Merge branch 'master' into tracking_toolstracking_tools

35 files changed, 1230 insertions, 402 deletions

diff --git a/source/blender/editors/include/ED_anim_api.h b/source/blender/editors/include/ED_anim_api.h
index da40eef87fd..8fe2d0ae60f 100644
--- a/source/blender/editors/include/ED_anim_api.h
+++ b/source/blender/editors/include/ED_anim_api.h
@@ -101,16 +101,16 @@ typedef struct bAnimContext {
 /* Main Data container types */
 typedef enum eAnimCont_Types {
   ANIMCONT_NONE = 0,      /* invalid or no data */
-  ANIMCONT_ACTION = 1,    /* action (bAction) */
-  ANIMCONT_SHAPEKEY = 2,  /* shapekey (Key) */
+  ANIMCONT_ACTION = 1,    /* action (#bAction) */
+  ANIMCONT_SHAPEKEY = 2,  /* shape-key (#Key) */
   ANIMCONT_GPENCIL = 3,   /* grease pencil (screen) */
-  ANIMCONT_DOPESHEET = 4, /* dopesheet (bDopesheet) */
-  ANIMCONT_FCURVES = 5,   /* animation F-Curves (bDopesheet) */
-  ANIMCONT_DRIVERS = 6,   /* drivers (bDopesheet) */
-  ANIMCONT_NLA = 7,       /* nla (bDopesheet) */
-  ANIMCONT_CHANNEL = 8,   /* animation channel (bAnimListElem) */
-  ANIMCONT_MASK = 9,      /* mask dopesheet */
-  ANIMCONT_TIMELINE = 10, /* "timeline" editor (bDopeSheet) */
+  ANIMCONT_DOPESHEET = 4, /* dope-sheet (#bDopesheet) */
+  ANIMCONT_FCURVES = 5,   /* animation F-Curves (#bDopesheet) */
+  ANIMCONT_DRIVERS = 6,   /* drivers (#bDopesheet) */
+  ANIMCONT_NLA = 7,       /* NLA (#bDopesheet) */
+  ANIMCONT_CHANNEL = 8,   /* animation channel (#bAnimListElem) */
+  ANIMCONT_MASK = 9,      /* mask dope-sheet */
+  ANIMCONT_TIMELINE = 10, /* "timeline" editor (#bDopeSheet) */
 } eAnimCont_Types;
 
 /** \} */
@@ -324,12 +324,17 @@ typedef enum eAnimFilter_Flags {
   /** duplicate entries for animation data attached to multi-user blocks must not occur */
   ANIMFILTER_NODUPLIS = (1 << 11),
 
+  /** avoid channel that does not have any F-curve data */
+  ANIMFILTER_FCURVESONLY = (1 << 12),
+
   /** for checking if we should keep some collapsed channel around (internal use only!) */
   ANIMFILTER_TMP_PEEK = (1 << 30),
 
   /** Ignore ONLYSEL flag from #bDopeSheet.filterflag (internal use only!) */
   ANIMFILTER_TMP_IGNORE_ONLYSEL = (1u << 31),
+
 } eAnimFilter_Flags;
+ENUM_OPERATORS(eAnimFilter_Flags, ANIMFILTER_TMP_IGNORE_ONLYSEL);
 
 /** \} */
 
@@ -514,6 +519,11 @@ void ANIM_animdata_update(bAnimContext *ac, ListBase *anim_data);
 
 void ANIM_animdata_freelist(ListBase *anim_data);
 
+/**
+ * Check if the given animation container can contain grease pencil layer keyframes.
+ */
+bool ANIM_animdata_can_have_greasepencil(const eAnimCont_Types type);
+
 /* ************************************************ */
 /* ANIMATION CHANNELS LIST */
 /* anim_channels_*.c */
@@ -1042,6 +1052,8 @@ void ED_keymap_anim(struct wmKeyConfig *keyconf);
 void ED_operatormacros_graph(void);
 /* space_action */
 void ED_operatormacros_action(void);
+/* space_nla*/
+void ED_operatormacros_nla(void);
 
 /** \} */
 
diff --git a/source/blender/editors/include/ED_armature.h b/source/blender/editors/include/ED_armature.h
index d969277fef5..8e7f728a3e7 100644
--- a/source/blender/editors/include/ED_armature.h
+++ b/source/blender/editors/include/ED_armature.h
@@ -312,7 +312,8 @@ void ED_pose_recalculate_paths(struct bContext *C,
 /**
  * \return True when pick finds an element or the selection changed.
  */
-bool ED_armature_pose_select_pick_bone(struct ViewLayer *view_layer,
+bool ED_armature_pose_select_pick_bone(const struct Scene *scene,
+                                       struct ViewLayer *view_layer,
                                        struct View3D *v3d,
                                        struct Object *ob,
                                        struct Bone *bone,
@@ -323,7 +324,8 @@ bool ED_armature_pose_select_pick_bone(struct ViewLayer *view_layer,
  *
  * \return True when pick finds an element or the selection changed.
  */
-bool ED_armature_pose_select_pick_with_buffer(struct ViewLayer *view_layer,
+bool ED_armature_pose_select_pick_with_buffer(const struct Scene *scene,
+                                              struct ViewLayer *view_layer,
                                               struct View3D *v3d,
                                               struct Base *base,
                                               const struct GPUSelectResult *buffer,
@@ -338,7 +340,8 @@ bool ED_armature_pose_select_pick_with_buffer(struct ViewLayer *view_layer,
  * It can't be set to the active object because we need
  * to keep this set to the weight paint object.
  */
-void ED_armature_pose_select_in_wpaint_mode(struct ViewLayer *view_layer,
+void ED_armature_pose_select_in_wpaint_mode(const struct Scene *scene,
+                                            struct ViewLayer *view_layer,
                                             struct Base *base_select);
 bool ED_pose_deselect_all_multi_ex(struct Base **bases,
                                    uint bases_len,
diff --git a/source/blender/editors/include/ED_clip.h b/source/blender/editors/include/ED_clip.h
index c5a45f8b73e..0f981e270a0 100644
--- a/source/blender/editors/include/ED_clip.h
+++ b/source/blender/editors/include/ED_clip.h
@@ -22,15 +22,53 @@ struct bScreen;
 
 /*  ** clip_editor.c ** */
 
-/* common poll functions */
+/* Returns true when the following conditions are met:
+ * - Current space is Space Clip.
+ * - There is a movie clip opened in it. */
 bool ED_space_clip_poll(struct bContext *C);
 
+/* Returns true when the following conditions are met:
+ * - Current space is Space Clip.
+ * - It is set to Clip view.
+ *
+ * It is not required to have movie clip opened for editing. */
 bool ED_space_clip_view_clip_poll(struct bContext *C);
 
+/* Returns true when the following conditions are met:
+ * - Current space is Space Clip.
+ * - It is set to Tracking mode.
+ *
+ * It is not required to have movie clip opened for editing. */
 bool ED_space_clip_tracking_poll(struct bContext *C);
+
+/* Returns true when the following conditions are met:
+ * - Current space is Space Clip.
+ * - It is set to Mask mode.
+ *
+ * It is not required to have mask opened for editing. */
 bool ED_space_clip_maskedit_poll(struct bContext *C);
+
+/* Returns true when the following conditions are met:
+ * - Current space is Space Clip.
+ * - It is set to Mask mode.
+ * - Mask has visible and editable splines.
+ *
+ * It is not required to have mask opened for editing. */
+bool ED_space_clip_maskedit_visible_splines_poll(struct bContext *C);
+
+/* Returns true when the following conditions are met:
+ * - Current space is Space Clip.
+ * - It is set to Mask mode.
+ * - The space has mask opened. */
 bool ED_space_clip_maskedit_mask_poll(struct bContext *C);
 
+/* Returns true when the following conditions are met:
+ * - Current space is Space Clip.
+ * - It is set to Mask mode.
+ * - The space has mask opened.
+ * - Mask has visible and editable splines. */
+bool ED_space_clip_maskedit_mask_visible_splines_poll(struct bContext *C);
+
 void ED_space_clip_get_size(struct SpaceClip *sc, int *width, int *height);
 void ED_space_clip_get_size_fl(struct SpaceClip *sc, float size[2]);
 void ED_space_clip_get_zoom(struct SpaceClip *sc,
diff --git a/source/blender/editors/include/ED_curves.h b/source/blender/editors/include/ED_curves.h
index 9233b65b2ce..00831ff7cc3 100644
--- a/source/blender/editors/include/ED_curves.h
+++ b/source/blender/editors/include/ED_curves.h
@@ -6,6 +6,8 @@
 
 #pragma once
 
+struct bContext;
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -19,10 +21,19 @@ void ED_operatortypes_curves(void);
 #ifdef __cplusplus
 
 #  include "BKE_curves.hh"
+#  include "BLI_vector_set.hh"
 
 namespace blender::ed::curves {
 
 bke::CurvesGeometry primitive_random_sphere(int curves_size, int points_per_curve);
+bool has_anything_selected(const Curves &curves_id);
+VectorSet<Curves *> get_unique_editable_curves(const bContext &C);
+void ensure_surface_deformation_node_exists(bContext &C, Object &curves_ob);
 
-}
+bool editable_curves_with_surface_poll(bContext *C);
+bool curves_with_surface_poll(bContext *C);
+bool editable_curves_poll(bContext *C);
+bool curves_poll(bContext *C);
+
+}  // namespace blender::ed::curves
 #endif
diff --git a/source/blender/editors/include/ED_curves_sculpt.h b/source/blender/editors/include/ED_curves_sculpt.h
index 8aab1533e25..b1c0b649d2b 100644
--- a/source/blender/editors/include/ED_curves_sculpt.h
+++ b/source/blender/editors/include/ED_curves_sculpt.h
@@ -10,8 +10,33 @@
 extern "C" {
 #endif
 
+struct Curves;
+
 void ED_operatortypes_sculpt_curves(void);
 
 #ifdef __cplusplus
 }
 #endif
+
+#ifdef __cplusplus
+
+#  include "BLI_index_mask.hh"
+#  include "BLI_vector.hh"
+
+namespace blender::ed::sculpt_paint {
+
+/**
+ * Find curves that have any point selected (a selection factor greater than zero),
+ * or curves that have their own selection factor greater than zero.
+ */
+IndexMask retrieve_selected_curves(const Curves &curves_id, Vector<int64_t> &r_indices);
+
+/**
+ * Find points that are selected (a selection factor greater than zero),
+ * or points in curves with a selection factor greater than zero).
+ */
+IndexMask retrieve_selected_points(const Curves &curves_id, Vector<int64_t> &r_indices);
+
+}  // namespace blender::ed::sculpt_paint
+
+#endif
diff --git a/source/blender/editors/include/ED_datafiles.h b/source/blender/editors/include/ED_datafiles.h
index c3a66e4a7dd..e3b091430e8 100644
--- a/source/blender/editors/include/ED_datafiles.h
+++ b/source/blender/editors/include/ED_datafiles.h
@@ -103,6 +103,9 @@ extern const char datatoc_multiply_png[];
 extern int datatoc_nudge_png_size;
 extern const char datatoc_nudge_png[];
 
+extern int datatoc_paint_select_png_size;
+extern const char datatoc_paint_select_png[];
+
 extern int datatoc_pinch_png_size;
 extern const char datatoc_pinch_png[];
 
@@ -284,6 +287,41 @@ extern const char datatoc_gp_brush_erase_hard_png[];
 extern int datatoc_gp_brush_erase_stroke_png_size;
 extern const char datatoc_gp_brush_erase_stroke_png[];
 
+/* curves sculpt brushes files */
+
+extern int datatoc_curves_sculpt_add_png_size;
+extern const char datatoc_curves_sculpt_add_png[];
+
+extern int datatoc_curves_sculpt_comb_png_size;
+extern const char datatoc_curves_sculpt_comb_png[];
+
+extern int datatoc_curves_sculpt_cut_png_size;
+extern const char datatoc_curves_sculpt_cut_png[];
+
+extern int datatoc_curves_sculpt_delete_png_size;
+extern const char datatoc_curves_sculpt_delete_png[];
+
+extern int datatoc_curves_sculpt_density_png_size;
+extern const char datatoc_curves_sculpt_density_png[];
+
+extern int datatoc_curves_sculpt_grow_shrink_png_size;
+extern const char datatoc_curves_sculpt_grow_shrink_png[];
+
+extern int datatoc_curves_sculpt_pinch_png_size;
+extern const char datatoc_curves_sculpt_pinch_png[];
+
+extern int datatoc_curves_sculpt_puff_png_size;
+extern const char datatoc_curves_sculpt_puff_png[];
+
+extern int datatoc_curves_sculpt_slide_png_size;
+extern const char datatoc_curves_sculpt_slide_png[];
+
+extern int datatoc_curves_sculpt_smooth_png_size;
+extern const char datatoc_curves_sculpt_smooth_png[];
+
+extern int datatoc_curves_sculpt_snake_hook_png_size;
+extern const char datatoc_curves_sculpt_snake_hook_png[];
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/blender/editors/include/ED_fileselect.h b/source/blender/editors/include/ED_fileselect.h
index e9fcd2bd5fe..9d5d8dd54cb 100644
--- a/source/blender/editors/include/ED_fileselect.h
+++ b/source/blender/editors/include/ED_fileselect.h
@@ -175,6 +175,14 @@ struct ScrArea *ED_fileselect_handler_area_find(const struct wmWindow *win,
  */
 struct ScrArea *ED_fileselect_handler_area_find_any_with_op(const struct wmWindow *win);
 
+/**
+ * If filepath property is not set on the operator, sets it to
+ * the blend file path (or untitled if file is not saved yet) with the given extension.
+ */
+void ED_fileselect_ensure_default_filepath(struct bContext *C,
+                                           struct wmOperator *op,
+                                           const char *extension);
+
 /* TODO: Maybe we should move this to BLI?
  * On the other hand, it's using defines from space-file area, so not sure... */
 int ED_path_extension_type(const char *path);
diff --git a/source/blender/editors/include/ED_gpencil.h b/source/blender/editors/include/ED_gpencil.h
index 01f60a81288..45e61592424 100644
--- a/source/blender/editors/include/ED_gpencil.h
+++ b/source/blender/editors/include/ED_gpencil.h
@@ -239,7 +239,7 @@ void ED_annotation_draw_ex(
 
 /* ----------- Grease-Pencil AnimEdit API ------------------ */
 /**
- * Loops over the gp-frames for a gp-layer, and applies the given callback.
+ * Loops over the GP-frames for a GP-layer, and applies the given callback.
  */
 bool ED_gpencil_layer_frames_looper(struct bGPDlayer *gpl,
                                     struct Scene *scene,
@@ -281,6 +281,11 @@ void ED_gpencil_select_frames(struct bGPDlayer *gpl, short select_mode);
 void ED_gpencil_select_frame(struct bGPDlayer *gpl, int selx, short select_mode);
 
