Add variable sized controls to TListBox

[diablow]

I add objects to ListBox using AddObject procedure. To set correct item heigth I use OnMeasure event, but it occurs too early - my object is not added to ListBox yet, so I am unable to check its height from OnMeasure event. After searching I found some code (http://chee-yang.blogspot.com/2008/02/tlistbox-review.html), but it uses SendMessage, which I should not use, in multiplatform software. Any ideas on how to set ListBox item height correctly?