Spreadsheet: Dataset region for spreadsheet editor

This patch adds a left aligned sidebar to the spreadsheet editor. This
Sidebar can be used to navigate the geometry component types and
attribute domains. It also provides a quick overview of domain sizes.
It replaces the two dropdowns in the regions header.
Next step will be to add the domain cycling shortcut
using the CTRL + mouse wheel.

Reviewer: Dalai Felinto (dfelinto), Julian Eisel (Severin),
Hans Goudey (HooglyBoogly).

Differential Revision: https://developer.blender.org/D11046

10 files changed, 695 insertions, 18 deletions

diff --git a/source/blender/editors/space_spreadsheet/CMakeLists.txt b/source/blender/editors/space_spreadsheet/CMakeLists.txt
index 7e3f3db9bc8..1ea6593588a 100644
--- a/source/blender/editors/space_spreadsheet/CMakeLists.txt
+++ b/source/blender/editors/space_spreadsheet/CMakeLists.txt
@@ -38,6 +38,8 @@ set(SRC
   spreadsheet_column.cc
   spreadsheet_data_source.cc
   spreadsheet_data_source_geometry.cc
+  spreadsheet_dataset_draw.cc
+  spreadsheet_dataset_layout.cc
   spreadsheet_draw.cc
   spreadsheet_layout.cc
   spreadsheet_ops.cc
@@ -50,6 +52,8 @@ set(SRC
   spreadsheet_column_values.hh
   spreadsheet_data_source.hh
   spreadsheet_data_source_geometry.hh
+  spreadsheet_dataset_draw.hh
+  spreadsheet_dataset_layout.hh
   spreadsheet_draw.hh
   spreadsheet_intern.hh
   spreadsheet_layout.hh
diff --git a/source/blender/editors/space_spreadsheet/space_spreadsheet.cc b/source/blender/editors/space_spreadsheet/space_spreadsheet.cc
index 8c42f28b5f4..f8654500044 100644
--- a/source/blender/editors/space_spreadsheet/space_spreadsheet.cc
+++ b/source/blender/editors/space_spreadsheet/space_spreadsheet.cc
@@ -47,6 +47,7 @@
 
 #include "spreadsheet_context.hh"
 #include "spreadsheet_data_source_geometry.hh"
+#include "spreadsheet_dataset_draw.hh"
 #include "spreadsheet_intern.hh"
 #include "spreadsheet_layout.hh"
 #include "spreadsheet_row_filter.hh"
@@ -80,6 +81,15 @@ static SpaceLink *spreadsheet_create(const ScrArea *UNUSED(area), const Scene *U
   }
 
   {
+    /* Dataset Region */
+    ARegion *region = (ARegion *)MEM_callocN(sizeof(ARegion), "spreadsheet dataset region");
+    BLI_addtail(&spreadsheet_space->regionbase, region);
+    region->regiontype = RGN_TYPE_CHANNELS;
+    region->alignment = RGN_ALIGN_LEFT;
+    region->v2d.scroll = (V2D_SCROLL_RIGHT | V2D_SCROLL_BOTTOM);
+  }
+
+  {
     /* Properties region. */
     ARegion *region = (ARegion *)MEM_callocN(sizeof(ARegion), "spreadsheet right region");
     BLI_addtail(&spreadsheet_space->regionbase, region);
@@ -195,7 +205,7 @@ static void spreadsheet_main_region_init(wmWindowManager *wm, ARegion *region)
   }
 }
 
-ID *ED_spreadsheet_get_current_id(struct SpaceSpreadsheet *sspreadsheet)
+ID *ED_spreadsheet_get_current_id(const struct SpaceSpreadsheet *sspreadsheet)
 {
   if (BLI_listbase_is_empty(&sspreadsheet->context_path)) {
     return nullptr;
@@ -263,7 +273,7 @@ static void update_context_path_from_context(const bContext *C)
   }
 }
 
-static void update_context_path(const bContext *C)
+void spreadsheet_update_context_path(const bContext *C)
 {
   SpaceSpreadsheet *sspreadsheet = CTX_wm_space_spreadsheet(C);
   if (sspreadsheet->flag & SPREADSHEET_FLAG_PINNED) {
@@ -274,28 +284,40 @@ static void update_context_path(const bContext *C)
   }
 }
 