 /**
+ * Set the layer's channel as active
+ */
+void ED_gpencil_set_active_channel(struct bGPdata *gpd, struct bGPDlayer *gpl);
+
+/**
  * Delete selected frames.
  */
 bool ED_gpencil_layer_frames_delete(struct bGPDlayer *gpl);
@@ -398,12 +403,11 @@ void ED_gpencil_stroke_init_data(struct bGPDstroke *gps,
  */
 void ED_gpencil_create_blank(struct bContext *C, struct Object *ob, float mat[4][4]);
 /**
- * Add a 2D Suzanne (original model created by Matias Mendiola).
+ * Add a 2D Suzanne.
  */
 void ED_gpencil_create_monkey(struct bContext *C, struct Object *ob, float mat[4][4]);
 /**
- * Add a Simple stroke with colors
- * (original design created by Daniel M. Lara and Matias Mendiola).
+ * Add a Simple stroke with colors.
  */
 void ED_gpencil_create_stroke(struct bContext *C, struct Object *ob, float mat[4][4]);
 /**
@@ -471,7 +475,8 @@ void ED_gpencil_stroke_reproject(struct Depsgraph *depsgraph,
                                  struct bGPDframe *gpf,
                                  struct bGPDstroke *gps,
                                  eGP_ReprojectModes mode,
-                                 bool keep_original);
+                                 bool keep_original,
+                                 const float offset);
 
 /**
  * Turn brush cursor in on/off.
@@ -579,7 +584,7 @@ void ED_gpencil_init_random_settings(struct Brush *brush,
  */
 bool ED_gpencil_stroke_check_collision(const struct GP_SpaceConversion *gsc,
                                        struct bGPDstroke *gps,
-                                       const float mouse[2],
+                                       const float mval[2],
                                        int radius,
                                        const float diff_mat[4][4]);
 /**
@@ -587,13 +592,13 @@ bool ED_gpencil_stroke_check_collision(const struct GP_SpaceConversion *gsc,
  *
  * \param gps: Stroke to check.
  * \param gsc: Space conversion data.
- * \param mouse: Mouse position.
+ * \param mval: Region relative cursor position.
  * \param diff_mat: View matrix.
  * \return True if the point is inside.
  */
 bool ED_gpencil_stroke_point_is_inside(const struct bGPDstroke *gps,
                                        const struct GP_SpaceConversion *gsc,
-                                       const int mouse[2],
+                                       const int mval[2],
                                        const float diff_mat[4][4]);
 /**
  * Get the bigger 2D bound box points.
diff --git a/source/blender/editors/include/ED_image.h b/source/blender/editors/include/ED_image.h
index b16844c01ea..da303f3552b 100644
--- a/source/blender/editors/include/ED_image.h
+++ b/source/blender/editors/include/ED_image.h
@@ -32,14 +32,15 @@ struct wmWindowManager;
 
 float ED_space_image_zoom_level(const struct View2D *v2d, int grid_dimension);
 void ED_space_image_grid_steps(struct SpaceImage *sima,
-                               float grid_steps[SI_GRID_STEPS_LEN],
+                               float grid_steps_x[SI_GRID_STEPS_LEN],
+                               float grid_steps_y[SI_GRID_STEPS_LEN],
                                int grid_dimension);
 /**
  * Calculate the increment snapping value for UV/image editor based on the zoom factor
  * The code in here (except the offset part) is used in `grid_frag.glsl` (see `grid_res`) for
  * drawing the grid overlay for the UV/Image editor.
  */
-float ED_space_image_increment_snap_value(int grid_dimesnions,
+float ED_space_image_increment_snap_value(int grid_dimensions,
                                           const float grid_steps[SI_GRID_STEPS_LEN],
                                           float zoom_factor);
 
@@ -137,8 +138,39 @@ bool ED_space_image_paint_curve(const struct bContext *C);
  * Matches clip function.
  */
 bool ED_space_image_check_show_maskedit(struct SpaceImage *sima, struct Object *obedit);
+
+/* Returns true when the following conditions are met:
+ * - Current space is Image Editor.
+ * - The image editor is not a UV Editor.
+ * - It is set to Mask mode.
+ *
+ * It is not required to have mask opened for editing. */
 bool ED_space_image_maskedit_poll(struct bContext *C);
+
+/* Returns true when the following conditions are met:
+ * - Current space is Image Editor.
+ * - The image editor is not a UV Editor.
+ * - It is set to Mask mode.
+ * - Mask has visible and editable splines.
+ *
+ * It is not required to have mask opened for editing. */
+bool ED_space_image_maskedit_visible_splines_poll(struct bContext *C);
+
+/* Returns true when the following conditions are met:
+ * - Current space is Image Editor.
+ * - The image editor is not an UV Editor.
+ * - It is set to Mask mode.
+ * - The space has mask opened. */
 bool ED_space_image_maskedit_mask_poll(struct bContext *C);
+
+/* Returns true when the following conditions are met:
+ * - Current space is Image Editor.
+ * - The image editor is not an UV Editor.
+ * - It is set to Mask mode.
+ * - The space has mask opened.
+ * - Mask has visible and editable splines. */
+bool ED_space_image_maskedit_mask_visible_splines_poll(struct bContext *C);
+
 bool ED_space_image_cursor_poll(struct bContext *C);
 
 /**
diff --git a/source/blender/editors/include/ED_keyframes_edit.h b/source/blender/editors/include/ED_keyframes_edit.h
index 163797d395d..e5bcdcdd282 100644
--- a/source/blender/editors/include/ED_keyframes_edit.h
+++ b/source/blender/editors/include/ED_keyframes_edit.h
@@ -229,6 +229,16 @@ typedef enum eKeyMergeMode {
   KEYFRAME_PASTE_MERGE_OVER_RANGE_ALL,
 } eKeyMergeMode;
 
+/* Possible errors occurring while pasting keys. */
+typedef enum eKeyPasteError {
+  /* No errors occurred */
+  KEYFRAME_PASTE_OK,
+  /* Nothing was copied */
+  KEYFRAME_PASTE_NOTHING_TO_PASTE,
+  /* No F-curves was selected to paste into. */
+  KEYFRAME_PASTE_NOWHERE_TO_PASTE
+} eKeyPasteError;
+
 /** \} */
 
 /* -------------------------------------------------------------------- */
@@ -378,9 +388,6 @@ bool keyframe_region_circle_test(const KeyframeEdit_CircleData *data_circle, con
 /* ************************************************ */
 /* Destructive Editing API (keyframes_general.c) */
 
-void delete_fcurve_key(struct FCurve *fcu, int index, bool do_recalc);
-bool delete_fcurve_keys(struct FCurve *fcu);
-void clear_fcurve_keys(struct FCurve *fcu);
 bool duplicate_fcurve_keys(struct FCurve *fcu);
 float get_default_rna_value(struct FCurve *fcu, struct PropertyRNA *prop, struct PointerRNA *ptr);
 
@@ -416,11 +423,11 @@ void sample_fcurve(struct FCurve *fcu);
 
 void ANIM_fcurves_copybuf_free(void);
 short copy_animedit_keys(struct bAnimContext *ac, ListBase *anim_data);
-short paste_animedit_keys(struct bAnimContext *ac,
-                          ListBase *anim_data,
-                          eKeyPasteOffset offset_mode,
-                          eKeyMergeMode merge_mode,
-                          bool flip);
+eKeyPasteError paste_animedit_keys(struct bAnimContext *ac,
+                                   ListBase *anim_data,
+                                   eKeyPasteOffset offset_mode,
+                                   eKeyMergeMode merge_mode,
+                                   bool flip);
 
 /* ************************************************ */
 
diff --git a/source/blender/editors/include/ED_mask.h b/source/blender/editors/include/ED_mask.h
index 7039d6d9fc7..8cadbfde185 100644
--- a/source/blender/editors/include/ED_mask.h
+++ b/source/blender/editors/include/ED_mask.h
@@ -22,6 +22,34 @@ struct wmKeyConfig;
 
 /* mask_edit.c */
 
+/* Returns true when the following conditions are met:
+ * - Current space supports mask editing.
+ * - The space is configured to interact with mask.
+ *
+ * It is not required to have mask opened for editing. */
+bool ED_maskedit_poll(struct bContext *C);
+
+/* Returns true when the following conditions are met:
+ * - Current space supports mask editing.
+ * - The space is configured to interact with mask.
+ * - Mask has visible and editable splines.
+ *
+ * It is not required to have mask opened for editing. */
+bool ED_maskedit_visible_splines_poll(struct bContext *C);
+
+/* Returns true when the following conditions are met:
+ * - Current space supports mask editing.
+ * - The space is configured to interact with mask.
+ * - The space has mask open for editing. */
+bool ED_maskedit_mask_poll(struct bContext *C);
+
+/* Returns true when the following conditions are met:
+ * - Current space supports mask editing.
+ * - The space is configured to interact with mask.
+ * - The space has mask opened.
+ * - Mask has visible and editable splines. */
+bool ED_maskedit_mask_visible_splines_poll(struct bContext *C);
+
 void ED_mask_deselect_all(const struct bContext *C);
 
 void ED_operatortypes_mask(void);
@@ -73,6 +101,7 @@ void ED_mask_draw_region(struct Depsgraph *depsgraph,
                          char draw_flag,
                          char draw_type,
                          eMaskOverlayMode overlay_mode,
+                         float blend_factor,
                          int width_i,
                          int height_i,
                          float aspx,
diff --git a/source/blender/editors/include/ED_mesh.h b/source/blender/editors/include/ED_mesh.h
index 30a98129ee6..a47ffe0b99a 100644
--- a/source/blender/editors/include/ED_mesh.h
+++ b/source/blender/editors/include/ED_mesh.h
@@ -137,14 +137,17 @@ void EDBM_update_extern(struct Mesh *me, bool do_tessellation, bool is_destructi
  */
 struct UvElementMap *BM_uv_element_map_create(struct BMesh *bm,
                                               const struct Scene *scene,
-                                              bool face_selected,
                                               bool uv_selected,
                                               bool use_winding,
+                                              bool use_seams,
                                               bool do_islands);
 void BM_uv_element_map_free(struct UvElementMap *element_map);
-struct UvElement *BM_uv_element_get(struct UvElementMap *map,
-                                    struct BMFace *efa,
-                                    struct BMLoop *l);
+struct UvElement *BM_uv_element_get(const struct UvElementMap *map,
+                                    const struct BMFace *efa,
+                                    const struct BMLoop *l);
+struct UvElement *BM_uv_element_get_head(struct UvElementMap *map, struct UvElement *child);
+
+struct UvElement **BM_uv_element_map_ensure_head_table(struct UvElementMap *element_map);
 
 /**
  * Can we edit UV's for this mesh?
@@ -181,16 +184,20 @@ void EDBM_project_snap_verts(struct bContext *C,
 
 /* editmesh_automerge.c */
 
-void EDBM_automerge(struct Object *ob, bool update, char hflag, float dist);
-void EDBM_automerge_and_split(
-    struct Object *ob, bool split_edges, bool split_faces, bool update, char hflag, float dist);
+void EDBM_automerge(struct Object *obedit, bool update, char hflag, float dist);
+void EDBM_automerge_and_split(struct Object *obedit,
+                              bool split_edges,
+                              bool split_faces,
+                              bool update,
+                              char hflag,
+                              float dist);
 
 /* editmesh_undo.c */
 
 /** Export for ED_undo_sys. */
 void ED_mesh_undosys_type(struct UndoType *ut);
 
-/* editmesh_select.c */
+/* editmesh_select.cc */
 
 void EDBM_select_mirrored(struct BMEditMesh *em,
                           const struct Mesh *me,
@@ -390,7 +397,10 @@ void ED_keymap_mesh(struct wmKeyConfig *keyconf);
  * Copy the face flags, most importantly selection from the mesh to the final derived mesh,
  * use in object mode when selecting faces (while painting).
  */
-void paintface_flush_flags(struct bContext *C, struct Object *ob, short flag);
+void paintface_flush_flags(struct bContext *C,
+                           struct Object *ob,
+                           bool flush_selection,
+                           bool flush_hidden);
 /**
  * \return True when pick finds an element or the selection changed.
  */
@@ -425,6 +435,9 @@ void paintvert_select_ungrouped(struct Object *ob, bool extend, bool flush_flags
 void paintvert_flush_flags(struct Object *ob);
 void paintvert_tag_select_update(struct bContext *C, struct Object *ob);
 
+void paintvert_hide(struct bContext *C, struct Object *ob, bool unselected);
+void paintvert_reveal(struct bContext *C, struct Object *ob, bool select);
+
 /* mirrtopo */
 typedef struct MirrTopoStore_t {
   intptr_t *index_lookup;
@@ -442,7 +455,7 @@ void ED_mesh_mirrtopo_init(struct BMEditMesh *em,
                            bool skip_em_vert_array_init);
 void ED_mesh_mirrtopo_free(MirrTopoStore_t *mesh_topo_store);
 
-/* object_vgroup.c */
+/* object_vgroup.cc */
 
 #define WEIGHT_REPLACE 1
 #define WEIGHT_ADD 2
@@ -550,16 +563,10 @@ void ED_mesh_uv_loop_reset_ex(struct Mesh *me, int layernum);
 bool ED_mesh_color_ensure(struct Mesh *me, const char *name);
 int ED_mesh_color_add(
     struct Mesh *me, const char *name, bool active_set, bool do_init, struct ReportList *reports);
-bool ED_mesh_color_remove_index(struct Mesh *me, int n);
-bool ED_mesh_color_remove_active(struct Mesh *me);
-bool ED_mesh_color_remove_named(struct Mesh *me, const char *name);
-
-bool ED_mesh_sculpt_color_ensure(struct Mesh *me, const char *name);
-int ED_mesh_sculpt_color_add(
-    struct Mesh *me, const char *name, bool active_set, bool do_init, struct ReportList *reports);
-bool ED_mesh_sculpt_color_remove_index(struct Mesh *me, int n);
-bool ED_mesh_sculpt_color_remove_active(struct Mesh *me);
-bool ED_mesh_sculpt_color_remove_named(struct Mesh *me, const char *name);
+int ED_mesh_sculpt_color_add(struct Mesh *me,
+                             const char *name,
+                             bool do_init,
+                             struct ReportList *reports);
 
 void ED_mesh_report_mirror(struct wmOperator *op, int totmirr, int totfail);
 void ED_mesh_report_mirror_ex(struct wmOperator *op, int totmirr, int totfail, char selectmode);
diff --git a/source/blender/editors/include/ED_object.h b/source/blender/editors/include/ED_object.h
index 39c7ad3556c..acb0e53aa55 100644
--- a/source/blender/editors/include/ED_object.h
+++ b/source/blender/editors/include/ED_object.h
@@ -112,6 +112,7 @@ struct XFormObjectSkipChild_Container;
 struct XFormObjectSkipChild_Container *ED_object_xform_skip_child_container_create(void);
 void ED_object_xform_skip_child_container_item_ensure_from_array(
     struct XFormObjectSkipChild_Container *xcs,
+    const struct Scene *scene,
     struct ViewLayer *view_layer,
     struct Object **objects,
     uint objects_len);
@@ -213,16 +214,20 @@ void ED_object_base_free_and_unlink(struct Main *bmain, struct Scene *scene, str
 void ED_object_base_free_and_unlink_no_indirect_check(struct Main *bmain,
                                                       struct Scene *scene,
                                                       struct Object *ob);
-bool ED_object_base_deselect_all_ex(struct ViewLayer *view_layer,
+bool ED_object_base_deselect_all_ex(const struct Scene *scene,
+                                    struct ViewLayer *view_layer,
                                     struct View3D *v3d,
                                     int action,
                                     bool *r_any_visible);
-bool ED_object_base_deselect_all(struct ViewLayer *view_layer, struct View3D *v3d, int action);
+bool ED_object_base_deselect_all(const struct Scene *scene,
+                                 struct ViewLayer *view_layer,
+                                 struct View3D *v3d,
+                                 int action);
 
