Cleanup: Outliner orphan data display mode

No functional changes. Code is ported to C++ with additional cleanups to
the logic and variable names.

Differential Revision: https://developer.blender.org/D9741

3 files changed, 115 insertions, 0 deletions

diff --git a/source/blender/editors/space_outliner/tree/tree_display.cc b/source/blender/editors/space_outliner/tree/tree_display.cc
index 1419295c81c..bf976d79103 100644
--- a/source/blender/editors/space_outliner/tree/tree_display.cc
+++ b/source/blender/editors/space_outliner/tree/tree_display.cc
@@ -40,7 +40,9 @@ TreeDisplay *outliner_tree_display_create(eSpaceOutliner_Mode mode, SpaceOutline
       tree_display = new TreeDisplaySequencer(*space_outliner);
       break;
     case SO_DATA_API:
+      break;
     case SO_ID_ORPHANS:
+      tree_display = new TreeDisplayIDOrphans(*space_outliner);
       break;
     case SO_VIEW_LAYER:
       tree_display = new TreeDisplayViewLayer(*space_outliner);
diff --git a/source/blender/editors/space_outliner/tree/tree_display.hh b/source/blender/editors/space_outliner/tree/tree_display.hh
index 0901451e5d3..a933a8d7609 100644
--- a/source/blender/editors/space_outliner/tree/tree_display.hh
+++ b/source/blender/editors/space_outliner/tree/tree_display.hh
@@ -134,4 +134,20 @@ class TreeDisplaySequencer final : public AbstractTreeDisplay {
   void add_seq_dup(Sequence *seq, TreeElement *te, short index) const;
 };
 
+/* -------------------------------------------------------------------- */
+/* Orphaned Data Tree-Display */
+
+/**
+ * \brief Tree-Display for the Orphaned Data display mode
+ */
+class TreeDisplayIDOrphans final : public AbstractTreeDisplay {
+ public:
+  TreeDisplayIDOrphans(SpaceOutliner &space_outliner);
+
+  ListBase buildTree(const TreeSourceData &source_data) override;
+
+ private:
+  bool datablock_has_orphans(ListBase &) const;
+};
+
 }  // namespace blender::ed::outliner
diff --git a/source/blender/editors/space_outliner/tree/tree_display_orphaned.cc b/source/blender/editors/space_outliner/tree/tree_display_orphaned.cc
new file mode 100644
index 00000000000..71c1d344057
--- /dev/null
+++ b/source/blender/editors/space_outliner/tree/tree_display_orphaned.cc
@@ -0,0 +1,97 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+/** \file
+ * \ingroup spoutliner
+ */
+
+#include "DNA_ID.h"
+
+#include "BLI_listbase.h"
+#include "BLI_listbase_wrapper.hh"
+#include "BLI_utildefines.h"
+
+#include "BKE_main.h"
+
+#include "../outliner_intern.h"
+#include "tree_display.hh"
+
+namespace blender::ed::outliner {
+
+/* Convenience/readability. */
+template<typename T> using List = ListBaseWrapper<T>;
+
+TreeDisplayIDOrphans::TreeDisplayIDOrphans(SpaceOutliner &space_outliner)
+    : AbstractTreeDisplay(space_outliner)
+{
+}
+
+ListBase TreeDisplayIDOrphans::buildTree(const TreeSourceData &source_data)
+{
+  ListBase tree = {nullptr};
+  ListBase *lbarray[MAX_LIBARRAY];
+  short filter_id_type = (space_outliner_.filter & SO_FILTER_ID_TYPE) ?
+                             space_outliner_.filter_id_type :
+                             0;
+
+  int tot;
+  if (filter_id_type) {
+    lbarray[0] = which_libbase(source_data.bmain, filter_id_type);
+    tot = 1;
+  }
+  else {
+    tot = set_listbasepointers(source_data.bmain, lbarray);
+  }
+
+  for (int a = 0; a < tot; a++) {
+    if (BLI_listbase_is_empty(lbarray[a])) {
+      continue;
+    }
+    if (!datablock_has_orphans(*lbarray[a])) {
+      continue;
+    }
+
+    /* Header for this type of data-block. */
+    TreeElement *te = nullptr;
+    if (!filter_id_type) {
+      ID *id = (ID *)lbarray[a]->first;
+      te = outliner_add_element(&space_outliner_, &tree, lbarray[a], NULL, TSE_ID_BASE, 0);
+      te->directdata = lbarray[a];
+      te->name = outliner_idcode_to_plural(GS(id->name));
+    }
+
+    /* Add the orphaned data-blocks - these will not be added with any subtrees attached. */
+    for (ID *id : List<ID>(lbarray[a])) {
+      if (ID_REAL_USERS(id) <= 0) {
+        outliner_add_element(&space_outliner_, (te) ? &te->subtree : &tree, id, te, 0, 0);
+      }
+    }
+  }
+
+  return tree;
+}
+
+bool TreeDisplayIDOrphans::datablock_has_orphans(ListBase &lb) const
+{
+  for (ID *id : List<ID>(lb)) {
+    if (ID_REAL_USERS(id) <= 0) {
+      return true;
+    }
+  }
+  return false;
+}
+
+}  // namespace blender::ed::outliner