kkallio@8: datatype panelState = Open | Closed
kkallio@8: 
adam@20: con formatCtl = fn ctx :: {Unit} => [body ~ ctx] =>
adam@21:                    {FormatPanel : xml (body ++ ctx) [] []
adam@21:                                   -> xml (body ++ ctx) [] []
adam@21:                                   -> xml (body ++ ctx) [] [],
adam@21:                     OpenCtl : transaction unit -> xml (body ++ ctx) [] [],
adam@21:                     CloseCtl : transaction unit -> xml (body ++ ctx) [] []}
kkallio@8: 
adam@20: val defaultFormat [body ~ []] =
adam@20:     {FormatPanel = fn ctl panel => <xml>{ctl}{panel}</xml>,
adam@20:      OpenCtl = fn behaviour => <xml><button value="Open" onclick={behaviour}/></xml>,
adam@20:      CloseCtl = fn behaviour => <xml><button value="Close" onclick={behaviour}/></xml>}
kkallio@8:                     
adam@20: con togglePanel t ctx = {PanelState : source panelState,
adam@20:                          FormatCtl : formatCtl ctx,
adam@20:                          Content : t}
kkallio@8: 
kkallio@8: open Gui
kkallio@8: 
adam@20: fun create [t ::: Type] [ctx ::: {Unit}] (f : formatCtl ctx) (content : t) (startOpen : bool) : transaction (togglePanel t ctx) =
kkallio@8:     state <- source (if startOpen then Open else Closed);
kkallio@8: 
kkallio@8:     return {PanelState = state,
adam@20:             FormatCtl = @f,
kkallio@8:             Content = content}
kkallio@8: 
adam@20: fun render [t ::: Type] [ctx ::: {Unit}] (_ : gui t ctx) [body ~ ctx] (panel : togglePanel t ctx) =
kkallio@8:     let
adam@20:         val format = panel.FormatCtl !
adam@20:         val openCtl = format.CloseCtl (set panel.PanelState Closed)
adam@20:         val closeCtl = format.OpenCtl (set panel.PanelState Open)
kkallio@8: 
kkallio@8:         val content = toXml panel.Content
kkallio@8:     in
adam@20:         format.FormatPanel
kkallio@8:             <xml>
kkallio@8:               <dyn signal={c <- signal panel.PanelState;
kkallio@8:                            return
kkallio@8:                                (case c of
kkallio@8:                                     Open => <xml>{openCtl}</xml>
kkallio@8:                                   | Closed => <xml>{closeCtl}</xml>)
kkallio@8:                           }/>
kkallio@8:             </xml>
kkallio@8: 
kkallio@8:             <xml>
kkallio@8:               <dyn signal={c <- signal panel.PanelState;
kkallio@8:                            return
kkallio@8:                                (case c of
kkallio@8:                                     Open => <xml>{content}</xml>
kkallio@8:                                   | Closed => <xml/>)
kkallio@8:                           }/>
kkallio@8:             </xml>
kkallio@8:     end
kkallio@8: 
adam@20: fun gui_togglePanel [t ::: Type] [ctx ::: {Unit}] (g : gui t ctx) = mkGui (@render g)