Sometimes in an application you want an element to track with the cursor for interactive placement. Here is a snippet, taken from one of our demo applications, that does just that.
' Set new graphics so they are hung off the mouse for placement
Dim newCategoryId As Long
Dim newOffset As Long
newCategoryId = GTVX1.GetLastDrawnCategoryId
newOffset = GTVX1.GetLastDrawnOffset
If GTVX1.SelectElement(newCategoryId, newOffset) Then ' newly placed graphics
GTVX1.ActivateSelectedElementMove ' activate selected element move mode
In case your app is not with GTVx, but is an external app for GTViewer, just change the "GTVX1" part to "docObj" for the two lines that get the new categoryId and offset, and change "GTVX1" to "viewObj" for the three lines in the "If" paragraph.
Happy app dev!