scripts/startup/bl_ui/space_view3d.py

@@ -6228,7 +6228,8 @@ class VIEW3D_PT_collections(Panel):
         # We pass index 0 here because the index is increased
         # so the first real index is 1
         # And we start with index as 1 because we skip the master collection
-        self._draw_collection(layout, view_layer, view.use_local_collections, view_layer.layer_collection, 0)
+        layout.template_scene_collection_tree()
+        # self._draw_collection(layout, view_layer, view.use_local_collections, view_layer.layer_collection, 0)
 
 
 class VIEW3D_PT_object_type_visibility(Panel):

source/blender/editors/include/UI_interface_c.hh

@@ -2668,6 +2668,8 @@ void uiTemplateGreasePencilLayerTree(uiLayout *layout, bContext *C);
 
 void uiTemplateNodeTreeInterface(struct uiLayout *layout, struct PointerRNA *ptr);
 
+void uiTemplateSceneCollectionTree(uiLayout *layout, bContext *C);
+
 /**
  * \return: A RNA pointer for the operator properties.
  */

source/blender/editors/interface/CMakeLists.txt

@@ -69,6 +69,7 @@ set(SRC
   interface_style.cc
   interface_template_asset_view.cc
   interface_template_attribute_search.cc
+  interface_template_collection_tree.cc
   interface_template_light_linking.cc
   interface_template_list.cc
   interface_template_node_tree_interface.cc

