@@ -2,41 +2,148 @@
22Module: Reflex.Vty.Widget
33Description: Basic set of widgets and building blocks for reflex-vty applications
44-}
5−{-# Language UndecidableInstances #-}
6−
7−module Reflex.Vty.Widget where
5+{-# LANGUAGE FlexibleContexts #-}
6+{-# LANGUAGE FlexibleInstances #-}
7+{-# LANGUAGE FunctionalDependencies #-}
8+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
9+{-# LANGUAGE LambdaCase #-}
10+{-# LANGUAGE MultiParamTypeClasses #-}
11+{-# LANGUAGE OverloadedStrings #-}
12+{-# LANGUAGE RankNTypes #-}
13+{-# LANGUAGE RecursiveDo #-}
14+{-# LANGUAGE ScopedTypeVariables #-}
15+{-# LANGUAGE StandaloneDeriving #-}
16+{-# LANGUAGE TypeFamilies #-}
17+{-# LANGUAGE UndecidableInstances #-}
18+module Reflex.Vty.Widget
19+ ( VtyWidgetCtx(..)
20+ , VtyWidget(..)
21+ , VtyWidgetOut(..)
22+ , runVtyWidget
23+ , mainWidget
24+ , mainWidgetWithHandle
25+ , HasDisplaySize(..)
26+ , displayWidth
27+ , displayHeight
28+ , HasFocus(..)
29+ , HasVtyInput(..)
30+ , Region(..)
31+ , regionSize
32+ , regionBlankImage
33+ , Drag(..)
34+ , drag
35+ , MouseDown(..)
36+ , MouseUp(..)
37+ , mouseDown
38+ , mouseUp
39+ , pane
40+ , modifyImages
41+ , tellImages
42+ , tellShutdown
43+ , splitV
44+ , splitVDrag
45+ , box
46+ , boxStatic
47+ , text
48+ , display
49+ , hyphenBoxStyle
50+ , singleBoxStyle
51+ , roundedBoxStyle
52+ , thickBoxStyle
53+ , doubleBoxStyle
54+ , fill
55+ , hRule
56+ ) where
857
958import Control.Applicative (liftA2)
1059import Control.Monad.Fix (MonadFix)
11−import Control.Monad.IO.Class (MonadIO)
12−import Control.Monad.Morph
13−import Control.Monad.NodeId
14−import Control.Monad.Reader (ReaderT, ask, local, runReaderT)
15−import Control.Monad.Ref
16−import Control.Monad.Trans (MonadTrans, lift)
17−import Data.Set (Set)
18−import qualified Data.Set as Set
60+import Control.Monad.Trans (lift)
61+import Control.Monad.Trans.Reader (ReaderT, runReaderT, asks, ask)
62+import Control.Monad.Trans.Writer (WriterT, runWriterT, censor, tell)
63+import Control.Monad.Writer.Adjustable ()
64+import Data.Default (Default(..))
65+import Data.Text (Text)
66+import qualified Data.Text as T
67+import qualified Data.Text.Zipper as TZ
1968import Graphics.Vty (Image)
2069import qualified Graphics.Vty as V
2170import Reflex
22−import Reflex.Class ()
23−import Reflex.Host.Class (MonadReflexCreateTrigger)
71+import Reflex.Class.Switchable
72+import Reflex.NotReady.Class
73+import Reflex.NotReady.Class.Orphans ()
74+
2475import Reflex.Vty.Host
2576
26−-- * Running a vty application
77+-- | The context within which a 'VtyWidget' runs
78+data VtyWidgetCtx t = VtyWidgetCtx
79+ { _vtyWidgetCtx_size :: Dynamic t (Int,Int)
80+ -- ^ The width and height of the region allocated to the widget.
81+ , _vtyWidgetCtx_focus :: Dynamic t Bool
82+ -- ^ Whether the widget should behave as if it has focus for keyboard input.
83+ , _vtyWidgetCtx_input :: Event t VtyEvent
84+ -- ^ User input events that the widget's parent chooses to share. These will generally
85+ -- be filtered for relevance:
86+ -- * Keyboard inputs are restricted to focused widgets
87+ -- * Mouse inputs are restricted to the region in which the widget resides and are
88+ -- translated into its internal coordinates.
