gistfile1.txt

    def scroll_after_add(self):
        if not self.scrolling:
            available_height = self.height
            index = self._index

            print 'index', index
            print 'available_height', available_height

            while available_height > 0:
                item_view = self.adapter.get_view(index)
                if item_view is None:
                    break
                index += 1
                available_height -= item_view.height

            print 'available_height', available_height

            if available_height <= 0:
                self._index += 1

            self.scrolling = True
            self.populate()
            self.dispatch('on_scroll_complete')

    def on_scroll_complete(self, *args):
        self.scrolling = False

    def data_changed(self, *dt):

        print 'data_changed callback', dt

        print self.adapter.data.range_change

        if self.adapter.data.range_change:
            first_item_view = self.container.children[-1]
            last_item_view = self.container.children[0]

            data_action, (start_index, end_index) = self.adapter.data.range_change

            change_in_range = False

            if (first_item_view.index <= start_index <= last_item_view.index
                or
                first_item_view.index <= end_index <= last_item_view.index):
                change_in_range = True

            if data_action == 'add':
                self.scroll_after_add()
            elif data_action == 'delete':
                cv = self.adapter.cached_views
                i = start_index
                j = end_index + 1
                slice_length = end_index - start_index
                deleted_views = []
                while j in cv and j < len(self.adapter.data) - slice_length:
                    deleted_views.append(cv[i])
                    cv[i] = cv[j]
                    cv[i].index = i
                    i += 1
                    j += 1
                if j in cv:
                    while j in cv:
                        del cv[j]
                        j += 1
                for deleted_view in deleted_views:
                    if deleted_view in self.adapter.selection:
                        self.adapter.selection.remove(deleted_view)
                self.adapter.check_for_empty_selection()
                if change_in_range:
                    self.scrolling = True
                    self.populate()
                    self.dispatch('on_scroll_complete')
            elif data_action == 'move':
                pass
            elif data_action == 'sort':
                pass