ed_undo.c

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/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2004 Blender Foundation
 * All rights reserved.
 */
 
#include <string.h>
 
#include "MEM_guardedalloc.h"
 
#include "CLG_log.h"
 
#include "DNA_object_types.h"
#include "DNA_scene_types.h"
 
#include "BLI_listbase.h"
#include "BLI_utildefines.h"
 
#include "BLT_translation.h"
 
#include "BKE_blender_undo.h"
#include "BKE_callbacks.h"
#include "BKE_context.h"
#include "BKE_global.h"
#include "BKE_layer.h"
#include "BKE_main.h"
#include "BKE_paint.h"
#include "BKE_report.h"
#include "BKE_scene.h"
#include "BKE_screen.h"
#include "BKE_undo_system.h"
#include "BKE_workspace.h"
 
#include "BLO_blend_validate.h"
 
#include "ED_gpencil.h"
#include "ED_object.h"
#include "ED_outliner.h"
#include "ED_render.h"
#include "ED_screen.h"
#include "ED_undo.h"
 
#include "WM_api.h"
#include "WM_toolsystem.h"
#include "WM_types.h"
 
#include "RNA_access.h"
#include "RNA_define.h"
 
#include "UI_interface.h"
#include "UI_resources.h"
 
static CLG_LogRef LOG = {"ed.undo"};
 
/* -------------------------------------------------------------------- */
bool ED_undo_is_state_valid(bContext *C)
{
  wmWindowManager *wm = CTX_wm_manager(C);
 
  /* Currently only checks matching begin/end calls. */
  if (wm->undo_stack == NULL) {
    /* No undo stack is valid, nothing to do. */
    return true;
  }
  if (wm->undo_stack->group_level != 0) {
    /* If this fails #ED_undo_grouped_begin, #ED_undo_grouped_end calls don't match. */
    return false;
  }
  if (wm->undo_stack->step_active != NULL) {
    if (wm->undo_stack->step_active->skip == true) {
      /* Skip is only allowed between begin/end calls,
       * a state that should never happen in main event loop. */
      return false;
    }
  }
  return true;
}
 
void ED_undo_group_begin(bContext *C)
{
  wmWindowManager *wm = CTX_wm_manager(C);
  BKE_undosys_stack_group_begin(wm->undo_stack);
}
 
void ED_undo_group_end(bContext *C)
{
  wmWindowManager *wm = CTX_wm_manager(C);
  BKE_undosys_stack_group_end(wm->undo_stack);
}
 
void ED_undo_push(bContext *C, const char *str)
{
  CLOG_INFO(&LOG, 1, "name='%s'", str);
  WM_file_tag_modified();
 
  wmWindowManager *wm = CTX_wm_manager(C);
  int steps = U.undosteps;
 
  /* Ensure steps that have been initialized are always pushed,
   * even when undo steps are zero.
   *
   * Note that some modes (paint, sculpt) initialize an undo step before an action runs,
   * then accumulate changes there, or restore data from it in the case of 2D painting.
   *
   * For this reason we need to handle the undo step even when undo steps is set to zero.
   */
  if ((steps <= 0) && wm->undo_stack->step_init != NULL) {
    steps = 1;
  }
  if (steps <= 0) {
    return;
  }
  if (G.background) {
    /* Python developers may have explicitly created the undo stack in background mode,
     * otherwise allow it to be NULL, see: T60934.
     * Otherwise it must never be NULL, even when undo is disabled. */
    if (wm->undo_stack == NULL) {
      return;
    }
  }
 
  UndoPushReturn push_retval;
 
  /* Only apply limit if this is the last undo step. */
  if (wm->undo_stack->step_active && (wm->undo_stack->step_active->next == NULL)) {
    BKE_undosys_stack_limit_steps_and_memory(wm->undo_stack, steps - 1, 0);
  }
 
  push_retval = BKE_undosys_step_push(wm->undo_stack, C, str);
 
  if (U.undomemory != 0) {
    const size_t memory_limit = (size_t)U.undomemory * 1024 * 1024;
    BKE_undosys_stack_limit_steps_and_memory(wm->undo_stack, -1, memory_limit);
  }
 
  if (CLOG_CHECK(&LOG, 1)) {
    BKE_undosys_print(wm->undo_stack);
  }
 
  if (push_retval & UNDO_PUSH_RET_OVERRIDE_CHANGED) {
    WM_main_add_notifier(NC_WM | ND_LIB_OVERRIDE_CHANGED, NULL);
  }
}
 
static void ed_undo_step_pre(bContext *C,
                             wmWindowManager *wm,
                             const enum eUndoStepDir undo_dir,
                             ReportList *reports)
{
  BLI_assert(ELEM(undo_dir, STEP_UNDO, STEP_REDO));
 