89+ }
90+
91+-- | The output of a 'VtyWidget'
92+data VtyWidgetOut t = VtyWidgetOut
93+ { _vtyWidgetOut_images :: Behavior t [Image]
94+ -- ^ The visual output of the 'VtyWidget'
95+ , _vtyWidgetOut_shutdown :: Event t ()
96+ }
97+
98+instance Reflex t => Semigroup (VtyWidgetOut t) where
99+ wo <> wo' = VtyWidgetOut
100+ { _vtyWidgetOut_images = _vtyWidgetOut_images wo <> _vtyWidgetOut_images wo'
101+ , _vtyWidgetOut_shutdown = _vtyWidgetOut_shutdown wo <> _vtyWidgetOut_shutdown wo'
102+ }
103+
104+instance (Reflex t) => Monoid (VtyWidgetOut t) where
105+ mempty = VtyWidgetOut mempty mempty
106+ mappend wo wo' = wo <> wo'
107+
108+instance Reflex t => Switchable t (VtyWidgetOut t) where
109+ switching e0 e = do
110+ shutdown <- switching (_vtyWidgetOut_shutdown e0) $ fmap _vtyWidgetOut_shutdown e
111+ images <- switching (_vtyWidgetOut_images e0) $ fmap _vtyWidgetOut_images e
112+ return $ VtyWidgetOut
113+ { _vtyWidgetOut_images = images
114+ , _vtyWidgetOut_shutdown = shutdown
115+ }
116+
117+-- | A widget that can read its context and produce image output
118+newtype VtyWidget t m a = VtyWidget
119+ { unVtyWidget :: WriterT (VtyWidgetOut t) (ReaderT (VtyWidgetCtx t) m) a
120+ }
121+ deriving (Functor, Applicative, Monad, MonadSample t, MonadHold t, MonadFix, NotReady t)
122+
123+instance (PostBuild t m, Reflex t) => PostBuild t (VtyWidget t m) where
124+ getPostBuild = VtyWidget $ lift getPostBuild
125+
126+instance (Adjustable t m, MonadHold t m, Reflex t) => Adjustable t (VtyWidget t m) where
127+ runWithReplace a0 a' = VtyWidget $ runWithReplace (unVtyWidget a0) $ fmap unVtyWidget a'
128+ traverseIntMapWithKeyWithAdjust f dm0 dm' = VtyWidget $
129+ traverseIntMapWithKeyWithAdjust (\k v -> unVtyWidget (f k v)) dm0 dm'
130+ traverseDMapWithKeyWithAdjust f dm0 dm' = VtyWidget $ do
131+ traverseDMapWithKeyWithAdjust (\k v -> unVtyWidget (f k v)) dm0 dm'
132+ traverseDMapWithKeyWithAdjustWithMove f dm0 dm' = VtyWidget $ do
133+ traverseDMapWithKeyWithAdjustWithMove (\k v -> unVtyWidget (f k v)) dm0 dm'
134+
135+-- | Runs a 'VtyWidget' with a given context
136+runVtyWidget
137+ :: Reflex t
138+ => VtyWidgetCtx t
139+ -> VtyWidget t m a
140+ -> m (a, VtyWidgetOut t)
141+runVtyWidget ctx w = runReaderT (runWriterT (unVtyWidget w)) ctx
27142
28−-- | Sets up the top-level context for a vty widget and runs it with that context
143+-- | Sets up the top-level context for a 'VtyWidget' and runs it with that context
29144mainWidgetWithHandle
30145 :: V.Vty
31− -> (forall t m.
