Cleanup: decentralize .blend I/O for space types

This adds callbacks to `SpaceType` to make each editor responsible to
manage their own .blend I/O, and moves relevant code from `screen.c`
to the editors files.

Differential Revision: D11069

2 files changed, 26 insertions, 590 deletions

diff --git a/source/blender/blenkernel/BKE_screen.h b/source/blender/blenkernel/BKE_screen.h
index 62b04785983..9a7d2bde810 100644
--- a/source/blender/blenkernel/BKE_screen.h
+++ b/source/blender/blenkernel/BKE_screen.h
@@ -108,6 +108,23 @@ typedef struct SpaceType {
   void (*space_subtype_set)(struct ScrArea *area, int value);
   void (*space_subtype_item_extend)(struct bContext *C, EnumPropertyItem **item, int *totitem);
 
+  /**
+   * Update pointers for all structs directly owned by this space.
+   */
+  void (*blend_read_data)(struct BlendDataReader *reader, struct SpaceLink *space_link);
+
+  /**
+   * Update pointers to other id data blocks.
+   */
+  void (*blend_read_lib)(struct BlendLibReader *reader,
+                         struct ID *parent_id,
+                         struct SpaceLink *space_link);
+
+  /**
+   * Write all structs that should be saved in a .blend file.
+   */
+  void (*blend_write)(struct BlendWriter *writer, struct SpaceLink *space_link);
+
   /* region type definitions */
   ListBase regiontypes;
 
diff --git a/source/blender/blenkernel/intern/screen.c b/source/blender/blenkernel/intern/screen.c
index 03f0c3ff1e9..8517995a0d8 100644
--- a/source/blender/blenkernel/intern/screen.c
+++ b/source/blender/blenkernel/intern/screen.c
@@ -1123,59 +1123,6 @@ static void write_uilist(BlendWriter *writer, uiList *ui_list)
   }
 }
 
-static void write_space_outliner(BlendWriter *writer, const SpaceOutliner *space_outliner)
-{
-  BLI_mempool *ts = space_outliner->treestore;
-
-  if (ts) {
-    const int elems = BLI_mempool_len(ts);
-    /* linearize mempool to array */
-    TreeStoreElem *data = elems ? BLI_mempool_as_arrayN(ts, "TreeStoreElem") : NULL;
-
-    if (data) {
-      BLO_write_struct(writer, SpaceOutliner, space_outliner);
-
-      /* To store #TreeStore (instead of the mempool), two unique memory addresses are needed,
-       * which can be used to identify the data on read:
-       * 1) One for the #TreeStore data itself.
-       * 2) One for the array of #TreeStoreElem's inside #TreeStore (#TreeStore.data).
-       *
-       * For 1) we just use the mempool's address (#SpaceOutliner::treestore).
-       * For 2) we don't have such a direct choice. We can't just use the array's address from
-       * above, since that may not be unique over all Outliners. So instead use an address relative
-       * to 1).
