Property controlling which McViewer.ViewerGroup is tracked.

A Long value.  

object.ViewerGroupsToTrack [= value]

The ViewerGroupsToTrack Property syntax has these parts:

When this McViews operator has an ancestor McImage, then IMcBasicView instances that display the ancestor McImage (e.g., via a call to the McDisplay.SetImageToDisplay method) will result in MC_NOTIFY_VIEW_IMAGE_DISPLAYED notifies being sent to our SpecialNotify method. In the SpecialNotify method, the IMcBasicView displaying the image will be automatically added to this McViews collection if and only if our ViewerGroupsToTrack property has a non-zero bitwise intersection with the displaying IMcBasicView's ViewerGroup property.

Typically an McViewer instance will be part of only one ViewerGroup (having a mcViewGroupEnum value such as vgMDIImageWindow). However, an McViews collection might wish to track many (or all) such groups. For example the standard Image.Views property has its ViewerGroupsToTrack set to the lower 28 bits of the 32 groups available. This means that the Image.Views collection will track the addition of virtually all ViewerGroup values.

By default ViewerGroupsToTrack is zero, so that no viewer groups are automatically tracked. However, for the McImage.Annotation, Image.Aoi, McImage.RegionFeatures, McImage.LineFeatures and McImage.PointFeatures objects, as well as any object created by the IMcFeatures.DisplayOverlays.Add method, then both the vgMDIImageWindow (a standard MDI Image Window) and vgImageMcDisplay (an McDisplay operator that is an immediate child of an McImage) groups.