 /**
  * Single object duplicate, if `dupflag == 0`, fully linked, else it uses the flags given.
  * Leaves selection of base/object unaltered.
- * \note don't call this within a loop since clear_* funcs loop over the entire database.
+ * \note don't call this within a loop since clear_* functions loop over the entire database.
  * \note caller must do `DAG_relations_tag_update(bmain);`
  * this is not done automatic since we may duplicate many objects in a batch.
  */
@@ -539,6 +544,7 @@ bool ED_object_modifier_move_to_index(struct ReportList *reports,
 bool ED_object_modifier_convert_psys_to_mesh(struct ReportList *reports,
                                              struct Main *bmain,
                                              struct Depsgraph *depsgraph,
+                                             struct Scene *scene,
                                              struct ViewLayer *view_layer,
                                              struct Object *ob,
                                              struct ModifierData *md);
@@ -662,7 +668,9 @@ void ED_object_check_force_modifiers(struct Main *bmain,
  * If id is not already an Object, try to find an object that uses it as data.
  * Prefers active, then selected, then visible/selectable.
  */
-struct Base *ED_object_find_first_by_data_id(struct ViewLayer *view_layer, struct ID *id);
+struct Base *ED_object_find_first_by_data_id(const struct Scene *scene,
+                                             struct ViewLayer *view_layer,
+                                             struct ID *id);
 
 /**
  * Select and make the target object active in the view layer.
diff --git a/source/blender/editors/include/ED_paint.h b/source/blender/editors/include/ED_paint.h
index ba5834fd508..048424cdee1 100644
--- a/source/blender/editors/include/ED_paint.h
+++ b/source/blender/editors/include/ED_paint.h
@@ -22,6 +22,7 @@ struct UndoType;
 struct bContext;
 struct wmKeyConfig;
 struct wmOperator;
+typedef struct PaintTileMap PaintTileMap;
 
 /* paint_ops.c */
 
@@ -76,7 +77,7 @@ void ED_image_undo_restore(struct UndoStep *us);
 /** Export for ED_undo_sys. */
 void ED_image_undosys_type(struct UndoType *ut);
 
-void *ED_image_paint_tile_find(struct ListBase *paint_tiles,
+void *ED_image_paint_tile_find(PaintTileMap *paint_tile_map,
                                struct Image *image,
                                struct ImBuf *ibuf,
                                struct ImageUser *iuser,
@@ -84,7 +85,7 @@ void *ED_image_paint_tile_find(struct ListBase *paint_tiles,
                                int y_tile,
                                unsigned short **r_mask,
                                bool validate);
-void *ED_image_paint_tile_push(struct ListBase *paint_tiles,
+void *ED_image_paint_tile_push(PaintTileMap *paint_tile_map,
                                struct Image *image,
                                struct ImBuf *ibuf,
                                struct ImBuf **tmpibuf,
@@ -98,7 +99,7 @@ void *ED_image_paint_tile_push(struct ListBase *paint_tiles,
 void ED_image_paint_tile_lock_init(void);
 void ED_image_paint_tile_lock_end(void);
 
-struct ListBase *ED_image_paint_tile_list_get(void);
+struct PaintTileMap *ED_image_paint_tile_map_get(void);
 
 #define ED_IMAGE_UNDO_TILE_BITS 6
 #define ED_IMAGE_UNDO_TILE_SIZE (1 << ED_IMAGE_UNDO_TILE_BITS)
diff --git a/source/blender/editors/include/ED_screen.h b/source/blender/editors/include/ED_screen.h
index aa62a6209e4..e1fd53ccdee 100644
--- a/source/blender/editors/include/ED_screen.h
+++ b/source/blender/editors/include/ED_screen.h
@@ -294,7 +294,7 @@ void ED_screen_refresh(struct wmWindowManager *wm, struct wmWindow *win);
 void ED_screen_ensure_updated(struct wmWindowManager *wm,
                               struct wmWindow *win,
                               struct bScreen *screen);
-void ED_screen_do_listen(struct bContext *C, struct wmNotifier *note);
+void ED_screen_do_listen(struct bContext *C, const struct wmNotifier *note);
 /**
  * \brief Change the active screen.
  *
@@ -353,8 +353,8 @@ struct ScrArea *ED_screen_state_toggle(struct bContext *C,
                                        struct ScrArea *area,
                                        short state);
 /**
- * Wrapper to open a temporary space either as fullscreen space, or as separate window, as defined
- * by \a display_type.
+ * Wrapper to open a temporary space either as full-screen space, or as separate window,
+ * as defined by \a display_type.
  *
  * \param title: Title to set for the window, if a window is spawned.
  * \param x, y: Position of the window, if a window is spawned.
@@ -469,6 +469,8 @@ bool ED_workspace_layout_cycle(struct WorkSpace *workspace, short direction, str
 
 void ED_workspace_status_text(struct bContext *C, const char *str);
 
+void ED_workspace_do_listen(struct bContext *C, const struct wmNotifier *note);
+
 /* anim */
 /**
  * Results in fully updated anim system.
@@ -595,7 +597,6 @@ bool ED_operator_object_active_local_editable_posemode_exclusive(struct bContext
 bool ED_operator_posemode_context(struct bContext *C);
 bool ED_operator_posemode(struct bContext *C);
 bool ED_operator_posemode_local(struct bContext *C);
-bool ED_operator_mask(struct bContext *C);
 bool ED_operator_camera_poll(struct bContext *C);
 
 /* screen_user_menu.c */
diff --git a/source/blender/editors/include/ED_screen_types.h b/source/blender/editors/include/ED_screen_types.h
index 21bb412d072..bf64be9f7a7 100644
--- a/source/blender/editors/include/ED_screen_types.h
+++ b/source/blender/editors/include/ED_screen_types.h
@@ -112,7 +112,7 @@ enum {
    */
   AZONE_REGION,
   /**
-   * Used when in editor fullscreen draw a corner to return to normal mode.
+   * Used when in editor full-screen draw a corner to return to normal mode.
    */
   AZONE_FULLSCREEN,
   /**
diff --git a/source/blender/editors/include/ED_sculpt.h b/source/blender/editors/include/ED_sculpt.h
index 54d67c50d5c..1c1ce41ef7a 100644
--- a/source/blender/editors/include/ED_sculpt.h
+++ b/source/blender/editors/include/ED_sculpt.h
@@ -20,6 +20,7 @@ struct rcti;
 struct wmMsgSubscribeKey;
 struct wmMsgSubscribeValue;
 struct wmRegionMessageSubscribeParams;
+struct wmOperator;
 
 /* sculpt.c */
 
@@ -33,7 +34,10 @@ bool ED_sculpt_mask_box_select(struct bContext *C,
 /* sculpt_transform.c */
 
 void ED_sculpt_update_modal_transform(struct bContext *C, struct Object *ob);
-void ED_sculpt_init_transform(struct bContext *C, struct Object *ob);
+void ED_sculpt_init_transform(struct bContext *C,
+                              struct Object *ob,
+                              const int mval[2],
+                              const char *undo_name);
 void ED_sculpt_end_transform(struct bContext *C, struct Object *ob);
 
 /* sculpt_undo.c */
@@ -41,7 +45,13 @@ void ED_sculpt_end_transform(struct bContext *C, struct Object *ob);
 /** Export for ED_undo_sys. */
 void ED_sculpt_undosys_type(struct UndoType *ut);
 
-void ED_sculpt_undo_geometry_begin(struct Object *ob, const char *name);
+/**
+ * Pushes an undo step using the operator name. This is necessary for
+ * redo panels to work; operators that do not support that may use
+ * #ED_sculpt_undo_geometry_begin_ex instead if so desired.
+ */
+void ED_sculpt_undo_geometry_begin(struct Object *ob, const struct wmOperator *op);
+void ED_sculpt_undo_geometry_begin_ex(struct Object *ob, const char *name);
 void ED_sculpt_undo_geometry_end(struct Object *ob);
 
 /* Face sets. */
@@ -51,7 +61,7 @@ void ED_sculpt_face_sets_initialize_none_to_id(struct Mesh *mesh, int new_id);
 
 int ED_sculpt_face_sets_active_update_and_get(struct bContext *C,
                                               struct Object *ob,
-                                              const float mval[2]);
+                                              const float mval_fl[2]);
 
 /* Undo for changes happening on a base mesh for multires sculpting.
  * if there is no multi-res sculpt active regular undo is used. */
diff --git a/source/blender/editors/include/ED_select_utils.h b/source/blender/editors/include/ED_select_utils.h
index fa02ebe18f6..8c856794ec8 100644
--- a/source/blender/editors/include/ED_select_utils.h
+++ b/source/blender/editors/include/ED_select_utils.h
@@ -40,11 +40,11 @@ typedef enum {
 } eSelectOp;
 
 /* Select Similar */
-enum {
+typedef enum {
   SIM_CMP_EQ = 0,
   SIM_CMP_GT,
   SIM_CMP_LT,
-};
+} eSimilarCmp;
 
 #define SEL_OP_USE_OUTSIDE(sel_op) (ELEM(sel_op, SEL_OP_AND))
 #define SEL_OP_USE_PRE_DESELECT(sel_op) (ELEM(sel_op, SEL_OP_SET))
@@ -63,11 +63,11 @@ int ED_select_op_action(eSelectOp sel_op, bool is_select, bool is_inside);
  */
 int ED_select_op_action_deselected(eSelectOp sel_op, bool is_select, bool is_inside);
 
-int ED_select_similar_compare_float(float delta, float thresh, int compare);
+bool ED_select_similar_compare_float(float delta, float thresh, eSimilarCmp compare);
 bool ED_select_similar_compare_float_tree(const struct KDTree_1d *tree,
                                           float length,
                                           float thresh,
-                                          int compare);
+                                          eSimilarCmp compare);
 
 /**
  * Utility to use for selection operations that run multiple times (circle select).
diff --git a/source/blender/editors/include/ED_space_api.h b/source/blender/editors/include/ED_space_api.h
index c69698f3f73..07d4f43bb2b 100644
--- a/source/blender/editors/include/ED_space_api.h
+++ b/source/blender/editors/include/ED_space_api.h
@@ -50,7 +50,7 @@ void ED_spacetype_spreadsheet(void);
 /** \} */
 
 /* -------------------------------------------------------------------- */
-/** \name Spacetype Static Data
+/** \name Space-type Static Data
  * Calls for instancing and freeing space-type static data called in #WM_init_exit
  * \{ */
 
diff --git a/source/blender/editors/include/ED_spreadsheet.h b/source/blender/editors/include/ED_spreadsheet.h
index da13e6d3636..736da367a44 100644
--- a/source/blender/editors/include/ED_spreadsheet.h
+++ b/source/blender/editors/include/ED_spreadsheet.h
@@ -7,7 +7,6 @@ struct Main;
 struct Object;
 struct SpaceNode;
 struct SpaceSpreadsheet;
-struct SpreadsheetContext;
 struct bContext;
 struct bNode;
 
@@ -15,29 +14,8 @@ struct bNode;
 extern "C" {
 #endif
 
-struct SpreadsheetContext *ED_spreadsheet_context_new(int type);
-void ED_spreadsheet_context_free(struct SpreadsheetContext *context);
-void ED_spreadsheet_context_path_clear(struct SpaceSpreadsheet *sspreadsheet);
-bool ED_spreadsheet_context_path_update_tag(struct SpaceSpreadsheet *sspreadsheet);
-uint64_t ED_spreadsheet_context_path_hash(const struct SpaceSpreadsheet *sspreadsheet);
-
 struct ID *ED_spreadsheet_get_current_id(const struct SpaceSpreadsheet *sspreadsheet);
 
-void ED_spreadsheet_context_path_set_geometry_node(struct SpaceSpreadsheet *sspreadsheet,
-                                                   struct SpaceNode *snode,
-                                                   struct bNode *node);
-void ED_spreadsheet_context_paths_set_geometry_node(struct Main *bmain,
-                                                    struct SpaceNode *snode,
-                                                    struct bNode *node);
-void ED_spreadsheet_context_path_set_evaluated_object(struct SpaceSpreadsheet *sspreadsheet,
-                                                      struct Object *object);
-
-void ED_spreadsheet_context_path_guess(const struct bContext *C,
-                                       struct SpaceSpreadsheet *sspreadsheet);
-bool ED_spreadsheet_context_path_is_active(const struct bContext *C,
-                                           struct SpaceSpreadsheet *sspreadsheet);
-bool ED_spreadsheet_context_path_exists(struct Main *bmain, struct SpaceSpreadsheet *sspreadsheet);
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/blender/editors/include/ED_transform.h b/source/blender/editors/include/ED_transform.h
index 82cc518f029..d7fb108809f 100644
--- a/source/blender/editors/include/ED_transform.h
+++ b/source/blender/editors/include/ED_transform.h
@@ -94,7 +94,8 @@ bool BIF_createTransformOrientation(struct bContext *C,
                                     bool overwrite);
 void BIF_selectTransformOrientation(struct bContext *C, struct TransformOrientation *target);
 
-void ED_getTransformOrientationMatrix(struct ViewLayer *view_layer,
+void ED_getTransformOrientationMatrix(const struct Scene *scene,
+                                      struct ViewLayer *view_layer,
                                       const struct View3D *v3d,
                                       struct Object *ob,
                                       struct Object *obedit,
diff --git a/source/blender/editors/include/ED_transform_snap_object_context.h b/source/blender/editors/include/ED_transform_snap_object_context.h
index 20353c21f93..f9ca578f282 100644
--- a/source/blender/editors/include/ED_transform_snap_object_context.h
+++ b/source/blender/editors/include/ED_transform_snap_object_context.h
@@ -57,9 +57,13 @@ struct SnapObjectParams {
   /* Geometry for snapping in edit mode. */
   eSnapEditType edit_mode_type;
   /* snap to the closest element, use when using more than one snap type */
-  bool use_occlusion_test : true;
+  bool use_occlusion_test : 1;
   /* exclude back facing geometry from snapping */
-  bool use_backface_culling : true;
+  bool use_backface_culling : 1;
+  /* Break nearest face snapping into steps to improve transformations across U-shaped targets. */
+  short face_nearest_steps;
+  /* Enable to force nearest face snapping to snap to target the source was initially near. */
+  bool keep_on_same_target : 1;
 };
 
 typedef struct SnapObjectContext SnapObjectContext;
@@ -114,12 +118,33 @@ bool ED_transform_snap_object_project_ray_all(SnapObjectContext *sctx,
                                               bool sort,
                                               struct ListBase *r_hit_list);
 