-       */
-      /* TODO the mempool could be moved to #SpaceOutliner_Runtime so that #SpaceOutliner could
-       * hold the #TreeStore directly. */
-
-      /* Address relative to the tree-store, as noted above.  */
-      void *data_addr = (void *)POINTER_OFFSET(ts, sizeof(void *));
-      /* There should be plenty of memory addresses within the mempool data that we can point into,
-       * just double-check we don't potentially end up with a memory address that another DNA
-       * struct might use. Assumes BLI_mempool uses the guarded allocator. */
-      BLI_assert(MEM_allocN_len(ts) >= sizeof(void *) * 2);
-
-      TreeStore ts_flat = {0};
-      ts_flat.usedelem = elems;
-      ts_flat.totelem = elems;
-      ts_flat.data = data_addr;
-
-      BLO_write_struct_at_address(writer, TreeStore, ts, &ts_flat);
-      BLO_write_struct_array_at_address(writer, TreeStoreElem, elems, data_addr, data);
-
-      MEM_freeN(data);
-    }
-    else {
-      SpaceOutliner space_outliner_flat = *space_outliner;
-      space_outliner_flat.treestore = NULL;
-      BLO_write_struct_at_address(writer, SpaceOutliner, space_outliner, &space_outliner_flat);
-    }
-  }
-  else {
-    BLO_write_struct(writer, SpaceOutliner, space_outliner);
-  }
-}
-
 static void write_panel_list(BlendWriter *writer, ListBase *lb)
 {
   LISTBASE_FOREACH (Panel *, panel, lb) {
@@ -1208,146 +1155,9 @@ static void write_area(BlendWriter *writer, ScrArea *area)
       write_region(writer, region, sl->spacetype);
     }
 
-    if (sl->spacetype == SPACE_VIEW3D) {
-      View3D *v3d = (View3D *)sl;
-      BLO_write_struct(writer, View3D, v3d);
-
-      if (v3d->localvd) {
-        BLO_write_struct(writer, View3D, v3d->localvd);
-      }
-
-      BKE_screen_view3d_shading_blend_write(writer, &v3d->shading);
-    }
-    else if (sl->spacetype == SPACE_GRAPH) {
-      SpaceGraph *sipo = (SpaceGraph *)sl;
-      ListBase tmpGhosts = sipo->runtime.ghost_curves;
-
-      /* temporarily disable ghost curves when saving */
-      BLI_listbase_clear(&sipo->runtime.ghost_curves);
-
-      BLO_write_struct(writer, SpaceGraph, sl);
-      if (sipo->ads) {
-        BLO_write_struct(writer, bDopeSheet, sipo->ads);
-      }
-
-      /* reenable ghost curves */
-      sipo->runtime.ghost_curves = tmpGhosts;
-    }
-    else if (sl->spacetype == SPACE_PROPERTIES) {
-      BLO_write_struct(writer, SpaceProperties, sl);
-    }
-    else if (sl->spacetype == SPACE_FILE) {
-      SpaceFile *sfile = (SpaceFile *)sl;
-
-      BLO_write_struct(writer, SpaceFile, sl);
-      if (sfile->params) {
-        BLO_write_struct(writer, FileSelectParams, sfile->params);
-      }
-      if (sfile->asset_params) {
-        BLO_write_struct(writer, FileAssetSelectParams, sfile->asset_params);
-      }
-    }
-    else if (sl->spacetype == SPACE_SEQ) {
-      BLO_write_struct(writer, SpaceSeq, sl);
-    }
-    else if (sl->spacetype == SPACE_OUTLINER) {
-      SpaceOutliner *space_outliner = (SpaceOutliner *)sl;
-      write_space_outliner(writer, space_outliner);
-    }
-    else if (sl->spacetype == SPACE_IMAGE) {
-      BLO_write_struct(writer, SpaceImage, sl);
-    }
-    else if (sl->spacetype == SPACE_TEXT) {
-      BLO_write_struct(writer, SpaceText, sl);
-    }
-    else if (sl->spacetype == SPACE_SCRIPT) {
-      SpaceScript *scr = (SpaceScript *)sl;
-      scr->but_refs = NULL;
-      BLO_write_struct(writer, SpaceScript, sl);
-    }
-    else if (sl->spacetype == SPACE_ACTION) {
-      BLO_write_struct(writer, SpaceAction, sl);
-    }
-    else if (sl->spacetype == SPACE_NLA) {
-      SpaceNla *snla = (SpaceNla *)sl;
-
-      BLO_write_struct(writer, SpaceNla, snla);
-      if (snla->ads) {
