public int getTopIndex () {
	checkWidget();
	int /*long*/ [] path = new int /*long*/ [1];
	OS.gtk_widget_realize (handle);
	if (!OS.gtk_tree_view_get_path_at_pos (handle, 1, 1, path, null, null, null)) return 0;
	if (path [0] == 0) return 0;
	int /*long*/ indices = OS.gtk_tree_path_get_indices (path[0]);
	int[] index = new int [1];
	if (indices != 0) OS.memmove (index, indices, 4);
	// If the topmost item is only partially visible, return the index
	// of the first completely visible item.
	GdkRectangle rect = new GdkRectangle();
	OS.gtk_tree_view_get_cell_area(handle, path [0], 0, rect);
	if(rect.y < 0 && index[0] < (itemCount-1)) index[0]++;
	OS.gtk_tree_path_free (path [0]);
	return index [0];
}