-static std::unique_ptr<DataSource> get_data_source(const bContext *C)
+Object *spreadsheet_get_object_eval(const SpaceSpreadsheet *sspreadsheet,
+                                    const Depsgraph *depsgraph)
 {
-  Depsgraph *depsgraph = CTX_data_depsgraph_pointer(C);
-  SpaceSpreadsheet *sspreadsheet = CTX_wm_space_spreadsheet(C);
   ID *used_id = ED_spreadsheet_get_current_id(sspreadsheet);
   if (used_id == nullptr) {
-    return {};
+    return nullptr;
   }
   const ID_Type id_type = GS(used_id->name);
   if (id_type != ID_OB) {
-    return {};
+    return nullptr;
   }
   Object *object_orig = (Object *)used_id;
   if (!ELEM(object_orig->type, OB_MESH, OB_POINTCLOUD, OB_VOLUME)) {
-    return {};
+    return nullptr;
   }
+
   Object *object_eval = DEG_get_evaluated_object(depsgraph, object_orig);
   if (object_eval == nullptr) {
-    return {};
+    return nullptr;
   }
 
-  return data_source_from_geometry(C, object_eval);
+  return object_eval;
+}
+
+static std::unique_ptr<DataSource> get_data_source(const bContext *C)
+{
+  Depsgraph *depsgraph = CTX_data_depsgraph_pointer(C);
+  SpaceSpreadsheet *sspreadsheet = CTX_wm_space_spreadsheet(C);
+
+  Object *object_eval = spreadsheet_get_object_eval(sspreadsheet, depsgraph);
+  if (object_eval) {
+    return data_source_from_geometry(C, object_eval);
+  }
+  return {};
 }
 
 static float get_column_width(const ColumnValues &values)
@@ -358,7 +380,7 @@ static void update_visible_columns(ListBase &columns, DataSource &data_source)
 static void spreadsheet_main_region_draw(const bContext *C, ARegion *region)
 {
   SpaceSpreadsheet *sspreadsheet = CTX_wm_space_spreadsheet(C);
-  update_context_path(C);
+  spreadsheet_update_context_path(C);
 
   std::unique_ptr<DataSource> data_source = get_data_source(C);
   if (!data_source) {
@@ -442,7 +464,7 @@ static void spreadsheet_header_region_init(wmWindowManager *UNUSED(wm), ARegion
 
 static void spreadsheet_header_region_draw(const bContext *C, ARegion *region)
 {
-  update_context_path(C);
+  spreadsheet_update_context_path(C);
   ED_region_header(C, region);
 }
 
@@ -534,6 +556,59 @@ static void spreadsheet_footer_region_listener(const wmRegionListenerParams *UNU
 {
 }
 
+static void spreadsheet_dataset_region_listener(const wmRegionListenerParams *params)
+{
+  ARegion *region = params->region;
+  wmNotifier *wmn = params->notifier;
+
+  switch (wmn->category) {
+    case NC_SCENE: {
+      switch (wmn->data) {
+        case ND_FRAME:
+          ED_region_tag_redraw(region);
+          break;
+      }
+      break;
+    }
+    case NC_TEXTURE:
+      ED_region_tag_redraw(region);
+      break;
+  }
+
+  spreadsheet_header_region_listener(params);
+}
+
+static void spreadsheet_dataset_region_init(wmWindowManager *wm, ARegion *region)
+{
+  region->v2d.scroll |= V2D_SCROLL_RIGHT;
+  region->v2d.scroll &= ~(V2D_SCROLL_LEFT | V2D_SCROLL_TOP | V2D_SCROLL_BOTTOM);
+  region->v2d.scroll |= V2D_SCROLL_HORIZONTAL_HIDE;
+  region->v2d.scroll |= V2D_SCROLL_VERTICAL_HIDE;
+
+  UI_view2d_region_reinit(&region->v2d, V2D_COMMONVIEW_LIST, region->winx, region->winy);
+
+  wmKeyMap *keymap = WM_keymap_ensure(
+      wm->defaultconf, "Spreadsheet Generic", SPACE_SPREADSHEET, 0);
+  WM_event_add_keymap_handler(&region->handlers, keymap);
+}
+
+static void spreadsheet_dataset_region_draw(const bContext *C, ARegion *region)
+{
+  spreadsheet_update_context_path(C);
+
+  View2D *v2d = &region->v2d;
+  UI_view2d_view_ortho(v2d);
+  UI_ThemeClearColor(TH_BACK);
+
+  draw_dataset_in_region(C, region);
+
+  /* reset view matrix */
+  UI_view2d_view_restore(C);
+
+  /* scrollers */
+  UI_view2d_scrollers_draw(v2d, NULL);
+}
+
 static void spreadsheet_sidebar_init(wmWindowManager *wm, ARegion *region)
 {
   UI_panel_category_active_set_default(region, "Filters");
@@ -619,5 +694,15 @@ void ED_spacetype_spreadsheet(void)
 
   register_row_filter_panels(*art);
 
