[Lazarus] visual component form guidelines

[BTree Computing Services]

In the Lazarus GUI, when components are placed on a form, vertical and 
horizontal design guidelines are drawn to assist in aligning the 
component relative to other components.  These lines are like 'laser 
lines' that shoot out from the edges.  Does anyone know how that 
technique is done or the source code so that I can implement a similar 
technique in my app?

Thanks