32− ( MonadVtyApp t m
33− , HasImageWriter t m
34− , MonadNodeId m
35− , HasDisplayRegion t m
36− , HasFocusReader t m
37− , HasInput t m
38− , HasTheme t m
39− ) => m (Event t ()))
146+ -> (forall t m. MonadVtyApp t m => VtyWidget t m ())
40147 -> IO ()
41148mainWidgetWithHandle vty child =
42149 runVtyAppWithHandle vty $ \dr0 inp -> do
@@ -46,178 +153,71 @@ mainWidgetWithHandle vty child =
46153 let inp' = fforMaybe inp $ \case
47154 V.EvResize {} -> Nothing
48155 x -> Just x
49− (shutdown, images) <- runThemeReader (constant V.defAttr) $
50− runFocusReader (pure True) $
51− runDisplayRegion (fmap (\(w, h) -> Region 0 0 w h) size) $
52− runImageWriter $
53− runNodeIdT $
54− runInput inp' $ do
55− tellImages . ffor (current size) $ \(w, h) -> [V.charFill V.defAttr ' ' w h]
56− child
156+ let ctx = VtyWidgetCtx
157+ { _vtyWidgetCtx_size = size
158+ , _vtyWidgetCtx_input = inp'
159+ , _vtyWidgetCtx_focus = constDyn True
160+ }
161+ ((), wo) <- runVtyWidget ctx $ do
162+ tellImages . ffor (current size) $ \(w, h) -> [V.charFill V.defAttr ' ' w h]
163+ child
57164 return $ VtyResult
58− { _vtyResult_picture = fmap (V.picForLayers . reverse) images
59− , _vtyResult_shutdown = shutdown
165+ { _vtyResult_picture = fmap (V.picForLayers . reverse) (_vtyWidgetOut_images wo)
166+ , _vtyResult_shutdown = _vtyWidgetOut_shutdown wo
60167 }
61168
62−-- | The output of a vty widget
63−data VtyWidgetOut t = VtyWidgetOut
64− { _vtyWidgetOut_shutdown :: Event t ()
65− }
66−
67169-- | Like 'mainWidgetWithHandle', but uses a default vty configuration
68170mainWidget
69− :: (forall t m.
70− ( MonadVtyApp t m
71− , HasImageWriter t m
72− , MonadNodeId m
73− , HasDisplayRegion t m
74− , HasFocusReader t m
75− , HasTheme t m
76− , HasInput t m
77− ) => m (Event t ()))
171+ :: (forall t m. MonadVtyApp t m => VtyWidget t m ())
78172 -> IO ()
79173mainWidget child = do
80174 vty <- getDefaultVty
81175 mainWidgetWithHandle vty child
82176
83−-- * Input Events
177+-- | A class for things that know their own display size dimensions
178+class (Reflex t, Monad m) => HasDisplaySize t m | m -> t where
179+ displaySize :: m (Dynamic t (Int, Int))
180+
181+instance (Reflex t, Monad m) => HasDisplaySize t (VtyWidget t m) where
182+ displaySize = VtyWidget . lift $ asks _vtyWidgetCtx_size
183+
184+-- | Retrieve the display width (columns)
185+displayWidth :: HasDisplaySize t m => m (Dynamic t Int)
186+displayWidth = fmap fst <$> displaySize
187+
188+-- | Retrieve the display height (rows)
189+displayHeight :: HasDisplaySize t m => m (Dynamic t Int)
190+displayHeight = fmap snd <$> displaySize
84191
85192-- | A class for things that can receive vty events as input
86−class HasInput t m | m -> t where
193+class HasVtyInput t m | m -> t where
87194 input :: m (Event t VtyEvent)
88− default input :: (f m' ~ m, Monad m', MonadTrans f, HasInput t m') => m (Event t VtyEvent)
89− input = lift input
90− -- | User input events that the widget's parent chooses to share. These will generally
91− -- be filtered for relevance.
