1 {-# LANGUAGE RecordWildCards, ExistentialQuantification #-}
6 Color, Rect(..), Point(..),
11 import qualified Graphics.UI.Gtk as Gtk
12 import Graphics.UI.Gtk (AttrOp(..)) -- For the := constructor
13 import qualified Graphics.Rendering.Cairo as Cairo
14 import qualified Graphics.UI.Gtk.Gdk.EventM as EventM
16 import Control.Monad.Trans -- for liftIO
18 import Control.Applicative
23 -- | A rectangle in two dimensional space
31 data Point = Point !Int !Int deriving (Show, Eq)
33 -- A color, with RGB values from 0 to 1
34 data Color = Color Double Double Double deriving (Show, Eq)
36 -- Create a Color from Red, Green and Blue values. The inputs should be
37 -- between 0 and 255 (inclusive).
38 rgb :: Int -> Int -> Int -> Color
39 rgb r g b = Color (conv r) (conv g) (conv b)
40 where conv = (/256) . fromIntegral
42 -- | Some predefined colours
46 white = rgb 0xff 0xff 0xff
48 -- | Helper functions for creating a Point
49 point, pt :: Int -> Int -> Point
54 = GfxLines Color [Point] -- coloured line through a list of points
55 | GfxPolygon Color [Point] -- filled polygon of given colour
56 | GfxPicture FilePath Point -- shows a picture
57 | GfxText Color Point String -- coloured string on position Point
58 | GfxRectangle Color Rect -- filled rectangle of given colour
59 | GfxEllipse Color Rect -- ellipse within given rectangle
60 | GfxDisc Color Rect -- filled ellipse within given rectangle
61 | GfxClear -- clears the graphical window
63 | GfxFont String Int -- changes to fontname of given size
64 | WinPrompt String String String -- pops up a window with an edit field
65 -- | WinFilePrompt Bool
66 | WinMenu [(String,[String])] -- adds a menu list to the graphical window
67 | WinTitle String -- gives a title to the graphical window
68 | FRead String -- read file with a given name
69 | FWrite String String -- writes a text file with a given filename
70 | ReqQuit -- quits the graphical system
74 = KeyIn Char -- touched key with given character
75 | MouseDoubleClick Point -- mouse event on position Point
76 | MouseDragged Point -- ibid
77 | MouseDown Point -- ibid
78 | MouseUp Point -- ibid
79 | MenuItem String String -- selected item from WinMenu with a given name
80 | PromptResponse String String String -- response to WinPrompt request
81 | FileContents String String -- response to FRead request
84 type TinaStep s = s -> Response -> (s,[Request])
85 data TinaProgram = forall s. Main
87 , initialRequests :: [Request]
88 , eventHandler :: TinaStep s
95 , initialRequests = [GfxText red (pt 0 0) "foo", GfxText blue (pt 100 100) "bar"]
96 , eventHandler = \s e -> (s+1,[GfxText green (pt 50 50) $ show (s,e)])
101 data IState = forall s. IS
102 { window :: Gtk.Window
103 , buffer :: IORef Cairo.Surface
104 , postponed :: IORef [Request]
105 , usrState :: IORef s
106 , usrProg :: TinaStep s
109 processPostponed :: IState -> IO ()
110 processPostponed s@IS {..} = do
111 ps <- readIORef postponed
112 unless (null ps) $ do
113 writeIORef postponed (tail ps)
114 rs <- handle s (head ps)
115 mapM (stepUserProgram s) rs
118 post s r = stepUserProgram s r >> processPostponed s
120 stepUserProgram :: IState -> Response -> IO ()
121 stepUserProgram IS {..} r = do
122 state <- readIORef usrState
123 let (state',reqs) = usrProg state r
124 writeIORef usrState state'
125 readIORef postponed >>= writeIORef postponed . (++ reqs)
127 handle :: IState -> Request -> IO [Response]
128 handle s@IS {..} r = do
129 resps <- maybe (fail $ "No handler for request " ++ show r) id $
130 fmap (>> return []) (gfxHandler s r <|> winHandler s r <|> miscHandler s r)
133 runTina :: TinaProgram -> IO ()
134 runTina Main {..} = do
135 usrState <- newIORef initialState
136 postponed <- newIORef (GfxText (rgb 0 0 0) (pt 50 50) "foo" : GfxClear :initialRequests)
137 let state = IS { window = undefined, buffer = undefined, usrProg = eventHandler, .. }
138 runGUI windowWidth windowHeight state
140 runGUI :: Int -> Int -> IState -> IO ()
141 runGUI w h (IS { .. }) = do
145 -- Create a window, which will make the mainloop terminated when
147 window <- Gtk.windowNew
149 Gtk.set window [ Gtk.containerBorderWidth := 10
150 , Gtk.windowTitle := "FP Practicum"
151 , Gtk.windowDefaultWidth := w
152 , Gtk.windowDefaultHeight := h
154 Gtk.onDestroy window Gtk.mainQuit
156 -- Create a buffer to draw on (name the actual buffer buffer', so we
157 -- can use IS { .. } syntax below to pack the state. Using a record update
158 -- wouldn't work, probably because Cairo.Surface contains an existential
160 -- We put the buffer in an IORef, so we can change it for a new one
161 -- later on (on window resizes).