-        BLO_write_struct(writer, bDopeSheet, snla->ads);
-      }
-    }
-    else if (sl->spacetype == SPACE_NODE) {
-      SpaceNode *snode = (SpaceNode *)sl;
-      BLO_write_struct(writer, SpaceNode, snode);
-
-      LISTBASE_FOREACH (bNodeTreePath *, path, &snode->treepath) {
-        BLO_write_struct(writer, bNodeTreePath, path);
-      }
-    }
-    else if (sl->spacetype == SPACE_CONSOLE) {
-      SpaceConsole *con = (SpaceConsole *)sl;
-
-      LISTBASE_FOREACH (ConsoleLine *, cl, &con->history) {
-        /* 'len_alloc' is invalid on write, set from 'len' on read */
-        BLO_write_struct(writer, ConsoleLine, cl);
-        BLO_write_raw(writer, (size_t)cl->len + 1, cl->line);
-      }
-      BLO_write_struct(writer, SpaceConsole, sl);
-    }
-    else if (sl->spacetype == SPACE_TOPBAR) {
-      BLO_write_struct(writer, SpaceTopBar, sl);
-    }
-    else if (sl->spacetype == SPACE_STATUSBAR) {
-      BLO_write_struct(writer, SpaceStatusBar, sl);
-    }
-    else if (sl->spacetype == SPACE_USERPREF) {
-      BLO_write_struct(writer, SpaceUserPref, sl);
-    }
-    else if (sl->spacetype == SPACE_CLIP) {
-      BLO_write_struct(writer, SpaceClip, sl);
-    }
-    else if (sl->spacetype == SPACE_INFO) {
-      BLO_write_struct(writer, SpaceInfo, sl);
-    }
-    else if (sl->spacetype == SPACE_SPREADSHEET) {
-      BLO_write_struct(writer, SpaceSpreadsheet, sl);
-      SpaceSpreadsheet *sspreadsheet = (SpaceSpreadsheet *)sl;
-
-      LISTBASE_FOREACH (SpreadsheetRowFilter *, row_filter, &sspreadsheet->row_filters) {
-        BLO_write_struct(writer, SpreadsheetRowFilter, row_filter);
-        BLO_write_string(writer, row_filter->value_string);
-      }
-
-      LISTBASE_FOREACH (SpreadsheetColumn *, column, &sspreadsheet->columns) {
-        BLO_write_struct(writer, SpreadsheetColumn, column);
-        BLO_write_struct(writer, SpreadsheetColumnID, column->id);
-        BLO_write_string(writer, column->id->name);
-        /* While the display name is technically runtime data, we write it here, otherwise the row
-         * filters might not now their type if their region draws before the main region.
-         * This would ideally be cleared here. */
-        BLO_write_string(writer, column->display_name);
-      }
-      LISTBASE_FOREACH (SpreadsheetContext *, context, &sspreadsheet->context_path) {
-        switch (context->type) {
-          case SPREADSHEET_CONTEXT_OBJECT: {
-            SpreadsheetContextObject *object_context = (SpreadsheetContextObject *)context;
-            BLO_write_struct(writer, SpreadsheetContextObject, object_context);
-            break;
-          }
-          case SPREADSHEET_CONTEXT_MODIFIER: {
-            SpreadsheetContextModifier *modifier_context = (SpreadsheetContextModifier *)context;
-            BLO_write_struct(writer, SpreadsheetContextModifier, modifier_context);
-            BLO_write_string(writer, modifier_context->modifier_name);
-            break;
-          }
-          case SPREADSHEET_CONTEXT_NODE: {
-            SpreadsheetContextNode *node_context = (SpreadsheetContextNode *)context;
-            BLO_write_struct(writer, SpreadsheetContextNode, node_context);
-            BLO_write_string(writer, node_context->node_name);
-            break;
-          }
-        }
-      }
+    SpaceType *space_type = BKE_spacetype_from_id(sl->spacetype);
+    if (space_type && space_type->blend_write) {
+      space_type->blend_write(writer, sl);
     }
   }
 }
@@ -1523,225 +1333,9 @@ static void direct_link_area(BlendDataReader *reader, ScrArea *area)
       direct_link_region(reader, region, sl->spacetype);
     }
 
-    if (sl->spacetype == SPACE_VIEW3D) {