92− localInput :: (Event t VtyEvent -> Event t VtyEvent) -> m a -> m a
93− default localInput :: (f m' ~ m, Monad m', MFunctor f, HasInput t m') => (Event t VtyEvent -> Event t VtyEvent) -> m a -> m a
94− localInput f = hoist (localInput f)
95−
96−instance (Reflex t, Monad m) => HasInput t (Input t m) where
97− input = Input ask
98− localInput f (Input m) = Input $ local f m
99−
100−-- | A widget that can receive input events. See 'Graphics.Vty.Event'
101−newtype Input t m a = Input
102− { unInput :: ReaderT (Event t VtyEvent) m a
103− } deriving
104− ( Functor
105− , Applicative
106− , Monad
107− , MonadSample t
108− , MonadHold t
109− , MonadFix
110− , MonadIO
111− , MonadRef
112− )
113−
114−instance (Adjustable t m, MonadHold t m, Reflex t) => Adjustable t (Input t m) where
115− runWithReplace a0 a' = Input $ runWithReplace (unInput a0) $ fmap unInput a'
116− traverseIntMapWithKeyWithAdjust f dm0 dm' = Input $
117− traverseIntMapWithKeyWithAdjust (\k v -> unInput (f k v)) dm0 dm'
118− traverseDMapWithKeyWithAdjust f dm0 dm' = Input $ do
119− traverseDMapWithKeyWithAdjust (\k v -> unInput (f k v)) dm0 dm'
120− traverseDMapWithKeyWithAdjustWithMove f dm0 dm' = Input $ do
121− traverseDMapWithKeyWithAdjustWithMove (\k v -> unInput (f k v)) dm0 dm'
122−
123−deriving instance MonadReflexCreateTrigger t m => MonadReflexCreateTrigger t (Input t m)
124−deriving instance NotReady t m => NotReady t (Input t m)
125−deriving instance PerformEvent t m => PerformEvent t (Input t m)
126−deriving instance PostBuild t m => PostBuild t (Input t m)
127−deriving instance TriggerEvent t m => TriggerEvent t (Input t m)
128−instance HasImageWriter t m => HasImageWriter t (Input t m)
129−instance HasDisplayRegion t m => HasDisplayRegion t (Input t m)
130−instance HasFocusReader t m => HasFocusReader t (Input t m)
131−
132−instance MonadTrans (Input t) where
133− lift f = Input $ lift f
134−
135−instance MFunctor (Input t) where
136− hoist f = Input . hoist f . unInput
137−
138−instance MonadNodeId m => MonadNodeId (Input t m)
139−
140−-- | Runs an 'Input' with a given context
141−runInput
142− :: Reflex t
143− => Event t VtyEvent
144− -> Input t m a
145− -> m a
146−runInput e w = runReaderT (unInput w) e
147−
148−-- ** Filtering input
149−
150−-- | Type synonym for a key and modifier combination
151−type KeyCombo = (V.Key, [V.Modifier])
152−
153−-- | Emits an event that fires on a particular key press (without modifiers)
154−key :: (Monad m, Reflex t, HasInput t m) => V.Key -> m (Event t KeyCombo)
155−key = keyCombos . Set.singleton . (,[])
156−
157−-- | Emits an event that fires on particular key presses (without modifiers)
158−keys :: (Monad m, Reflex t, HasInput t m) => [V.Key] -> m (Event t KeyCombo)
159−keys = keyCombos . Set.fromList . fmap (,[])
160−
161−-- | Emit an event that fires whenever the provided key combination occurs
162−keyCombo
163− :: (Reflex t, Monad m, HasInput t m)
164− => KeyCombo
165− -> m (Event t KeyCombo)
166−keyCombo = keyCombos . Set.singleton
167−
168−-- | Emit an event that fires whenever any of the provided key combinations occur
169−keyCombos
170− :: (Reflex t, Monad m, HasInput t m)
171− => Set KeyCombo
172− -> m (Event t KeyCombo)
173−keyCombos ks = do
174− i <- input
175− return $ fforMaybe i $ \case
176− V.EvKey k m -> if Set.member (k, m) ks
177− then Just (k, m)
178− else Nothing
179− _ -> Nothing
180195
181−-- | Filter the keyboard input that a child widget may receive
182−filterKeys :: (Reflex t, HasInput t m) => (KeyCombo -> Bool) -> m a -> m a
183−filterKeys f x = localInput (ffilter (\case
184− V.EvKey k mods -> f (k, mods)
185− _ -> True)) x
186−
187−-- | Filter mouse input events based on whether they target a particular region
188−-- and translate them to the internal coordinate system of that region.