+/**
+ * Perform snapping.
+ *
+ * Given a 2D region value, snap to vert/edge/face/grid.
+ *
+ * \param sctx: Snap context.
+ * \param snap_to: Target elements to snap source to.
+ * \param params: Addition snapping options.
+ * \param init_co: Initial world-space coordinate of source (optional).
+ * \param mval: Current transformed screen-space coordinate or mouse position (optional).
+ * \param prev_co: Current transformed world-space coordinate of source (optional).
+ * \param dist_px: Maximum distance to snap (in pixels).
+ * \param r_loc: Snapped world-space coordinate.
+ * \param r_no: Snapped world-space normal (optional).
+ * \param r_index: Index of snapped-to target element (optional).
+ * \param r_ob: Snapped-to target object (optional).
+ * \param r_obmat: Matrix of snapped-to target object (optional).
+ * \param r_face_nor: World-space normal of snapped-to target face (optional).
+ * \return Snapped-to element, #eSnapMode.
+ */
 eSnapMode ED_transform_snap_object_project_view3d_ex(struct SnapObjectContext *sctx,
                                                      struct Depsgraph *depsgraph,
                                                      const ARegion *region,
                                                      const View3D *v3d,
-                                                     eSnapMode snap_to,
+                                                     const eSnapMode snap_to,
                                                      const struct SnapObjectParams *params,
+                                                     const float init_co[3],
                                                      const float mval[2],
                                                      const float prev_co[3],
                                                      float *dist_px,
@@ -135,19 +160,23 @@ eSnapMode ED_transform_snap_object_project_view3d_ex(struct SnapObjectContext *s
  * Given a 2D region value, snap to vert/edge/face.
  *
  * \param sctx: Snap context.
- * \param mval: Screenspace coordinate.
- * \param prev_co: Coordinate for perpendicular point calculation (optional).
+ * \param snap_to: Target elements to snap source to.
+ * \param params: Addition snapping options.
+ * \param init_co: Initial world-space coordinate of source (optional).
+ * \param mval: Current transformed screen-space coordinate or mouse position (optional).
+ * \param prev_co: Current transformed world-space coordinate of source (optional).
  * \param dist_px: Maximum distance to snap (in pixels).
- * \param r_loc: hit location.
- * \param r_no: hit normal (optional).
- * \return Snap success.
+ * \param r_loc: Snapped world-space coordinate.
+ * \param r_no: Snapped world-space normal (optional).
+ * \return Snapped-to element, #eSnapMode.
  */
 eSnapMode ED_transform_snap_object_project_view3d(struct SnapObjectContext *sctx,
                                                   struct Depsgraph *depsgraph,
                                                   const ARegion *region,
                                                   const View3D *v3d,
-                                                  eSnapMode snap_to,
+                                                  const eSnapMode snap_to,
                                                   const struct SnapObjectParams *params,
+                                                  const float init_co[3],
                                                   const float mval[2],
                                                   const float prev_co[3],
                                                   float *dist_px,
diff --git a/source/blender/editors/include/ED_types.h b/source/blender/editors/include/ED_types.h
deleted file mode 100644
index eba93ed6744..00000000000
--- a/source/blender/editors/include/ED_types.h
+++ /dev/null
@@ -1,27 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later
- * Copyright 2008 Blender Foundation. All rights reserved. */
-
-/** \file
- * \ingroup editors
- */
-
-#pragma once
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/* **************** GENERAL EDITOR-WIDE TYPES AND DEFINES ************************** */
-
-/* old blender defines... should be deprecated? */
-#define DESELECT 0
-#define SELECT 1
-#define ACTIVE 2
-
-/* proposal = put scene pointers on function calls? */
-// #define BASACT                    (scene->basact)
-// #define OBACT                     (BASACT ? BASACT->object : NULL)
-
-#ifdef __cplusplus
-}
-#endif
diff --git a/source/blender/editors/include/ED_undo.h b/source/blender/editors/include/ED_undo.h
index 8c5f25e6b67..39bbd8adc75 100644
--- a/source/blender/editors/include/ED_undo.h
+++ b/source/blender/editors/include/ED_undo.h
@@ -15,6 +15,7 @@ extern "C" {
 struct Base;
 struct CLG_LogRef;
 struct Object;
+struct Scene;
 struct UndoStack;
 struct ViewLayer;
 struct bContext;
@@ -79,9 +80,12 @@ void ED_undo_object_editmode_restore_helper(struct bContext *C,
                                             uint object_array_len,
                                             uint object_array_stride);
 
-struct Object **ED_undo_editmode_objects_from_view_layer(struct ViewLayer *view_layer,
+struct Object **ED_undo_editmode_objects_from_view_layer(const struct Scene *scene,
+                                                         struct ViewLayer *view_layer,
                                                          uint *r_len);
-struct Base **ED_undo_editmode_bases_from_view_layer(struct ViewLayer *view_layer, uint *r_len);
+struct Base **ED_undo_editmode_bases_from_view_layer(const struct Scene *scene,
+                                                     struct ViewLayer *view_layer,
+                                                     uint *r_len);
 
 /**
  * Ideally we won't access the stack directly,
diff --git a/source/blender/editors/include/ED_uvedit.h b/source/blender/editors/include/ED_uvedit.h
index 80a75da27f8..b499ae0ce59 100644
--- a/source/blender/editors/include/ED_uvedit.h
+++ b/source/blender/editors/include/ED_uvedit.h
@@ -107,7 +107,7 @@ bool uvedit_uv_select_test(const struct Scene *scene, struct BMLoop *l, int cd_l
  * Changes selection state of a single UV Face.
  */
 void uvedit_face_select_set(const struct Scene *scene,
-                            struct BMEditMesh *em,
+                            struct BMesh *bm,
                             struct BMFace *efa,
                             bool select,
                             bool do_history,
@@ -118,7 +118,7 @@ void uvedit_face_select_set(const struct Scene *scene,
  * Changes selection state of a single UV Edge.
  */
 void uvedit_edge_select_set(const struct Scene *scene,
-                            struct BMEditMesh *em,
+                            struct BMesh *bm,
                             struct BMLoop *l,
                             bool select,
                             bool do_history,
@@ -129,7 +129,7 @@ void uvedit_edge_select_set(const struct Scene *scene,
  * Changes selection state of a single UV vertex.
  */
 void uvedit_uv_select_set(const struct Scene *scene,
-                          struct BMEditMesh *em,
+                          struct BMesh *bm,
                           struct BMLoop *l,
                           bool select,
                           bool do_history,
@@ -139,30 +139,30 @@ void uvedit_uv_select_set(const struct Scene *scene,
  * use. */
 
 void uvedit_face_select_enable(const struct Scene *scene,
-                               struct BMEditMesh *em,
+                               struct BMesh *bm,
                                struct BMFace *efa,
                                bool do_history,
                                int cd_loop_uv_offset);
 void uvedit_face_select_disable(const struct Scene *scene,
-                                struct BMEditMesh *em,
+                                struct BMesh *bm,
                                 struct BMFace *efa,
                                 int cd_loop_uv_offset);
 void uvedit_edge_select_enable(const struct Scene *scene,
-                               struct BMEditMesh *em,
+                               struct BMesh *bm,
                                struct BMLoop *l,
                                bool do_history,
                                int cd_loop_uv_offset);
 void uvedit_edge_select_disable(const struct Scene *scene,
-                                struct BMEditMesh *em,
+                                struct BMesh *bm,
                                 struct BMLoop *l,
                                 int cd_loop_uv_offset);
 void uvedit_uv_select_enable(const struct Scene *scene,
-                             struct BMEditMesh *em,
+                             struct BMesh *bm,
                              struct BMLoop *l,
                              bool do_history,
                              int cd_loop_uv_offset);
 void uvedit_uv_select_disable(const struct Scene *scene,
-                              struct BMEditMesh *em,
+                              struct BMesh *bm,
                               struct BMLoop *l,
                               int cd_loop_uv_offset);
 
@@ -179,13 +179,13 @@ void uvedit_edge_select_set_with_sticky(const struct Scene *scene,
                                         struct BMLoop *l,
                                         bool select,
                                         bool do_history,
-                                        uint cd_loop_uv_offset);
+                                        int cd_loop_uv_offset);
 void uvedit_uv_select_set_with_sticky(const struct Scene *scene,
                                       struct BMEditMesh *em,
                                       struct BMLoop *l,
                                       bool select,
                                       bool do_history,
-                                      uint cd_loop_uv_offset);
+                                      int cd_loop_uv_offset);
 
 /* Low level functions for sticky element selection (sticky mode independent). Type of sticky
  * selection is specified explicitly (using sticky_flag, except for face selection). */
@@ -305,6 +305,29 @@ void ED_uvedit_buttons_register(struct ARegionType *art);
 
 /* uvedit_islands.c */
 
+struct FaceIsland {
+  struct FaceIsland *next;
+  struct FaceIsland *prev;
+  struct BMFace **faces;
+  int faces_len;
+  rctf bounds_rect;
+  /**
+   * \note While this is duplicate information,
+   * it allows islands from multiple meshes to be stored in the same list.
+   */
+  int cd_loop_uv_offset;
+  float aspect_y;
+};
+
+int bm_mesh_calc_uv_islands(const Scene *scene,
+                            struct BMesh *bm,
+                            ListBase *island_list,
+                            const bool only_selected_faces,
+                            const bool only_selected_uvs,
+                            const bool use_seams,
+                            const float aspect_y,
+                            const int cd_loop_uv_offset);
+
 struct UVMapUDIM_Params {
   const struct Image *image;
   /** Copied from #SpaceImage.tile_grid_shape */
@@ -318,8 +341,6 @@ bool ED_uvedit_udim_params_from_image_space(const struct SpaceImage *sima,
 
 struct UVPackIsland_Params {
   uint rotate : 1;
-  /** -1 not to align to axis, otherwise 0,1 for X,Y. */
-  int rotate_align_axis : 2;
   uint only_selected_uvs : 1;
   uint only_selected_faces : 1;
   uint use_seams : 1;
diff --git a/source/blender/editors/include/ED_view3d.h b/source/blender/editors/include/ED_view3d.h
index 0298983ed26..52aa5f56fee 100644
--- a/source/blender/editors/include/ED_view3d.h
+++ b/source/blender/editors/include/ED_view3d.h
@@ -228,6 +228,7 @@ typedef enum {
   /** outside range (mainly for short), (can't avoid) */
   V3D_PROJ_RET_OVERFLOW = 6,
 } eV3DProjStatus;
+ENUM_OPERATORS(eV3DProjStatus, V3D_PROJ_RET_OVERFLOW);
 
 /* some clipping tests are optional */
 typedef enum {
@@ -350,7 +351,7 @@ void ED_view3d_cursor_snap_draw_util(struct RegionView3D *rv3d,
                                      const uchar color_point[4],
                                      eSnapMode snap_elem_type);
 
-/* view3d_iterators.c */
+/* view3d_iterators.cc */
 
 /* foreach iterators */
 
@@ -456,7 +457,9 @@ void ED_view3d_project_float_v3_m4(const struct ARegion *region,
                                    float r_co[3],
                                    const float mat[4][4]);
 
-eV3DProjStatus ED_view3d_project_base(const struct ARegion *region, struct Base *base);
+eV3DProjStatus ED_view3d_project_base(const struct ARegion *region,
+                                      struct Base *base,
+                                      float r_co[2]);
 
 /* *** short *** */
 eV3DProjStatus ED_view3d_project_short_ex(const struct ARegion *region,
@@ -711,7 +714,7 @@ bool ED_view3d_win_to_segment_clipped(const struct Depsgraph *depsgraph,
                                       float r_ray_start[3],
                                       float r_ray_end[3],
                                       bool do_clip_planes);
-void ED_view3d_ob_project_mat_get(const struct RegionView3D *v3d,
+void ED_view3d_ob_project_mat_get(const struct RegionView3D *rv3d,
                                   const struct Object *ob,
                                   float r_pmat[4][4]);
 void ED_view3d_ob_project_mat_get_from_obmat(const struct RegionView3D *rv3d,
@@ -950,7 +953,7 @@ int view3d_opengl_select_with_id_filter(struct ViewContext *vc,
                                         eV3DSelectObjectFilter select_filter,
                                         uint select_id);
 
-/* view3d_select.c */
+/* view3d_select.cc */
 
 float ED_view3d_select_dist_px(void);
 void ED_view3d_viewcontext_init(struct bContext *C,
@@ -1171,7 +1174,7 @@ void ED_view3d_camera_lock_init(const struct Depsgraph *depsgraph,
  *
  * Apply the 3D Viewport transformation back to the camera object.
  *
- * \return true if the camera is moved.
+ * \return true if the camera (or one of it's parents) was moved.
  */
 bool ED_view3d_camera_lock_sync(const struct Depsgraph *depsgraph,
                                 struct View3D *v3d,
@@ -1196,6 +1199,36 @@ bool ED_view3d_camera_lock_autokey(struct View3D *v3d,
 
 void ED_view3d_lock_clear(struct View3D *v3d);
 
+/**
+ * Check if creating an undo step should be performed if the viewport moves.
+ * \return true if #ED_view3d_camera_lock_undo_push would do an undo push.
+ */
+bool ED_view3d_camera_lock_undo_test(const View3D *v3d,
+                                     const RegionView3D *rv3d,
+                                     struct bContext *C);
+
+/**
+ * Create an undo step when the camera is locked to the view.
+ * \param str: The name of the undo step (typically #wmOperatorType.name should be used).
+ *
+ * \return true when the call to push an undo step was made.
+ */
+bool ED_view3d_camera_lock_undo_push(const char *str,
+                                     const View3D *v3d,
+                                     const struct RegionView3D *rv3d,
+                                     struct bContext *C);
+
+/**
+ * A version of #ED_view3d_camera_lock_undo_push that performs a grouped undo push.
+ *
+ * \note use for actions that are likely to be repeated such as mouse wheel to zoom,
+ * where adding a separate undo step each time isn't desirable.
+ */
+bool ED_view3d_camera_lock_undo_grouped_push(const char *str,
+                                             const View3D *v3d,
+                                             const struct RegionView3D *rv3d,
+                                             struct bContext *C);
+
 #define VIEW3D_MARGIN 1.4f
 #define VIEW3D_DIST_FALLBACK 1.0f
 
@@ -1281,7 +1314,7 @@ void ED_view3d_draw_bgpic_test(const struct Scene *scene,
                                bool do_foreground,
                                bool do_camera_frame);
 
-/* view3d_gizmo_preselect_type.c */
+/* view3d_gizmo_preselect_type.cc */
 
 void ED_view3d_gizmo_mesh_preselect_get_active(struct bContext *C,
                                                struct wmGizmo *gz,
@@ -1289,7 +1322,7 @@ void ED_view3d_gizmo_mesh_preselect_get_active(struct bContext *C,
                                                struct BMElem **r_ele);
 void ED_view3d_gizmo_mesh_preselect_clear(struct wmGizmo *gz);
 
