Edje: Add clip as a property of a part description

Since masking, for performance and themeing reasons, it becomes
interesting to be able to switch clippers on the fly. In particular,
switching from an IMAGE mask to a standard RECT clipper can save a
lot of power when masking is not required.

This new flag "description.clip_to" will behave a bit like a mix of
rel.to and visible:

- It points to a part by name, just like part.clip_to. This will
  override the clipper set by the part, or override the default clipper.

- Like "visible", it can not be interpolated between two values, so
  it will switch only at the end of a transition.

- By default there is no clip override, which means Edje will fallback
  to the part's clipper, if any, or the base (group's) clipper.

NOTE:
- Since a clipper that does not clip anything becomes a standard object,
  it is visible and rendered. This will in 99.999% cases not be the
  intended behaviour. Currently we can simply use a transparent RECT
  in order to always have something clipped by the clipper, but this is
  a hack and this will trigger rendering of masks in their surfaces even
  when they are not actually used.
  Ideally, there should be a flag indicating to Edje & Evas that an object
  should be considered a clipper in all situations, and never be rendered
  on screen.

TODO:
- Support Edje Edit
- Add Embryo & Lua functions
- Add support in edje_convert
- Add Edje/Evas flag to mark objects as "no_render"

@feature

7 files changed, 152 insertions, 44 deletions

diff --git a/src/bin/edje/edje_cc_handlers.c b/src/bin/edje/edje_cc_handlers.c
index 1cb5b6ef10..b371aec5ca 100644
--- a/src/bin/edje/edje_cc_handlers.c
+++ b/src/bin/edje/edje_cc_handlers.c
@@ -326,6 +326,7 @@ static void st_collections_group_parts_part_description_rel2_to_set(const char *
 static void st_collections_group_parts_part_description_rel2_to(void);
 static void st_collections_group_parts_part_description_rel2_to_x(void);
 static void st_collections_group_parts_part_description_rel2_to_y(void);
+static void st_collections_group_parts_part_description_clip_to_id(void);
 static void st_collections_group_parts_part_description_image_normal(void);
 static void st_collections_group_parts_part_description_image_tween(void);
 static void st_collections_group_parts_part_description_image_border(void);
@@ -771,6 +772,7 @@ New_Statement_Handler statement_handlers[] =
      {"collections.group.parts.part.description.rel2.to", st_collections_group_parts_part_description_rel2_to},
      {"collections.group.parts.part.description.rel2.to_x", st_collections_group_parts_part_description_rel2_to_x},
      {"collections.group.parts.part.description.rel2.to_y", st_collections_group_parts_part_description_rel2_to_y},
+     {"collections.group.parts.part.description.clip_to", st_collections_group_parts_part_description_clip_to_id},
      {"collections.group.parts.part.description.image.normal", st_collections_group_parts_part_description_image_normal},
      {"collections.group.parts.part.description.image.tween", st_collections_group_parts_part_description_image_tween},
      IMAGE_SET_STATEMENTS("collections.group.parts.part.description.image")
@@ -1496,6 +1498,7 @@ _edje_part_description_alloc(unsigned char type, const char *collection, const c
    result->physics.depth = 30;
 #endif
 
+   result->clip_to_id = -1;
    return result;
 }
 
@@ -4581,6 +4584,7 @@ _part_desc_free(Edje_Part_Collection *pc,
    part_lookup_del(pc, &(ed->rel1.id_y));
    part_lookup_del(pc, &(ed->rel2.id_x));
    part_lookup_del(pc, &(ed->rel2.id_y));
+   part_lookup_del(pc, &(ed->clip_to_id));
    part_lookup_del(pc, &(ed->map.id_persp));
    part_lookup_del(pc, &(ed->map.id_light));
    part_lookup_del(pc, &(ed->map.rot.id_center));
@@ -5381,11 +5385,11 @@ st_collections_group_parts_part_clip_to_id(void)
 
    pc = eina_list_data_get(eina_list_last(edje_collections));
      {
-	char *name;
+        char *name;
 
-	name = parse_str(0);
-	data_queue_part_lookup(pc, name, &(current_part->clip_to_id));
-	free(name);
+        name = parse_str(0);
+        data_queue_part_lookup(pc, name, &(current_part->clip_to_id));
+        free(name);
      }
 }
 
