module tut12_1

// ********************************************************************************
// Clean tutorial example program.
//
// This program creates a dialogue to display and change the current content
// of the clipboard.
// ********************************************************************************

import StdEnv, StdIO

Start :: *World -> *World
Start world
# (showId, world)   = openId world
# (setId, world)    = openId world
= startProcesses (Process NDI Void (initialise showId setId) []) world

initialise showId setId pst
# (error, pst)      = openDialog Void clipView pst
| error <> NoError  = closeProcess pst
| otherwise         = pst
where
    clipView        = Dialog "Clipboard Editor" (showClip :+: setClip :+: quit) []

    showClip        = EditControl "" width nrlines [ControlId showId, ControlPos (Left, zero), ControlSelectState Unable] :+:
                        ButtonControl "Show" [ControlFunction (noLS show)]
    setClip         = EditControl "" width nrlines [ControlId setId, ControlPos (Left, zero)] :+:
                        ButtonControl "Set" [ControlFunction (noLS set)]
    quit            = ButtonControl "Quit" [ControlFunction (noLS closeProcess), ControlPos (Center, zero)]

    width = PixelWidth (hmm 50.0)
    nrlines = 4

    show pst
    # (cont, pst)   = getClipboard pst
    # text          = getString cont
    = appPIO (setControlText showId text) pst

    set pst
    # (wst, pst)    = accPIO (getParentWindow showId) pst
    # text          = fromJust (snd (getControlText setId (fromJust wst)))
    = setClipboard [toClipboard text] pst

    getString :: [ClipboardItem] -> String
    getString []    = ""
    getString [clip:clips]
    # item          = fromClipboard clip
    | isNothing item = getString clips
    | otherwise     = fromJust item