  Main *bmain = CTX_data_main(C);
  Scene *scene = CTX_data_scene(C);
  ScrArea *area = CTX_wm_area(C);
 
  /* undo during jobs are running can easily lead to freeing data using by jobs,
   * or they can just lead to freezing job in some other cases */
  WM_jobs_kill_all(wm);
 
  if (G.debug & G_DEBUG_IO) {
    if (bmain->lock != NULL) {
      BKE_report(reports, RPT_INFO, "Checking sanity of current .blend file *BEFORE* undo step");
      BLO_main_validate_libraries(bmain, reports);
    }
  }
 
  if (area && (area->spacetype == SPACE_VIEW3D)) {
    Object *obact = CTX_data_active_object(C);
    if (obact && (obact->type == OB_GPENCIL)) {
      ED_gpencil_toggle_brush_cursor(C, false, NULL);
    }
  }
 
  /* App-Handlers (pre). */
  {
    /* Note: ignore grease pencil for now. */
    wm->op_undo_depth++;
    BKE_callback_exec_id(
        bmain, &scene->id, (undo_dir == STEP_UNDO) ? BKE_CB_EVT_UNDO_PRE : BKE_CB_EVT_REDO_PRE);
    wm->op_undo_depth--;
  }
}
 
static void ed_undo_step_post(bContext *C,
                              wmWindowManager *wm,
                              const enum eUndoStepDir undo_dir,
                              ReportList *reports)
{
  BLI_assert(ELEM(undo_dir, STEP_UNDO, STEP_REDO));
 
  Main *bmain = CTX_data_main(C);
  Scene *scene = CTX_data_scene(C);
  ScrArea *area = CTX_wm_area(C);
 
  /* Set special modes for grease pencil */
  if (area != NULL && (area->spacetype == SPACE_VIEW3D)) {
    Object *obact = CTX_data_active_object(C);
    if (obact && (obact->type == OB_GPENCIL)) {
      /* set cursor */
      if (ELEM(obact->mode,
               OB_MODE_PAINT_GPENCIL,
               OB_MODE_SCULPT_GPENCIL,
               OB_MODE_WEIGHT_GPENCIL,
               OB_MODE_VERTEX_GPENCIL)) {
        ED_gpencil_toggle_brush_cursor(C, true, NULL);
      }
      else {
        ED_gpencil_toggle_brush_cursor(C, false, NULL);
      }
      /* set workspace mode */
      Base *basact = CTX_data_active_base(C);
      ED_object_base_activate(C, basact);
    }
  }
 
  /* App-Handlers (post). */
  {
    wm->op_undo_depth++;
    BKE_callback_exec_id(
        bmain, &scene->id, (undo_dir == STEP_UNDO) ? BKE_CB_EVT_UNDO_POST : BKE_CB_EVT_REDO_POST);
    wm->op_undo_depth--;
  }
 
  if (G.debug & G_DEBUG_IO) {
    if (bmain->lock != NULL) {
      BKE_report(reports, RPT_INFO, "Checking sanity of current .blend file *AFTER* undo step");
      BLO_main_validate_libraries(bmain, reports);
    }
  }
 
  WM_event_add_notifier(C, NC_WINDOW, NULL);
  WM_event_add_notifier(C, NC_WM | ND_UNDO, NULL);
 
  WM_toolsystem_refresh_active(C);
  WM_toolsystem_refresh_screen_all(bmain);
 
  if (CLOG_CHECK(&LOG, 1)) {
    BKE_undosys_print(wm->undo_stack);
  }
}
 
static int ed_undo_step_direction(bContext *C, enum eUndoStepDir step, ReportList *reports)
{
  BLI_assert(ELEM(step, STEP_UNDO, STEP_REDO));
 
