ecore_evas: add API for finding out if event is used

Summary:
ecore_x_dnd_send_status can be used to indicate if a item can be dropped
on a client or not. However, we should only indicate that this can be
dropped, if there is a object we signaled that a drop is in.

Long story short: there is no assertion that after indicating that
things can be dropped, that a notify for the data is sent. A drag
implementation should always listen to a mouse up event, and abort the
drag if no further operations are sent.
Depends on D11698

Reviewers: zmike, stefan_schmidt, raster

Reviewed By: zmike

Subscribers: cedric, #reviewers, #committers

Tags: #efl

Differential Revision: https://phab.enlightenment.org/D11699

src/lib/ecore_evas/ecore_evas.c

@@ -5699,6 +5699,7 @@ ecore_evas_callback_drop_drop_set(Ecore_Evas *ee, Ecore_Evas_Drop_Cb cb)
 typedef struct {
    Eina_Array *available_mime_types;
    Eina_Position2D pos;
+   Eina_Bool last_motion_was_used;
 } Ecore_Evas_Active_Dnd;
 
 static void
@@ -5734,18 +5735,34 @@ ecore_evas_dnd_enter(Ecore_Evas *ee, unsigned int seat, Eina_Iterator *available
      ee->func.fn_dnd_state_change(ee, seat, pos, EINA_TRUE);
 }
 
-EAPI void
+EAPI Eina_Bool
 ecore_evas_dnd_position_set(Ecore_Evas *ee, unsigned int seat, Eina_Position2D pos)
 {
    Ecore_Evas_Active_Dnd *dnd;
 
+   ECORE_EVAS_CHECK_GOTO(ee, err);
+   EINA_SAFETY_ON_NULL_GOTO(ee->active_drags, err);
+   dnd = eina_hash_find(ee->active_drags, &seat);
+   EINA_SAFETY_ON_NULL_GOTO(dnd, err);
+   dnd->pos = pos;
+   dnd->last_motion_was_used = EINA_FALSE;
+   if (ee->func.fn_dnd_motion)
+     ee->func.fn_dnd_motion(ee, seat, pos);
+   return dnd->last_motion_was_used;
+err:
+   return EINA_FALSE;
+}
+
+EAPI void
+ecore_evas_dnd_mark_motion_used(Ecore_Evas *ee, unsigned int seat)
+{
+   Ecore_Evas_Active_Dnd *dnd;
+
    ECORE_EVAS_CHECK(ee);
    EINA_SAFETY_ON_NULL_RETURN(ee->active_drags);
    dnd = eina_hash_find(ee->active_drags, &seat);
    EINA_SAFETY_ON_NULL_RETURN(dnd);
-   dnd->pos = pos;
-   if (ee->func.fn_dnd_motion)
-     ee->func.fn_dnd_motion(ee, seat, pos);
+   dnd->last_motion_was_used = EINA_TRUE;
 }
 
 EAPI void

src/lib/ecore_evas/ecore_evas_private.h

@@ -522,8 +522,8 @@ EAPI Eina_Bool ecore_evas_render(Ecore_Evas *ee);
 
 EAPI Evas *ecore_evas_evas_new(Ecore_Evas *ee, int w, int h);
 EAPI void ecore_evas_done(Ecore_Evas *ee, Eina_Bool single_window);
-
-EAPI void ecore_evas_dnd_position_set(Ecore_Evas *ee, unsigned int seat, Eina_Position2D pos);
+EAPI void ecore_evas_dnd_mark_motion_used(Ecore_Evas *ee, unsigned int seat);
+EAPI Eina_Bool ecore_evas_dnd_position_set(Ecore_Evas *ee, unsigned int seat, Eina_Position2D pos);
 EAPI void ecore_evas_dnd_leave(Ecore_Evas *ee, unsigned int seat, Eina_Position2D pos);
 EAPI void ecore_evas_dnd_enter(Ecore_Evas *ee, unsigned int seat, Eina_Iterator *available_types, Eina_Position2D pos);
 EAPI Eina_Position2D ecore_evas_dnd_pos_get(Ecore_Evas *ee, unsigned int seat);

src/lib/elementary/efl_ui_win.c

@@ -9268,15 +9268,18 @@ _motion_cb(Ecore_Evas *ee, unsigned int seat, Eina_Position2D p)
           {
              target->currently_inside = EINA_FALSE;
              efl_event_callback_call(target->obj, EFL_UI_DND_EVENT_DROP_LEFT, &ev);
+             ecore_evas_dnd_mark_motion_used(ee, seat);
           }
         else if (!target->currently_inside && inside)
           {
              target->currently_inside = EINA_TRUE;
              efl_event_callback_call(target->obj, EFL_UI_DND_EVENT_DROP_ENTERED, &ev);
+             ecore_evas_dnd_mark_motion_used(ee, seat);
           }
         else if (target->currently_inside && inside)
           {
              efl_event_callback_call(target->obj, EFL_UI_DND_EVENT_DROP_POSITION_CHANGED, &ev);
+             ecore_evas_dnd_mark_motion_used(ee, seat);
           }
         eina_accessor_free(ev.available_types);
      }

src/modules/ecore_evas/engines/x/ecore_evas_x.c

@@ -4185,8 +4185,9 @@ _ecore_evas_x_dnd_position(void *udata EINA_UNUSED, int type EINA_UNUSED, void *
    ee = ecore_event_window_match(pos->win);
    EINA_SAFETY_ON_NULL_GOTO(ee, end);
    ecore_evas_geometry_get(ee, &x, &y, &w, &h);
-   ecore_evas_dnd_position_set(ee, 1, EINA_POSITION2D(pos->position.x - x, pos->position.y - y));
-   ecore_x_dnd_send_status(EINA_TRUE, EINA_FALSE, (Ecore_X_Rectangle){x,y,w,h}, pos->action);
+   Eina_Bool used = ecore_evas_dnd_position_set(ee, 1, EINA_POSITION2D(pos->position.x - x, pos->position.y - y));
+   if (used)
+     ecore_x_dnd_send_status(EINA_TRUE, EINA_FALSE, (Ecore_X_Rectangle){x,y,w,h}, pos->action);
 end:
    return ECORE_CALLBACK_PASS_ON;
 }