Original Article Date: Oct 6, 2004
There has been a subtle but very important change in the way that the Level Display dialog responds to a level display state change. Read this to understand what’s going on, why you may notice a delay when turning on or off the display of a level, and how to force MicroStation to behave as it did in previous versions.
In MicroStation 08.05.00.64 it was discovered that under a certain condition doing a double-click in the Level Display dialog did not set the level as active, but resulted in two level display state changes. In other words, rather than setting the selected level as the Active Level, it actually first turned it off and then turned it back on. The condition was simply trying to set a level active that contained a large number of elements. When this problem was encountered MicroStation would take considerable time and memory usage to complete the state changes.
So, that brings us to MicroStation 08.05.01.25 and the apparent slow response when changing the level display state. In this new version, the Level Display dialog no longer attempts to change the level display state during a double click, even if the level contains a large number of elements. This change consequently slightly slowed down the time to turn a level on or off.
It was understood that not everybody would encounter the problem that led to this change, so a new configuration variable was added to 08.05.01.25 that allows users to change the behavior of the Level Display dialog. Setting MS_LEVEL_PREVIOUS_LD_SELECTION_BEHAVIOR causes MicroStation to revert to pre-08.05.01.25 selection behavior, but also introduces the possibility of encountering the problem previously discussed.
If you do set the variable to realize a quicker response time to level display state changes, but do not want to encounter the problem, it is suggested that you choose another method to set the active level. For example, if you are in the Level Display dialog and the level you wish to set active contains 100,000+ elements, you could always set the level as active using the right click menu. There are many other ways to this end, so you can use the workflow that is most comfortable.
AskInga Article #222