+  /* regions: channels */
+  art = (ARegionType *)MEM_callocN(sizeof(ARegionType), "spreadsheet dataset region");
+  art->regionid = RGN_TYPE_CHANNELS;
+  art->prefsizex = 200 + V2D_SCROLL_WIDTH;
+  art->keymapflag = ED_KEYMAP_UI | ED_KEYMAP_VIEW2D;
+  art->init = spreadsheet_dataset_region_init;
+  art->draw = spreadsheet_dataset_region_draw;
+  art->listener = spreadsheet_dataset_region_listener;
+  BLI_addhead(&st->regiontypes, art);
+
   BKE_spacetype_register(st);
 }
diff --git a/source/blender/editors/space_spreadsheet/spreadsheet_context.cc b/source/blender/editors/space_spreadsheet/spreadsheet_context.cc
index 3eb43338908..af6ab5d1b92 100644
--- a/source/blender/editors/space_spreadsheet/spreadsheet_context.cc
+++ b/source/blender/editors/space_spreadsheet/spreadsheet_context.cc
@@ -255,11 +255,11 @@ void ED_spreadsheet_context_path_update_tag(SpaceSpreadsheet *sspreadsheet)
   blender::ed::spreadsheet::spreadsheet_context_update_tag(sspreadsheet);
 }
 
-uint64_t ED_spreadsheet_context_path_hash(SpaceSpreadsheet *sspreadsheet)
+uint64_t ED_spreadsheet_context_path_hash(const SpaceSpreadsheet *sspreadsheet)
 {
   BLI_HashMurmur2A mm2;
   BLI_hash_mm2a_init(&mm2, 1234);
-  LISTBASE_FOREACH (SpreadsheetContext *, context, &sspreadsheet->context_path) {
+  LISTBASE_FOREACH (const SpreadsheetContext *, context, &sspreadsheet->context_path) {
     blender::ed::spreadsheet::spreadsheet_context_hash(context, &mm2);
   }
   return BLI_hash_mm2a_end(&mm2);
diff --git a/source/blender/editors/space_spreadsheet/spreadsheet_data_source_geometry.cc b/source/blender/editors/space_spreadsheet/spreadsheet_data_source_geometry.cc
index 0c76c8b7a15..6d244a1bda6 100644
--- a/source/blender/editors/space_spreadsheet/spreadsheet_data_source_geometry.cc
+++ b/source/blender/editors/space_spreadsheet/spreadsheet_data_source_geometry.cc
@@ -385,9 +385,9 @@ int InstancesDataSource::tot_rows() const
   return component_->instances_amount();
 }
 
-static GeometrySet get_display_geometry_set(SpaceSpreadsheet *sspreadsheet,
-                                            Object *object_eval,
-                                            const GeometryComponentType used_component_type)
+GeometrySet spreadsheet_get_display_geometry_set(const SpaceSpreadsheet *sspreadsheet,
+                                                 Object *object_eval,
+                                                 const GeometryComponentType used_component_type)
 {
   GeometrySet geometry_set;
   if (sspreadsheet->object_eval_state == SPREADSHEET_OBJECT_EVAL_STATE_ORIGINAL) {
@@ -470,7 +470,8 @@ std::unique_ptr<DataSource> data_source_from_geometry(const bContext *C, Object
   SpaceSpreadsheet *sspreadsheet = CTX_wm_space_spreadsheet(C);
   const AttributeDomain domain = (AttributeDomain)sspreadsheet->attribute_domain;
   const GeometryComponentType component_type = get_display_component_type(C, object_eval);
-  GeometrySet geometry_set = get_display_geometry_set(sspreadsheet, object_eval, component_type);
+  GeometrySet geometry_set = spreadsheet_get_display_geometry_set(
+      sspreadsheet, object_eval, component_type);
 