  CLOG_INFO(&LOG, 1, "direction=%s", (step == STEP_UNDO) ? "STEP_UNDO" : "STEP_REDO");
 
  /* TODO(campbell): undo_system: use undo system */
  /* grease pencil can be can be used in plenty of spaces, so check it first */
  /* FIXME: This gpencil undo effectively only supports the one step undo/redo, undo based on name
   * or index is fully not implemented.
   * FIXME: However, it seems to never be used in current code (`ED_gpencil_session_active` seems
   * to always return false). */
  if (ED_gpencil_session_active()) {
    return ED_undo_gpencil_step(C, step);
  }
 
  wmWindowManager *wm = CTX_wm_manager(C);
 
  ed_undo_step_pre(C, wm, step, reports);
 
  if (step == STEP_UNDO) {
    BKE_undosys_step_undo(wm->undo_stack, C);
  }
  else {
    BKE_undosys_step_redo(wm->undo_stack, C);
  }
 
  ed_undo_step_post(C, wm, step, reports);
 
  return OPERATOR_FINISHED;
}
 
static int ed_undo_step_by_name(bContext *C, const char *undo_name, ReportList *reports)
{
  BLI_assert(undo_name != NULL);
 
  /* FIXME: See comments in `ed_undo_step_direction`. */
  if (ED_gpencil_session_active()) {
    BLI_assert(!"Not implemented currently.");
  }
 
  wmWindowManager *wm = CTX_wm_manager(C);
  UndoStep *undo_step_from_name = BKE_undosys_step_find_by_name(wm->undo_stack, undo_name);
  if (undo_step_from_name == NULL) {
    CLOG_ERROR(&LOG, "Step name='%s' not found in current undo stack", undo_name);
 
    return OPERATOR_CANCELLED;
  }
 
  UndoStep *undo_step_target = undo_step_from_name->prev;
  if (undo_step_target == NULL) {
    CLOG_ERROR(&LOG, "Step name='%s' cannot be undone", undo_name);
 
    return OPERATOR_CANCELLED;
  }
 
  const int undo_dir_i = BKE_undosys_step_calc_direction(wm->undo_stack, undo_step_target, NULL);
  BLI_assert(ELEM(undo_dir_i, -1, 1));
  const enum eUndoStepDir undo_dir = (undo_dir_i == -1) ? STEP_UNDO : STEP_REDO;
 
  CLOG_INFO(&LOG,
            1,
            "name='%s', found direction=%s",
            undo_name,
            (undo_dir == STEP_UNDO) ? "STEP_UNDO" : "STEP_REDO");
 
  ed_undo_step_pre(C, wm, undo_dir, reports);
 
  BKE_undosys_step_load_data_ex(wm->undo_stack, C, undo_step_target, NULL, true);
 
  ed_undo_step_post(C, wm, undo_dir, reports);
 
  return OPERATOR_FINISHED;
}
 
static int ed_undo_step_by_index(bContext *C, const int undo_index, ReportList *reports)
{
  BLI_assert(undo_index >= 0);
 
  /* FIXME: See comments in `ed_undo_step_direction`. */
  if (ED_gpencil_session_active()) {
    BLI_assert(!"Not implemented currently.");
  }
 
  wmWindowManager *wm = CTX_wm_manager(C);
  const int active_step_index = BLI_findindex(&wm->undo_stack->steps, wm->undo_stack->step_active);
  const enum eUndoStepDir undo_dir = (undo_index < active_step_index) ? STEP_UNDO : STEP_REDO;
 
  CLOG_INFO(&LOG,
            1,
            "index='%d', found direction=%s",
            undo_index,
            (undo_dir == STEP_UNDO) ? "STEP_UNDO" : "STEP_REDO");
 
  ed_undo_step_pre(C, wm, undo_dir, reports);
 
