TEMP XDnD: support large images retrieval.devs/jackdanielz/DnD

Large images require a special process during pasting, as the data
is sent in chunks and not in only one part. The INCR mechanism
(ICCCM 2.7.2) is needed for this.

Currently: seems stable, doesn't block
Still todo:
- after a lot of one shot pastes, takes time to come back to stability
- sometimes receives UTF8_STRING from firefox. why?

@feature

2 files changed, 124 insertions, 6 deletions

diff --git a/src/lib/ecore_x/ecore_x_events.c b/src/lib/ecore_x/ecore_x_events.c
index 0049fca25d..10c7b431f0 100644
--- a/src/lib/ecore_x/ecore_x_events.c
+++ b/src/lib/ecore_x/ecore_x_events.c
@@ -22,6 +22,14 @@
 #define CODESET "INVALID"
 #endif /* ifndef CODESET */
 
+/* INCR mechanism variables */
+static unsigned long _clipboard_incr_data_length = 0; /* Current received data length */
+static char *_clipboard_incr_data = NULL; /* Current received data */
+static Ecore_X_Event_Selection_Notify *_clipboard_incr_event = NULL; /* Event to send once the data is ready */
+Eina_Bool _clipboard_incr_start = EINA_FALSE;
+static Atom _clipboard_data_atom;
+static unsigned long _clipboard_incr_data_expected_length = 0;
+
 typedef struct _Ecore_X_Mouse_Down_Info
 {
    EINA_INLIST;
@@ -179,7 +187,7 @@ _ecore_x_event_free_selection_notify(void *data EINA_UNUSED,
 
    e = ev;
    sel = e->data;
-   if (sel->free)
+   if (sel && sel->free)
      sel->free(sel);
 
    free(e->target);
@@ -1362,6 +1370,69 @@ _ecore_x_event_handle_circulate_request(XEvent *xevent)
 void
 _ecore_x_event_handle_property_notify(XEvent *xevent)
 {
+   /* ICCCM 2.7.2: incremental data sending
+    * The process has been initiated during selection_notify
+    * event (specifically in ecore_x_window_prop_property_get).
+    * This code retrieves the data from the owner and appends
+    * it to a buffer.
+    * A property returning a size equal to zero indicates the end
+    * of the sending and results in sending the event to the upper
+    * layer with all the data.
+    */
+   if (xevent->xproperty.state == PropertyNewValue && _clipboard_incr_start)
+     {
+        Atom type_ret = 0;
+        int size_ret = 0;
+        unsigned long num_ret = 0, bytes = 0, dummy;
+        unsigned char *prop_ret = NULL;
+        XGetWindowProperty(_ecore_x_disp, xevent->xproperty.window,
+              xevent->xproperty.atom, 0, 0, False, AnyPropertyType,
+              &type_ret, &size_ret, &num_ret, &bytes, &prop_ret);
+        XFree(prop_ret);
+        if (type_ret == _clipboard_data_atom)
+          {
+             printf("%s/%d: Type %s == %s\n", __FUNCTION__, __LINE__, ecore_x_atom_name_get(type_ret), ecore_x_atom_name_get(_clipboard_data_atom));
+             if (bytes <= 0)
+               {
+                  printf("Sizes: %d - %d\n", _clipboard_incr_data_length, _clipboard_incr_data_expected_length);
+                  if (_clipboard_incr_data_length == _clipboard_incr_data_expected_length)
+                    {
+                       /* The transaction is now finished. Th selection notify event can be sent
+                        * with all the retrieved data. */
+                       _clipboard_incr_event->data = _ecore_x_selection_parse(_clipboard_incr_event->target,
+                             _clipboard_incr_data, _clipboard_incr_data_length, size_ret);
+
+                       ecore_event_add(ECORE_X_EVENT_SELECTION_NOTIFY, _clipboard_incr_event,
+                             _ecore_x_event_free_selection_notify, NULL);
+                       ecore_x_window_prop_property_del(xevent->xproperty.window, xevent->xproperty.atom);
+                       printf("%s/%d: End of image (%d)\n", __FUNCTION__, __LINE__, _clipboard_incr_data_length);
+                    }
+                  else
+                    {
+                       free(_clipboard_incr_data);
+                       _ecore_x_event_free_selection_notify(NULL, _clipboard_incr_event);
+                    }
+                  _clipboard_incr_start = EINA_FALSE;
+                  _clipboard_incr_data = NULL;
+                  _clipboard_incr_data_length = 0;
+                  _clipboard_incr_event = NULL;
+                  return;
+               }
+             /* Retrieval of the chunk */
+             XGetWindowProperty(_ecore_x_disp, xevent->xproperty.window,
+                   xevent->xproperty.atom, 0, bytes, False, AnyPropertyType,
+                   &type_ret, &size_ret, &num_ret, &dummy, &prop_ret);
+             bytes = num_ret * size_ret / 8;
+             _clipboard_incr_data = realloc(_clipboard_incr_data, _clipboard_incr_data_length + bytes);
+             memcpy(_clipboard_incr_data + _clipboard_incr_data_length, prop_ret, bytes);
+             printf("%s/%d: Data %.8X\n", __FUNCTION__, __LINE__, *(unsigned int *)prop_ret);
+             XFree(prop_ret);
+             _clipboard_incr_data_length += bytes;
+             /* We delete the property to indicate the owner to send the next chunk */
+             ecore_x_window_prop_property_del(xevent->xproperty.window, xevent->xproperty.atom);
+             return;
+          }
+     }
    _ecore_x_last_event_mouse_move = 0;
    {
       Ecore_X_Event_Window_Property *e;
@@ -1491,11 +1562,15 @@ _ecore_x_event_handle_selection_notify(XEvent *xevent)
    unsigned char *data = NULL;
    Ecore_X_Atom selection;
    int num_ret, format;
+   Eina_Bool incr_already_started = _clipboard_incr_start;
 