@@ -6397,6 +6401,7 @@ _copied_map_colors_get(Edje_Part_Description_Common *parent)
             fixed: 0 0;
             step: 0 0;
             aspect: 1 1;
+            clip_to: "clip_override_part_name";
 
             rel1 {
                 ..
@@ -6428,6 +6433,7 @@ ob_collections_group_parts_part_description(void)
    ed->rel1.id_y = -1;
    ed->rel2.id_x = -1;
    ed->rel2.id_y = -1;
+   ed->clip_to_id = -1;
 
    if (!ep->default_desc)
      {
@@ -6628,6 +6634,8 @@ st_collections_group_parts_part_description_inherit(void)
    data_queue_copied_part_lookup(pc, &parent->rel2.id_x, &ed->rel2.id_x);
    data_queue_copied_part_lookup(pc, &parent->rel2.id_y, &ed->rel2.id_y);
 
+   data_queue_copied_part_lookup(pc, &parent->clip_to_id, &ed->clip_to_id);
+
    data_queue_copied_part_lookup(pc, &parent->map.id_persp, &ed->map.id_persp);
    data_queue_copied_part_lookup(pc, &parent->map.id_light, &ed->map.id_light);
    data_queue_copied_part_lookup(pc, &parent->map.rot.id_center, &ed->map.rot.id_center);
@@ -7625,6 +7633,23 @@ st_collections_group_parts_part_description_rel2_to_y(void)
    }
 }
 
+static void
+st_collections_group_parts_part_description_clip_to_id(void)
+{
+   Edje_Part_Collection *pc;
+
+   check_arg_count(1);
+
+   pc = eina_list_data_get(eina_list_last(edje_collections));
+     {
+        char *name;
+
+        name = parse_str(0);
+        data_queue_part_lookup(pc, name, &(current_desc->clip_to_id));
+        free(name);
+     }
+}
+
 /** @edcsubsection{collections_group_parts_description_image,
  *                 Group.Parts.Part.Description.Image} */
 
diff --git a/src/bin/edje/edje_cc_out.c b/src/bin/edje/edje_cc_out.c
index 485aa8c0dc..78d3fab431 100755
--- a/src/bin/edje/edje_cc_out.c
+++ b/src/bin/edje/edje_cc_out.c
@@ -465,6 +465,19 @@ check_nameless_state(Edje_Part_Collection *pc, Edje_Part *ep, Edje_Part_Descript
 }
 
 static void
+check_state(Edje_Part_Collection *pc, Edje_Part *ep, Edje_Part_Description_Common *ed, Eet_File *ef)
+{
+   /* FIXME: When smart masks are supported, remove this check */
+   if (ed->clip_to_id != -1 &&
+       (pc->parts[ed->clip_to_id]->type != EDJE_PART_TYPE_RECTANGLE) &&
+       (pc->parts[ed->clip_to_id]->type != EDJE_PART_TYPE_IMAGE))
+     error_and_abort(ef, "Collection %i: description.clip_to point to a non RECT/IMAGE part '%s' !",
+                     pc->id, pc->parts[ed->clip_to_id]->name);
+
+   check_nameless_state(pc, ep, ed, ef);
+}
+
+static void
 check_part(Edje_Part_Collection *pc, Edje_Part *ep, Eet_File *ef)
 {
    unsigned int i;
@@ -475,7 +488,7 @@ check_part(Edje_Part_Collection *pc, Edje_Part *ep, Eet_File *ef)
 		     "for part \"%s\"", pc->id, ep->name);
 
    for (i = 0; i < ep->other.desc_count; ++i)
-     check_nameless_state(pc, ep, ep->other.desc[i], ef);
+     check_state(pc, ep, ep->other.desc[i], ef);
 
    if (ep->type == EDJE_PART_TYPE_IMAGE)
      {
@@ -490,7 +503,7 @@ check_part(Edje_Part_Collection *pc, Edje_Part *ep, Eet_File *ef)
    else if (ep->type == EDJE_PART_TYPE_GROUP)
      check_source_links(pc, ep, ef, group_path);
 