  BKE_undosys_step_load_from_index(wm->undo_stack, C, undo_index);
 
  ed_undo_step_post(C, wm, undo_dir, reports);
 
  return OPERATOR_FINISHED;
}
 
void ED_undo_grouped_push(bContext *C, const char *str)
{
  /* do nothing if previous undo task is the same as this one (or from the same undo group) */
  wmWindowManager *wm = CTX_wm_manager(C);
  const UndoStep *us = wm->undo_stack->step_active;
  if (us && STREQ(str, us->name)) {
    BKE_undosys_stack_clear_active(wm->undo_stack);
  }
 
  /* push as usual */
  ED_undo_push(C, str);
}
 
void ED_undo_pop(bContext *C)
{
  ed_undo_step_direction(C, STEP_UNDO, NULL);
}
void ED_undo_redo(bContext *C)
{
  ed_undo_step_direction(C, STEP_REDO, NULL);
}
 
void ED_undo_push_op(bContext *C, wmOperator *op)
{
  /* in future, get undo string info? */
  ED_undo_push(C, op->type->name);
}
 
void ED_undo_grouped_push_op(bContext *C, wmOperator *op)
{
  if (op->type->undo_group[0] != '\0') {
    ED_undo_grouped_push(C, op->type->undo_group);
  }
  else {
    ED_undo_grouped_push(C, op->type->name);
  }
}
 
void ED_undo_pop_op(bContext *C, wmOperator *op)
{
  /* search back a couple of undo's, in case something else added pushes */
  ed_undo_step_by_name(C, op->type->name, op->reports);
}
 
/* name optionally, function used to check for operator redo panel */
bool ED_undo_is_valid(const bContext *C, const char *undoname)
{
  wmWindowManager *wm = CTX_wm_manager(C);
  return BKE_undosys_stack_has_undo(wm->undo_stack, undoname);
}
 
bool ED_undo_is_memfile_compatible(const bContext *C)
{
  /* Some modes don't co-exist with memfile undo, disable their use: T60593
   * (this matches 2.7x behavior). */
  ViewLayer *view_layer = CTX_data_view_layer(C);
  if (view_layer != NULL) {
    Object *obact = OBACT(view_layer);
    if (obact != NULL) {
      if (obact->mode & OB_MODE_EDIT) {
        return false;
      }
    }
  }
  return true;
}
 
bool ED_undo_is_legacy_compatible_for_property(struct bContext *C, ID *id)
{
  ViewLayer *view_layer = CTX_data_view_layer(C);
  if (view_layer != NULL) {
    Object *obact = OBACT(view_layer);
    if (obact != NULL) {
      if (obact->mode & OB_MODE_ALL_PAINT) {
        /* Don't store property changes when painting
         * (only do undo pushes on brush strokes which each paint operator handles on its own). */
        CLOG_INFO(&LOG, 1, "skipping undo for paint-mode");
        return false;
      }
      if (obact->mode & OB_MODE_EDIT) {
        if ((id == NULL) || (obact->data == NULL) ||
            (GS(id->name) != GS(((ID *)obact->data)->name))) {
          /* No undo push on id type mismatch in edit-mode. */
          CLOG_INFO(&LOG, 1, "skipping undo for edit-mode");
          return false;
        }
      }
    }
  }
  return true;
}
 
UndoStack *ED_undo_stack_get(void)
{
  wmWindowManager *wm = G_MAIN->wm.first;
  return wm->undo_stack;
}
 
/* -------------------------------------------------------------------- */
static int ed_undo_exec(bContext *C, wmOperator *op)
{
  /* "last operator" should disappear, later we can tie this with undo stack nicer */
  WM_operator_stack_clear(CTX_wm_manager(C));
  int ret = ed_undo_step_direction(C, STEP_UNDO, op->reports);
  if (ret & OPERATOR_FINISHED) {
    /* Keep button under the cursor active. */
    WM_event_add_mousemove(CTX_wm_window(C));
  }
 