   if (!geometry_set.has(component_type)) {
     return {};
diff --git a/source/blender/editors/space_spreadsheet/spreadsheet_dataset_draw.cc b/source/blender/editors/space_spreadsheet/spreadsheet_dataset_draw.cc
new file mode 100644
index 00000000000..1fa6e47fcdf
--- /dev/null
+++ b/source/blender/editors/space_spreadsheet/spreadsheet_dataset_draw.cc
@@ -0,0 +1,277 @@
+/*
+ * 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.
+ */
+
+#include <array>
+
+#include "DNA_space_types.h"
+#include "DNA_windowmanager_types.h"
+
+#include "BKE_context.h"
+
+#include "BLF_api.h"
+
+#include "BLI_rect.h"
+
+#include "RNA_access.h"
+
+#include "UI_interface.h"
+#include "UI_view2d.h"
+
+#include "WM_types.h"
+
+#include "spreadsheet_dataset_draw.hh"
+#include "spreadsheet_draw.hh"
+#include "spreadsheet_intern.hh"
+
+static int is_component_row_selected(struct uiBut *but, const void *arg)
+{
+  SpaceSpreadsheet *sspreadsheet = (SpaceSpreadsheet *)arg;
+
+  GeometryComponentType component = (GeometryComponentType)UI_but_datasetrow_component_get(but);
+  AttributeDomain domain = (AttributeDomain)UI_but_datasetrow_domain_get(but);
+
+  const bool is_component_selected = (GeometryComponentType)
+                                         sspreadsheet->geometry_component_type == component;
+  const bool is_domain_selected = (AttributeDomain)sspreadsheet->attribute_domain == domain;
+  bool is_selected = is_component_selected && is_domain_selected;
+
+  if (component == GEO_COMPONENT_TYPE_INSTANCES) {
+    is_selected = is_component_selected;
+  }
+
+  return is_selected;
+}
+
+namespace blender::ed::spreadsheet {
+
+/* -------------------------------------------------------------------- */
+/* Draw Context */
+
+class DatasetDrawContext {
+  std::array<int, 2> mval_;
+
+ public:
+  const SpaceSpreadsheet *sspreadsheet;
+  Object *object_eval;
+  /* Current geometry set, changes per component. */
+  GeometrySet current_geometry_set;
+
+  DatasetDrawContext(const bContext *C);
+
+  GeometrySet geometry_set_from_component(GeometryComponentType component);
+  const std::array<int, 2> &cursor_mval() const;
+};
+
+DatasetDrawContext::DatasetDrawContext(const bContext *C)
+    : sspreadsheet(CTX_wm_space_spreadsheet(C)),
+      object_eval(spreadsheet_get_object_eval(sspreadsheet, CTX_data_depsgraph_pointer(C)))
+{
+  const wmWindow *win = CTX_wm_window(C);
+  const ARegion *region = CTX_wm_region(C);
+  mval_ = {win->eventstate->x - region->winrct.xmin, win->eventstate->y - region->winrct.ymin};
+}
+
+GeometrySet DatasetDrawContext::geometry_set_from_component(GeometryComponentType component)
+{
+  return spreadsheet_get_display_geometry_set(sspreadsheet, object_eval, component);
+}
+
+const std::array<int, 2> &DatasetDrawContext::cursor_mval() const
+{
+  return mval_;
+}
+
+/* -------------------------------------------------------------------- */
+/* Drawer */
+
+DatasetRegionDrawer::DatasetRegionDrawer(const ARegion *region,
+                                         uiBlock &block,
+                                         DatasetDrawContext &draw_context)
+    : row_height(UI_UNIT_Y),
+      xmin(region->v2d.cur.xmin),
+      xmax(region->v2d.cur.xmax),
+      block(block),
+      v2d(region->v2d),
+      draw_context(draw_context)
+{
+}
+
+void DatasetRegionDrawer::draw_hierarchy(const DatasetLayoutHierarchy &layout)
+{
+  for (const DatasetComponentLayoutInfo &component : layout.components) {
+    draw_context.current_geometry_set = draw_context.geometry_set_from_component(component.type);
+
+    draw_component_row(component);
+
+    /* Iterate attribute domains, skip unset ones (storage has to be in a enum-based, fixed size
+     * array so uses optionals to support skipping enum values that shouldn't be displayed for a
+     * component). */
+    for (auto &optional_domain : component.attr_domains) {
+      if (!optional_domain) {
+        continue;
+      }
+
+      const DatasetAttrDomainLayoutInfo &domain_info = *optional_domain;
+      draw_attribute_domain_row(component, domain_info);
+    }
+  }
+}
+
+static int element_count_from_component_domain(const GeometrySet &geometry_set,