-   /* FIXME: When mask are supported remove this check */
+   /* FIXME: When smart masks are supported, remove this check */
    if (ep->clip_to_id != -1 &&
        (pc->parts[ep->clip_to_id]->type != EDJE_PART_TYPE_RECTANGLE) &&
        (pc->parts[ep->clip_to_id]->type != EDJE_PART_TYPE_IMAGE))
diff --git a/src/lib/edje/edje_calc.c b/src/lib/edje/edje_calc.c
index f6627152ed..f213d85eef 100644
--- a/src/lib/edje/edje_calc.c
+++ b/src/lib/edje/edje_calc.c
@@ -8,6 +8,7 @@ static void                          _edje_part_recalc_single(Edje *ed, Edje_Rea
                                                               Edje_Real_Part *center, Edje_Real_Part *light, Edje_Real_Part *persp,
                                                               Edje_Real_Part *rel1_to_x, Edje_Real_Part *rel1_to_y,
                                                               Edje_Real_Part *rel2_to_x, Edje_Real_Part *rel2_to_y,
+                                                              Edje_Real_Part *clip_to,
                                                               Edje_Real_Part *confine_to, Edje_Real_Part *threshold,
                                                               Edje_Calc_Params *params,
                                                               Evas_Coord mmw, Evas_Coord mmh,
@@ -746,7 +747,7 @@ _edje_recalc_do(Edje *ed)
         Edje_Real_Part *ep;
 
         ep = ed->table_parts[i];
-        ep->calculated = FLAG_NONE;
+        ep->calculated = FLAG_NONE; // FIXME: this is dubious (see below)
         ep->calculating = FLAG_NONE;
      }
    for (i = 0; i < ed->table_parts_size; i++)
@@ -754,7 +755,7 @@ _edje_recalc_do(Edje *ed)
         Edje_Real_Part *ep;
 
         ep = ed->table_parts[i];
-        if (ep->calculated != FLAG_XY)
+        if (ep->calculated != FLAG_XY) // FIXME: this is always true (see for above)
           _edje_part_recalc(ed, ep, (~ep->calculated) & FLAG_XY, NULL);
      }
    if (!ed->calc_only) ed->recalc = EINA_FALSE;
@@ -2346,6 +2347,7 @@ _edje_part_recalc_single(Edje *ed,
                          Edje_Real_Part *rel1_to_y,
                          Edje_Real_Part *rel2_to_x,
                          Edje_Real_Part *rel2_to_y,
+                         Edje_Real_Part *clip_to,
                          Edje_Real_Part *confine_to,
                          Edje_Real_Part *threshold,
                          Edje_Calc_Params *params,
@@ -2397,6 +2399,9 @@ _edje_part_recalc_single(Edje *ed,
    /* visible */
    params->visible = desc->visible;
 
+   /* clip override */
+   params->clip_to = clip_to;
+
    /* set parameters, some are required for recalc_single_text[block] */
    switch (ep->part->type)
      {
@@ -3232,11 +3237,13 @@ _edje_part_recalc(Edje *ed, Edje_Real_Part *ep, int flags, Edje_Calc_Params *sta
    int statel2 = -1;
    int statep1 = -1;
    int statep2 = -1;
+   int statecl = -1;
    Edje_Real_Part *center[2] = { NULL, NULL };
    Edje_Real_Part *light[2] = { NULL, NULL };
    Edje_Real_Part *persp[2] = { NULL, NULL };
    Edje_Real_Part *rp1[4] = { NULL, NULL, NULL, NULL };
    Edje_Real_Part *rp2[4] = { NULL, NULL, NULL, NULL };
+   Edje_Real_Part *clip1 = NULL, *clip2 = NULL;
    Edje_Calc_Params *p1, *pf;
    Edje_Part_Description_Common *chosen_desc;
    Edje_Real_Part *confine_to = NULL;
@@ -3344,6 +3351,8 @@ _edje_part_recalc(Edje *ed, Edje_Real_Part *ep, int flags, Edje_Calc_Params *sta
           rp1[Rel1Y] = ed->table_parts[ep->param1.description->rel1.id_y];
         if (ep->param1.description->rel2.id_y >= 0)
           rp1[Rel2Y] = ed->table_parts[ep->param1.description->rel2.id_y];
+        if (ep->param1.description->clip_to_id >= 0)
+          clip1 = ed->table_parts[ep->param1.description->clip_to_id % ed->table_parts_size];
      }
    if (ep->param2)
      {
@@ -3355,6 +3364,8 @@ _edje_part_recalc(Edje *ed, Edje_Real_Part *ep, int flags, Edje_Calc_Params *sta
           rp2[Rel1Y] = ed->table_parts[ep->param2->description->rel1.id_y];
         if (ep->param2->description->rel2.id_y >= 0)
           rp2[Rel2Y] = ed->table_parts[ep->param2->description->rel2.id_y];
+        if (ep->param2->description->clip_to_id >= 0)
+          clip2 = ed->table_parts[ep->param2->description->clip_to_id % ed->table_parts_size];
      }
 
