onMoveCursor  
  The GtkTreeView::move-cursor signal is a class@Gtk.SignalAction which gets emitted when the user presses one of the cursor keys.
Applications should not connect to it, but may emit it with g_signal_emit_by_name() if they need to control the cursor programmatically. In contrast to gtk_tree_view_set_cursor() and gtk_tree_view_set_cursor_on_cell() when moving horizontally GtkTreeView::move-cursor does not reset the current selection.
Parameters
a combination of ConnectFlags
the Callback to connect. Params: step the granularity of the move, as a GtkMovementStep.     %GTK_MOVEMENT_LOGICAL_POSITIONS, %GTK_MOVEMENT_VISUAL_POSITIONS,     %GTK_MOVEMENT_DISPLAY_LINES, %GTK_MOVEMENT_PAGES and     %GTK_MOVEMENT_BUFFER_ENDS are supported.     %GTK_MOVEMENT_LOGICAL_POSITIONS and %GTK_MOVEMENT_VISUAL_POSITIONS     are treated identically.; direction the direction to move: +1 to move forwards; -1 to move     backwards. The resulting movement is undefined for all other values.; extend whether to extend the selection; modify whether to modify the selection. Returns true if @step is supported, false otherwise.