I'm building a wizard, so I want the page widget to be replaced by the next one when the user clicks "Next". I tried (in the container model, in the callback for the next button): pageModel := PageModel owner: self. self needRebuild: false. self buildWithSpec. It "worked" in that it replaced the page, but it looked really weird... the vertical spacing of the controls was off and all the text widgets were invisible, even though they were there and working if clicked on. Before: <http://forum.world.st/file/n4652378/Screen_Shot_2012-10-21_at_12.32.02_PM.pn...> After: <http://forum.world.st/file/n4652378/Screen_Shot_2012-10-21_at_12.32.14_PM.pn...> -- View this message in context: http://forum.world.st/Spec-Dynamically-replacing-widgets-tp4652378.html Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.