  ED_outliner_select_sync_from_all_tag(C);
  return ret;
}
 
static int ed_undo_push_exec(bContext *C, wmOperator *op)
{
  if (G.background) {
    /* Exception for background mode, see: T60934.
     * Note: since the undo stack isn't initialized on startup, background mode behavior
     * won't match regular usage, this is just for scripts to do explicit undo pushes. */
    wmWindowManager *wm = CTX_wm_manager(C);
    if (wm->undo_stack == NULL) {
      wm->undo_stack = BKE_undosys_stack_create();
    }
  }
  char str[BKE_UNDO_STR_MAX];
  RNA_string_get(op->ptr, "message", str);
  ED_undo_push(C, str);
  return OPERATOR_FINISHED;
}
 
static int ed_redo_exec(bContext *C, wmOperator *op)
{
  int ret = ed_undo_step_direction(C, STEP_REDO, op->reports);
  if (ret & OPERATOR_FINISHED) {
    /* Keep button under the cursor active. */
    WM_event_add_mousemove(CTX_wm_window(C));
  }
 
  ED_outliner_select_sync_from_all_tag(C);
  return ret;
}
 
static int ed_undo_redo_exec(bContext *C, wmOperator *UNUSED(op))
{
  wmOperator *last_op = WM_operator_last_redo(C);
  int ret = ED_undo_operator_repeat(C, last_op);
  ret = ret ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
  if (ret & OPERATOR_FINISHED) {
    /* Keep button under the cursor active. */
    WM_event_add_mousemove(CTX_wm_window(C));
  }
  return ret;
}
 
/* Disable in background mode, we could support if it's useful, T60934. */
 
static bool ed_undo_is_init_poll(bContext *C)
{
  wmWindowManager *wm = CTX_wm_manager(C);
  if (wm->undo_stack == NULL) {
    CTX_wm_operator_poll_msg_set(C, "Undo disabled at startup");
    return false;
  }
  return true;
}
 
static bool ed_undo_is_init_and_screenactive_poll(bContext *C)
{
  if (ed_undo_is_init_poll(C) == false) {
    return false;
  }
  return ED_operator_screenactive(C);
}
 
static bool ed_undo_redo_poll(bContext *C)
{
  wmOperator *last_op = WM_operator_last_redo(C);
  return (last_op && ed_undo_is_init_and_screenactive_poll(C) &&
          WM_operator_check_ui_enabled(C, last_op->type->name));
}
 
static bool ed_undo_poll(bContext *C)
{
  if (!ed_undo_is_init_and_screenactive_poll(C)) {
    return false;
  }
  UndoStack *undo_stack = CTX_wm_manager(C)->undo_stack;
  return (undo_stack->step_active != NULL) && (undo_stack->step_active->prev != NULL);
}
 
void ED_OT_undo(wmOperatorType *ot)
{
  /* identifiers */
  ot->name = "Undo";
  ot->description = "Undo previous action";
  ot->idname = "ED_OT_undo";
 
  /* api callbacks */
  ot->exec = ed_undo_exec;
  ot->poll = ed_undo_poll;
}
 
void ED_OT_undo_push(wmOperatorType *ot)
{
  /* identifiers */
  ot->name = "Undo Push";
  ot->description = "Add an undo state (internal use only)";
  ot->idname = "ED_OT_undo_push";
 
  /* api callbacks */
  ot->exec = ed_undo_push_exec;
  /* Unlike others undo operators this initializes undo stack. */
  ot->poll = ED_operator_screenactive;
 
  ot->flag = OPTYPE_INTERNAL;
 
  RNA_def_string(ot->srna,
                 "message",
                 "Add an undo step *function may be moved*",
                 BKE_UNDO_STR_MAX,
                 "Undo Message",
                 "");
}
 
static bool ed_redo_poll(bContext *C)
{
  if (!ed_undo_is_init_and_screenactive_poll(C)) {
    return false;
  }
  UndoStack *undo_stack = CTX_wm_manager(C)->undo_stack;
  return (undo_stack->step_active != NULL) && (undo_stack->step_active->next != NULL);
}
 
void ED_OT_redo(wmOperatorType *ot)
{
  /* identifiers */
  ot->name = "Redo";
  ot->description = "Redo previous action";
  ot->idname = "ED_OT_redo";
 
  /* api callbacks */
  ot->exec = ed_redo_exec;
  ot->poll = ed_redo_poll;
}
 
void ED_OT_undo_redo(wmOperatorType *ot)
{
  /* identifiers */
  ot->name = "Undo and Redo";
  ot->description = "Undo and redo previous action";
  ot->idname = "ED_OT_undo_redo";
 