-/* space_view3d.c */
+/* space_view3d.cc */
 
 void ED_view3d_buttons_region_layout_ex(const struct bContext *C,
                                         struct ARegion *region,
diff --git a/source/blender/editors/include/ED_viewer_path.hh b/source/blender/editors/include/ED_viewer_path.hh
new file mode 100644
index 00000000000..957dfddb8af
--- /dev/null
+++ b/source/blender/editors/include/ED_viewer_path.hh
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#pragma once
+
+#include <optional>
+
+#include "BLI_string_ref.hh"
+#include "BLI_vector.hh"
+
+#include "BKE_viewer_path.h"
+
+struct Main;
+struct SpaceNode;
+struct bNode;
+struct bContext;
+struct Object;
+
+namespace blender::ed::viewer_path {
+
+/**
+ * Activates the given node in the context provided by the editor. This indirectly updates all
+ * non-pinned viewer paths in other editors (spreadsheet and 3d view).
+ */
+void activate_geometry_node(Main &bmain, SpaceNode &snode, bNode &node);
+
+/**
+ * Returns the object referenced by the viewer path. This only returns something if the viewer path
+ * *only* contains the object and nothing more.
+ */
+Object *parse_object_only(const ViewerPath &viewer_path);
+
+/**
+ * Represents a parsed #ViewerPath for easier consumption.
+ */
+struct ViewerPathForGeometryNodesViewer {
+  Object *object;
+  blender::StringRefNull modifier_name;
+  blender::Vector<blender::StringRefNull> group_node_names;
+  blender::StringRefNull viewer_node_name;
+};
+
+/**
+ * Parses a #ViewerPath into a #ViewerPathForGeometryNodesViewer or returns none if that does not
+ * work.
+ */
+std::optional<ViewerPathForGeometryNodesViewer> parse_geometry_nodes_viewer(
+    const ViewerPath &viewer_path);
+
+/**
+ * Finds the node referenced by the #ViewerPath within the provided editor. If no node is
+ * referenced, null is returned. When two different editors show the same node group but in a
+ * different context, it's possible that the same node is active in one editor but not the other.
+ */
+bNode *find_geometry_nodes_viewer(const ViewerPath &viewer_path, SpaceNode &snode);
+
+/**
+ * Checks if the node referenced by the viewer path and its entire context still exists. The node
+ * does not have to be visible for this to return true.
+ */
+bool exists_geometry_nodes_viewer(const ViewerPathForGeometryNodesViewer &parsed_viewer_path);
+
+/**
+ * Checks if the node referenced by the viewer and its entire context is still active, i.e. some
+ * editor is showing it.
+ */
+bool is_active_geometry_nodes_viewer(const bContext &C,
+                                     const ViewerPathForGeometryNodesViewer &parsed_viewer_path);
+
+}  // namespace blender::ed::viewer_path
diff --git a/source/blender/editors/include/UI_abstract_view.hh b/source/blender/editors/include/UI_abstract_view.hh
new file mode 100644
index 00000000000..dfddace8899
--- /dev/null
+++ b/source/blender/editors/include/UI_abstract_view.hh
@@ -0,0 +1,280 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+/** \file
+ * \ingroup editorui
+ *
+ * Base class for all views (UIs to display data sets) and view items, supporting common features.
+ * https://wiki.blender.org/wiki/Source/Interface/Views
+ *
+ * One of the most important responsibilities of the base class is managing reconstruction,
+ * enabling state that is persistent over reconstructions/redraws. Other features:
+ * - Renaming
+ * - Custom context menus
+ * - Notifier listening
+ * - Drag controllers (dragging view items)
+ * - Drop controllers (dropping onto/into view items)
+ */
+
+#pragma once
+
+#include <array>
+#include <memory>
+
+#include "DNA_defs.h"
+
+#include "BLI_span.hh"
+#include "BLI_string_ref.hh"
+
+struct bContext;
+struct uiBlock;
+struct uiBut;
+struct uiLayout;
+struct uiViewItemHandle;
+struct wmDrag;
+struct wmNotifier;
+
+namespace blender::ui {
+
+class AbstractViewItem;
+class AbstractViewItemDropController;
+class AbstractViewItemDragController;
+
+class AbstractView {
+  friend class AbstractViewItem;
+
+  bool is_reconstructed_ = false;
+  /**
+   * Only one item can be renamed at a time. So rather than giving each item an own rename buffer
+   * (which just adds unused memory in most cases), have one here that is managed by the view.
+   *
+   * This fixed-size buffer is needed because that's what the rename button requires. In future we
+   * may be able to bind the button to a `std::string` or similar.
+   */
+  std::unique_ptr<std::array<char, MAX_NAME>> rename_buffer_;
+
+ public:
+  virtual ~AbstractView() = default;
+
+  /** Listen to a notifier, returning true if a redraw is needed. */
+  virtual bool listen(const wmNotifier &) const;
+
+  /**
+   * Makes \a item valid for display in this view. Behavior is undefined for items not registered
+   * with this.
+   */
+  void register_item(AbstractViewItem &item);
+
+  /** Only one item can be renamed at a time. */
+  bool is_renaming() const;
+  /** \return If renaming was started successfully. */
+  bool begin_renaming();
+  void end_renaming();
+  Span<char> get_rename_buffer() const;
+  MutableSpan<char> get_rename_buffer();
+
+ protected:
+  AbstractView() = default;
+
+  virtual void update_children_from_old(const AbstractView &old_view) = 0;
+
+  /**
+   * Match the view and its items against an earlier version of itself (if any) and copy the old UI
+   * state (e.g. collapsed, active, selected, renaming, etc.) to the new one. See
+   * #AbstractViewItem.update_from_old().
+   * After this, reconstruction is complete (see #is_reconstructed()).
+   */
+  void update_from_old(uiBlock &new_block);
+  /**
+   * Check if the view is fully (re-)constructed. That means, both the build function and
+   * #update_from_old() have finished.
+   */
+  bool is_reconstructed() const;
+};
+
+class AbstractViewItem {
+  friend class AbstractView;
+  friend class ViewItemAPIWrapper;
+
+ protected:
+  /**
+   * The view this item is a part of, and was registered for using #AbstractView::register_item().
+   * If this wasn't done, the behavior of items is undefined.
+   */
+  AbstractView *view_ = nullptr;
+  bool is_active_ = false;
+  bool is_renaming_ = false;
+
+ public:
+  virtual ~AbstractViewItem() = default;
+
+  virtual void build_context_menu(bContext &C, uiLayout &column) const;
+
+  /**
+   * Queries if the view item supports renaming in principle. Renaming may still fail, e.g. if
+   * another item is already being renamed.
+   */
+  virtual bool supports_renaming() const;
+  /**
+   * Try renaming the item, or the data it represents. Can assume
+   * #AbstractViewItem::supports_renaming() returned true. Sub-classes that override this should
+   * usually call this, unless they have a custom #AbstractViewItem.matches() implementation.
+   *
+   * \return True if the renaming was successful.
+   */
+  virtual bool rename(StringRefNull new_name);
+  /**
+   * Get the string that should be used for renaming, typically the item's label. This string will
+   * not be modified, but if the renaming is canceled, the value will be reset to this.
+   */
+  virtual StringRef get_rename_string() const;
+
+  /**
+   * If an item wants to support being dragged, it has to return a drag controller here.
+   * That is an object implementing #AbstractViewItemDragController.
+   */
+  virtual std::unique_ptr<AbstractViewItemDragController> create_drag_controller() const;
+  /**
+   * If an item wants to support dropping data into it, it has to return a drop controller here.
+   * That is an object implementing #AbstractViewItemDropController.
+   *
+   * \note This drop controller may be requested for each event. The view doesn't keep a drop
+   *       controller around currently. So it can not contain persistent state.
+   */
+  virtual std::unique_ptr<AbstractViewItemDropController> create_drop_controller() const;
+
+  /** Get the view this item is registered for using #AbstractView::register_item(). */
+  AbstractView &get_view() const;
+
+  /**
+   * Requires the view to have completed reconstruction, see #is_reconstructed(). Otherwise we
+   * can't be sure about the item state.
+   */
+  bool is_active() const;
+
+  bool is_renaming() const;
+  void begin_renaming();
+  void end_renaming();
+  void rename_apply();
+
+  template<typename ToType = AbstractViewItem>
+  static ToType *from_item_handle(uiViewItemHandle *handle);
+
+ protected:
+  AbstractViewItem() = default;
+
+  /**
+   * Compare this item's identity to \a other to check if they represent the same data.
+   * Implementations can assume that the types match already (caller must check).
+   *
+   * Used to recognize an item from a previous redraw, to be able to keep its state (e.g. active,
+   * renaming, etc.).
+   */
+  virtual bool matches(const AbstractViewItem &other) const = 0;
+
+  /**
+   * Copy persistent state (e.g. active, selection, etc.) from a matching item of
+   * the last redraw to this item. If sub-classes introduce more advanced state they should
+   * override this and make it update their state accordingly.
+   *
+   * \note Always call the base class implementation when overriding this!
+   */
+  virtual void update_from_old(const AbstractViewItem &old);
+
+  /**
+   * Add a text button for renaming the item to \a block. This must be used for the built-in
+   * renaming to work. This button is meant to appear temporarily. It is removed when renaming is
+   * done.
+   */
+  void add_rename_button(uiBlock &block);
+};
+
+template<typename ToType> ToType *AbstractViewItem::from_item_handle(uiViewItemHandle *handle)
+{
+  static_assert(std::is_base_of<AbstractViewItem, ToType>::value,
+                "Type must derive from and implement the AbstractViewItem interface");
+
+  return dynamic_cast<ToType *>(reinterpret_cast<AbstractViewItem *>(handle));
+}
+
+/* ---------------------------------------------------------------------- */
+/** \name Drag 'n Drop
+ * \{ */
+
+/**
+ * Class to enable dragging a view item. An item can return a drop controller for itself by
+ * implementing #AbstractViewItem::create_drag_controller().
+ */
+class AbstractViewItemDragController {
+ protected:
+  AbstractView &view_;
+
+ public:
+  AbstractViewItemDragController(AbstractView &view);
+  virtual ~AbstractViewItemDragController() = default;
+
+  virtual int get_drag_type() const = 0;
+  virtual void *create_drag_data() const = 0;
+  virtual void on_drag_start();
+
+  /** Request the view the item is registered for as type #ViewType. Throws a `std::bad_cast`
+   * exception if the view is not of the requested type. */
+  template<class ViewType> inline ViewType &get_view() const;
+};
+
+/**
+ * Class to define the behavior when dropping something onto/into a view item, plus the behavior
+ * when dragging over this item. An item can return a drop controller for itself via a custom
+ * implementation of #AbstractViewItem::create_drop_controller().
+ */
+class AbstractViewItemDropController {
+ protected:
+  AbstractView &view_;
+
+ public:
+  AbstractViewItemDropController(AbstractView &view);
+  virtual ~AbstractViewItemDropController() = default;
+
+  /**
+   * Check if the data dragged with \a drag can be dropped on the item this controller is for.
+   * \param r_disabled_hint: Return a static string to display to the user, explaining why dropping
+   *                         isn't possible on this item. Shouldn't be done too aggressively, e.g.
+   *                         don't set this if the drag-type can't be dropped here; only if it can
+   *                         but there's another reason it can't be dropped.
+   *                         Can assume this is a non-null pointer.
+   */
+  virtual bool can_drop(const wmDrag &drag, const char **r_disabled_hint) const = 0;
+  /**
+   * Custom text to display when dragging over a view item. Should explain what happens when
+   * dropping the data onto this item. Will only be used if #AbstractViewItem::can_drop()
+   * returns true, so the implementing override doesn't have to check that again.
+   * The returned value must be a translated string.
+   */
+  virtual std::string drop_tooltip(const wmDrag &drag) const = 0;
+  /**
+   * Execute the logic to apply a drop of the data dragged with \a drag onto/into the item this
+   * controller is for.
+   */
+  virtual bool on_drop(struct bContext *C, const wmDrag &drag) = 0;
+
+  /** Request the view the item is registered for as type #ViewType. Throws a `std::bad_cast`
+   * exception if the view is not of the requested type. */
+  template<class ViewType> inline ViewType &get_view() const;
+};
+
+template<class ViewType> ViewType &AbstractViewItemDragController::get_view() const
+{
+  static_assert(std::is_base_of<AbstractView, ViewType>::value,
+                "Type must derive from and implement the ui::AbstractView interface");
+  return dynamic_cast<ViewType &>(view_);
+}
+
+template<class ViewType> ViewType &AbstractViewItemDropController::get_view() const
+{
+  static_assert(std::is_base_of<AbstractView, ViewType>::value,
+                "Type must derive from and implement the ui::AbstractView interface");
+  return dynamic_cast<ViewType &>(view_);
+}
+
+/** \} */
+
+}  // namespace blender::ui
diff --git a/source/blender/editors/include/UI_grid_view.hh b/source/blender/editors/include/UI_grid_view.hh
new file mode 100644
index 00000000000..402c0c8512f
--- /dev/null
+++ b/source/blender/editors/include/UI_grid_view.hh
@@ -0,0 +1,229 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+/** \file
+ * \ingroup editorui
+ *
+ * API for simple creation of grid UIs, supporting typically needed features.
+ * https://wiki.blender.org/wiki/Source/Interface/Views/Grid_Views
+ */
+
+#pragma once
+
+#include "BLI_function_ref.hh"
+#include "BLI_map.hh"
+#include "BLI_vector.hh"
+
+#include "UI_abstract_view.hh"
+#include "UI_resources.h"
+
+struct bContext;
+struct PreviewImage;
+struct uiBlock;
+struct uiButViewItem;
+struct uiLayout;
+struct View2D;
+struct wmNotifier;
+
+namespace blender::ui {
+
+class AbstractGridView;
+
+/* ---------------------------------------------------------------------- */
+/** \name Grid-View Item Type
+ * \{ */
+
+class AbstractGridViewItem : public AbstractViewItem {
+  friend class AbstractGridView;
+  friend class GridViewLayoutBuilder;
+
+ protected:
+  /** Reference to a string that uniquely identifies this item in the view. */
+  StringRef identifier_{};
+  /** Every visible item gets a button of type #UI_BTYPE_VIEW_ITEM during the layout building. */
+  uiButViewItem *view_item_but_ = nullptr;
+
+ public:
+  virtual ~AbstractGridViewItem() = default;
+
+  virtual void build_grid_tile(uiLayout &layout) const = 0;
+
+  const AbstractGridView &get_view() const;
+
+ protected:
+  AbstractGridViewItem(StringRef identifier);
+
+  /** See AbstractViewItem::matches(). */
+  virtual bool matches(const AbstractViewItem &other) const override;
+
+  /** Called when the item's state changes from inactive to active. */
+  virtual void on_activate();
+  /**
+   * If the result is not empty, it controls whether the item should be active or not,
+   * usually depending on the data that the view represents.
+   */
+  virtual std::optional<bool> should_be_active() const;
+
+  /**
+   * Activates this item, deactivates other items, and calls the
+   * #AbstractGridViewItem::on_activate() function.
+   * Requires the tree to have completed reconstruction, see #is_reconstructed(). Otherwise the
+   * actual item state is unknown, possibly calling state-change update functions incorrectly.
+   */
+  void activate();
+  void deactivate();
+
+ private:
+  /** See #AbstractTreeView::change_state_delayed() */
+  void change_state_delayed();
+  static void grid_tile_click_fn(bContext *, void *but_arg1, void *);
+  void add_grid_tile_button(uiBlock &block);
+};
+
+/** \} */
+
+/* ---------------------------------------------------------------------- */
+/** \name Grid-View Base Class
+ * \{ */
+
+struct GridViewStyle {
+  GridViewStyle(int width, int height);
+  int tile_width = 0;
+  int tile_height = 0;
+};
+
+class AbstractGridView : public AbstractView {
+  friend class AbstractGridViewItem;
+  friend class GridViewBuilder;
+  friend class GridViewLayoutBuilder;
+
+ protected:
+  Vector<std::unique_ptr<AbstractGridViewItem>> items_;
+  /** <identifier, item> map to lookup items by identifier, used for efficient lookups in
+   * #update_from_old(). */
+  Map<StringRef, AbstractGridViewItem *> item_map_;
+  GridViewStyle style_;
+
+ public:
+  AbstractGridView();
+  virtual ~AbstractGridView() = default;
+
+  using ItemIterFn = FunctionRef<void(AbstractGridViewItem &)>;
+  void foreach_item(ItemIterFn iter_fn) const;
+
+  /**
+   * Convenience wrapper constructing the item by forwarding given arguments to the constructor of
+   * the type (\a ItemT).
+   *
+   * E.g. if your grid-item type has the following constructor:
+   * \code{.cpp}
+   * MyGridItem(std::string str, int i);
+   * \endcode
+   * You can add an item like this:
+   * \code
+   * add_item<MyGridItem>("blabla", 42);
+   * \endcode
+   */
+  template<class ItemT, typename... Args> inline ItemT &add_item(Args &&...args);
+  const GridViewStyle &get_style() const;
+  int get_item_count() const;
+
+ protected:
+  virtual void build_items() = 0;
+
+ private:
+  void update_children_from_old(const AbstractView &old_view) override;
+  AbstractGridViewItem *find_matching_item(const AbstractGridViewItem &item_to_match,
+                                           const AbstractGridView &view_to_search_in) const;
+  /**
+   * Items may want to do additional work when state changes. But these state changes can only be
+   * reliably detected after the view has completed reconstruction (see #is_reconstructed()). So
+   * the actual state changes are done in a delayed manner through this function.
+   */
+  void change_state_delayed();
+
+  /**
+   * Add an already constructed item, moving ownership to the grid-view.
+   * All items must be added through this, it handles important invariants!
+   */
+  AbstractGridViewItem &add_item(std::unique_ptr<AbstractGridViewItem> item);
+};
+
+/** \} */
+
+/* ---------------------------------------------------------------------- */
+/** \name Grid-View Builder
+ *
+ *  TODO unify this with `TreeViewBuilder` and call view-specific functions via type erased view?
+ * \{ */
+
+class GridViewBuilder {
+  uiBlock &block_;
+
+ public:
+  GridViewBuilder(uiBlock &block);
+
+  /** Build \a grid_view into the previously provided block, clipped by \a view_bounds (view space,
+   * typically `View2D.cur`). */
+  void build_grid_view(AbstractGridView &grid_view, const View2D &v2d);
+};
+
+/** \} */
+
+/* ---------------------------------------------------------------------- */
+/** \name Predefined Grid-View Item Types
+ *
+ *  Common, Basic Grid-View Item Types.
+ * \{ */
+
+/**
+ * A grid item that shows preview image icons at a nicely readable size (multiple of the normal UI
+ * unit size).
+ */
+class PreviewGridItem : public AbstractGridViewItem {
+ public:
+  using IsActiveFn = std::function<bool()>;
+  using ActivateFn = std::function<void(PreviewGridItem &new_active)>;
+
+ protected:
+  /** See #set_on_activate_fn() */
+  ActivateFn activate_fn_;
+  /** See #set_is_active_fn() */
+  IsActiveFn is_active_fn_;
+
+ public:
+  std::string label{};
+  int preview_icon_id = ICON_NONE;
+
+  PreviewGridItem(StringRef identifier, StringRef label, int preview_icon_id);
+
+  void build_grid_tile(uiLayout &layout) const override;
+
+  /**
+   * Set a custom callback to execute when activating this view item. This way users don't have to
+   * sub-class #PreviewGridItem, just to implement custom activation behavior (a common thing to
+   * do).
+   */
+  void set_on_activate_fn(ActivateFn fn);
+  /**
+   * Set a custom callback to check if this item should be active.
+   */
+  void set_is_active_fn(IsActiveFn fn);
+
+ private:
+  std::optional<bool> should_be_active() const override;
+  void on_activate() override;
+};
+
+/** \} */
+
+/* ---------------------------------------------------------------------- */
+
+template<class ItemT, typename... Args> inline ItemT &AbstractGridView::add_item(Args &&...args)
+{
+  static_assert(std::is_base_of<AbstractGridViewItem, ItemT>::value,
+                "Type must derive from and implement the AbstractGridViewItem interface");
+
+  return dynamic_cast<ItemT &>(add_item(std::make_unique<ItemT>(std::forward<Args>(args)...)));
+}
+
+}  // namespace blender::ui
diff --git a/source/blender/editors/include/UI_icons.h b/source/blender/editors/include/UI_icons.h
index d650f4215b9..31c766e95f2 100644
--- a/source/blender/editors/include/UI_icons.h
+++ b/source/blender/editors/include/UI_icons.h
@@ -472,8 +472,8 @@ DEF_ICON_BLANK(742)
 DEF_ICON_BLANK(743)
 DEF_ICON_MODIFIER(CON_ACTION)
 DEF_ICON_BLANK(745)
-DEF_ICON_BLANK(746)
-DEF_ICON_BLANK(747)
+DEF_ICON_MODIFIER(MOD_ENVELOPE)
+DEF_ICON_MODIFIER(MOD_OUTLINE)
 DEF_ICON_MODIFIER(MOD_LENGTH)
 DEF_ICON_MODIFIER(MOD_DASH)
 DEF_ICON_MODIFIER(MOD_LINEART)
@@ -652,7 +652,7 @@ DEF_ICON(PARTICLE_TIP)
 DEF_ICON(PARTICLE_PATH)
 
