GTK Drag-and-drop Validation X11 Cursor lock up within drag_get_data

I have been unable to get drag and drop validation working in pygtk. I am out of ideas and would like a second opinion.

My goal is to only allow files which contain .jpg to be dropped.

Specifically, whenever I call widget.drag_get_data within the drag-motion callback The X11 cursor locks up. Making debugging tedious and aggravating since I have to kill X11 and re launch everything.

Here is my source code, I think the issue lies specifically in the drag_motion_cb and drag_data_received_cb methods. I have left the commented out sections I have tried before.

Using Google code search searching for drag_get_data doesn't show anyone else doing advanced validation. So I'm guessing others failed as well.

I am out of ideas and will end up just using simple DnD in my linux port (without proper validation) if I cannot figure this out.

Thanks in advance.

import pygtk 
pygtk.require('2.0')
import gobject
import gtk

TARGET_TEXT_URI_LIST = 0

drop_targets = [
  ("text/uri-list", 0, TARGET_TEXT_URI_LIST)
]

class TestApp(gobject.GObject):
  builder = gtk.Builder()
  window = None
  button = None

def init(self):
    gobject.GObject.init(self)

assert self.builder != None
self.builder.add_from_file("MainWindow.glade");
self.window = self.builder.get_object("window1")
self.button = self.builder.get_object("button1")

self.window.connect("destroy", gtk.main_quit)

self.button.drag_dest_set(gtk.DEST_DEFAULT_ALL, drop_targets, gtk.gdk.ACTION_COPY|gtk.gdk.ACTION_LINK|gtk.gdk.ACTION_MOVE)

self.button.connect("drag-data-received", self.drag_data_received_cb)
self.button.connect("drag-drop", self.drag_drop_cb)
self.button.connect("drag-motion", self.drag_motion_cb)
self.button.connect("drag-leave", self.drag_leave_cb)

self.window.show_all()


drop_data_ready = False
  drop_occurred = False
  drop_highlight = False
  drop_data = None

def drag_data_received_cb(self,widget,context,x,y,data,info,timestamp):
    print "drag_data_received_cb"

# Check to see if we have the drop data yet.
if False == self.drop_data_ready:
  # If this is data we expected or can handle, then process it.
  if TARGET_TEXT_URI_LIST == info and data.get_format() == 8 and data.get_length() > 0:
    self.drop_data = data.get_uris()
    self.drop_data_ready = True
  context.drag_status(gtk.gdk.ACTION_COPY, timestamp)

# Actual drop handling code.
if True == self.drop_occurred:
  # Reset state.
  self.drop_occurred = False

  print "RECEIVED DROP",self.drop_data

  # Notify whether we handled the drop or not.
  context.finish(True,False,timestamp)

  # Clean up.
  self.drag_leave_cb(widget, context, timestamp)
return True


def drag_drop_cb(self,widget,context,x,y,timestamp):
    target = widget.drag_dest_find_target(context, widget.drag_dest_get_target_list())

# Is it something we can handle?

if target == gtk.gdk.atom_intern("text/uri-list", False):
  # Tell data recieved handler (do_drag_data_received) we can actually handle the drop.
  self.drop_occurred = True

  widget.drag_get_data(context,target,timestamp)

  # We can handle this data type.
  return True
else:
  # We cannot handle the drop.
  return False
pass


def drag_motion_cb(self,widget,context,x,y,timestamp):

if not self.drop_data_ready:
  widget.drag_get_data(context, gtk.gdk.atom_intern("text/uri-list",False), timestamp)
  return False



"""
target = widget.drag_dest_find_target(context, widget.drag_dest_get_target_list())
if target == gtk.gdk.atom_intern("text/uri-list", False):
  if True == self.drop_data_ready:
    pass
  else:


    #widget.drag_get_data(context, target, timestamp)
    pass
  """



context.drag_status(gtk.gdk.ACTION_COPY, timestamp)
"""

if target == gtk.gdk.atom_intern("text/uri-list", False):
  if True == self.drop_data_ready:
    if repr(drop_data).find(".jpg") != -1:
      # Tell Gdk we can handle this.
      context.drag_status(gtk.gdk.ACTION_COPY, timestamp)

      # Draw drop highlight (but only once).
      if False == self.drop_highlight:
        widget.drag_highlight()
        self.drop_highlight = True

      # Return here, don't fall through.
      return True
  else:
    # Request drag data from the s开发者_如何转开发ource.
    widget.drag_get_data(context, target, timestamp)

    # Fall-through to not allowing.
"""

# not something we can handle
#context.drag_status(0, timestamp) # Don't allow drop.
return True


pass


def drag_leave_cb(self,widget,context,timestamp):
    # Cleanup drag data.
    if True == self.drop_data_ready:
      self.drop_data = None
      self.drop_data_ready = False

# Un-draw the highlight.
if True == self.drop_highlight:
  widget.drag_unhighlight()
  self.drop_highlight = False
pass


gobject.type_register(TestApp)

def main():
  car = TestApp()
  gtk.main()

if name == 'main':
  main()

I think you must do something like this in drag_data_received_cb

def drag_data_received_cb(self, obj, context, x, y, selection, target_id, etime):
    try:
        dtype = selection.get_data_type()
    except AttributeError:## Old PyGTK
        dtype = selection.type
    if dtype=='image/jpeg':
        image_data = selection.data
        ## do somthing with image_data
        return True
    return False