-      View3D *v3d = (View3D *)sl;
-
-      memset(&v3d->runtime, 0x0, sizeof(v3d->runtime));
-
-      if (v3d->gpd) {
-        BLO_read_data_address(reader, &v3d->gpd);
-        BKE_gpencil_blend_read_data(reader, v3d->gpd);
-      }
-      BLO_read_data_address(reader, &v3d->localvd);
-
-      /* render can be quite heavy, set to solid on load */
-      if (v3d->shading.type == OB_RENDER) {
-        v3d->shading.type = OB_SOLID;
-      }
-      v3d->shading.prev_type = OB_SOLID;
-
-      BKE_screen_view3d_shading_blend_read_data(reader, &v3d->shading);
-
-      BKE_screen_view3d_do_versions_250(v3d, &sl->regionbase);
-    }
-    else if (sl->spacetype == SPACE_GRAPH) {
-      SpaceGraph *sipo = (SpaceGraph *)sl;
-
-      BLO_read_data_address(reader, &sipo->ads);
-      memset(&sipo->runtime, 0x0, sizeof(sipo->runtime));
-    }
-    else if (sl->spacetype == SPACE_NLA) {
-      SpaceNla *snla = (SpaceNla *)sl;
-
-      BLO_read_data_address(reader, &snla->ads);
-    }
-    else if (sl->spacetype == SPACE_OUTLINER) {
-      SpaceOutliner *space_outliner = (SpaceOutliner *)sl;
-
-      /* use #BLO_read_get_new_data_address_no_us and do not free old memory avoiding double
-       * frees and use of freed memory. this could happen because of a
-       * bug fixed in revision 58959 where the treestore memory address
-       * was not unique */
-      TreeStore *ts = BLO_read_get_new_data_address_no_us(reader, space_outliner->treestore);
-      space_outliner->treestore = NULL;
-      if (ts) {
-        TreeStoreElem *elems = BLO_read_get_new_data_address_no_us(reader, ts->data);
-
-        space_outliner->treestore = BLI_mempool_create(
-            sizeof(TreeStoreElem), ts->usedelem, 512, BLI_MEMPOOL_ALLOW_ITER);
-        if (ts->usedelem && elems) {
-          for (int i = 0; i < ts->usedelem; i++) {
-            TreeStoreElem *new_elem = BLI_mempool_alloc(space_outliner->treestore);
-            *new_elem = elems[i];
-          }
-        }
-        /* we only saved what was used */
-        space_outliner->storeflag |= SO_TREESTORE_CLEANUP; /* at first draw */
-      }
-      space_outliner->tree.first = space_outliner->tree.last = NULL;
-      space_outliner->runtime = NULL;
-    }
-    else if (sl->spacetype == SPACE_IMAGE) {
-      SpaceImage *sima = (SpaceImage *)sl;
-
-      sima->iuser.scene = NULL;
-      sima->scopes.waveform_1 = NULL;
-      sima->scopes.waveform_2 = NULL;
-      sima->scopes.waveform_3 = NULL;
-      sima->scopes.vecscope = NULL;
-      sima->scopes.ok = 0;
-
-      /* WARNING: gpencil data is no longer stored directly in sima after 2.5
-       * so sacrifice a few old files for now to avoid crashes with new files!
-       * committed: r28002 */
-#if 0
-      sima->gpd = newdataadr(fd, sima->gpd);
-      if (sima->gpd) {
-        BKE_gpencil_blend_read_data(fd, sima->gpd);
-      }
-#endif
-    }
-    else if (sl->spacetype == SPACE_NODE) {
-      SpaceNode *snode = (SpaceNode *)sl;
-
-      if (snode->gpd) {
-        BLO_read_data_address(reader, &snode->gpd);
-        BKE_gpencil_blend_read_data(reader, snode->gpd);
-      }
-
-      BLO_read_list(reader, &snode->treepath);
-      snode->edittree = NULL;
-      snode->runtime = NULL;
-    }
-    else if (sl->spacetype == SPACE_TEXT) {
-      SpaceText *st = (SpaceText *)sl;
-      memset(&st->runtime, 0x0, sizeof(st->runtime));
-    }
-    else if (sl->spacetype == SPACE_SEQ) {
-      SpaceSeq *sseq = (SpaceSeq *)sl;
-
-      /* grease pencil data is not a direct data and can't be linked from direct_link*
-       * functions, it should be linked from lib_link* functions instead
-       *
-       * otherwise it'll lead to lost grease data on open because it'll likely be