 /* EDITING */
-DEF_ICON_BLANK(669)
+DEF_ICON(SNAP_FACE_NEAREST)
 DEF_ICON(SNAP_FACE_CENTER)
 DEF_ICON(SNAP_PERPENDICULAR)
 DEF_ICON(SNAP_MIDPOINT)
@@ -891,6 +891,7 @@ DEF_ICON_COLOR(BRUSH_LAYER)
 DEF_ICON_COLOR(BRUSH_MASK)
 DEF_ICON_COLOR(BRUSH_MIX)
 DEF_ICON_COLOR(BRUSH_NUDGE)
+DEF_ICON_COLOR(BRUSH_PAINT_SELECT)
 DEF_ICON_COLOR(BRUSH_PINCH)
 DEF_ICON_COLOR(BRUSH_SCRAPE)
 DEF_ICON_COLOR(BRUSH_SCULPT_DRAW)
@@ -928,6 +929,19 @@ DEF_ICON_COLOR(GPBRUSH_ERASE_SOFT)
 DEF_ICON_COLOR(GPBRUSH_ERASE_HARD)
 DEF_ICON_COLOR(GPBRUSH_ERASE_STROKE)
 
+/* Curves sculpt. */
+DEF_ICON_COLOR(BRUSH_CURVES_ADD)
+DEF_ICON_COLOR(BRUSH_CURVES_COMB)
+DEF_ICON_COLOR(BRUSH_CURVES_CUT)
+DEF_ICON_COLOR(BRUSH_CURVES_DELETE)
+DEF_ICON_COLOR(BRUSH_CURVES_DENSITY)
+DEF_ICON_COLOR(BRUSH_CURVES_GROW_SHRINK)
+DEF_ICON_COLOR(BRUSH_CURVES_PINCH)
+DEF_ICON_COLOR(BRUSH_CURVES_PUFF)
+DEF_ICON_COLOR(BRUSH_CURVES_SLIDE)
+DEF_ICON_COLOR(BRUSH_CURVES_SMOOTH)
+DEF_ICON_COLOR(BRUSH_CURVES_SNAKE_HOOK)
+
 /* Vector icons. */
 DEF_ICON_VECTOR(KEYTYPE_KEYFRAME_VEC)
 DEF_ICON_VECTOR(KEYTYPE_BREAKDOWN_VEC)
diff --git a/source/blender/editors/include/UI_interface.h b/source/blender/editors/include/UI_interface.h
index 22f5ecb35b8..2a1941f0d9e 100644
--- a/source/blender/editors/include/UI_interface.h
+++ b/source/blender/editors/include/UI_interface.h
@@ -64,6 +64,7 @@ struct wmKeyMapItem;
 struct wmMsgBus;
 struct wmOperator;
 struct wmOperatorType;
+struct wmRegionListenerParams;
 struct wmWindow;
 
 typedef struct uiBlock uiBlock;
@@ -71,10 +72,10 @@ typedef struct uiBut uiBut;
 typedef struct uiButExtraOpIcon uiButExtraOpIcon;
 typedef struct uiLayout uiLayout;
 typedef struct uiPopupBlockHandle uiPopupBlockHandle;
-/* C handle for C++ #ui::AbstractTreeView type. */
-typedef struct uiTreeViewHandle uiTreeViewHandle;
-/* C handle for C++ #ui::AbstractTreeViewItem type. */
-typedef struct uiTreeViewItemHandle uiTreeViewItemHandle;
+/* C handle for C++ #ui::AbstractView type. */
+typedef struct uiViewHandle uiViewHandle;
+/* C handle for C++ #ui::AbstractViewItem type. */
+typedef struct uiViewItemHandle uiViewItemHandle;
 
 /* Defines */
 
@@ -84,7 +85,7 @@ typedef struct uiTreeViewItemHandle uiTreeViewItemHandle;
 
 /* Separator for text in search menus (right pointing arrow).
  * keep in sync with `string_search.cc`. */
-#define UI_MENU_ARROW_SEP "\xe2\x96\xb6"
+#define UI_MENU_ARROW_SEP "\xe2\x96\xb8"
 
 /* names */
 #define UI_MAX_DRAW_STR 400
@@ -353,7 +354,7 @@ typedef enum {
   UI_BTYPE_LABEL = 20 << 9,
   UI_BTYPE_KEY_EVENT = 24 << 9,
   UI_BTYPE_HSVCUBE = 26 << 9,
-  /** menu (often used in headers), **_MENU /w different draw-type */
+  /** Menu (often used in headers), `*_MENU` with different draw-type. */
   UI_BTYPE_PULLDOWN = 27 << 9,
   UI_BTYPE_ROUNDBOX = 28 << 9,
   UI_BTYPE_COLORBAND = 30 << 9,
@@ -388,8 +389,8 @@ typedef enum {
   /** Resize handle (resize uilist). */
   UI_BTYPE_GRIP = 57 << 9,
   UI_BTYPE_DECORATOR = 58 << 9,
-  /* An item in a tree view. Parent items may be collapsible. */
-  UI_BTYPE_TREEROW = 59 << 9,
+  /* An item a view (see #ui::AbstractViewItem). */
+  UI_BTYPE_VIEW_ITEM = 59 << 9,
 } eButType;
 
 #define BUTTYPE (63 << 9)
@@ -531,6 +532,7 @@ typedef struct ARegion *(*uiButSearchTooltipFn)(struct bContext *C,
                                                 const struct rcti *item_rect,
                                                 void *arg,
                                                 void *active);
+typedef void (*uiButSearchListenFn)(const struct wmRegionListenerParams *params, void *arg);
 
 /* Must return allocated string. */
 typedef char *(*uiButToolTipFunc)(struct bContext *C, void *argN, const char *tip);
@@ -1391,6 +1393,7 @@ void UI_but_extra_icon_string_info_get(struct bContext *C, uiButExtraOpIcon *ext
  * - AutoButR: RNA property button with type automatically defined.
  */
 enum {
+  UI_ID_NOP = 0,
   UI_ID_RENAME = 1 << 0,
   UI_ID_BROWSE = 1 << 1,
   UI_ID_ADD_NEW = 1 << 2,
@@ -1658,6 +1661,7 @@ void UI_but_func_search_set(uiBut *but,
                             void *active);
 void UI_but_func_search_set_context_menu(uiBut *but, uiButSearchContextMenuFn context_menu_fn);
 void UI_but_func_search_set_tooltip(uiBut *but, uiButSearchTooltipFn tooltip_fn);
+void UI_but_func_search_set_listen(uiBut *but, uiButSearchListenFn listen_fn);
 /**
  * \param search_sep_string: when not NULL, this string is used as a separator,
  * showing the icon and highlighted text after the last instance of this string.
@@ -1680,8 +1684,6 @@ int UI_search_items_find_index(uiSearchItems *items, const char *name);
  */
 void UI_but_hint_drawstr_set(uiBut *but, const char *string);
 
-void UI_but_treerow_indentation_set(uiBut *but, int indentation);
-
 void UI_but_node_link_set(uiBut *but, struct bNodeSocket *socket, const float draw_color[4]);
 
 void UI_but_number_step_size_set(uiBut *but, float step_size);
@@ -1740,6 +1742,14 @@ struct PointerRNA *UI_but_extra_operator_icon_add(uiBut *but,
 struct wmOperatorType *UI_but_extra_operator_icon_optype_get(struct uiButExtraOpIcon *extra_icon);
 struct PointerRNA *UI_but_extra_operator_icon_opptr_get(struct uiButExtraOpIcon *extra_icon);
 
+/**
+ * A decent size for a button (typically #UI_BTYPE_PREVIEW_TILE) to display a nicely readable
+ * preview with label in.
+ */
+int UI_preview_tile_size_x(void);
+int UI_preview_tile_size_y(void);
+int UI_preview_tile_size_y_no_label(void);
+
 /* Autocomplete
  *
  * Tab complete helper functions, for use in uiButCompleteFunc callbacks.
@@ -2475,7 +2485,7 @@ enum uiTemplateListFlags {
 ENUM_OPERATORS(enum uiTemplateListFlags, UI_TEMPLATE_LIST_FLAGS_LAST);
 
 void uiTemplateList(uiLayout *layout,
-                    struct bContext *C,
+                    const struct bContext *C,
                     const char *listtype_name,
                     const char *list_id,
                     struct PointerRNA *dataptr,
@@ -2489,7 +2499,7 @@ void uiTemplateList(uiLayout *layout,
                     int columns,
                     enum uiTemplateListFlags flags);
 struct uiList *uiTemplateList_ex(uiLayout *layout,
-                                 struct bContext *C,
+                                 const struct bContext *C,
                                  const char *listtype_name,
                                  const char *list_id,
                                  struct PointerRNA *dataptr,
@@ -2559,7 +2569,7 @@ enum {
   UI_TEMPLATE_ASSET_DRAW_NO_LIBRARY = (1 << 2),
 };
 void uiTemplateAssetView(struct uiLayout *layout,
-                         struct bContext *C,
+                         const struct bContext *C,
                          const char *list_id,
                          struct PointerRNA *asset_library_dataptr,
                          const char *asset_library_propname,
@@ -3185,43 +3195,47 @@ void UI_interface_tag_script_reload(void);
 /* Support click-drag motion which presses the button and closes a popover (like a menu). */
 #define USE_UI_POPOVER_ONCE
 
