Specifies the timeout in milliseconds of the asynchronous line metrics calculation after any change which is affecting the geometry. Note that the calculation will be splitted into short line ranges (except if timeout is zero). The default value is 150 and will be changed only in seldom cases. For most applications this value offers a good responsiveness, and gives the impression of a better performance, compared to the behavior with a low timeout.

When set to zero the line metrics update will be performed synchronous; this means the whole update will be performed immediately; with most applications this behavior would cause performance problems. When set to 1 the computation is already asynchronous, but the computation starts with each event loop cycle.