+    }
+
+    BLI_STATIC_ASSERT(offsetof(FileSelectAssetLibraryUID, type) ==
+                          offsetof(AssetLibraryReference, type),
+                      "Expected FileSelectAssetLibraryUID to match AssetLibraryReference");
+    BLI_STATIC_ASSERT(offsetof(FileSelectAssetLibraryUID, custom_library_index) ==
+                          offsetof(AssetLibraryReference, custom_library_index),
+                      "Expected FileSelectAssetLibraryUID to match AssetLibraryReference");
+
+    CTX_data_pointer_set(
+        result, &screen->id, &RNA_AssetLibraryReference, &asset_params->asset_library);
+    return CTX_RESULT_OK;
+  }
   if (CTX_data_equals(member, "id")) {
     const FileDirEntry *file = filelist_file(sfile->files, params->active_file);
     if (file == NULL) {