189−--
190−-- NB: Non-mouse events are passed through unfiltered and unchanged
191−mouseInRegion :: Region -> VtyEvent -> Maybe VtyEvent
192−mouseInRegion (Region l t w h) e = case e of
193− V.EvMouseDown x y btn m -> mouse (\u v -> V.EvMouseDown u v btn m) x y
194− V.EvMouseUp x y btn -> mouse (\u v -> V.EvMouseUp u v btn) x y
195− _ -> Just e
196− where
197− mouse con x y
198− | or [ x < l
199− , y < t
200− , x >= l + w
201− , y >= t + h ] = Nothing
202− | otherwise =
203− Just (con (x - l) (y - t))
204−
205−-- | Filter mouse input outside the current display region and
206−-- all input if the region is not focused
207−inputInFocusedRegion
208− :: (HasDisplayRegion t m, HasFocusReader t m, HasInput t m)
209− => m (Event t VtyEvent)
210−inputInFocusedRegion = do
211− inp <- input
212− reg <- current <$> askRegion
213− foc <- current <$> focus
214− pure $ fmapMaybe id $ attachWith filterInput ((,) <$> reg <*> foc) inp
215− where
216− filterInput (r, f) = \case
217− V.EvKey {} | not f -> Nothing
218− x -> mouseInRegion r x
196+instance (Reflex t, Monad m) => HasVtyInput t (VtyWidget t m) where
197+ input = VtyWidget . lift $ asks _vtyWidgetCtx_input
219198
220−-- * Getting and setting the display region
199+-- | A class for things that can dynamically gain and lose focus
200+class HasFocus t m | m -> t where
201+ focus :: m (Dynamic t Bool)
202+
203+instance (Reflex t, Monad m) => HasFocus t (VtyWidget t m) where
204+ focus = VtyWidget . lift $ asks _vtyWidgetCtx_focus
205+
206+-- | A class for widgets that can produce images to draw to the display
207+class (Reflex t, Monad m) => ImageWriter t m | m -> t where
208+ -- | Send images upstream for rendering
209+ tellImages :: Behavior t [Image] -> m ()
210+
211+instance (Reflex t, Monad m) => ImageWriter t (VtyWidget t m) where
212+ tellImages imgs = VtyWidget $ tell (mempty { _vtyWidgetOut_images = imgs })
213+
214+-- | A class for things that can shut down the vty application
215+class (Reflex t, Monad m) => Shutdown t m where
216+ -- | Signals that the vty application should shut down
217+ tellShutdown :: Event t () -> m ()
218+
219+instance (Reflex t, Monad m) => Shutdown t (VtyWidget t m) where
220+ tellShutdown sd = VtyWidget $ tell (mempty { _vtyWidgetOut_shutdown = sd })
221221
222222-- | A chunk of the display area
223223data Region = Region
@@ -228,293 +228,14 @@ data Region = Region
228228 }
229229 deriving (Show, Read, Eq, Ord)
230230
231−-- | A region that occupies no space.
232−nilRegion :: Region
233−nilRegion = Region 0 0 0 0
234−
235231-- | The width and height of a 'Region'
236232regionSize :: Region -> (Int, Int)
237233regionSize (Region _ _ w h) = (w, h)
238234
239235-- | Produces an 'Image' that fills a region with space characters
240−regionBlankImage :: V.Attr -> Region -> Image
241−regionBlankImage attr r@(Region _ _ width height) =
242− withinImage r $ V.charFill attr ' ' width height
243−
244−-- | A class for things that know their own display size dimensions
245−class (Reflex t, Monad m) => HasDisplayRegion t m | m -> t where
246− -- | Retrieve the display region
247− askRegion :: m (Dynamic t Region)
248− default askRegion :: (f m' ~ m, MonadTrans f, HasDisplayRegion t m') => m (Dynamic t Region)
249− askRegion = lift askRegion
250− -- | Run an action in a local region, by applying a transformation to the region
251− localRegion :: (Dynamic t Region -> Dynamic t Region) -> m a -> m a