    if (flags & FLAG_X)
@@ -3433,6 +3444,17 @@ _edje_part_recalc(Edje *ed, Edje_Real_Part *ep, int flags, Edje_Calc_Params *sta
                }
           }
      }
+   if (clip1)
+     {
+        _edje_part_recalc(ed, clip1, flags, NULL);
+        statecl = clip1->state;
+     }
+   if (clip2)
+     {
+        _edje_part_recalc(ed, clip2, flags, NULL);
+        if (statecl < clip2->state)
+          statecl = clip2->state;
+     }
    if (ep->drag)
      {
         if (ep->drag->confine_to)
@@ -3530,6 +3552,7 @@ _edje_part_recalc(Edje *ed, Edje_Real_Part *ep, int flags, Edje_Calc_Params *sta
             (statec1 >= ep->param1.state) ||
             (statel1 >= ep->param1.state) ||
             (statep1 >= ep->param1.state) ||
+            (statecl >= ep->param1.state) ||
             proxy_invalidate ||
             state ||
             ed->need_map_update ||
@@ -3541,7 +3564,7 @@ _edje_part_recalc(Edje *ed, Edje_Real_Part *ep, int flags, Edje_Calc_Params *sta
            _edje_part_recalc_single(ed, ep, ep->param1.description,
                                     chosen_desc, center[0], light[0],
                                     persp[0], rp1[Rel1X], rp1[Rel1Y],
-                                    rp1[Rel2X], rp1[Rel2Y], confine_to,
+                                    rp1[Rel2X], rp1[Rel2Y], clip1, confine_to,
                                     threshold, p1, mmw, mmh,
                                     pos);
 #ifdef EDJE_CALC_CACHE
@@ -3598,6 +3621,7 @@ _edje_part_recalc(Edje *ed, Edje_Real_Part *ep, int flags, Edje_Calc_Params *sta
             (statec2 >= ep->param2->state) ||
             (statel2 >= ep->param2->state) ||
             (statep2 >= ep->param2->state) ||
+            (statecl >= ep->param2->state) ||
             proxy_invalidate ||
             state ||
             ed->need_map_update ||
@@ -3609,7 +3633,7 @@ _edje_part_recalc(Edje *ed, Edje_Real_Part *ep, int flags, Edje_Calc_Params *sta
            _edje_part_recalc_single(ed, ep, ep->param2->description,
                                     chosen_desc, center[1], light[1],
                                     persp[1], rp2[Rel1X], rp2[Rel1Y],
-                                    rp2[Rel2X], rp2[Rel2Y], confine_to,
+                                    rp2[Rel2X], rp2[Rel2Y], clip2, confine_to,
                                     threshold, p2, mmw, mmh,
                                     pos);
 #ifdef EDJE_CALC_CACHE
@@ -3632,6 +3656,16 @@ _edje_part_recalc(Edje *ed, Edje_Real_Part *ep, int flags, Edje_Calc_Params *sta
         else
           p3->visible = p1->visible;
 
+        /* clip_to will behave a bit like visible */
+        if (pos == ZERO)
+          p3->clip_to = p1->clip_to;
+        else if (pos == FROM_INT(1))
+          p3->clip_to = p2->clip_to;
+        else if (!p1->clip_to)
+          p3->clip_to = p2->clip_to;
+        else
+          p3->clip_to = p1->clip_to;
+
         p3->smooth = (beginning_pos) ? p1->smooth : p2->smooth;
 
