DoubleMenuAniamtion.elm

-- Create a helper function that organizes your animations
-- You might consider listing the literal animations here.  
-- Meaning embed "Animation.interrupt..." instead of referring it to the value closeMenuStyle.
-- This is probably the only place those animation definitions are going to live and 
-- it's nice to have one place to go to understand whats going on.
runAnimation menu model =
    case menu of
        UserMenu Open ->
            { model
                | navbarUserToggleStyle = closeToggleStyle model.navbarUserToggleStyle
                , navbarUserMenuStyle = closeMenuStyle model.navbarUserMenuStyle
            }
                

        UserMenu Close ->
            { model
                | navbarUserToggleStyle = openToggleStyle model.navbarUserToggleStyle
                , navbarUserMenuStyle = openMenuStyle model.navbarUserMenuStyle
            }
                

        AddMenu Open ->
            { model
                | navbarAddToggleStyle = openToggleStyle model.navbarAddToggleStyle
                , navbarAddMenuStyle = openMenuStyle model.navbarAddMenuStyle
            }
                

        AddMenu Close ->
            { model
                | navbarAddToggleStyle = closeToggleStyle model.navbarAddToggleStyle
                , navbarAddMenuStyle = closeMenuStyle model.navbarAddMenuStyle
            }
                
-- A convenience function that we'll use in a moment
noCmd : Model -> (Model, Cmd Msg)
noCmd model = model ! []


-- The revised Update funciton
         ToggleNavbarDropdown menu ->
             let
                 maybeNewMenu =
                     if model.openNavbarDropdownMenu == menu then
                         Nothing
                     else
                         menu
             in
                 case maybeNewMenu of
                     Just NavbarAddMenu ->
                        model
                          |> runAnimation UserMenu Open
                          |> runAnimation AddMenu Closed
                          |> noCmd

                     Just NavbarUserMenu ->
                         model
                          |> runAnimation UserMenu Open
                          |> runAnimation AddMenu Closed
                          |> noCmd

                     Nothing ->
                         model
                          |> runAnimation UserMenu Closed
                          |> runAnimation AddMenu Closed
                          |> noCmd