252− default localRegion :: (f m' ~ m, Monad m', MFunctor f, HasDisplayRegion t m') => (Dynamic t Region -> Dynamic t Region) -> m a -> m a
253− localRegion f = hoist (localRegion f)
254−
255−-- | Retrieve the display width
256−displayWidth :: HasDisplayRegion t m => m (Dynamic t Int)
257−displayWidth = fmap _region_width <$> askRegion
258−
259−-- | Retrieve the display height
260−displayHeight :: HasDisplayRegion t m => m (Dynamic t Int)
261−displayHeight = fmap _region_height <$> askRegion
262−
263−instance HasDisplayRegion t m => HasDisplayRegion t (ReaderT x m)
264−instance HasDisplayRegion t m => HasDisplayRegion t (BehaviorWriterT t x m)
265−instance HasDisplayRegion t m => HasDisplayRegion t (DynamicWriterT t x m)
266−instance HasDisplayRegion t m => HasDisplayRegion t (EventWriterT t x m)
267−instance HasDisplayRegion t m => HasDisplayRegion t (NodeIdT m)
268−
269−-- | A widget that has access to a particular region of the vty display
270−newtype DisplayRegion t m a = DisplayRegion
271− { unDisplayRegion :: ReaderT (Dynamic t Region) m a }
272− deriving
273− ( Functor
274− , Applicative
275− , Monad
276− , MonadFix
277− , MonadHold t
278− , MonadIO
279− , MonadRef
280− , MonadSample t
281− )
282−
283−instance (Monad m, Reflex t) => HasDisplayRegion t (DisplayRegion t m) where
284− askRegion = DisplayRegion ask
285− localRegion f = DisplayRegion . local f . unDisplayRegion
286−
287−deriving instance MonadReflexCreateTrigger t m => MonadReflexCreateTrigger t (DisplayRegion t m)
288−deriving instance NotReady t m => NotReady t (DisplayRegion t m)
289−deriving instance PerformEvent t m => PerformEvent t (DisplayRegion t m)
290−deriving instance PostBuild t m => PostBuild t (DisplayRegion t m)
291−deriving instance TriggerEvent t m => TriggerEvent t (DisplayRegion t m)
292−instance HasImageWriter t m => HasImageWriter t (DisplayRegion t m)
293−instance HasFocusReader t m => HasFocusReader t (DisplayRegion t m)
294−
295−instance (Adjustable t m, MonadFix m, MonadHold t m) => Adjustable t (DisplayRegion t m) where
296− runWithReplace (DisplayRegion a) e = DisplayRegion $ runWithReplace a $ fmap unDisplayRegion e
297− traverseIntMapWithKeyWithAdjust f m e = DisplayRegion $ traverseIntMapWithKeyWithAdjust (\k v -> unDisplayRegion $ f k v) m e
298− traverseDMapWithKeyWithAdjust f m e = DisplayRegion $ traverseDMapWithKeyWithAdjust (\k v -> unDisplayRegion $ f k v) m e
299− traverseDMapWithKeyWithAdjustWithMove f m e = DisplayRegion $ traverseDMapWithKeyWithAdjustWithMove (\k v -> unDisplayRegion $ f k v) m e
300−
301−instance MonadTrans (DisplayRegion t) where
302− lift = DisplayRegion . lift
303−
304−instance MFunctor (DisplayRegion t) where
305− hoist f = DisplayRegion . hoist f . unDisplayRegion
306−
307−instance MonadNodeId m => MonadNodeId (DisplayRegion t m)
308−
309−-- | Run a 'DisplayRegion' action with a given 'Region'
310−runDisplayRegion
311− :: (Reflex t, Monad m)
312− => Dynamic t Region
313− -> DisplayRegion t m a
314− -> m a
315−runDisplayRegion r = flip runReaderT r . unDisplayRegion
316−
317−-- * Getting focus state
318−
319−-- | A class for things that can dynamically gain and lose focus
320−class (Reflex t, Monad m) => HasFocusReader t m | m -> t where
321− focus :: m (Dynamic t Bool)
322− default focus :: (f m' ~ m, Monad m', MonadTrans f, HasFocusReader t m') => m (Dynamic t Bool)
323− focus = lift focus