+                                               GeometryComponentType component,
+                                               AttributeDomain domain)
+{
+  if (geometry_set.has_mesh() && component == GEO_COMPONENT_TYPE_MESH) {
+    const MeshComponent *mesh_component = geometry_set.get_component_for_read<MeshComponent>();
+    return mesh_component->attribute_domain_size(domain);
+  }
+
+  if (geometry_set.has_pointcloud() && component == GEO_COMPONENT_TYPE_POINT_CLOUD) {
+    const PointCloudComponent *point_cloud_component =
+        geometry_set.get_component_for_read<PointCloudComponent>();
+    return point_cloud_component->attribute_domain_size(domain);
+  }
+
+  if (geometry_set.has_instances() && component == GEO_COMPONENT_TYPE_INSTANCES) {
+    const InstancesComponent *instances_component =
+        geometry_set.get_component_for_read<InstancesComponent>();
+    return instances_component->instances_amount();
+  }
+
+  if (geometry_set.has_volume() && component == GEO_COMPONENT_TYPE_VOLUME) {
+    const VolumeComponent *volume_component =
+        geometry_set.get_component_for_read<VolumeComponent>();
+    return volume_component->attribute_domain_size(domain);
+  }
+
+  if (geometry_set.has_curve() && component == GEO_COMPONENT_TYPE_CURVE) {
+    const CurveComponent *curve_component = geometry_set.get_component_for_read<CurveComponent>();
+    return curve_component->attribute_domain_size(domain);
+  }
+
+  return 0;
+}
+
+void DatasetRegionDrawer::draw_dataset_row(const int indentation,
+                                           const GeometryComponentType component,
+                                           const std::optional<AttributeDomain> domain,
+                                           BIFIconID icon,
+                                           const char *label,
+                                           const bool is_active)
+{
+
+  const float row_height = UI_UNIT_Y;
+  const float padding_x = UI_UNIT_X * 0.25f;
+
+  const rctf rect = {float(xmin) + padding_x,
+                     float(xmax) - V2D_SCROLL_HANDLE_WIDTH,
+                     ymin_offset - row_height,
+                     ymin_offset};
+
+  char element_count[7];
+  BLI_str_format_attribute_domain_size(
+      element_count,
+      domain ? element_count_from_component_domain(
+                   draw_context.current_geometry_set, component, *domain) :
+               0);
+
+  std::string label_and_element_count = label;
+  label_and_element_count += UI_SEP_CHAR;
+  label_and_element_count += element_count;
+
+  uiBut *bt = uiDefIconTextButO(&block,
+                                UI_BTYPE_DATASETROW,
+                                "SPREADSHEET_OT_change_spreadsheet_data_source",
+                                0,
+                                icon,
+                                label,
+                                rect.xmin,
+                                rect.ymin,
+                                BLI_rctf_size_x(&rect),
+                                BLI_rctf_size_y(&rect),
+                                NULL);
+
+  UI_but_datasetrow_indentation_set(bt, indentation);
+
+  if (is_active) {
+    UI_but_hint_drawstr_set(bt, element_count);
+    UI_but_datasetrow_component_set(bt, component);
+    if (domain) {
+      UI_but_datasetrow_domain_set(bt, *domain);
+    }
+    UI_but_func_pushed_state_set(bt, &is_component_row_selected, draw_context.sspreadsheet);
+
+    PointerRNA *but_ptr = UI_but_operator_ptr_get((uiBut *)bt);
+    RNA_int_set(but_ptr, "component_type", component);
+    if (domain) {
+      RNA_int_set(but_ptr, "attribute_domain_type", *domain);
+    }
+  }
+
+  ymin_offset -= row_height;
+}
+
+void DatasetRegionDrawer::draw_component_row(const DatasetComponentLayoutInfo &component_info)
+{
+  if (component_info.type == GEO_COMPONENT_TYPE_INSTANCES) {
+    draw_dataset_row(
+        0, component_info.type, std::nullopt, component_info.icon, component_info.label, true);
+  }
+  else {
+    draw_dataset_row(
+        0, component_info.type, std::nullopt, component_info.icon, component_info.label, false);
+  }
+}
+
+void DatasetRegionDrawer::draw_attribute_domain_row(
+    const DatasetComponentLayoutInfo &component_info,
