elm_widget: add signal for parent changes

Summary:
this signal is emitted when a new subobject is added by calling
elm_widget_sub_object_add.

Reviewers: raster

Subscribers: cedric, jpeg

Differential Revision: https://phab.enlightenment.org/D3992

2 files changed, 34 insertions, 0 deletions

diff --git a/src/lib/elementary/elm_widget.c b/src/lib/elementary/elm_widget.c
index 7aa146bc69..8b87d8ed24 100644
--- a/src/lib/elementary/elm_widget.c
+++ b/src/lib/elementary/elm_widget.c
@@ -1118,10 +1118,13 @@ _elm_widget_sub_object_add(Eo *obj, Elm_Widget_Smart_Data *sd, Evas_Object *sobj
    if (_elm_widget_is(sobj))
      {
         ELM_WIDGET_DATA_GET(sobj, sdc);
+        Eo *old_parent;
+        Elm_Parent_Change change;
 
         if (sdc->parent_obj == obj) goto end;
         if (sdc->parent_obj)
           {
+             old_parent = obj;
              if (!elm_widget_sub_object_del(sdc->parent_obj, sobj))
                return EINA_FALSE;
           }
@@ -1159,6 +1162,11 @@ _elm_widget_sub_object_add(Eo *obj, Elm_Widget_Smart_Data *sd, Evas_Object *sobj
                   sdp->child_can_focus = EINA_TRUE;
                }
           }
+        //drop a event because of this change
+        change.child = sobj;
+        change.old_parent = old_parent;
+
+        eo_event_callback_call(sobj, ELM_WIDGET_EVENT_PARENT_CHANGED, &change);
      }
    else
      {
@@ -5766,6 +5774,24 @@ elm_widget_tree_dot_dump(const Evas_Object *top,
 #endif
 }
 
+static Eina_Bool
+_parent_changed(void *data EINA_UNUSED, const Eo_Event *event)
+{
+   ELM_WIDGET_DATA_GET(event->object, pd);
+   Elm_Parent_Change *change = event->info;
+   Eina_List *node;
+   Elm_Widget *sobj;
+
+   printf("PARENT CHANGE %p\n", change);
+
+   EINA_LIST_FOREACH(pd->subobjs, node, sobj)
+     {
+        eo_event_callback_call(sobj, ELM_WIDGET_EVENT_PARENT_CHANGED, event->info);
+     }
+
+   return EO_CALLBACK_CONTINUE;
+}
+
 EOLIAN static Eo *
 _elm_widget_eo_base_constructor(Eo *obj, Elm_Widget_Smart_Data *sd EINA_UNUSED)
 {
@@ -5779,6 +5805,8 @@ _elm_widget_eo_base_constructor(Eo *obj, Elm_Widget_Smart_Data *sd EINA_UNUSED)
    elm_obj_widget_parent_set(obj, parent);
    sd->on_create = EINA_FALSE;
 
+   eo_event_callback_add(obj, ELM_WIDGET_EVENT_PARENT_CHANGED, _parent_changed, NULL);
+
    elm_interface_atspi_accessible_role_set(obj, ELM_ATSPI_ROLE_UNKNOWN);
    return obj;
 }
diff --git a/src/lib/elementary/elm_widget.eo b/src/lib/elementary/elm_widget.eo
index ccf3799bdd..56e62e8461 100644
--- a/src/lib/elementary/elm_widget.eo
+++ b/src/lib/elementary/elm_widget.eo
@@ -17,6 +17,11 @@ enum Elm.Activate
    back,
 }
 
+struct Elm.Parent_Change {
+   child : Elm.Widget; [[the child where the parent changed]]
+   old_parent : Elm.Widget; [[the old parent which was changed]]
+}
+
 struct Elm.Tooltip;
 struct Elm.Cursor;
 struct @extern Elm.Theme;
@@ -877,5 +882,6 @@ abstract Elm.Widget (Evas.Object.Smart, Elm.Interface.Atspi_Accessible, Elm.Inte
       unfocused;
       language,changed;
       access,changed;
+      parent,changed : Elm.Parent_Change*;
    }
 }