ScreenUpdating

ScreenUpdating is a term used in graphical user interface programming to describe a mechanism that controls whether the user interface is refreshed during a series of updates. When screen updating is disabled, the UI may accumulate changes and repaint only once after the updates are complete. This can reduce flicker and significantly improve performance for bulk operations that would otherwise trigger many individual redraws.

In many environments, screen updating is exposed as a boolean property or a pair of begin/end calls. A common pattern is to turn updating off, perform all modifications, and then re-enable updating so the final state is drawn. A well-known example is Excel's VBA: you can set Application.ScreenUpdating = False to suspend redraws, execute your data or formatting changes, and then set Application.ScreenUpdating = True to refresh the display.

Best practices include limiting the duration for which screen updating is disabled, and ensuring it is re-enabled even if errors occur. This is typically achieved with proper error handling or a finally-like construct that guarantees restoration to the visible state. Developers should also consider user experience; while updates are suspended, the interface may appear unresponsive or frozen, so long operations should provide feedback or progress indicators if possible.

Related concepts include painting, redraw control, and double buffering, all of which address similar concerns about visual flicker and rendering efficiency. ScreenUpdating is a practical, often language-specific feature that helps optimize bulk UI changes while preserving a smooth final presentation.