  /* api callbacks */
  ot->exec = ed_undo_redo_exec;
  ot->poll = ed_undo_redo_poll;
}
 
/* -------------------------------------------------------------------- */
/* ui callbacks should call this rather than calling WM_operator_repeat() themselves */
int ED_undo_operator_repeat(bContext *C, wmOperator *op)
{
  int ret = 0;
 
  if (op) {
    CLOG_INFO(&LOG, 1, "idname='%s'", op->type->idname);
    wmWindowManager *wm = CTX_wm_manager(C);
    struct Scene *scene = CTX_data_scene(C);
 
    /* keep in sync with logic in view3d_panel_operator_redo() */
    ARegion *region_orig = CTX_wm_region(C);
    ARegion *region_win = BKE_area_find_region_active_win(CTX_wm_area(C));
 
    if (region_win) {
      CTX_wm_region_set(C, region_win);
    }
 
    if ((WM_operator_repeat_check(C, op)) && (WM_operator_poll(C, op->type)) &&
        /* note, undo/redo cant run if there are jobs active,
         * check for screen jobs only so jobs like material/texture/world preview
         * (which copy their data), wont stop redo, see T29579],
         *
         * note, - WM_operator_check_ui_enabled() jobs test _must_ stay in sync with this */
        (WM_jobs_test(wm, scene, WM_JOB_TYPE_ANY) == 0)) {
      int retval;
 
      if (G.debug & G_DEBUG) {
        printf("redo_cb: operator redo %s\n", op->type->name);
      }
 
      WM_operator_free_all_after(wm, op);
 
      ED_undo_pop_op(C, op);
 
      if (op->type->check) {
        if (op->type->check(C, op)) {
          /* check for popup and re-layout buttons */
          ARegion *region_menu = CTX_wm_menu(C);
          if (region_menu) {
            ED_region_tag_refresh_ui(region_menu);
          }
        }
      }
 
      retval = WM_operator_repeat(C, op);
      if ((retval & OPERATOR_FINISHED) == 0) {
        if (G.debug & G_DEBUG) {
          printf("redo_cb: operator redo failed: %s, return %d\n", op->type->name, retval);
        }
        ED_undo_redo(C);
      }
      else {
        ret = 1;
      }
    }
    else {
      if (G.debug & G_DEBUG) {
        printf("redo_cb: WM_operator_repeat_check returned false %s\n", op->type->name);
      }
    }
 
    /* set region back */
    CTX_wm_region_set(C, region_orig);
  }
  else {
    CLOG_WARN(&LOG, "called with NULL 'op'");
  }
 
  return ret;
}
 
void ED_undo_operator_repeat_cb(bContext *C, void *arg_op, void *UNUSED(arg_unused))
{
  ED_undo_operator_repeat(C, (wmOperator *)arg_op);
}
 
void ED_undo_operator_repeat_cb_evt(bContext *C, void *arg_op, int UNUSED(arg_unused))
{
  ED_undo_operator_repeat(C, (wmOperator *)arg_op);
}
 
/* -------------------------------------------------------------------- */
/* create enum based on undo items */
static const EnumPropertyItem *rna_undo_itemf(bContext *C, int *totitem)
{
  EnumPropertyItem item_tmp = {0}, *item = NULL;
  int i = 0;
 
  wmWindowManager *wm = CTX_wm_manager(C);
  if (wm->undo_stack == NULL) {
    return NULL;
  }
 
  for (UndoStep *us = wm->undo_stack->steps.first; us; us = us->next, i++) {
    if (us->skip == false) {
      item_tmp.identifier = us->name;
      item_tmp.name = IFACE_(us->name);
      if (us == wm->undo_stack->step_active) {
        item_tmp.icon = ICON_LAYER_ACTIVE;
      }
      else {
        item_tmp.icon = ICON_NONE;
      }
      item_tmp.value = i;
      RNA_enum_item_add(&item, totitem, &item_tmp);
    }
  }
  RNA_enum_item_end(&item, totitem);
 
  return item;
}
 
static int undo_history_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
{
  int totitem = 0;
 