-bool UI_tree_view_item_is_active(const uiTreeViewItemHandle *item);
-bool UI_tree_view_item_matches(const uiTreeViewItemHandle *a, const uiTreeViewItemHandle *b);
+void UI_block_views_listen(const uiBlock *block,
+                           const struct wmRegionListenerParams *listener_params);
+
+bool UI_view_item_is_active(const uiViewItemHandle *item_handle);
+bool UI_view_item_matches(const uiViewItemHandle *a_handle, const uiViewItemHandle *b_handle);
 /**
- * Attempt to start dragging the tree-item \a item_. This will not work if the tree item doesn't
- * support dragging, i.e. it won't create a drag-controller upon request.
- * \return True if dragging started successfully, otherwise false.
+ * Can \a item_handle be renamed right now? Note that this isn't just a mere wrapper around
+ * #AbstractViewItem::supports_renaming(). This also checks if there is another item being renamed,
+ * and returns false if so.
  */
-bool UI_tree_view_item_drag_start(struct bContext *C, uiTreeViewItemHandle *item_);
-bool UI_tree_view_item_can_drop(const uiTreeViewItemHandle *item_,
-                                const struct wmDrag *drag,
-                                const char **r_disabled_hint);
-char *UI_tree_view_item_drop_tooltip(const uiTreeViewItemHandle *item, const struct wmDrag *drag);
+bool UI_view_item_can_rename(const uiViewItemHandle *item_handle);
+void UI_view_item_begin_rename(uiViewItemHandle *item_handle);
+
+void UI_view_item_context_menu_build(struct bContext *C,
+                                     const uiViewItemHandle *item_handle,
+                                     uiLayout *column);
+
 /**
- * Let a tree-view item handle a drop event.
- * \return True if the drop was handled by the tree-view item.
+ * Attempt to start dragging \a item_. This will not work if the view item doesn't
+ * support dragging, i.e. if it won't create a drag-controller upon request.
+ * \return True if dragging started successfully, otherwise false.
  */
-bool UI_tree_view_item_drop_handle(struct bContext *C,
-                                   const uiTreeViewItemHandle *item_,
-                                   const struct ListBase *drags);
+bool UI_view_item_drag_start(struct bContext *C, const uiViewItemHandle *item_);
+bool UI_view_item_can_drop(const uiViewItemHandle *item_,
+                           const struct wmDrag *drag,
+                           const char **r_disabled_hint);
+char *UI_view_item_drop_tooltip(const uiViewItemHandle *item, const struct wmDrag *drag);
 /**
- * Can \a item_handle be renamed right now? Not that this isn't just a mere wrapper around
- * #AbstractTreeViewItem::can_rename(). This also checks if there is another item being renamed,
- * and returns false if so.
+ * Let a view item handle a drop event.
+ * \return True if the drop was handled by the view item.
  */
-bool UI_tree_view_item_can_rename(const uiTreeViewItemHandle *item_handle);
-void UI_tree_view_item_begin_rename(uiTreeViewItemHandle *item_handle);
-
-void UI_tree_view_item_context_menu_build(struct bContext *C,
-                                          const uiTreeViewItemHandle *item,
-                                          uiLayout *column);
+bool UI_view_item_drop_handle(struct bContext *C,
+                              const uiViewItemHandle *item_,
+                              const struct ListBase *drags);
 
 /**
- * \param xy: Coordinate to find a tree-row item at, in window space.
+ * \param xy: Coordinate to find a view item at, in window space.
  */
-uiTreeViewItemHandle *UI_block_tree_view_find_item_at(const struct ARegion *region,
-                                                      const int xy[2]) ATTR_NONNULL(1, 2);
-uiTreeViewItemHandle *UI_block_tree_view_find_active_item(const struct ARegion *region);
+uiViewItemHandle *UI_region_views_find_item_at(const struct ARegion *region, const int xy[2])
+    ATTR_NONNULL();
+uiViewItemHandle *UI_region_views_find_active_item(const struct ARegion *region);
 
 #ifdef __cplusplus
 }
diff --git a/source/blender/editors/include/UI_interface.hh b/source/blender/editors/include/UI_interface.hh
index db43ec54431..6c756984203 100644
--- a/source/blender/editors/include/UI_interface.hh
+++ b/source/blender/editors/include/UI_interface.hh
@@ -13,7 +13,7 @@
 
 #include "UI_resources.h"
 
-namespace blender::nodes::geometry_nodes_eval_log {
+namespace blender::nodes::geo_eval_log {
 struct GeometryAttributeInfo;
 }
 
@@ -23,6 +23,7 @@ struct uiSearchItems;
 
 namespace blender::ui {
 
+class AbstractGridView;
 class AbstractTreeView;
 
 /**
@@ -43,18 +44,21 @@ void context_path_add_generic(Vector<ContextPathItem> &path,
 
 void template_breadcrumbs(uiLayout &layout, Span<ContextPathItem> context_path);
 
-void attribute_search_add_items(
-    StringRefNull str,
-    bool is_output,
-    Span<const nodes::geometry_nodes_eval_log::GeometryAttributeInfo *> infos,
-    uiSearchItems *items,
-    bool is_first);
+void attribute_search_add_items(StringRefNull str,
+                                bool can_create_attribute,
+                                Span<const nodes::geo_eval_log::GeometryAttributeInfo *> infos,
+                                uiSearchItems *items,
+                                bool is_first);
 
 }  // namespace blender::ui
 
 /**
- * Override this for all available tree types.
+ * Override this for all available view types.
  */
+blender::ui::AbstractGridView *UI_block_add_view(
+    uiBlock &block,
+    blender::StringRef idname,
+    std::unique_ptr<blender::ui::AbstractGridView> grid_view);
 blender::ui::AbstractTreeView *UI_block_add_view(
     uiBlock &block,
     blender::StringRef idname,
diff --git a/source/blender/editors/include/UI_resources.h b/source/blender/editors/include/UI_resources.h
index 22e747e37ad..9a46728097c 100644
--- a/source/blender/editors/include/UI_resources.h
+++ b/source/blender/editors/include/UI_resources.h
@@ -291,6 +291,8 @@ typedef enum ThemeColorID {
 
   TH_WIDGET_EMBOSS,
   TH_WIDGET_TEXT_CURSOR,
+  TH_WIDGET_TEXT_SELECTION,
+  TH_WIDGET_TEXT_HIGHLIGHT,
   TH_EDITOR_OUTLINE,
 
   TH_TRANSPARENT_CHECKER_PRIMARY,
diff --git a/source/blender/editors/include/UI_tree_view.hh b/source/blender/editors/include/UI_tree_view.hh
index 5504e426f34..872a6085060 100644
--- a/source/blender/editors/include/UI_tree_view.hh
+++ b/source/blender/editors/include/UI_tree_view.hh
@@ -9,7 +9,6 @@
 
 #pragma once
 
-#include <array>
 #include <functional>
 #include <memory>
 #include <string>
@@ -19,22 +18,19 @@
 #include "BLI_function_ref.hh"
 #include "BLI_vector.hh"
 
+#include "UI_abstract_view.hh"
 #include "UI_resources.h"
 
 struct bContext;
 struct uiBlock;
 struct uiBut;
-struct uiButTreeRow;
+struct uiButViewItem;
 struct uiLayout;
-struct wmDrag;
-struct wmEvent;
 
 namespace blender::ui {
 
 class AbstractTreeView;
 class AbstractTreeViewItem;
-class AbstractTreeViewItemDropController;
-class AbstractTreeViewItemDragController;
 
 /* ---------------------------------------------------------------------- */
 /** \name Tree-View Item Container
@@ -111,42 +107,20 @@ using TreeViewOrItem = TreeViewItemContainer;
 /** \name Tree-View Base Class
  * \{ */
 
-class AbstractTreeView : public TreeViewItemContainer {
+class AbstractTreeView : public AbstractView, public TreeViewItemContainer {
   friend class AbstractTreeViewItem;
   friend class TreeViewBuilder;
 
-  /**
-   * Only one item can be renamed at a time. So the tree is informed about the renaming state to
-   * enforce that.
-   */
-  std::unique_ptr<std::array<char, MAX_NAME>> rename_buffer_;
-
-  bool is_reconstructed_ = false;
-
  public:
   virtual ~AbstractTreeView() = default;
 
   void foreach_item(ItemIterFn iter_fn, IterOptions options = IterOptions::None) const;
 
-  /** Only one item can be renamed at a time. */
-  bool is_renaming() const;
-
  protected:
   virtual void build_tree() = 0;
 
-  /**
-   * Check if the tree is fully (re-)constructed. That means, both #build_tree() and
-   * #update_from_old() have finished.
-   */
-  bool is_reconstructed() const;
-
  private:
-  /**
-   * Match the tree-view against an earlier version of itself (if any) and copy the old UI state
-   * (e.g. collapsed, active, selected, renaming, etc.) to the new one. See
-   * #AbstractTreeViewItem.update_from_old().
-   */
-  void update_from_old(uiBlock &new_block);
+  void update_children_from_old(const AbstractView &old_view) override;
   static void update_children_from_old_recursive(const TreeViewOrItem &new_items,
                                                  const TreeViewOrItem &old_items);
   static AbstractTreeViewItem *find_matching_child(const AbstractTreeViewItem &lookup_item,
@@ -173,7 +147,7 @@ class AbstractTreeView : public TreeViewItemContainer {
  * It also stores state information that needs to be persistent over redraws, like the collapsed
  * state.
  */
-class AbstractTreeViewItem : public TreeViewItemContainer {
+class AbstractTreeViewItem : public AbstractViewItem, public TreeViewItemContainer {
   friend class AbstractTreeView;
   friend class TreeViewLayoutBuilder;
   /* Higher-level API. */
@@ -181,20 +155,17 @@ class AbstractTreeViewItem : public TreeViewItemContainer {
 
  private:
   bool is_open_ = false;
-  bool is_active_ = false;
-  bool is_renaming_ = false;
 
  protected:
-  /** This label is used for identifying an item within its parent. */
+  /** This label is used as the default way to identifying an item within its parent. */
   std::string label_{};
-  /** Every visible item gets a button of type #UI_BTYPE_TREEROW during the layout building. */
-  uiButTreeRow *tree_row_but_ = nullptr;
+  /** Every visible item gets a button of type #UI_BTYPE_VIEW_ITEM during the layout building. */
+  uiButViewItem *view_item_but_ = nullptr;
 
  public:
   virtual ~AbstractTreeViewItem() = default;
 
   virtual void build_row(uiLayout &row) = 0;
-  virtual void build_context_menu(bContext &C, uiLayout &column) const;
 
   AbstractTreeView &get_tree_view() const;
 
@@ -206,11 +177,6 @@ class AbstractTreeViewItem : public TreeViewItemContainer {
    * can't be sure about the item state.
    */
   bool is_collapsed() const;
-  /**
-   * Requires the tree to have completed reconstruction, see #is_reconstructed(). Otherwise we
-   * can't be sure about the item state.
-   */
-  bool is_active() const;
 
  protected:
   /**
@@ -223,31 +189,21 @@ class AbstractTreeViewItem : public TreeViewItemContainer {
    */
   virtual std::optional<bool> should_be_active() const;
 
-  /**
-   * Queries if the tree-view item supports renaming in principle. Renaming may still fail, e.g. if
-   * another item is already being renamed.
-   */
-  virtual bool supports_renaming() const;
-  /**
-   * Try renaming the item, or the data it represents. Can assume
-   * #AbstractTreeViewItem::supports_renaming() returned true. Sub-classes that override this
-   * should usually call this, unless they have a custom #AbstractTreeViewItem.matches().
-   *
-   * \return True if the renaming was successful.
-   */
-  virtual bool rename(StringRefNull new_name);
+  /** See AbstractViewItem::get_rename_string(). */
+  virtual StringRef get_rename_string() const override;
+  /** See AbstractViewItem::rename(). */
+  virtual bool rename(StringRefNull new_name) override;
 
   /**
    * Return whether the item can be collapsed. Used to disable collapsing for items with children.
    */
   virtual bool supports_collapsing() const;
 
-  /**
-   * Copy persistent state (e.g. is-collapsed flag, selection, etc.) from a matching item of
-   * the last redraw to this item. If sub-classes introduce more advanced state they should
-   * override this and make it update their state accordingly.
-   */
-  virtual void update_from_old(const AbstractTreeViewItem &old);
+  /** See #AbstractViewItem::matches(). */
+  virtual bool matches(const AbstractViewItem &other) const override;
+
+  /** See #AbstractViewItem::update_from_old(). */
+  virtual void update_from_old(const AbstractViewItem &old) override;
 
   /**
    * Compare this item to \a other to check if they represent the same data.
@@ -255,22 +211,11 @@ class AbstractTreeViewItem : public TreeViewItemContainer {
    * open/closed, active, etc.). Items are only matched if their parents also match.
    * By default this just matches the item's label (if the parents match!). If that isn't
    * good enough for a sub-class, that can override it.
-   */
-  virtual bool matches(const AbstractTreeViewItem &other) const;
-
-  /**
-   * If an item wants to support being dragged, it has to return a drag controller here.
-   * That is an object implementing #AbstractTreeViewItemDragController.
-   */
-  virtual std::unique_ptr<AbstractTreeViewItemDragController> create_drag_controller() const;
-  /**
-   * If an item wants to support dropping data into it, it has to return a drop controller here.
-   * That is an object implementing #AbstractTreeViewItemDropController.
    *
-   * \note This drop controller may be requested for each event. The tree-view doesn't keep a drop
-   *       controller around currently. So it can not contain persistent state.
+   * TODO #matches_single() is a rather temporary name, used to indicate that this only compares
+   * the item itself, not the parents. Item matching is expected to change quite a bit anyway.
    */
-  virtual std::unique_ptr<AbstractTreeViewItemDropController> create_drop_controller() const;
+  virtual bool matches_single(const AbstractTreeViewItem &other) const;
 
   /**
    * Activates this item, deactivates other items, calls the #AbstractTreeViewItem::on_activate()
@@ -288,29 +233,24 @@ class AbstractTreeViewItem : public TreeViewItemContainer {
    */
   bool is_hovered() const;
   bool is_collapsible() const;
-  bool is_renaming() const;
 
   void ensure_parents_uncollapsed();
 
-  uiButTreeRow *tree_row_button();
+  uiButViewItem *view_item_button();
 
  private:
-  static void rename_button_fn(bContext *, void *, char *);
-  static AbstractTreeViewItem *find_tree_item_from_rename_button(const uiBut &but);
   static void tree_row_click_fn(struct bContext *, void *, void *);
   static void collapse_chevron_click_fn(bContext *, void *but_arg1, void *);
   static bool is_collapse_chevron_but(const uiBut *but);
 