         /* FIXME: do x and y separately base on flag */
@@ -4015,12 +4049,20 @@ _edje_part_recalc(Edje *ed, Edje_Real_Part *ep, int flags, Edje_Calc_Params *sta
 
              if (ep->nested_smart) /* Move, Resize all nested parts */
                {   /* Not really needed but will improve the bounding box evaluation done by Evas */
-                 eo_do(ep->nested_smart,
-                       efl_gfx_position_set(ed->x + pf->final.x, ed->y + pf->final.y),
-                       efl_gfx_size_set(pf->final.w, pf->final.h));
+                  eo_do(ep->nested_smart,
+                        efl_gfx_position_set(ed->x + pf->final.x, ed->y + pf->final.y),
+                        efl_gfx_size_set(pf->final.w, pf->final.h));
                }
              if (ep->part->entry_mode > EDJE_ENTRY_EDIT_MODE_NONE)
                _edje_entry_real_part_configure(ed, ep);
+
+             /* handle clip overrides */
+             if (pf->clip_to && pf->clip_to->object)
+               evas_object_clip_set(ep->object, pf->clip_to->object);
+             else if (ep->part->clip_to_id >= 0)
+               evas_object_clip_set(ep->object, ed->table_parts[ep->part->clip_to_id % ed->table_parts_size]->object);
+             else
+               evas_object_clip_set(ep->object, ed->base->clipper);
              break;
 
            case EDJE_PART_TYPE_TEXT:
@@ -4085,6 +4127,13 @@ _edje_part_recalc(Edje *ed, Edje_Real_Part *ep, int flags, Edje_Calc_Params *sta
              (ep->typedata.swallow)) &&
             (ep->typedata.swallow->swallowed_object))
           {
+             if (pf->clip_to && pf->clip_to->object)
+               evas_object_clip_set(ep->typedata.swallow->swallowed_object, pf->clip_to->object);
+             else if (ep->part->clip_to_id >= 0)
+               evas_object_clip_set(ep->typedata.swallow->swallowed_object, ed->table_parts[ep->part->clip_to_id % ed->table_parts_size]->object);
+             else
+               evas_object_clip_set(ep->typedata.swallow->swallowed_object, ed->base->clipper);
+
              if (pf->visible)
                {
                   Eina_Bool vis = EINA_TRUE;
diff --git a/src/lib/edje/edje_data.c b/src/lib/edje/edje_data.c
index d0eae225e7..d81ad241ff 100644
--- a/src/lib/edje/edje_data.c
+++ b/src/lib/edje/edje_data.c
@@ -75,16 +75,21 @@ Eet_Data_Descriptor *_edje_edd_edje_physics_face = NULL;
 Eet_Data_Descriptor *_edje_edd_edje_map_colors = NULL;
 Eet_Data_Descriptor *_edje_edd_edje_map_colors_pointer = NULL;
 
+/* allocate a description struct.
+ * this initializes clip_to_id as this field will not be present in most
+ * edje files.
+ */
 #define EMP(Type, Minus)                            \
   EAPI Eina_Mempool *_emp_##Type = NULL;            \
                                                     \
   static void *                                     \
   mem_alloc_##Minus(size_t size)                    \
   {                                                 \
-     void *data;                                    \
+     Edje_Part_Description_Common *data;            \
                                                     \
      data = eina_mempool_malloc(_emp_##Type, size); \
      memset(data, 0, size);                         \
+     data->clip_to_id = -1;                         \
      return data;                                   \
   }                                                 \
                                                     \
@@ -94,20 +99,21 @@ Eet_Data_Descriptor *_edje_edd_edje_map_colors_pointer = NULL;
      eina_mempool_free(_emp_##Type, data);          \
   }
 
-EMP(RECTANGLE, rectangle);
-EMP(TEXT, text);
-EMP(IMAGE, image);
-EMP(PROXY, proxy);
-EMP(SWALLOW, swallow);
-EMP(TEXTBLOCK, textblock);
-EMP(GROUP, group);
-EMP(BOX, box);
-EMP(TABLE, table);
-EMP(EXTERNAL, external);
-EMP(SPACER, spacer);
-EMP(MESH_NODE, mesh_node);
-EMP(LIGHT, light);
-EMP(CAMERA, camera);
+EMP(RECTANGLE, rectangle)
+EMP(TEXT, text)
+EMP(IMAGE, image)
+EMP(PROXY, proxy)
+EMP(SWALLOW, swallow)
+EMP(TEXTBLOCK, textblock)
+EMP(GROUP, group)
+EMP(BOX, box)
+EMP(TABLE, table)
+EMP(EXTERNAL, external)
+EMP(SPACER, spacer)
+EMP(MESH_NODE, mesh_node)
+EMP(LIGHT, light)
+EMP(CAMERA, camera)
+#undef EMP
 