  {
    const EnumPropertyItem *item = rna_undo_itemf(C, &totitem);
 
    if (totitem > 0) {
      uiPopupMenu *pup = UI_popup_menu_begin(
          C, WM_operatortype_name(op->type, op->ptr), ICON_NONE);
      uiLayout *layout = UI_popup_menu_layout(pup);
      uiLayout *split = uiLayoutSplit(layout, 0.0f, false);
      uiLayout *column = NULL;
      const int col_size = 20 + totitem / 12;
      int i, c;
      bool add_col = true;
 
      for (c = 0, i = totitem; i--;) {
        if (add_col && !(c % col_size)) {
          column = uiLayoutColumn(split, false);
          add_col = false;
        }
        if (item[i].identifier) {
          uiItemIntO(column, item[i].name, item[i].icon, op->type->idname, "item", item[i].value);
          c++;
          add_col = true;
        }
      }
 
      MEM_freeN((void *)item);
 
      UI_popup_menu_end(C, pup);
    }
  }
  return OPERATOR_CANCELLED;
}
 
/* note: also check ed_undo_step() in top if you change notifiers */
static int undo_history_exec(bContext *C, wmOperator *op)
{
  PropertyRNA *prop = RNA_struct_find_property(op->ptr, "item");
  if (RNA_property_is_set(op->ptr, prop)) {
    int item = RNA_property_int_get(op->ptr, prop);
    WM_operator_stack_clear(CTX_wm_manager(C));
    ed_undo_step_by_index(C, item, op->reports);
    WM_event_add_notifier(C, NC_WINDOW, NULL);
    return OPERATOR_FINISHED;
  }
  return OPERATOR_CANCELLED;
}
 
static bool undo_history_poll(bContext *C)
{
  if (!ed_undo_is_init_and_screenactive_poll(C)) {
    return false;
  }
  UndoStack *undo_stack = CTX_wm_manager(C)->undo_stack;
  /* More than just original state entry. */
  return BLI_listbase_count_at_most(&undo_stack->steps, 2) > 1;
}
 
void ED_OT_undo_history(wmOperatorType *ot)
{
  /* identifiers */
  ot->name = "Undo History";
  ot->description = "Redo specific action in history";
  ot->idname = "ED_OT_undo_history";
 
  /* api callbacks */
  ot->invoke = undo_history_invoke;
  ot->exec = undo_history_exec;
  ot->poll = undo_history_poll;
 
  RNA_def_int(ot->srna, "item", 0, 0, INT_MAX, "Item", "", 0, INT_MAX);
}
 
/* -------------------------------------------------------------------- */
void ED_undo_object_set_active_or_warn(
    Scene *scene, ViewLayer *view_layer, Object *ob, const char *info, CLG_LogRef *log)
{
  Object *ob_prev = OBACT(view_layer);
  if (ob_prev != ob) {
    Base *base = BKE_view_layer_base_find(view_layer, ob);
    if (base != NULL) {
      view_layer->basact = base;
      ED_object_base_active_refresh(G_MAIN, scene, view_layer);
    }
    else {
      /* Should never fail, may not crash but can give odd behavior. */
      CLOG_WARN(log, "'%s' failed to restore active object: '%s'", info, ob->id.name + 2);
    }
  }
}
 
void ED_undo_object_editmode_restore_helper(struct bContext *C,
                                            Object **object_array,
                                            uint object_array_len,
                                            uint object_array_stride)
{
  Main *bmain = CTX_data_main(C);
  ViewLayer *view_layer = CTX_data_view_layer(C);
  uint bases_len = 0;
  /* Don't request unique data because we want to de-select objects when exiting edit-mode
   * for that to be done on all objects we can't skip ones that share data. */
  Base **bases = ED_undo_editmode_bases_from_view_layer(view_layer, &bases_len);
  for (uint i = 0; i < bases_len; i++) {
    ((ID *)bases[i]->object->data)->tag |= LIB_TAG_DOIT;
  }
  Scene *scene = CTX_data_scene(C);
  Object **ob_p = object_array;
  for (uint i = 0; i < object_array_len; i++, ob_p = POINTER_OFFSET(ob_p, object_array_stride)) {
    Object *obedit = *ob_p;
    ED_object_editmode_enter_ex(bmain, scene, obedit, EM_NO_CONTEXT);
    ((ID *)obedit->data)->tag &= ~LIB_TAG_DOIT;
  }
  for (uint i = 0; i < bases_len; i++) {
    ID *id = bases[i]->object->data;
    if (id->tag & LIB_TAG_DOIT) {
      ED_object_editmode_exit_ex(bmain, scene, bases[i]->object, EM_FREEDATA);
      /* Ideally we would know the selection state it was before entering edit-mode,
       * for now follow the convention of having them unselected when exiting the mode. */
      ED_object_base_select(bases[i], BA_DESELECT);
    }
  }
  MEM_freeN(bases);
}
 