324− localFocus :: (Dynamic t Bool -> Dynamic t Bool) -> m a -> m a
325− default localFocus :: (f m' ~ m, Monad m', MFunctor f, HasFocusReader t m') => (Dynamic t Bool -> Dynamic t Bool) -> m a -> m a
326− localFocus f = hoist (localFocus f)
327−
328−instance HasFocusReader t m => HasFocusReader t (ReaderT x m)
329−instance HasFocusReader t m => HasFocusReader t (BehaviorWriterT t x m)
330−instance HasFocusReader t m => HasFocusReader t (DynamicWriterT t x m)
331−instance HasFocusReader t m => HasFocusReader t (EventWriterT t x m)
332−instance HasFocusReader t m => HasFocusReader t (NodeIdT m)
333−
334−-- | A widget that has access to information about whether it is focused
335−newtype FocusReader t m a = FocusReader
336− { unFocusReader :: ReaderT (Dynamic t Bool) m a }
337− deriving
338− ( Functor
339− , Applicative
340− , Monad
341− , MonadFix
342− , MonadHold t
343− , MonadIO
344− , MonadRef
345− , MonadSample t
346− )
347−
348−instance (Monad m, Reflex t) => HasFocusReader t (FocusReader t m) where
349− focus = FocusReader ask
350− localFocus f = FocusReader . local f . unFocusReader
351−
352−deriving instance MonadReflexCreateTrigger t m => MonadReflexCreateTrigger t (FocusReader t m)
353−deriving instance NotReady t m => NotReady t (FocusReader t m)
354−deriving instance PerformEvent t m => PerformEvent t (FocusReader t m)
355−deriving instance PostBuild t m => PostBuild t (FocusReader t m)
356−deriving instance TriggerEvent t m => TriggerEvent t (FocusReader t m)
357−instance HasImageWriter t m => HasImageWriter t (FocusReader t m)
358−
359−instance (Adjustable t m, MonadFix m, MonadHold t m) => Adjustable t (FocusReader t m) where
360− runWithReplace (FocusReader a) e = FocusReader $ runWithReplace a $ fmap unFocusReader e
361− traverseIntMapWithKeyWithAdjust f m e = FocusReader $ traverseIntMapWithKeyWithAdjust (\k v -> unFocusReader $ f k v) m e
362− traverseDMapWithKeyWithAdjust f m e = FocusReader $ traverseDMapWithKeyWithAdjust (\k v -> unFocusReader $ f k v) m e
363− traverseDMapWithKeyWithAdjustWithMove f m e = FocusReader $ traverseDMapWithKeyWithAdjustWithMove (\k v -> unFocusReader $ f k v) m e
364−
365−instance MonadTrans (FocusReader t) where
366− lift = FocusReader . lift
367−
368−instance MFunctor (FocusReader t) where
369− hoist f = FocusReader . hoist f . unFocusReader
370−
371−instance MonadNodeId m => MonadNodeId (FocusReader t m)
372−
373−-- | Run a 'FocusReader' action with the given focus value
374−runFocusReader
375− :: (Reflex t, Monad m)
376− => Dynamic t Bool
377− -> FocusReader t m a
378− -> m a
379−runFocusReader b = flip runReaderT b . unFocusReader
380−
381−-- * "Image" output
382−
383−-- | A class for widgets that can produce images to draw to the display
384−class (Reflex t, Monad m) => HasImageWriter t m | m -> t where
385− -- | Send images upstream for rendering
386− tellImages :: Behavior t [Image] -> m ()
387− default tellImages :: (f m' ~ m, Monad m', MonadTrans f, HasImageWriter t m') => Behavior t [Image] -> m ()
388− tellImages = lift . tellImages
389− -- | Apply a transformation to the images produced by the child actions
390− mapImages :: (Behavior t [Image] -> Behavior t [Image]) -> m a -> m a
391− default mapImages :: (f m' ~ m, Monad m', MFunctor f, HasImageWriter t m') => (Behavior t [Image] -> Behavior t [Image]) -> m a -> m a
392− mapImages f = hoist (mapImages f)
393−
