A visual code designer is provided that allows a user to manipulate control objects on a common design surface. Each control object has extensible snaplines that define alignment characteristics for the control. The snaplines are extensible in that a developer can define and/or specify matching and alignment criteria such as type, filter and offset information. Further, the visual code designer assists the user in positioning a control on the common design surface by automatically aligning the control during design-time without the use of gridlines.