Applies to
Declaration
type TUpdateMode = (umImmediate, umOnNeed, umBackground);
property UpdateMode: TupdateMode;
Description
This property is used to specify whether keyword parsing and formatting paragraphs into lines should occur
right after every text modifications or
can be processed in the background (its default value) or
deferred until needed for display.
Setting UpdateMode to umImmediate ensures that all internal processing has been done when your application code has control. Loading in a big amount of text or changing the width of the control may imply a significant delay before the user can continue to work. The values umOnNeed and umBackground permits returning almost instantly the control to the user in these situations; the drawback is that your application does not necessarily knows exactly how many lines are required to display the text. Also, there may be some slight flickering when dragging the scrollbars.
We advise that you should use the value umOnNeed with no word wrapping and no start-stop keys, and umBackground otherwise. The value umImmediate should be used if you find that the background processing interferes with the normal behavior of your application.