162 buffer' <- Cairo.createImageSurface Cairo.FormatARGB32 w h
163 buffer <- newIORef buffer'
165 -- Register the expose event
166 Gtk.on window Gtk.exposeEvent $ onExpose buffer
169 let state = IS { .. }
171 -- Process any initial requests
172 processPostponed state
174 -- Show the window and start the Gtk mainloop.
175 Gtk.widgetShowAll window
179 -- | Copy the given surface to the exposed window on an expose event.
180 onExpose :: IORef Cairo.Surface -> EventM.EventM EventM.EExpose Bool
182 current_buffer <- liftIO $ readIORef buffer
183 dw <- EventM.eventWindow
184 -- Copy the buffer to the window
185 liftIO $ Gtk.renderWithDrawable dw $ do
186 Cairo.setSourceSurface current_buffer 0 0
188 return True -- No clue what this means
191 runGUI s IS {..} = do
193 [ text := "FP Practicum"
196 buffer <- memoryDCCreate
197 bitmapCreateEmpty s 24 >>= memoryDCSelectObject buffer
198 withBrushStyle (BrushStyle BrushSolid white) (dcSetBackground buffer)
201 [ fontFace := "Courier New"
203 , brushColor := rgb 0 0 0
204 , brushKind := BrushSolid
205 , penColor := rgb 0 0 0
206 , penKind := PenSolid
208 sPanel <- panel sFrame [ size := s ]
211 [ on paint := onPaint state
212 , on doubleClick := post state . MouseDoubleClick
213 , on click := post state . MouseDown
214 , on drag := post state . MouseDragged
215 , on unclick := post state . MouseUp
216 , on anyKey := transKey (post state . KeyIn)
219 [ on closing := sFrame `set` [ visible := False ] >> wxcAppExit
220 , on anyKey := transKey (post state . KeyIn)
221 , layout := widget sPanel
223 windowSetFocus sFrame
224 processPostponed state
225 onPaint :: IState -> DC a -> Rect -> IO ()
226 onPaint IS {..} dest va = do
227 dcBlit dest va buffer (Point 0 0) wxCOPY False >> return ()
229 transKey :: (Char -> IO ()) -> Key -> IO ()
230 transKey prod (KeyChar c) = prod c
231 transKey prod KeySpace = prod ' '
232 transKey prod KeyEscape = prod '\ESC'
233 transKey prod KeyReturn = prod '\n'
234 transKey prod KeyTab = prod '\t'
235 transKey _ _ = return ()
239 -- | Handlers for various requests.
