efl_ui_item: rework parent relation

this commit ensures that there is a public way of setting the container
to a item. This was also like this before, just with the difference that
it was set and unset in all privacy, however, we want to have this class
also ready for bindings, so we should stop making things privat like
this.

Note: the removed fields from grid and list have not been used.

ref T7905

Reviewed-by: SangHyeon Jade Lee <sh10233.lee@samsung.com>
Differential Revision: https://phab.enlightenment.org/D9262

src/lib/elementary/efl_ui_grid.c

@@ -750,8 +750,7 @@ _grid_item_process(Eo *obj, Efl_Ui_Grid_Data *pd, EINA_UNUSED Efl_Ui_Grid_Item *
    EFL_UI_GRID_ITEM_DATA_GET_OR_RETURN(it, gd, EINA_FALSE);
    EFL_UI_ITEM_DATA_GET_OR_RETURN(it, id, EINA_FALSE);
    id->select_mode = &(pd->select_mode);
-   id->parent = obj;
-   gd->parent = obj;
+   efl_ui_item_container_set(it, obj);
    efl_canvas_group_member_add(pd->pan, it);
    efl_ui_mirrored_set(it, efl_ui_mirrored_get(obj));
 
@@ -772,8 +771,7 @@ _grid_item_unpack_internal(Eo *obj, Efl_Ui_Grid_Data *pd, Efl_Ui_Grid_Item *it)
    EFL_UI_GRID_ITEM_DATA_GET_OR_RETURN(it, gd);
    EFL_UI_ITEM_DATA_GET_OR_RETURN(it, id);
    id->select_mode = NULL;
-   id->parent = NULL;
-   gd->parent = NULL;
+   efl_ui_item_container_set(it, NULL);
 
    pd->items = eina_list_remove(pd->items, it);
    if (efl_ui_item_selected_get(it))

src/lib/elementary/efl_ui_grid_item_private.h

@@ -7,7 +7,6 @@ typedef struct _Efl_Ui_Grid_Item_Data
 {
    // Eo Objects
    Eo *obj; /* Self-Object */
-   Eo *parent; /* Parent Widget */
    Eina_Rect  geo;
    int index;
    struct {

src/lib/elementary/efl_ui_item.c

@@ -380,6 +380,19 @@ _efl_ui_item_selected_get(const Eo *obj EINA_UNUSED, Efl_Ui_Item_Data *pd)
    return pd->selected;
 }
 
+EOLIAN static void
+_efl_ui_item_container_set(Eo *obj EINA_UNUSED, Efl_Ui_Item_Data *pd, Efl_Ui_Widget *container)
+{
+   pd->parent = container;
+}
+
+EOLIAN static Efl_Ui_Widget*
+_efl_ui_item_container_get(const Eo *obj EINA_UNUSED, Efl_Ui_Item_Data *pd)
+{
+   return pd->parent;
+}
+
+
 /* Internal EO APIs and hidden overrides */
 
 #define EFL_UI_ITEM_EXTRA_OPS \

src/lib/elementary/efl_ui_item.eo

@@ -18,6 +18,15 @@ abstract @beta Efl.Ui.Item extends Efl.Ui.Layout_Base implements Efl.Ui.Selectab
             select: bool;
          }
       }
+      @property container {
+         [[The container this object is part of.
+
+           You should never use this property yourself, the container will set it. Unsetting this while the item is packed into a container does not have an impact on its state in the container.
+         ]]
+         values {
+            container : Efl.Ui.Widget; [[The container this item is in.]]
+         }
+      }
    }
    implements {
       //Efl.Object

src/lib/elementary/efl_ui_list.c

@@ -675,8 +675,7 @@ _list_item_process(Eo *obj, Efl_Ui_List_Data *pd, EINA_UNUSED Efl_Ui_List_Item *
    EFL_UI_LIST_ITEM_DATA_GET_OR_RETURN(it, ld, EINA_FALSE);
    EFL_UI_ITEM_DATA_GET_OR_RETURN(it, id, EINA_FALSE);
    id->select_mode = &(pd->select_mode);
-   id->parent = obj;
-   ld->parent = obj;
+   efl_ui_item_container_set(it, obj);
    efl_ui_mirrored_set(it, efl_ui_mirrored_get(obj));
 
    efl_event_callback_add(it, EFL_UI_EVENT_PRESSED, _list_item_pressed, obj);
@@ -695,8 +694,7 @@ _list_item_clear(Eo *obj, Efl_Ui_List_Data *pd EINA_UNUSED, EINA_UNUSED Efl_Ui_L
    EFL_UI_LIST_ITEM_DATA_GET_OR_RETURN(it, ld);
    EFL_UI_ITEM_DATA_GET_OR_RETURN(it, id);
    id->select_mode = NULL;
-   id->parent = NULL;
-   ld->parent = NULL;
+   efl_ui_item_container_set(it, NULL);
 
    efl_event_callback_del(it, EFL_UI_EVENT_PRESSED, _list_item_pressed, obj);
    efl_event_callback_del(it, EFL_UI_EVENT_UNPRESSED, _list_item_unpressed, obj);

src/lib/elementary/efl_ui_list_item_private.h

@@ -7,7 +7,6 @@ typedef struct _Efl_Ui_List_Item_Data
 {
    // Eo Objects
    Eo *obj; /* Self-Object */
-   Eo *parent; /* Parent Widget */
    Eina_Bool  needs_size_calc : 1; /* Flag for Size calculation */
 } Efl_Ui_List_Item_Data;