+    const DatasetAttrDomainLayoutInfo &domain_info)
+{
+  draw_dataset_row(
+      1, component_info.type, domain_info.type, domain_info.icon, domain_info.label, true);
+}
+
+/* -------------------------------------------------------------------- */
+/* Drawer */
+
+void draw_dataset_in_region(const bContext *C, ARegion *region)
+{
+  DatasetDrawContext draw_context{C};
+  if (!draw_context.object_eval) {
+    /* No object means nothing to display. Keep the region empty. */
+    return;
+  }
+
+  uiBlock *block = UI_block_begin(C, region, __func__, UI_EMBOSS);
+
+  DatasetRegionDrawer drawer{region, *block, draw_context};
+
+  /* Start with an offset to align buttons to spreadsheet rows. Use spreadsheet drawing info for
+   * that. */
+  drawer.ymin_offset = -SpreadsheetDrawer().top_row_height + drawer.row_height;
+
+  const DatasetLayoutHierarchy hierarchy = dataset_layout_hierarchy();
+  drawer.draw_hierarchy(hierarchy);
+#ifndef NDEBUG
+  dataset_layout_hierarchy_sanity_check(hierarchy);
+#endif
+
+  UI_block_end(C, block);
+  UI_view2d_totRect_set(&region->v2d, region->winx, abs(drawer.ymin_offset));
+  UI_block_draw(C, block);
+}
+
+}  // namespace blender::ed::spreadsheet
diff --git a/source/blender/editors/space_spreadsheet/spreadsheet_dataset_draw.hh b/source/blender/editors/space_spreadsheet/spreadsheet_dataset_draw.hh
new file mode 100644
index 00000000000..d9e6d882c2a
--- /dev/null
+++ b/source/blender/editors/space_spreadsheet/spreadsheet_dataset_draw.hh
@@ -0,0 +1,64 @@
+/*
+ * 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.
+ */
+
+#pragma once
+
+#include <array>
+
+#include "BKE_geometry_set.hh"
+#include "UI_interface.h"
+#include "spreadsheet_dataset_layout.hh"
+
+struct ARegion;
+struct uiBlock;
+struct View2D;
+struct bContext;
+
+namespace blender::ed::spreadsheet {
+
+class DatasetDrawContext;
+
+class DatasetRegionDrawer {
+ public:
+  const int row_height;
+  float ymin_offset = 0;
+
+  int xmin;
+  int xmax;
+  uiBlock &block;
+  const View2D &v2d;
+  DatasetDrawContext &draw_context;
+
+  DatasetRegionDrawer(const ARegion *region, uiBlock &block, DatasetDrawContext &draw_context);
+
+  void draw_hierarchy(const DatasetLayoutHierarchy &layout);
+
+  void draw_attribute_domain_row(const DatasetComponentLayoutInfo &component,
+                                 const DatasetAttrDomainLayoutInfo &domain_info);
+  void draw_component_row(const DatasetComponentLayoutInfo &component_info);
+
+ private:
+  void draw_dataset_row(const int indentation,
+                        const GeometryComponentType component,
+                        const std::optional<AttributeDomain> domain,
+                        const BIFIconID icon,
+                        const char *label,
+                        const bool is_active);
+};
+
+void draw_dataset_in_region(const bContext *C, ARegion *region);
+
+}  // namespace blender::ed::spreadsheet
diff --git a/source/blender/editors/space_spreadsheet/spreadsheet_dataset_layout.cc b/source/blender/editors/space_spreadsheet/spreadsheet_dataset_layout.cc
new file mode 100644
index 00000000000..e9f2c51a6da
--- /dev/null
+++ b/source/blender/editors/space_spreadsheet/spreadsheet_dataset_layout.cc
@@ -0,0 +1,112 @@
+/*
+ * 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.
+ */
+
+#include <optional>
+
+#include "BLI_span.hh"
+
+#include "BLT_translation.h"
+
+#include "spreadsheet_dataset_layout.hh"
+
+namespace blender::ed::spreadsheet {
+
+#define ATTR_INFO(type, label, icon) \
+  std::optional<DatasetAttrDomainLayoutInfo> \
+  { \
+    std::in_place, type, label, icon \
+  }
+#define ATTR_INFO_NONE(type) \
+  { \
+    std::nullopt \
+  }
+
+/**
+ * Definion for the component->attribute-domain hierarchy.
+ * Constructed at compile time.
+ *
+ * \warning: Order of attribute-domains matters! It __must__ match the #AttributeDomain definition
+ *           and fill gaps with unset optionals (i.e. `std::nullopt`). Would be nice to use array
+ *           designators for this (which C++ doesn't support).
+ */
+constexpr DatasetComponentLayoutInfo DATASET_layout_hierarchy[] = {
+    {
+        GEO_COMPONENT_TYPE_MESH,
+        N_("Mesh"),
+        ICON_MESH_DATA,