-       * read from file after all other users of grease pencil and newdataadr would
-       * simple return NULL here (sergey)
-       */
-#if 0
-      if (sseq->gpd) {
-        sseq->gpd = newdataadr(fd, sseq->gpd);
-        BKE_gpencil_blend_read_data(fd, sseq->gpd);
-      }
-#endif
-      sseq->scopes.reference_ibuf = NULL;
-      sseq->scopes.zebra_ibuf = NULL;
-      sseq->scopes.waveform_ibuf = NULL;
-      sseq->scopes.sep_waveform_ibuf = NULL;
-      sseq->scopes.vector_ibuf = NULL;
-      sseq->scopes.histogram_ibuf = NULL;
-      memset(&sseq->runtime, 0x0, sizeof(sseq->runtime));
-    }
-    else if (sl->spacetype == SPACE_PROPERTIES) {
-      SpaceProperties *sbuts = (SpaceProperties *)sl;
-
-      sbuts->path = NULL;
-      sbuts->texuser = NULL;
-      sbuts->mainbo = sbuts->mainb;
-      sbuts->mainbuser = sbuts->mainb;
-      sbuts->runtime = NULL;
-    }
-    else if (sl->spacetype == SPACE_CONSOLE) {
-      SpaceConsole *sconsole = (SpaceConsole *)sl;
-
-      BLO_read_list(reader, &sconsole->scrollback);
-      BLO_read_list(reader, &sconsole->history);
-
-      /* Comma expressions, (e.g. expr1, expr2, expr3) evaluate each expression,
-       * from left to right.  the right-most expression sets the result of the comma
-       * expression as a whole. */
-      LISTBASE_FOREACH_MUTABLE (ConsoleLine *, cl, &sconsole->history) {
-        BLO_read_data_address(reader, &cl->line);
-        if (cl->line) {
-          /* The allocated length is not written, so reset here. */
-          cl->len_alloc = cl->len + 1;
-        }
-        else {
-          BLI_remlink(&sconsole->history, cl);
-          MEM_freeN(cl);
-        }
-      }
-    }
-    else if (sl->spacetype == SPACE_FILE) {
-      SpaceFile *sfile = (SpaceFile *)sl;
-
-      /* this sort of info is probably irrelevant for reloading...
-       * plus, it isn't saved to files yet!
-       */
-      sfile->folders_prev = sfile->folders_next = NULL;
-      BLI_listbase_clear(&sfile->folder_histories);
-      sfile->files = NULL;
-      sfile->layout = NULL;
-      sfile->op = NULL;
-      sfile->previews_timer = NULL;
-      sfile->tags = 0;
-      sfile->runtime = NULL;
-      BLO_read_data_address(reader, &sfile->params);
-      BLO_read_data_address(reader, &sfile->asset_params);
-      if (sfile->params) {
-        sfile->params->rename_id = NULL;
-      }
-      if (sfile->asset_params) {
-        sfile->asset_params->base_params.rename_id = NULL;
-      }
-    }
-    else if (sl->spacetype == SPACE_ACTION) {
-      SpaceAction *saction = (SpaceAction *)sl;
-
-      memset(&saction->runtime, 0x0, sizeof(saction->runtime));
-    }
-    else if (sl->spacetype == SPACE_CLIP) {
-      SpaceClip *sclip = (SpaceClip *)sl;
-
-      sclip->scopes.track_search = NULL;
-      sclip->scopes.track_preview = NULL;
-      sclip->scopes.ok = 0;
-    }
-    else if (sl->spacetype == SPACE_SPREADSHEET) {
-      SpaceSpreadsheet *sspreadsheet = (SpaceSpreadsheet *)sl;
-
-      sspreadsheet->runtime = NULL;
-      BLO_read_list(reader, &sspreadsheet->row_filters);
-      LISTBASE_FOREACH (SpreadsheetRowFilter *, row_filter, &sspreadsheet->row_filters) {
-        BLO_read_data_address(reader, &row_filter->value_string);
-      }
-      BLO_read_list(reader, &sspreadsheet->columns);
-      LISTBASE_FOREACH (SpreadsheetColumn *, column, &sspreadsheet->columns) {
-        BLO_read_data_address(reader, &column->id);
-        BLO_read_data_address(reader, &column->id->name);
-        /* While the display name is technically runtime data, it is loaded here, otherwise the row
-         * filters might not now their type if their region draws before the main region.
