UI: Revert design changes to data-block selector for the 2.92 release

Partially reverts 2250b5cefee7.

Removing the user count and fake user count icons was controversial (which was
expected) and there are a few further changes needed, that won't make it in
time for the release, see D9946.
While there is a design to bring back the user count and fake user indicators,
a new design idea was proposed that the UI team wants to follow. This came too
late for the 2.92 release, the new design is targeted at the 2.93 release now.
Meanwhile, UI team decision was to simply revert the design changes.

The new design is being worked on in https://developer.blender.org/T84669.

Note that this commit does not revert some internal changes done in
2250b5cefee7. Namely the introduction of `ed_util_ops.c` and data-block
operators in there. These will still be needed in the new design.

3 files changed, 61 insertions, 120 deletions

diff --git a/source/blender/editors/space_action/action_data.c b/source/blender/editors/space_action/action_data.c
index 4d5a93f75e0..3a584a7f0cb 100644
--- a/source/blender/editors/space_action/action_data.c
+++ b/source/blender/editors/space_action/action_data.c
@@ -158,78 +158,7 @@ static void actedit_change_action(bContext *C, bAction *act)
   RNA_property_update(C, &ptr, prop);
 }
 
-/* ******************** New Action Operators *********************** */
-
-static void action_creation_assign(bContext *C,
-                                   bAction *action,
-                                   PointerRNA *ptr,
-                                   PropertyRNA *prop)
-{
-  PointerRNA idptr;
-  /* Set the new action.
-   * NOTE: we can't use actedit_change_action, as this function is also called from the NLA. */
-  RNA_id_pointer_create(&action->id, &idptr);
-  RNA_property_pointer_set(ptr, prop, idptr, NULL);
-  RNA_property_update(C, ptr, prop);
-}
-
-/**
- * Stash the previously active action to prevent it from being lost.
- * \return The old action if any.
- */
-static bAction *action_creation_stash_old(bContext *C, PointerRNA *ptr, PropertyRNA *prop)
-{
-  bAction *oldact = NULL;
-  AnimData *adt = NULL;
-
-  if (prop) {
-    /* The operator was called from a button. */
-    PointerRNA oldptr;
-
-    oldptr = RNA_property_pointer_get(ptr, prop);
-    oldact = (bAction *)oldptr.owner_id;
-
-    /* stash the old action to prevent it from being lost */
-    if (ptr->type == &RNA_AnimData) {
-      adt = ptr->data;
-    }
-    else if (ptr->type == &RNA_SpaceDopeSheetEditor) {
-      adt = ED_actedit_animdata_from_context(C);
-    }
-  }
-  else {
-    adt = ED_actedit_animdata_from_context(C);
-    oldact = adt->action;
-  }
-
-  if (!adt || !oldact) {
-    /* Found nothing to stash in current context. */
-    return NULL;
-  }
-
-  /* Perform stashing operation. */
-  if (BKE_nla_action_stash(adt, ID_IS_OVERRIDE_LIBRARY(ptr->owner_id))) {
-    /* The stash operation will remove the user already
-     * (and unlink the action from the AnimData action slot).
-     * Hence, we must unset the ref to the action in the
-     * action editor too (if this is where we're being called from)
-     * first before setting the new action once it is created,
-     * or else the user gets decremented twice!
-     */
-    if (ptr->type == &RNA_SpaceDopeSheetEditor) {
-      SpaceAction *saction = ptr->data;
-      saction->action = NULL;
-    }
-  }
-  else {
-#if 0
-    printf("WARNING: Failed to stash %s. It may already exist in the NLA stack though\n",
-           oldact->id.name);
-#endif
-  }
-
-  return oldact;
-}
+/* ******************** New Action Operator *********************** */
 
 /* Criteria:
  *  1) There must be an dopesheet/action editor, and it must be in a mode which uses actions...
@@ -278,17 +207,71 @@ static bool action_new_poll(bContext *C)
 
 static int action_new_exec(bContext *C, wmOperator *UNUSED(op))
 {
-  PointerRNA ptr;
+  PointerRNA ptr, idptr;
   PropertyRNA *prop;
 
+  bAction *oldact = NULL;
+  AnimData *adt = NULL;
   /* hook into UI */
   UI_context_active_but_prop_get_templateID(C, &ptr, &prop);
 