 EAPI Eina_Mempool *_emp_part = NULL;
 
@@ -661,6 +667,7 @@ _edje_edd_init(void)
   EET_DATA_DESCRIPTOR_ADD_BASIC(Edd, Type, "rel2.offset_y", rel2.offset_y, EET_T_INT);                         \
   EET_DATA_DESCRIPTOR_ADD_BASIC(Edd, Type, "rel2.id_x", rel2.id_x, EET_T_INT);                                 \
   EET_DATA_DESCRIPTOR_ADD_BASIC(Edd, Type, "rel2.id_y", rel2.id_y, EET_T_INT);                                 \
+  EET_DATA_DESCRIPTOR_ADD_BASIC(Edd, Type, "clip_to_id", clip_to_id, EET_T_INT);                               \
   EET_DATA_DESCRIPTOR_ADD_BASIC(Edd, Type, "color_class", color_class, EET_T_STRING);                          \
   EET_DATA_DESCRIPTOR_ADD_BASIC(Edd, Type, "color.r", color.r, EET_T_UCHAR);                                   \
   EET_DATA_DESCRIPTOR_ADD_BASIC(Edd, Type, "color.g", color.g, EET_T_UCHAR);                                   \
@@ -751,6 +758,7 @@ _edje_edd_init(void)
   EET_DATA_DESCRIPTOR_ADD_BASIC(Edd, Type, "rel2.offset_y", Dec.rel2.offset_y, EET_T_INT);                         \
   EET_DATA_DESCRIPTOR_ADD_BASIC(Edd, Type, "rel2.id_x", Dec.rel2.id_x, EET_T_INT);                                 \
   EET_DATA_DESCRIPTOR_ADD_BASIC(Edd, Type, "rel2.id_y", Dec.rel2.id_y, EET_T_INT);                                 \
+  EET_DATA_DESCRIPTOR_ADD_BASIC(Edd, Type, "clip_to_id", Dec.clip_to_id, EET_T_INT);                               \
   EET_DATA_DESCRIPTOR_ADD_BASIC(Edd, Type, "color_class", Dec.color_class, EET_T_STRING);                          \
   EET_DATA_DESCRIPTOR_ADD_BASIC(Edd, Type, "color.r", Dec.color.r, EET_T_UCHAR);                                   \
   EET_DATA_DESCRIPTOR_ADD_BASIC(Edd, Type, "color.g", Dec.color.g, EET_T_UCHAR);                                   \
diff --git a/src/lib/edje/edje_edit.c b/src/lib/edje/edje_edit.c
index 73d7777a66..4e6b94f98d 100644
--- a/src/lib/edje/edje_edit.c
+++ b/src/lib/edje/edje_edit.c
@@ -532,6 +532,7 @@ _edje_part_description_id_set(int type, Edje_Part_Description_Common *c, int old
    if (c->rel1.id_y == old_id) c->rel1.id_y = new_id;
    if (c->rel2.id_x == old_id) c->rel2.id_x = new_id;
    if (c->rel2.id_y == old_id) c->rel2.id_y = new_id;
+   if (c->clip_to_id == old_id) c->clip_to_id = new_id;
 
    if (type == EDJE_PART_TYPE_TEXT
        || type == EDJE_PART_TYPE_TEXTBLOCK)
@@ -630,18 +631,26 @@ _edje_part_id_set(Edje *ed, Edje_Real_Part *rp, int new_id)
 static void
 _edje_part_description_id_switch(int type, Edje_Part_Description_Common *c, int id1, int id2)
 {
-   if (c->rel1.id_x == id1) c->rel1.id_x = id2;
+   if (c->rel1.id_x == id1)
+     c->rel1.id_x = id2;
    else if (c->rel1.id_x == id2)
      c->rel1.id_x = id1;
-   if (c->rel1.id_y == id1) c->rel1.id_y = id2;
+   if (c->rel1.id_y == id1)
+     c->rel1.id_y = id2;
    else if (c->rel1.id_y == id2)
      c->rel1.id_y = id1;
-   if (c->rel2.id_x == id1) c->rel2.id_x = id2;
+   if (c->rel2.id_x == id1)
+     c->rel2.id_x = id2;
    else if (c->rel2.id_x == id2)
      c->rel2.id_x = id1;
-   if (c->rel2.id_y == id1) c->rel2.id_y = id2;
+   if (c->rel2.id_y == id1)
+     c->rel2.id_y = id2;
    else if (c->rel2.id_y == id2)
      c->rel2.id_y = id1;
+   if (c->clip_to_id == id1)
+     c->clip_to_id = id2;
+   else if (c->clip_to_id == id2)
+     c->clip_to_id = id1;
 
