The with-atomic-redisplay macro delays the updating of a pane until all state changes have been performed.
Most CAPI pane slot writers update the visual appearance of the pane at the point that their state changes, but it is sometimes necessary to cause all updates to the pane to be left until after they are all completed. The macro with-atomic-redisplay defers all visible changes to the state of the pane until the end of the scope of the macro.