source/blender/editors/interface/interface_template_collection_tree.cc

@@ -0,0 +1,181 @@
+/* SPDX-FileCopyrightText: 2023 Blender Authors
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later */
+
+/** \file
+ * \ingroup edinterface
+ */
+
+#include "DNA_collection_types.h"
+#include "DNA_layer_types.h"
+#include "DNA_scene_types.h"
+
+#include "BKE_context.h"
+#include "BKE_layer.h"
+
+#include "RNA_access.hh"
+#include "RNA_prototypes.h"
+
+#include "WM_api.hh"
+
+#include "UI_tree_view.hh"
+
+namespace blender::ui {
+
+class CollectionTreeView : public AbstractTreeView {
+  Scene &scene_;
+  ViewLayer &view_layer_;
+  /** View3D from context, if any. Used for local overrides (local collections toggle). */
+  View3D *view3d_ = nullptr;
+
+  bool use_local_collections_ = false;
+  bool show_viewport_visibility_ = false;
+
+  friend class CollectionTreeViewItem;
+
+ public:
+  CollectionTreeView(Scene &scene, ViewLayer &view_layer, View3D *view3d)
+      : scene_(scene), view_layer_(view_layer), view3d_(view3d)
+  {
+  }
+  void build_tree() override;
+
+  void set_use_local_collections(const bool use_local_collections)
+  {
+    use_local_collections_ = use_local_collections;
+  }
+  void enable_viewport_visibility_toggle()
+  {
+    show_viewport_visibility_ = true;
+  }
+};
+
+/* ---------------------------------------------------------------------- */
+
+class CollectionTreeViewItem : public BasicTreeViewItem {
+  LayerCollection &collection_;
+  LayerCollection &parent_collection_;
+
+ public:
+  CollectionTreeViewItem(LayerCollection &collection, LayerCollection &parent_collection)
+      : BasicTreeViewItem(collection.collection->id.name + 2),
+        collection_(collection),
+        parent_collection_(parent_collection)
+  {
+  }
+
+  std::optional<bool> should_be_active() const override
+  {
+    const CollectionTreeView &view = static_cast<CollectionTreeView &>(get_tree_view());
+    return BKE_view_layer_active_collection_get(&view.view_layer_) == &collection_;
+  }
+
+  void on_activate(bContext &C) override
+  {
+    CollectionTreeView &view = static_cast<CollectionTreeView &>(get_tree_view());
+    BKE_layer_collection_activate(&view.view_layer_, &collection_);
+    /* A very precise notifier - ND_LAYER alone is quite vague, we want to avoid unnecessary
+     * work when only the active collection changes. */
+    WM_event_add_notifier(&C, NC_SCENE | ND_LAYER | NS_LAYER_COLLECTION | NA_ACTIVATED, nullptr);
+  }
+
+  void add_viewport_visibility_toggle(uiLayout &layout, PointerRNA &collection_ptr)
+  {
+    CollectionTreeView &view = static_cast<CollectionTreeView &>(get_tree_view());
+    if (view.use_local_collections_ && view.view3d_) {
+      const bool visible_in_viewport =
+          ((view.view3d_->local_collections_uuid & collection_.local_collections_bits) &&
+           !(parent_collection_.runtime_flag & LAYER_COLLECTION_HIDE_VIEWPORT));
+
+      uiLayoutSetActive(&layout, visible_in_viewport);
+
+      PointerRNA opptr;
+      uiItemFullO(&layout,
+                  "object.hide_collection",
+                  "",
+                  ICON_HIDE_OFF,
+                  nullptr,
+                  WM_OP_INVOKE_DEFAULT,
+                  UI_ITEM_NONE,
+                  &opptr);
+      RNA_int_set(&opptr,
+                  "collection_index",
+                  BKE_layer_collection_findindex(&view.view_layer_, &collection_));
+      RNA_boolean_set(&opptr, "toggle", true);
+    }
+    else {
+      uiLayoutSetActive(&layout,
+                        parent_collection_.runtime_flag & LAYER_COLLECTION_VISIBLE_VIEW_LAYER);
+      uiItemR(&layout, &collection_ptr, "hide_viewport", UI_ITEM_R_COMPACT, "", ICON_HIDE_OFF);
+    }
+  }
+
+  void build_row(uiLayout &row) override
+  {
+    add_label(row);
+
+    uiLayout *sub = uiLayoutRow(&row, false);
+    uiLayoutSetAlignment(sub, UI_LAYOUT_ALIGN_RIGHT);
+    CollectionTreeView &view = static_cast<CollectionTreeView &>(get_tree_view());
+
+    PointerRNA collection_ptr = RNA_pointer_create(
+        &view.scene_.id, &RNA_LayerCollection, &collection_);
+
+    if (view.show_viewport_visibility_) {
+      add_viewport_visibility_toggle(*sub, collection_ptr);
+    }
+  }
+};
+
+/* ---------------------------------------------------------------------- */
+
+static void add_children_recursive(TreeViewOrItem &parent_item, LayerCollection &parent_collection)
+{
+  LISTBASE_FOREACH (LayerCollection *, child, &parent_collection.layer_collections) {
+    if (child->flag & LAYER_COLLECTION_EXCLUDE) {
+      continue;
+    }
+    if (child->collection->flag & COLLECTION_HIDE_VIEWPORT) {
+      continue;
+    }
+
+    AbstractTreeViewItem &new_item = parent_item.add_tree_item<CollectionTreeViewItem>(
+        *child, parent_collection);
+    add_children_recursive(new_item, *child);
+  }
+}
+
+void CollectionTreeView::build_tree()
+{
+  LayerCollection &scene_collection = *static_cast<LayerCollection *>(
+      view_layer_.layer_collections.first);
+  add_children_recursive(*this, scene_collection);
+}
+
+}  // namespace blender::ui
+
+/* ---------------------------------------------------------------------- */
+
+using namespace blender;
+
+void uiTemplateSceneCollectionTree(uiLayout *layout, bContext *C)
+{
+  Scene *scene = CTX_data_scene(C);
+  ViewLayer *view_layer = CTX_data_view_layer(C);
+  /* May me null if this is not displayed in a 3D view! */
+  View3D *view3d = CTX_wm_view3d(C);
+
+  uiBlock *block = uiLayoutGetBlock(layout);
+
+  std::unique_ptr collection_view = std::make_unique<ui::CollectionTreeView>(
+      *scene, *view_layer, view3d);
+  collection_view->set_min_rows(5);
+  /* These things could be turned into options for the template (or there could be multiple
+   * templates displaying the tree in different ways). For now keep it entirely context based. */
+  collection_view->set_use_local_collections(view3d && (view3d->flag & V3D_LOCAL_COLLECTIONS));
+  collection_view->enable_viewport_visibility_toggle();
+
+  ui::AbstractTreeView *tree_view = UI_block_add_view(
+      *block, "Collection Tree View", std::move(collection_view));
+  ui::TreeViewBuilder::build_tree_view(*tree_view, *layout);
+}

source/blender/editors/interface/views/tree_view.cc

@@ -623,6 +623,8 @@ void TreeViewLayoutBuilder::build_row(AbstractTreeViewItem &item) const
   eUIEmbossType previous_emboss = UI_block_emboss_get(&block_);
 
   uiLayout *overlap = uiLayoutOverlap(&prev_layout);
+  uiLayoutSetPropSep(overlap, false);
+  uiLayoutSetPropDecorate(overlap, false);
 
   if (!item.is_interactive_) {
     uiLayoutSetActive(overlap, false);

source/blender/makesrna/intern/rna_ui_api.cc

@@ -2108,6 +2108,10 @@ void RNA_api_ui_layout(StructRNA *srna)
   RNA_def_parameter_flags(parm, PROP_NEVER_NULL, PARM_REQUIRED);
   api_ui_item_rna_common(func);
 
+  func = RNA_def_function(srna, "template_scene_collection_tree", "uiTemplateSceneCollectionTree");
+  RNA_def_function_ui_description(func, "Display the current scene's collection hierarchy");
+  RNA_def_function_flag(func, FUNC_USE_CONTEXT);
+
 #  ifdef WITH_GREASE_PENCIL_V3
   func = RNA_def_function(
       srna, "template_grease_pencil_layer_tree", "uiTemplateGreasePencilLayerTree");