+        {
+            ATTR_INFO(ATTR_DOMAIN_POINT, N_("Vertex"), ICON_VERTEXSEL),
+            ATTR_INFO(ATTR_DOMAIN_EDGE, N_("Edge"), ICON_EDGESEL),
+            ATTR_INFO(ATTR_DOMAIN_FACE, N_("Face"), ICON_FACESEL),
+            ATTR_INFO(ATTR_DOMAIN_CORNER, N_("Face Corner"), ICON_NODE_CORNER),
+        },
+    },
+    {
+        GEO_COMPONENT_TYPE_CURVE,
+        N_("Curves"),
+        ICON_CURVE_DATA,
+        {
+            ATTR_INFO(ATTR_DOMAIN_POINT, N_("Control Point"), ICON_CURVE_BEZCIRCLE),
+            ATTR_INFO_NONE(ATTR_DOMAIN_EDGE),
+            ATTR_INFO_NONE(ATTR_DOMAIN_CORNER),
+            ATTR_INFO_NONE(ATTR_DOMAIN_FACE),
+            ATTR_INFO(ATTR_DOMAIN_CURVE, N_("Spline"), ICON_CURVE_PATH),
+        },
+    },
+    {
+        GEO_COMPONENT_TYPE_POINT_CLOUD,
+        N_("Point Cloud"),
+        ICON_POINTCLOUD_DATA,
+        {
+            ATTR_INFO(ATTR_DOMAIN_POINT, N_("Point"), ICON_PARTICLE_POINT),
+        },
+    },
+    {
+        GEO_COMPONENT_TYPE_INSTANCES,
+        N_("Instances"),
+        ICON_EMPTY_AXIS,
+        {},
+    },
+};
+
+#undef ATTR_INFO
+#undef ATTR_INFO_LABEL
+
+DatasetLayoutHierarchy dataset_layout_hierarchy()
+{
+  return DatasetLayoutHierarchy{
+      Span{DATASET_layout_hierarchy, ARRAY_SIZE(DATASET_layout_hierarchy)}};
+}
+
+#ifndef NDEBUG
+/**
+ * Debug-only sanity check for correct attribute domain initialization (order/indices must
+ * match AttributeDomain). This doesn't check for all possible missuses, but should catch the most
+ * likely mistakes.
+ */
+void dataset_layout_hierarchy_sanity_check(const DatasetLayoutHierarchy &hierarchy)
+{
+  for (const DatasetComponentLayoutInfo &component : hierarchy.components) {
+    for (uint i = 0; i < component.attr_domains.size(); i++) {
+      if (component.attr_domains[i]) {
+        BLI_assert(component.attr_domains[i]->type == static_cast<AttributeDomain>(i));
+      }
+    }
+  }
+}
+#endif
+
+}  // namespace blender::ed::spreadsheet
diff --git a/source/blender/editors/space_spreadsheet/spreadsheet_dataset_layout.hh b/source/blender/editors/space_spreadsheet/spreadsheet_dataset_layout.hh
new file mode 100644
index 00000000000..d463739a0fa
--- /dev/null
+++ b/source/blender/editors/space_spreadsheet/spreadsheet_dataset_layout.hh
@@ -0,0 +1,68 @@
+/*
+ * 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.
+ */
+
+#pragma once
+
+#include <array>
+#include <optional>
+
+/* Enum definitions... */
+#include "BKE_attribute.h"
+#include "BKE_geometry_set.h"
+
+#include "BLI_span.hh"
+
+/* More enum definitions... */
+#include "UI_resources.h"
+
+#pragma once
+
+namespace blender::ed::spreadsheet {
+
+struct DatasetAttrDomainLayoutInfo {
+  AttributeDomain type;
+  const char *label;
+  BIFIconID icon;
+
+  constexpr DatasetAttrDomainLayoutInfo(AttributeDomain type, const char *label, BIFIconID icon)
+      : type(type), label(label), icon(icon)
+  {
+  }
+};
+
+struct DatasetComponentLayoutInfo {
+  GeometryComponentType type;
+  const char *label;
+  BIFIconID icon;
+  /** Array of attribute-domains. Has to be fixed size based on #AttributeDomain enum, but not all
+   * values need displaying for all parent components. Hence the optional use. */
+  using AttrDomainArray = std::array<std::optional<DatasetAttrDomainLayoutInfo>, ATTR_DOMAIN_NUM>;
+  const AttrDomainArray attr_domains;
+};
+
+struct DatasetLayoutHierarchy {
+  /** The components for display (with layout info like icon and label). Each component stores
+   * the attribute domains it wants to display (also with layout info like icon and label). */
+  const Span<DatasetComponentLayoutInfo> components;
+};
+
+DatasetLayoutHierarchy dataset_layout_hierarchy();
+
+#ifndef NDEBUG
+void dataset_layout_hierarchy_sanity_check(const DatasetLayoutHierarchy &hierarchy);
+#endif
+
+}  // namespace blender::ed::spreadsheet
diff --git a/source/blender/editors/space_spreadsheet/spreadsheet_intern.hh b/source/blender/editors/space_spreadsheet/spreadsheet_intern.hh
index 7e3b79a6706..8be5283fd63 100644
--- a/source/blender/editors/space_spreadsheet/spreadsheet_intern.hh
+++ b/source/blender/editors/space_spreadsheet/spreadsheet_intern.hh
@@ -16,10 +16,23 @@
 