-  action_creation_stash_old(C, &ptr, prop);
-
-  bAction *action = action_create_new(C, NULL);
   if (prop) {
-    action_creation_assign(C, action, &ptr, prop);
+    /* The operator was called from a button. */
+    PointerRNA oldptr;
+
+    oldptr = RNA_property_pointer_get(&ptr, prop);
+    oldact = (bAction *)oldptr.owner_id;
+
+    /* stash the old action to prevent it from being lost */
+    if (ptr.type == &RNA_AnimData) {
+      adt = ptr.data;
+    }
+    else if (ptr.type == &RNA_SpaceDopeSheetEditor) {
+      adt = ED_actedit_animdata_from_context(C);
+    }
+  }
+  else {
+    adt = ED_actedit_animdata_from_context(C);
+    oldact = adt->action;
+  }
+  {
+    bAction *action = NULL;
+
+    /* Perform stashing operation - But only if there is an action */
+    if (adt && oldact) {
+      /* stash the action */
+      if (BKE_nla_action_stash(adt, ID_IS_OVERRIDE_LIBRARY(ptr.owner_id))) {
+        /* The stash operation will remove the user already
+         * (and unlink the action from the AnimData action slot).
+         * Hence, we must unset the ref to the action in the
+         * action editor too (if this is where we're being called from)
+         * first before setting the new action once it is created,
+         * or else the user gets decremented twice!
+         */
+        if (ptr.type == &RNA_SpaceDopeSheetEditor) {
+          SpaceAction *saction = ptr.data;
+          saction->action = NULL;
+        }
+      }
+      else {
+#if 0
+        printf("WARNING: Failed to stash %s. It may already exist in the NLA stack though\n",
+               oldact->id.name);
+#endif
+      }
+    }
+
+    /* create action */
+    action = action_create_new(C, oldact);
+
+    if (prop) {
+      /* set this new action
+       * NOTE: we can't use actedit_change_action, as this function is also called from the NLA
+       */
+      RNA_id_pointer_create(&action->id, &idptr);
+      RNA_property_pointer_set(&ptr, prop, idptr, NULL);
+      RNA_property_update(C, &ptr, prop);
+    }
   }
 
   /* set notifier that keyframes have changed */
@@ -302,7 +285,7 @@ void ACTION_OT_new(wmOperatorType *ot)
   /* identifiers */
   ot->name = "New Action";
   ot->idname = "ACTION_OT_new";
-  ot->description = "Create a new action";
+  ot->description = "Create new action";
 
   /* api callbacks */
   ot->exec = action_new_exec;
@@ -312,45 +295,6 @@ void ACTION_OT_new(wmOperatorType *ot)
   ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
 }
 
-static int action_duplicate_assign_exec(bContext *C, wmOperator *UNUSED(op))
-{
-  PointerRNA ptr;
-  PropertyRNA *prop;
-
-  /* hook into UI */
-  UI_context_active_but_prop_get_templateID(C, &ptr, &prop);
-
-  bAction *old_action = action_creation_stash_old(C, &ptr, prop);
-
-  bAction *new_action = action_create_new(C, old_action);
-  if (prop) {
-    action_creation_assign(C, new_action, &ptr, prop);
-  }
-
-  /* set notifier that keyframes have changed */
-  WM_event_add_notifier(C, NC_ANIMATION | ND_KEYFRAME | NA_ADDED, NULL);
-
-  return OPERATOR_FINISHED;
-}
-
-/**
- * Duplicate an action assigned to a templateID and update it's assignment - based on UI context.
- */
-void ACTION_OT_duplicate_assign(wmOperatorType *ot)
-{
-  /* identifiers */
-  ot->name = "Duplicate & Assign Action";
-  ot->idname = "ACTION_OT_duplicate_assign";
-  ot->description = "Create a copy of an existing action and assign it";
-
-  /* api callbacks */
-  ot->exec = action_duplicate_assign_exec;
-  ot->poll = action_new_poll;
-
-  /* flags */
-  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO | OPTYPE_INTERNAL;
-}
-
 /* ******************* Action Push-Down Operator ******************** */
 
 /* Criteria:
diff --git a/source/blender/editors/space_action/action_intern.h b/source/blender/editors/space_action/action_intern.h
index 4bce6c62a1a..ffe0606c98f 100644
--- a/source/blender/editors/space_action/action_intern.h
+++ b/source/blender/editors/space_action/action_intern.h
@@ -106,7 +106,6 @@ void ACTION_OT_snap(struct wmOperatorType *ot);
 void ACTION_OT_mirror(struct wmOperatorType *ot);
 
 void ACTION_OT_new(struct wmOperatorType *ot);
-void ACTION_OT_duplicate_assign(struct wmOperatorType *ot);
 void ACTION_OT_unlink(struct wmOperatorType *ot);
 
 void ACTION_OT_push_down(struct wmOperatorType *ot);
diff --git a/source/blender/editors/space_action/action_ops.c b/source/blender/editors/space_action/action_ops.c
index 329c3a9f6f6..7422c05511c 100644
--- a/source/blender/editors/space_action/action_ops.c
+++ b/source/blender/editors/space_action/action_ops.c
@@ -73,9 +73,7 @@ void action_operatortypes(void)
   WM_operatortype_append(ACTION_OT_copy);
   WM_operatortype_append(ACTION_OT_paste);
 
-  /* UI-context based operators. */
   WM_operatortype_append(ACTION_OT_new);
-  WM_operatortype_append(ACTION_OT_duplicate_assign);
   WM_operatortype_append(ACTION_OT_unlink);
 
   WM_operatortype_append(ACTION_OT_push_down);