I don´t know if I understand correctly the question... The design code is saved in a basic message #specmorph: specMorph | cLStatusbar container cLPanel | "container" container := CLPanel new. self containerSpec: container. container visible: false. container openInWorld. "cLPanel" cLPanel := CLPanel new. container addMorph: cLPanel. self cLPanelSpec: cLPanel. "cLStatusbar" cLStatusbar := CLStatusbar new. cLPanel addMorph: cLStatusbar. self cLStatusbarSpec: cLStatusbar. ^container and another spec method for define each control of view, in current example be #cLPanelSpec:, #cLStatusbarSpec: and #containerSpec:, for example: cLPanelSpec: aTCLControl aTCLControl name: 'cLPanel'. aTCLControl usePolymorphStyleMechanism: false. aTCLControl balloonText: nil. aTCLControl enabled: true. aTCLControl location: 0@0. aTCLControl extent: 530@377. aTCLControl anchors: {true .true .true .true .}. aTCLControl imageResource: nil. aTCLControl style: {(BorderStyle width: 0 color: Color transparent) .(Color r: 0.892 g: 0.887 b: 0.879) .(Color r: 0.503 g: 0.553 b: 0.662) .false .true .}. aTCLControl minWidth: 2. aTCLControl minHeight: 2. aTCLControl layout: {ProportionalLayout .#spaceFill .#spaceFill .0 .false .false .false .0 .0 .1073741823 .#topToBottom .#none .#center .#topLeft .#topLeft .#none .#none .}. I believe the definition of UI must be do with XUL, or XAML. Of that way don´t need a designer in Smalltalk, else could be use some of tools for create XAML o XUL uis. Later, a "Reader" could parse the XML and build a Morphic GUI or a Seaside GUI. Regards -- View this message in context: http://forum.world.st/Best-way-for-change-a-window-style-tp3032341p3175227.h... Sent from the Pharo Smalltalk mailing list archive at Nabble.com.