-         * This would ideally be cleared here. */
-        BLO_read_data_address(reader, &column->display_name);
-      }
-
-      BLO_read_list(reader, &sspreadsheet->context_path);
-      LISTBASE_FOREACH (SpreadsheetContext *, context, &sspreadsheet->context_path) {
-        switch (context->type) {
-          case SPREADSHEET_CONTEXT_NODE: {
-            SpreadsheetContextNode *node_context = (SpreadsheetContextNode *)context;
-            BLO_read_data_address(reader, &node_context->node_name);
-            break;
-          }
-          case SPREADSHEET_CONTEXT_MODIFIER: {
-            SpreadsheetContextModifier *modifier_context = (SpreadsheetContextModifier *)context;
-            BLO_read_data_address(reader, &modifier_context->modifier_name);
-            break;
-          }
-          case SPREADSHEET_CONTEXT_OBJECT: {
-            break;
-          }
-        }
-      }
+    SpaceType *space_type = BKE_spacetype_from_id(sl->spacetype);
+    if (space_type && space_type->blend_read_data) {
+      space_type->blend_read_data(reader, sl);
     }
   }
 
@@ -1785,185 +1379,10 @@ void BKE_screen_area_blend_read_lib(BlendLibReader *reader, ID *parent_id, ScrAr
   memset(&area->runtime, 0x0, sizeof(area->runtime));
 
   LISTBASE_FOREACH (SpaceLink *, sl, &area->spacedata) {
-    switch (sl->spacetype) {
-      case SPACE_VIEW3D: {
-        View3D *v3d = (View3D *)sl;
+    SpaceType *space_type = BKE_spacetype_from_id(sl->spacetype);
 
-        BLO_read_id_address(reader, parent_id->lib, &v3d->camera);
-        BLO_read_id_address(reader, parent_id->lib, &v3d->ob_center);
-
-        if (v3d->localvd) {
-          BLO_read_id_address(reader, parent_id->lib, &v3d->localvd->camera);
-        }
-        break;
-      }
-      case SPACE_GRAPH: {
-        SpaceGraph *sipo = (SpaceGraph *)sl;
-        bDopeSheet *ads = sipo->ads;
-
-        if (ads) {
-          BLO_read_id_address(reader, parent_id->lib, &ads->source);
-          BLO_read_id_address(reader, parent_id->lib, &ads->filter_grp);
-        }
-        break;
-      }
-      case SPACE_PROPERTIES: {
-        SpaceProperties *sbuts = (SpaceProperties *)sl;
-        BLO_read_id_address(reader, parent_id->lib, &sbuts->pinid);
-        if (sbuts->pinid == NULL) {
-          sbuts->flag &= ~SB_PIN_CONTEXT;
-        }
-        break;
-      }
-      case SPACE_FILE: {
-        SpaceFile *sfile = (SpaceFile *)sl;
-        sfile->tags |= FILE_TAG_REBUILD_MAIN_FILES;
-        break;
-      }
-      case SPACE_ACTION: {
-        SpaceAction *saction = (SpaceAction *)sl;
-        bDopeSheet *ads = &saction->ads;
-
-        if (ads) {
-          BLO_read_id_address(reader, parent_id->lib, &ads->source);
-          BLO_read_id_address(reader, parent_id->lib, &ads->filter_grp);
-        }
-
-        BLO_read_id_address(reader, parent_id->lib, &saction->action);
-        break;
-      }
-      case SPACE_IMAGE: {
-        SpaceImage *sima = (SpaceImage *)sl;
-
-        BLO_read_id_address(reader, parent_id->lib, &sima->image);
-        BLO_read_id_address(reader, parent_id->lib, &sima->mask_info.mask);
-
-        /* NOTE: pre-2.5, this was local data not lib data, but now we need this as lib data
-         * so fingers crossed this works fine!
-         */
-        BLO_read_id_address(reader, parent_id->lib, &sima->gpd);
-        break;
-      }
-      case SPACE_SEQ: {
-        SpaceSeq *sseq = (SpaceSeq *)sl;
-
-        /* NOTE: pre-2.5, this was local data not lib data, but now we need this as lib data
-         * so fingers crossed this works fine!