240 miscHandler, winHandler, gfxHandler :: IState -> Request -> Maybe (IO ())
242 miscHandler s@IS {..} (FRead fn ) = Just $ readFile fn >>= post s . FileContents fn
243 miscHandler IS {..} (FWrite fn cnts) = Just $ writeFile fn cnts
244 miscHandler IS {..} ReqQuit = Just $ putStrLn "Quiting" >> wxcAppExit
246 miscHandler IS {..} _ = Nothing
249 winHandler s@IS {..} (WinPrompt st1 st2 st3) = Just $ textDialog sFrame st1 st2 st3 >>= post s . PromptResponse st1 st2
250 winHandler IS {..} (WinTitle st) = Just $ sFrame `set` [text := st]
251 winHandler s@IS {..} (WinMenu ms) = Just $ mkMenu >>= \ms' -> sFrame `set` [menuBar := ms']
255 p <- menuPane [ text := name ]
258 i <- menuItem p [ text := item ]
259 sFrame `set` [on (menu i) := post s (MenuItem name item)]
262 | (name,items) <- ms ]
264 winHandler _ _ = Nothing
266 gfxHandler s req = case gfxHandler' req of
268 Just render -> Just $ do
269 buf <- readIORef (buffer s)
270 Cairo.renderWith buf render
271 Gtk.widgetQueueDraw (window s)
274 gfxHandler IS {..} (GfxLines col ps) = Just $ polyline buffer ps [penColor := col] >> dirtyPts sPanel ps
275 gfxHandler IS {..} (GfxPolygon col ps) = Just $ polygon buffer ps [penColor := col, brushColor := col] >> dirtyPts sPanel ps
276 gfxHandler IS {..} (GfxText col xy st) = Just $ drawText buffer st xy [textColor := col] >> getTextExtent buffer st >>= dirtyRect' sPanel xy
277 gfxHandler IS {..} (GfxRectangle col rt) = Just $ drawRect buffer rt [penColor := col, brushColor := col] >> dirtyRect sPanel rt
278 gfxHandler IS {..} (GfxEllipse col rt) = Just $ ellipse buffer rt [penColor := col, brushKind := BrushTransparent] >> dirtyRect sPanel rt
279 gfxHandler IS {..} (GfxDisc col rt) = Just $ ellipse buffer rt [penColor := col, brushColor := col] >> dirtyRect sPanel rt
280 gfxHandler IS {..} (GfxFont st sz) = Just $ buffer `set` [ fontSize := sz, fontFace := st ]
281 gfxHandler IS {..} (GfxPicture fd pt) = Just $ bitmapCreateFromFile fd >>= \bm -> drawBitmap buffer bm pt False [] >> bitmapGetSize bm >>= dirtyRect' sPanel pt
283 -- | Helper function for gfxHanlder
284 gfxHandler' :: Request -> Maybe (Cairo.Render ())
285 gfxHandler' (GfxText col (Point x y) st) = Just $ do
286 -- Set the source color, move to the requested position and draw the
289 Cairo.moveTo (fromIntegral x) (fromIntegral y)
291 gfxHandler' GfxClear = Just $ do
292 -- Set the source to white and paint the entire surface with it
293 Cairo.setSourceRGB 1 1 1
295 gfxHandler' _ = Nothing
297 -- | Sets the source to a pattern fill of the given color
298 setSourceColor :: Color -> Cairo.Render ()
299 setSourceColor (Color r g b) =
300 Cairo.setSourceRGB r g b
303 dirtyPts :: Window a -> [Point] -> IO ()
304 dirtyPts dc ps = dirtyRect' dc (pt x y) Size {..}
310 sizeW = maximum xs - x
311 sizeH = maximum ys - y
313 dirtyRect' :: Window a -> Point -> Size -> IO ()
314 dirtyRect' dc Point {..} Size {..} = dirtyRect dc $ Rect pointX pointY sizeW sizeH
316 dirtyRect :: Window a -> Rect -> IO ()
317 dirtyRect dc rect = windowRefreshRect dc False (grow 2 rect)
319 rectanglify :: Point -> Size -> Rect
320 rectanglify Point {..} Size {..} = Rect pointX pointY sizeW sizeH
322 grow :: Int -> Rect -> Rect
323 grow n Rect {..} = Rect
324 { rectLeft = rectLeft - n
325 , rectTop = rectTop - n
326 , rectWidth = rectWidth + 2 * n
327 , rectHeight = rectHeight + 2 * n }