   /** See #AbstractTreeView::change_state_delayed() */
   void change_state_delayed();
-  void end_renaming();
 
   void add_treerow_button(uiBlock &block);
   void add_indent(uiLayout &row) const;
   void add_collapse_chevron(uiBlock &block) const;
   void add_rename_button(uiLayout &row);
 
-  bool matches_including_parents(const AbstractTreeViewItem &other) const;
   bool has_active_child() const;
   int count_parents() const;
 };
@@ -318,69 +258,6 @@ class AbstractTreeViewItem : public TreeViewItemContainer {
 /** \} */
 
 /* ---------------------------------------------------------------------- */
-/** \name Drag 'n Drop
- * \{ */
-
-/**
- * Class to enable dragging a tree-item. An item can return a drop controller for itself via a
- * custom implementation of #AbstractTreeViewItem::create_drag_controller().
- */
-class AbstractTreeViewItemDragController {
- protected:
-  AbstractTreeView &tree_view_;
-
- public:
-  AbstractTreeViewItemDragController(AbstractTreeView &tree_view);
-  virtual ~AbstractTreeViewItemDragController() = default;
-
-  virtual int get_drag_type() const = 0;
-  virtual void *create_drag_data() const = 0;
-  virtual void on_drag_start();
-
-  template<class TreeViewType> inline TreeViewType &tree_view() const;
-};
-
-/**
- * Class to customize the drop behavior of a tree-item, plus the behavior when dragging over this
- * item. An item can return a drop controller for itself via a custom implementation of
- * #AbstractTreeViewItem::create_drop_controller().
- */
-class AbstractTreeViewItemDropController {
- protected:
-  AbstractTreeView &tree_view_;
-
- public:
-  AbstractTreeViewItemDropController(AbstractTreeView &tree_view);
-  virtual ~AbstractTreeViewItemDropController() = default;
-
-  /**
-   * Check if the data dragged with \a drag can be dropped on the item this controller is for.
-   * \param r_disabled_hint: Return a static string to display to the user, explaining why dropping
-   *                         isn't possible on this item. Shouldn't be done too aggressively, e.g.
-   *                         don't set this if the drag-type can't be dropped here; only if it can
-   *                         but there's another reason it can't be dropped.
-   *                         Can assume this is a non-null pointer.
-   */
-  virtual bool can_drop(const wmDrag &drag, const char **r_disabled_hint) const = 0;
-  /**
-   * Custom text to display when dragging over a tree item. Should explain what happens when
-   * dropping the data onto this item. Will only be used if #AbstractTreeViewItem::can_drop()
-   * returns true, so the implementing override doesn't have to check that again.
-   * The returned value must be a translated string.
-   */
-  virtual std::string drop_tooltip(const wmDrag &drag) const = 0;
-  /**
-   * Execute the logic to apply a drop of the data dragged with \a drag onto/into the item this
-   * controller is for.
-   */
-  virtual bool on_drop(struct bContext *C, const wmDrag &drag) = 0;
-
-  template<class TreeViewType> inline TreeViewType &tree_view() const;
-};
-
-/** \} */
-
-/* ---------------------------------------------------------------------- */
 /** \name Predefined Tree-View Item Types
  *
  *  Common, Basic Tree-View Item Types.
@@ -451,18 +328,4 @@ inline ItemT &TreeViewItemContainer::add_tree_item(Args &&...args)
       add_tree_item(std::make_unique<ItemT>(std::forward<Args>(args)...)));
 }
 
-template<class TreeViewType> TreeViewType &AbstractTreeViewItemDragController::tree_view() const
-{
-  static_assert(std::is_base_of<AbstractTreeView, TreeViewType>::value,
-                "Type must derive from and implement the AbstractTreeView interface");
-  return static_cast<TreeViewType &>(tree_view_);
-}
-
-template<class TreeViewType> TreeViewType &AbstractTreeViewItemDropController::tree_view() const
-{
-  static_assert(std::is_base_of<AbstractTreeView, TreeViewType>::value,
-                "Type must derive from and implement the AbstractTreeView interface");
-  return static_cast<TreeViewType &>(tree_view_);
-}
-
 }  // namespace blender::ui
diff --git a/source/blender/editors/include/UI_view2d.h b/source/blender/editors/include/UI_view2d.h
index 23dbd3ed36f..c357b67722d 100644
--- a/source/blender/editors/include/UI_view2d.h
+++ b/source/blender/editors/include/UI_view2d.h
@@ -16,41 +16,56 @@
 extern "C" {
 #endif
 
-/* ------------------------------------------ */
-/* Settings and Defines:                      */
+/* -------------------------------------------------------------------- */
+/** \name General Defines
+ * \{ */
 
-/* ---- General Defines ---- */
-
-/* generic value to use when coordinate lies out of view when converting */
+/** Generic value to use when coordinate lies out of view when converting. */
 #define V2D_IS_CLIPPED 12000
 
-/* Common View2D view types
- * NOTE: only define a type here if it completely sets all (+/- a few) of the relevant flags
- *       and settings for a View2D region, and that set of settings is used in more
- *       than one specific place
+/**
+ * Common View2D view types.
+ *
+ * \note only define a type here if it completely sets all (+/- a few) of the relevant flags and
+ * settings for a View2D region, and that set of settings is used in more than one specific place.
  */
 enum eView2D_CommonViewTypes {
-  /* custom view type (region has defined all necessary flags already) */
+  /** custom view type (region has defined all necessary flags already). */
   V2D_COMMONVIEW_CUSTOM = -1,
-  /* standard (only use this when setting up a new view, as a sensible base for most settings) */
+  /** standard (only use this when setting up a new view, as a sensible base for most settings). */
   V2D_COMMONVIEW_STANDARD,
-  /* listview (i.e. Outliner) */
+  /** List-view (i.e. Outliner). */
   V2D_COMMONVIEW_LIST,
-  /* Stack-view (this is basically a list where new items are added at the top). */
+  /** Stack-view (this is basically a list where new items are added at the top). */
   V2D_COMMONVIEW_STACK,
-  /* headers (this is basically the same as listview, but no y-panning) */
+  /** headers (this is basically the same as list-view, but no Y-panning). */
   V2D_COMMONVIEW_HEADER,
-  /* ui region containing panels */
+  /** UI region containing panels. */
   V2D_COMMONVIEW_PANELS_UI,
 };
 
-/* ---- Defines for Scroller Arguments ----- */
+/** \} */
 
-/* ------ Defines for Scrollers ----- */
+/* -------------------------------------------------------------------- */
+/** \name Defines for Scroll Bars
+ * \{ */
 
 /** Scroll bar area. */
-#define V2D_SCROLL_HEIGHT (0.45f * U.widget_unit)
-#define V2D_SCROLL_WIDTH (0.45f * U.widget_unit)
+
+/* Maximum has to include outline which varies with line width. */
+#define V2D_SCROLL_HEIGHT ((0.45f * U.widget_unit) + (2.0f * U.pixelsize))
+#define V2D_SCROLL_WIDTH ((0.45f * U.widget_unit) + (2.0f * U.pixelsize))
+
+/* Alpha of scroll-bar when at minimum size. */
+#define V2D_SCROLL_MIN_ALPHA (0.4f)
+
+/* Minimum size needs to include outline which varies with line width. */
+#define V2D_SCROLL_MIN_WIDTH ((5.0f * U.dpi_fac) + (2.0f * U.pixelsize))
+
+/* When to start showing the full-width scroller. */
+#define V2D_SCROLL_HIDE_WIDTH (AREAMINX * U.dpi_fac)
+#define V2D_SCROLL_HIDE_HEIGHT (HEADERY * U.dpi_fac)
+
 /** Scroll bars with 'handles' used for scale (zoom). */
 #define V2D_SCROLL_HANDLE_HEIGHT (0.6f * U.widget_unit)
 #define V2D_SCROLL_HANDLE_WIDTH (0.6f * U.widget_unit)
@@ -61,25 +76,35 @@ enum eView2D_CommonViewTypes {
 /** Don't allow scroll thumb to show below this size (so it's never too small to click on). */
 #define V2D_SCROLL_THUMB_SIZE_MIN (30.0 * UI_DPI_FAC)
 
-/* ------ Define for UI_view2d_sync ----- */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Define for #UI_view2d_sync
+ * \{ */
 
 /* means copy it from another v2d */
 #define V2D_LOCK_SET 0
 /* means copy it to the other v2ds */
 #define V2D_LOCK_COPY 1
 
-/* ------------------------------------------ */
-/* Macros:                                    */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Macros
+ * \{ */
 
-/* test if mouse in a scrollbar (assume that scroller availability has been tested) */
+/* Test if mouse in a scroll-bar (assume that scroller availability has been tested). */
 #define IN_2D_VERT_SCROLL(v2d, co) (BLI_rcti_isect_pt_v(&v2d->vert, co))
 #define IN_2D_HORIZ_SCROLL(v2d, co) (BLI_rcti_isect_pt_v(&v2d->hor, co))
 
 #define IN_2D_VERT_SCROLL_RECT(v2d, rct) (BLI_rcti_isect(&v2d->vert, rct, NULL))
 #define IN_2D_HORIZ_SCROLL_RECT(v2d, rct) (BLI_rcti_isect(&v2d->hor, rct, NULL))
 
-/* ------------------------------------------ */
-/* Type definitions:                          */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Foeard Declarations
+ * \{ */
 
 struct View2D;
 struct View2DScrollers;
@@ -99,8 +124,11 @@ struct wmOperatorType;
 
 typedef struct View2DScrollers View2DScrollers;
 
-/* ----------------------------------------- */
-/* Prototypes:                               */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Prototypes
+ * \{ */
 
 /**
  * Refresh and validation (of view rects).
@@ -148,7 +176,12 @@ void UI_view2d_mask_from_win(const struct View2D *v2d, struct rcti *r_mask);
 
 void UI_view2d_zoom_cache_reset(void);
 
-/* view matrix operations */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name View Matrix Operations
+ * \{ */
+
 /**
  * Set view matrices to use 'cur' rect as viewing frame for View2D drawing.
  */
@@ -165,7 +198,11 @@ void UI_view2d_view_orthoSpecial(struct ARegion *region, struct View2D *v2d, boo
  */
 void UI_view2d_view_restore(const struct bContext *C);
 
-/* grid drawing */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Grid Drawing
+ * \{ */
 
 /**
  * Draw a multi-level grid in given 2d-region.
@@ -228,7 +265,11 @@ void UI_view2d_draw_scale_x__frames_or_seconds(const struct ARegion *region,
                                                bool display_seconds,
                                                int colorid);
 
-/* Scroll-bar drawing. */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Scroll-bar Drawing
+ * \{ */
 
 /**
  * Calculate relevant scroller properties.
@@ -236,12 +277,20 @@ void UI_view2d_draw_scale_x__frames_or_seconds(const struct ARegion *region,
 void UI_view2d_scrollers_calc(struct View2D *v2d,
                               const struct rcti *mask_custom,
                               struct View2DScrollers *r_scrollers);
+
 /**
  * Draw scroll-bars in the given 2D-region.
  */
+void UI_view2d_scrollers_draw_ex(struct View2D *v2d,
+                                 const struct rcti *mask_custom,
+                                 bool use_full_hide);
 void UI_view2d_scrollers_draw(struct View2D *v2d, const struct rcti *mask_custom);
 
-/* List view tools. */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name List View Tools
+ * \{ */
 
 /**
  * Get the 'cell' (row, column) that the given 2D-view coordinates
@@ -264,7 +313,11 @@ void UI_view2d_listview_view_to_cell(float columnwidth,
                                      int *r_column,
                                      int *r_row);
 
-/* Coordinate conversion. */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Coordinate Conversion
+ * \{ */
 
 float UI_view2d_region_to_view_x(const struct View2D *v2d, float x);
 float UI_view2d_region_to_view_y(const struct View2D *v2d, float y);
@@ -292,6 +345,12 @@ float UI_view2d_view_to_region_y(const struct View2D *v2d, float y);
 bool UI_view2d_view_to_region_clip(
     const struct View2D *v2d, float x, float y, int *r_region_x, int *r_region_y) ATTR_NONNULL();
 
+bool UI_view2d_view_to_region_segment_clip(const View2D *v2d,
+                                           const float xy_a[2],
+                                           const float xy_b[2],
+                                           int r_region_a[2],
+                                           int r_region_b[2]) ATTR_NONNULL();
+
 /**
  * Convert from 2d-view space to screen/region space
  *
@@ -315,7 +374,11 @@ bool UI_view2d_view_to_region_rcti_clip(const struct View2D *v2d,
                                         const struct rctf *rect_src,
                                         struct rcti *rect_dst) ATTR_NONNULL();
 
-/* Utilities. */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Utilities
+ * \{ */
 
 /**
  * View2D data by default resides in region, so get from region stored in context.
@@ -327,10 +390,12 @@ struct View2D *UI_view2d_fromcontext(const struct bContext *C);
 struct View2D *UI_view2d_fromcontext_rwin(const struct bContext *C);
 
 /**
- * Get scrollbar sizes of the current 2D view.
- * The size will be zero if the view has its scrollbars disabled.
+ * Get scroll-bar sizes of the current 2D view.
+ * The size will be zero if the view has its scroll-bars disabled.
+ *
+ * \param mapped: whether to use view2d_scroll_mapped which changes flags
  */
-void UI_view2d_scroller_size_get(const struct View2D *v2d, float *r_x, float *r_y);
+void UI_view2d_scroller_size_get(const struct View2D *v2d, bool mapped, float *r_x, float *r_y);
 /**
  * Calculate the scale per-axis of the drawing-area
  *
@@ -407,7 +472,11 @@ void UI_view2d_text_cache_add_rectf(struct View2D *v2d,
                                     const unsigned char col[4]);
 void UI_view2d_text_cache_draw(struct ARegion *region);
 
-/* Operators. */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Operators
+ * \{ */
 
 void ED_operatortypes_view2d(void);
 void ED_keymap_view2d(struct wmKeyConfig *keyconf);
@@ -424,7 +493,11 @@ void UI_view2d_smooth_view(const struct bContext *C,
 #define UI_MARKER_MARGIN_Y (42 * UI_DPI_FAC)
 #define UI_TIME_SCRUB_MARGIN_Y (23 * UI_DPI_FAC)
 
-/* Gizmo Types. */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Gizmo Types
+ * \{ */
 
 /* view2d_gizmo_navigate.c */
 
@@ -433,7 +506,11 @@ void UI_view2d_smooth_view(const struct bContext *C,
  */
 void VIEW2D_GGT_navigate_impl(struct wmGizmoGroupType *gzgt, const char *idname);
 
-/* Edge pan. */
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Edge Pan
+ * \{ */
 
 /**
  * Custom-data for view panning operators.
@@ -534,6 +611,8 @@ void UI_view2d_edge_pan_operator_init(struct bContext *C,
                                       struct View2DEdgePanData *vpd,
                                       struct wmOperator *op);
 
+/** \} */
+
 #ifdef __cplusplus
 }
 #endif