-         */
-        BLO_read_id_address(reader, parent_id->lib, &sseq->gpd);
-        break;
-      }
-      case SPACE_NLA: {
-        SpaceNla *snla = (SpaceNla *)sl;
-        bDopeSheet *ads = snla->ads;
-
-        if (ads) {
-          BLO_read_id_address(reader, parent_id->lib, &ads->source);
-          BLO_read_id_address(reader, parent_id->lib, &ads->filter_grp);
-        }
-        break;
-      }
-      case SPACE_TEXT: {
-        SpaceText *st = (SpaceText *)sl;
-
-        BLO_read_id_address(reader, parent_id->lib, &st->text);
-        break;
-      }
-      case SPACE_SCRIPT: {
-        SpaceScript *scpt = (SpaceScript *)sl;
-        /*scpt->script = NULL; - 2.45 set to null, better re-run the script */
-        if (scpt->script) {
-          BLO_read_id_address(reader, parent_id->lib, &scpt->script);
-          if (scpt->script) {
-            SCRIPT_SET_NULL(scpt->script);
-          }
-        }
-        break;
-      }
-      case SPACE_OUTLINER: {
-        SpaceOutliner *space_outliner = (SpaceOutliner *)sl;
-
-        if (space_outliner->treestore) {
-          TreeStoreElem *tselem;
-          BLI_mempool_iter iter;
-
-          BLI_mempool_iternew(space_outliner->treestore, &iter);
-          while ((tselem = BLI_mempool_iterstep(&iter))) {
-            BLO_read_id_address(reader, NULL, &tselem->id);
-          }
-          /* rebuild hash table, because it depends on ids too */
-          space_outliner->storeflag |= SO_TREESTORE_REBUILD;
-        }
-        break;
-      }
-      case SPACE_NODE: {
-        SpaceNode *snode = (SpaceNode *)sl;
-
-        /* node tree can be stored locally in id too, link this first */
-        BLO_read_id_address(reader, parent_id->lib, &snode->id);
-        BLO_read_id_address(reader, parent_id->lib, &snode->from);
-
-        bNodeTree *ntree = snode->id ? ntreeFromID(snode->id) : NULL;
-        if (ntree) {
-          snode->nodetree = ntree;
-        }
-        else {
-          BLO_read_id_address(reader, parent_id->lib, &snode->nodetree);
-        }
-
-        bNodeTreePath *path;
-        for (path = snode->treepath.first; path; path = path->next) {
-          if (path == snode->treepath.first) {
-            /* first nodetree in path is same as snode->nodetree */
-            path->nodetree = snode->nodetree;
-          }
-          else {
-            BLO_read_id_address(reader, parent_id->lib, &path->nodetree);
-          }
-
-          if (!path->nodetree) {
-            break;
-          }
-        }
-
-        /* remaining path entries are invalid, remove */
-        bNodeTreePath *path_next;
-        for (; path; path = path_next) {
-          path_next = path->next;
-
-          BLI_remlink(&snode->treepath, path);
-          MEM_freeN(path);
-        }
-
-        /* edittree is just the last in the path,
-         * set this directly since the path may have been shortened above */
-        if (snode->treepath.last) {
-          path = snode->treepath.last;
-          snode->edittree = path->nodetree;
-        }
-        else {
-          snode->edittree = NULL;
-        }
-        break;
-      }
-      case SPACE_CLIP: {
-        SpaceClip *sclip = (SpaceClip *)sl;
-        BLO_read_id_address(reader, parent_id->lib, &sclip->clip);
-        BLO_read_id_address(reader, parent_id->lib, &sclip->mask_info.mask);
-        break;
-      }
-      case SPACE_SPREADSHEET: {
-        SpaceSpreadsheet *sspreadsheet = (SpaceSpreadsheet *)sl;
-        LISTBASE_FOREACH (SpreadsheetContext *, context, &sspreadsheet->context_path) {
-          if (context->type == SPREADSHEET_CONTEXT_OBJECT) {
-            BLO_read_id_address(
-                reader, parent_id->lib, &((SpreadsheetContextObject *)context)->object);
-          }
-        }
-        break;
-      }
-      default:
-        break;
+    if (space_type && space_type->blend_read_lib) {
+      space_type->blend_read_lib(reader, parent_id, sl);
     }
   }
 }