 #pragma once
 
+#include "BKE_geometry_set.hh"
+
 typedef struct SpaceSpreadsheet_Runtime {
   int visible_rows;
   int tot_rows;
   int tot_columns;
 } SpaceSpreadsheet_Runtime;
 
+struct bContext;
+
 void spreadsheet_operatortypes(void);
+void spreadsheet_update_context_path(const bContext *C);
+Object *spreadsheet_get_object_eval(const SpaceSpreadsheet *sspreadsheet,
+                                    const Depsgraph *depsgraph);
+
+namespace blender::ed::spreadsheet {
+GeometrySet spreadsheet_get_display_geometry_set(const SpaceSpreadsheet *sspreadsheet,
+                                                 Object *object_eval,
+                                                 const GeometryComponentType used_component_type);
+}
diff --git a/source/blender/editors/space_spreadsheet/spreadsheet_ops.cc b/source/blender/editors/space_spreadsheet/spreadsheet_ops.cc
index fcbc37346e6..ceb4cd84cde 100644
--- a/source/blender/editors/space_spreadsheet/spreadsheet_ops.cc
+++ b/source/blender/editors/space_spreadsheet/spreadsheet_ops.cc
@@ -13,6 +13,17 @@
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
+#include "BKE_screen.h"
+
+#include "DNA_space_types.h"
+
+#include "ED_screen.h"
+
+#include "RNA_access.h"
+#include "RNA_define.h"
+
+#include "WM_api.h"
+#include "WM_types.h"
 
 #include "BLI_listbase.h"
 
@@ -89,8 +100,50 @@ static void SPREADSHEET_OT_remove_row_filter_rule(wmOperatorType *ot)
   RNA_def_int(ot->srna, "index", 0, 0, INT_MAX, "Index", "", 0, INT_MAX);
 }
 
+static int select_component_domain_invoke(bContext *C,
+                                          wmOperator *op,
+                                          const wmEvent *UNUSED(event))
+{
+  GeometryComponentType component_type = static_cast<GeometryComponentType>(
+      RNA_int_get(op->ptr, "component_type"));
+  AttributeDomain attribute_domain = static_cast<AttributeDomain>(
+      RNA_int_get(op->ptr, "attribute_domain_type"));
+
+  SpaceSpreadsheet *sspreadsheet = CTX_wm_space_spreadsheet(C);
+  sspreadsheet->geometry_component_type = component_type;
+  sspreadsheet->attribute_domain = attribute_domain;
+
+  /* Refresh header and main region. */
+  WM_main_add_notifier(NC_SPACE | ND_SPACE_SPREADSHEET, NULL);
+
+  return OPERATOR_FINISHED;
+}
+
+static void SPREADSHEET_OT_change_spreadsheet_data_source(wmOperatorType *ot)
+{
+  ot->name = "Change Visible Data Source";
+  ot->description = "Change visible data source in the spreadsheet";
+  ot->idname = "SPREADSHEET_OT_change_spreadsheet_data_source";
+
+  ot->invoke = select_component_domain_invoke;
+
+  RNA_def_int(ot->srna, "component_type", 0, 0, INT16_MAX, "Component Type", "", 0, INT16_MAX);
+  RNA_def_int(ot->srna,
+              "attribute_domain_type",
+              0,
+              0,
+              INT16_MAX,
+              "Attribute Domain Type",
+              "",
+              0,
+              INT16_MAX);
+
+  ot->flag = OPTYPE_INTERNAL;
+}
+
 void spreadsheet_operatortypes()
 {
   WM_operatortype_append(SPREADSHEET_OT_add_row_filter_rule);
   WM_operatortype_append(SPREADSHEET_OT_remove_row_filter_rule);
+  WM_operatortype_append(SPREADSHEET_OT_change_spreadsheet_data_source);
 }