/* -------------------------------------------------------------------- */
static int undo_editmode_objects_from_view_layer_prepare(ViewLayer *view_layer, Object *obact)
{
  const short object_type = obact->type;
 
  LISTBASE_FOREACH (Base *, base, &view_layer->object_bases) {
    Object *ob = base->object;
    if ((ob->type == object_type) && (ob->mode & OB_MODE_EDIT)) {
      ID *id = ob->data;
      id->tag &= ~LIB_TAG_DOIT;
    }
  }
 
  int len = 0;
  LISTBASE_FOREACH (Base *, base, &view_layer->object_bases) {
    Object *ob = base->object;
    if ((ob->type == object_type) && (ob->mode & OB_MODE_EDIT)) {
      ID *id = ob->data;
      if ((id->tag & LIB_TAG_DOIT) == 0) {
        len += 1;
        id->tag |= LIB_TAG_DOIT;
      }
    }
  }
  return len;
}
 
Object **ED_undo_editmode_objects_from_view_layer(ViewLayer *view_layer, uint *r_len)
{
  Base *baseact = BASACT(view_layer);
  if ((baseact == NULL) || (baseact->object->mode & OB_MODE_EDIT) == 0) {
    return MEM_mallocN(0, __func__);
  }
  const int len = undo_editmode_objects_from_view_layer_prepare(view_layer, baseact->object);
  const short object_type = baseact->object->type;
  int i = 0;
  Object **objects = MEM_malloc_arrayN(len, sizeof(*objects), __func__);
  /* Base iteration, starting with the active-base to ensure it's the first item in the array.
   * Looping over the active-base twice is OK as the tag check prevents it being handled twice. */
  for (Base *base = baseact, *base_next = FIRSTBASE(view_layer); base;
       base = base_next, base_next = base_next ? base_next->next : NULL) {
    Object *ob = base->object;
    if ((ob->type == object_type) && (ob->mode & OB_MODE_EDIT)) {
      ID *id = ob->data;
      if (id->tag & LIB_TAG_DOIT) {
        objects[i++] = ob;
        id->tag &= ~LIB_TAG_DOIT;
      }
    }
  }
  BLI_assert(i == len);
  BLI_assert(objects[0] == baseact->object);
  *r_len = len;
  return objects;
}
 
Base **ED_undo_editmode_bases_from_view_layer(ViewLayer *view_layer, uint *r_len)
{
  Base *baseact = BASACT(view_layer);
  if ((baseact == NULL) || (baseact->object->mode & OB_MODE_EDIT) == 0) {
    return MEM_mallocN(0, __func__);
  }
  const int len = undo_editmode_objects_from_view_layer_prepare(view_layer, baseact->object);
  const short object_type = baseact->object->type;
  int i = 0;
  Base **base_array = MEM_malloc_arrayN(len, sizeof(*base_array), __func__);
  /* Base iteration, starting with the active-base to ensure it's the first item in the array.
   * Looping over the active-base twice is OK as the tag check prevents it being handled twice. */
  for (Base *base = BASACT(view_layer), *base_next = FIRSTBASE(view_layer); base;
       base = base_next, base_next = base_next ? base_next->next : NULL) {
    Object *ob = base->object;
    if ((ob->type == object_type) && (ob->mode & OB_MODE_EDIT)) {
      ID *id = ob->data;
      if (id->tag & LIB_TAG_DOIT) {
        base_array[i++] = base;
        id->tag &= ~LIB_TAG_DOIT;
      }
    }
  }
 
  BLI_assert(i == len);
  BLI_assert(base_array[0] == baseact);
  *r_len = len;
  return base_array;
}