    LOGFN(__FILE__, __LINE__, __FUNCTION__);
    _ecore_x_last_event_mouse_move = 0;
    selection = xevent->xselection.selection;
 
+   printf("%s/%d: Target %s (%sINCR)\n", __FUNCTION__, __LINE__, ecore_x_atom_name_get(xevent->xselection.target),
+         _clipboard_incr_start?"":"No ");
+   _clipboard_incr_start = EINA_FALSE;
    if (xevent->xselection.target == ECORE_X_ATOM_SELECTION_TARGETS)
      {
         format = ecore_x_window_prop_property_get(xevent->xselection.requestor,
@@ -1520,9 +1595,21 @@ _ecore_x_event_handle_selection_notify(XEvent *xevent)
                                                   xevent->xselection.property,
                                                   AnyPropertyType, 8, &data,
                                                   &num_ret);
-        if (!format) return;
+        if (!_clipboard_incr_start && !format) return;
      }
 
+   printf("%s/%d: NEW_INCR: %s CURR_INCR: %s\n", __FUNCTION__, __LINE__,
+         _clipboard_incr_start?"Yes":"No ",
+         incr_already_started?"Yes":"No");
+   if (_clipboard_incr_start && incr_already_started)
+     {
+        /* We don't do anything if another INCR request is received when one
+         * is already under process */
+        if (data) free(data);
+        return;
+     }
+   _clipboard_incr_start = _clipboard_incr_start ^ incr_already_started;
+
    e = calloc(1, sizeof(Ecore_X_Event_Selection_Notify));
    if (!e)
      {
@@ -1547,10 +1634,23 @@ _ecore_x_event_handle_selection_notify(XEvent *xevent)
    else
      e->selection = ECORE_X_SELECTION_OTHER;
 
-   e->data = _ecore_x_selection_parse(e->target, data, num_ret, format);
-
-   ecore_event_add(ECORE_X_EVENT_SELECTION_NOTIFY, e,
-                   _ecore_x_event_free_selection_notify, NULL);
+   if (!_clipboard_incr_start)
+     {
+        e->data = _ecore_x_selection_parse(e->target, data, num_ret, format);
+        ecore_event_add(ECORE_X_EVENT_SELECTION_NOTIFY, e,
+              _ecore_x_event_free_selection_notify, NULL);
+     }
+   else
+     {
+        /* In case of INCR, the event is stored until the data is ready */
+        if (_clipboard_incr_event) _ecore_x_event_free_selection_notify(NULL, _clipboard_incr_event);
+        _clipboard_incr_data_expected_length = *(int *)data;
+        printf("%s/%d: Target %s Size %d\n", __FUNCTION__, __LINE__, e->target, _clipboard_incr_data_expected_length);
+        _clipboard_incr_event = e;
+        _clipboard_data_atom = xevent->xselection.target;
+        ecore_x_window_prop_property_del(xevent->xselection.requestor, xevent->xselection.property);
+        free(data);
+     }
 }
 
 void
diff --git a/src/lib/ecore_x/ecore_x_window_prop.c b/src/lib/ecore_x/ecore_x_window_prop.c
index 043e50e391..39a1215bb3 100644
--- a/src/lib/ecore_x/ecore_x_window_prop.c
+++ b/src/lib/ecore_x/ecore_x_window_prop.c
@@ -16,6 +16,8 @@
   XChangeProperty(_ecore_x_disp, win, atom, XA_CARDINAL, 32, PropModeReplace, \
                   (unsigned char *)p_val, cnt)
 
+extern Eina_Bool _clipboard_incr_start;
+
 /*
  * Set CARD32 (array) property
  */
@@ -555,6 +557,21 @@ ecore_x_window_prop_property_get(Ecore_X_Window win,
    if (_ecore_xlib_sync) ecore_x_sync();
    if (ret != Success)
      return 0;
+   if (type_ret != type)
+     {
+        /* In case of INCR (ICCCM 2.7.2), we have to delete
+         * the property to request the owner to send the data
+         * chunks.
+         * Data is retrieved by the function _ecore_x_event_handle_property_notify.
+         * This part of code needs to be in this function, as
+         * this is the highest layer knowing of the type_ret,
+         * needed to identify the INCR request.
+         */
+        char *atom_name = ecore_x_atom_name_get(type_ret);
+        printf("%s/%d: type %s\n", __FUNCTION__, __LINE__, atom_name);
+        _clipboard_incr_start = (atom_name && !strcmp(atom_name, "INCR"));
+        free(atom_name);
+     }
    if ((!num_ret) || (size_ret <= 0))
      {
         XFree(prop_ret);
@@ -583,6 +600,7 @@ ecore_x_window_prop_property_get(Ecore_X_Window win,
           ((unsigned int *)*data)[i] = ((unsigned long *)prop_ret)[i];
         break;
      }
+   printf("Data %s\n", *data);
 
    XFree(prop_ret);