source/blender/editors/include/ED_undo.hh

@@ -40,6 +40,7 @@ void ED_undo_pop(bContext *C);
 void ED_undo_redo(bContext *C);
 void ED_OT_undo(wmOperatorType *ot);
 void ED_OT_undo_push(wmOperatorType *ot);
+void ED_OT_undo_push_snapshot(wmOperatorType *ot);
 void ED_OT_redo(wmOperatorType *ot);
 void ED_OT_undo_redo(wmOperatorType *ot);
 void ED_OT_undo_history(wmOperatorType *ot);

source/blender/editors/space_topbar/space_topbar.cc

@@ -216,34 +216,30 @@ static void undo_history_draw_menu(const bContext *C, Menu *menu)
     return;
   }
 
-  int undo_step_count = 0;
-  int undo_step_count_all = 0;
-  LISTBASE_FOREACH_BACKWARD (UndoStep *, us, &wm->undo_stack->steps) {
-    undo_step_count_all += 1;
-    if (us->skip) {
-      continue;
-    }
-    undo_step_count += 1;
-  }
-
   uiLayout *split = uiLayoutSplit(menu->layout, 0.0f, false);
-  uiLayout *column = nullptr;
+  uiLayout *column = uiLayoutColumn(split, false);
 
-  const int col_size = 20 + (undo_step_count / 12);
+  uiItemO(column, IFACE_("Add Snapshot"), ICON_ADD, "ED_OT_undo_push_snapshot");
+  uiItemS(column);
 
-  undo_step_count = 0;
+  int rows = 2;
+
+  int undo_steps = BLI_listbase_count(&wm->undo_stack->steps);
+  const int col_size = 20 + (undo_steps / 12);
 
   /* Reverse the order so the most recent state is first in the menu. */
-  int i = undo_step_count_all - 1;
-  for (UndoStep *us = static_cast<UndoStep *>(wm->undo_stack->steps.last); us; us = us->prev, i--)
-  {
+  int i = undo_steps;
+  LISTBASE_FOREACH_BACKWARD (UndoStep *, us, &wm->undo_stack->steps) {
+    i--;
     if (us->skip) {
       continue;
     }
-    if (!(undo_step_count % col_size)) {
+
+    if (rows > 0 && !(rows % col_size)) {
       column = uiLayoutColumn(split, false);
     }
     const bool is_active = (us == wm->undo_stack->step_active);
+
     uiLayout *row = uiLayoutRow(column, false);
     uiLayoutSetEnabled(row, !is_active);
     uiItemIntO(row,
@@ -252,7 +248,7 @@ static void undo_history_draw_menu(const bContext *C, Menu *menu)
                "ED_OT_undo_history",
                "item",
                i);
-    undo_step_count += 1;
+    rows += 1;
   }
 }
 

source/blender/editors/undo/ed_undo.cc

@@ -16,6 +16,7 @@
 #include "DNA_scene_types.h"
 
 #include "BLI_listbase.h"
+#include "BLI_string.h"
 #include "BLI_utildefines.h"
 
 #include "BLT_translation.hh"
@@ -625,6 +626,67 @@ void ED_OT_undo_push(wmOperatorType *ot)
                  "");
 }
 
+static int ed_undo_push_snapshot_exec(bContext *C, wmOperator *op)
+{
+  if (G.background) {
+    /* Exception for background mode, see: #60934.
+     * 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 == nullptr) {
+      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);
+  RNA_string_set(op->ptr, "message", "");
+  return OPERATOR_FINISHED;
+}
+
+static int ed_undo_push_snapshot_invoke(bContext *C, wmOperator *op, const wmEvent * /*event*/)
+{
+  return WM_operator_props_dialog_popup(C, op, 200, IFACE_("Add Undo Snapshot"), IFACE_("Add"));
+}
+
+static void ed_undo_push_snapshot_ui(bContext *C, wmOperator *op)
+{
+  uiLayout *layout = op->layout;
+  wmWindowManager *wm = CTX_wm_manager(C);
+
+  char str[FILE_MAX];
+  RNA_string_get(op->ptr, "message", str);
+  if (!str[0]) {
+    time_t time_now = time(NULL);
+    struct tm *tm_local = localtime(&time_now);
+    char time_str[26];
+    strftime(time_str, 26, "%H:%M:%S", tm_local);
+    SNPRINTF_RLEN(str, "Snapshot at %s", time_str);
+    RNA_string_set(op->ptr, "message", str);
+  }
+
+  uiItemL(layout, "Description", ICON_NONE);
+  uiItemR(layout, op->ptr, "message", UI_ITEM_NONE, "", ICON_NONE);
+}
+
+void ED_OT_undo_push_snapshot(wmOperatorType *ot)
+{
+  /* identifiers */
+  ot->name = "Add Snapshot";
+  ot->description = "Add an undo snapshot";
+  ot->idname = "ED_OT_undo_push_snapshot";
+
+  /* api callbacks */
+  ot->invoke = ed_undo_push_snapshot_invoke;
+  ot->exec = ed_undo_push_snapshot_exec;
+  ot->poll = ED_operator_screenactive;
+  ot->ui = ed_undo_push_snapshot_ui;
+
+  /* properties */
+  RNA_def_string(ot->srna, "message", nullptr, BKE_UNDO_STR_MAX, "Snapshot description", "");
+}
+
 static bool ed_redo_poll(bContext *C)
 {
   if (!ed_undo_is_init_and_screenactive_poll(C)) {

source/blender/editors/util/ed_util_ops.cc

@@ -415,6 +415,7 @@ void ED_operatortypes_edutils()
 
   WM_operatortype_append(ED_OT_undo);
   WM_operatortype_append(ED_OT_undo_push);
+  WM_operatortype_append(ED_OT_undo_push_snapshot);
   WM_operatortype_append(ED_OT_redo);
   WM_operatortype_append(ED_OT_undo_redo);
   WM_operatortype_append(ED_OT_undo_history);