    if (type == EDJE_PART_TYPE_TEXT
        || type == EDJE_PART_TYPE_TEXTBLOCK)
@@ -5262,6 +5271,7 @@ edje_edit_state_add(Evas_Object *obj, const char *part, const char *name, double
    pd->rel2.offset_y = -1;
    pd->rel2.id_x = -1;
    pd->rel2.id_y = -1;
+   pd->clip_to_id = -1;
    pd->color_class = NULL;
    pd->color.r = 255;
    pd->color.g = 255;
diff --git a/src/lib/edje/edje_load.c b/src/lib/edje/edje_load.c
index 0457c8157e..5839e6dc03 100644
--- a/src/lib/edje/edje_load.c
+++ b/src/lib/edje/edje_load.c
@@ -846,6 +846,8 @@ _edje_object_file_set_internal(Evas_Object *obj, const Eina_File *file, const ch
                     }
                   for (i = 0; i < ed->table_parts_size; i++)
                     {
+                       Edje_Real_Part *clip_to = NULL;
+
                        rp = ed->table_parts[i];
                        if (rp->param1.description)   /* FIXME: prevent rel to gone radient part to go wrong. You may
                                                         be able to remove this when all theme are correctly rewritten. */
@@ -859,20 +861,18 @@ _edje_object_file_set_internal(Evas_Object *obj, const Eina_File *file, const ch
                             if (rp->param1.description->rel2.id_y >= 0)
                               rp->param1.description->rel2.id_y %= ed->table_parts_size;
                          }
-                       if (rp->part->clip_to_id >= 0)
-                         {
-                            Edje_Real_Part *clip_to;
 
-                            clip_to = ed->table_parts[rp->part->clip_to_id % ed->table_parts_size];
-                            if (clip_to &&
-                                clip_to->object &&
-                                rp->object)
-                              {
-                                 evas_object_pass_events_set(clip_to->object, 1);
-                                 evas_object_pointer_mode_set(clip_to->object, EVAS_OBJECT_POINTER_MODE_NOGRAB);
-                                 evas_object_clip_set(rp->object, clip_to->object);
-                              }
+                       if (rp->param1.description && (rp->param1.description->clip_to_id >= 0))
+                         clip_to = ed->table_parts[rp->param1.description->clip_to_id % ed->table_parts_size];
+                       else if (rp->part->clip_to_id >= 0)
+                         clip_to = ed->table_parts[rp->part->clip_to_id % ed->table_parts_size];
+                       if (clip_to && clip_to->object && rp->object)
+                         {
+                            evas_object_pass_events_set(clip_to->object, 1);
+                            evas_object_pointer_mode_set(clip_to->object, EVAS_OBJECT_POINTER_MODE_NOGRAB);
+                            evas_object_clip_set(rp->object, clip_to->object);
                          }
+
                        if (rp->drag)
                          {
                             if (rp->part->dragable.confine_id >= 0)
diff --git a/src/lib/edje/edje_private.h b/src/lib/edje/edje_private.h
index 3b41699627..ee28bba0c8 100644
--- a/src/lib/edje/edje_private.h
+++ b/src/lib/edje/edje_private.h
@@ -1174,6 +1174,8 @@ struct _Edje_Part_Description_Common
    Edje_Color color;
    Edje_Color color2;
 
+   int        clip_to_id; /* state clip override @since 1.15 */
+
    struct {
       FLOAT_T        relative_x;
       FLOAT_T        relative_y;
@@ -1715,6 +1717,7 @@ struct _Edje_Calc_Params
 #ifdef HAVE_EPHYSICS
    const Edje_Calc_Params_Physics *physics; // 90
 #endif
+   Edje_Real_Part  *clip_to; /* state clip override @since 1.15 */
    unsigned char    persp_on : 1;
    unsigned char    lighted : 1;
    unsigned char    mapped : 1;