394−-- | A widget that can produce images to draw onto the display
395−newtype ImageWriter t m a = ImageWriter
396− { unImageWriter :: BehaviorWriterT t [Image] m a }
397− deriving
398− ( Functor
399− , Applicative
400− , Monad
401− , MonadFix
402− , MonadHold t
403− , MonadIO
404− , MonadRef
405− , MonadReflexCreateTrigger t
406− , MonadSample t
407− , NotReady t
408− , PerformEvent t
409− , PostBuild t
410− , TriggerEvent t
411− )
412−
413−instance MonadTrans (ImageWriter t) where
414− lift = ImageWriter . lift
415−
416−instance MFunctor (ImageWriter t) where
417− hoist f = ImageWriter . (hoist f) . unImageWriter
418−
419−instance (Adjustable t m, MonadFix m, MonadHold t m) => Adjustable t (ImageWriter t m) where
420− runWithReplace (ImageWriter a) e = ImageWriter $ runWithReplace a $ fmap unImageWriter e
421− traverseIntMapWithKeyWithAdjust f m e = ImageWriter $ traverseIntMapWithKeyWithAdjust (\k v -> unImageWriter $ f k v) m e
422− traverseDMapWithKeyWithAdjust f m e = ImageWriter $ traverseDMapWithKeyWithAdjust (\k v -> unImageWriter $ f k v) m e
423− traverseDMapWithKeyWithAdjustWithMove f m e = ImageWriter $ traverseDMapWithKeyWithAdjustWithMove (\k v -> unImageWriter $ f k v) m e
424−
425−instance HasImageWriter t m => HasImageWriter t (ReaderT x m)
426−instance HasImageWriter t m => HasImageWriter t (BehaviorWriterT t x m)
427−instance HasImageWriter t m => HasImageWriter t (DynamicWriterT t x m)
428−instance HasImageWriter t m => HasImageWriter t (EventWriterT t x m)
429−instance HasImageWriter t m => HasImageWriter t (NodeIdT m)
430−
431−instance (Monad m, Reflex t) => HasImageWriter t (ImageWriter t m) where
432− tellImages = ImageWriter . tellBehavior
433− mapImages f (ImageWriter x) = ImageWriter $ do
434− (a, images) <- lift $ runBehaviorWriterT x
435− tellBehavior $ f images
436− pure a
437−
438−instance HasDisplayRegion t m => HasDisplayRegion t (ImageWriter t m)
439−instance HasFocusReader t m => HasFocusReader t (ImageWriter t m)
440−
441−-- | Run a widget that can produce images
442−runImageWriter
443− :: (Reflex t, Monad m)
444− => ImageWriter t m a
445− -> m (a, Behavior t [Image])
446−runImageWriter = runBehaviorWriterT . unImageWriter
447−
448−-- * Theming
449−
450−-- | A class for things that can be visually styled
451−class (Reflex t, Monad m) => HasTheme t m | m -> t where
452− theme :: m (Behavior t V.Attr)
453− default theme :: (f m' ~ m, Monad m', MonadTrans f, HasTheme t m') => m (Behavior t V.Attr)
454− theme = lift theme
455− localTheme :: (Behavior t V.Attr -> Behavior t V.Attr) -> m a -> m a
456− default localTheme :: (f m' ~ m, Monad m', MFunctor f, HasTheme t m') => (Behavior t V.Attr -> Behavior t V.Attr) -> m a -> m a
457− localTheme f = hoist (localTheme f)
458−
459−instance HasTheme t m => HasTheme t (ReaderT x m)
460−instance HasTheme t m => HasTheme t (BehaviorWriterT t x m)
461−instance HasTheme t m => HasTheme t (DynamicWriterT t x m)
462−instance HasTheme t m => HasTheme t (EventWriterT t x m)
463−instance HasTheme t m => HasTheme t (NodeIdT m)
464−instance HasTheme t m => HasTheme t (Input t m)
465−instance HasTheme t m => HasTheme t (ImageWriter t m)
466−instance HasTheme t m => HasTheme t (DisplayRegion t m)
467−instance HasTheme t m => HasTheme t (FocusReader t m)
468−
469−-- | A widget that has access to theme information
470−newtype ThemeReader t m a = ThemeReader
471− { unThemeReader :: ReaderT (Behavior t V.Attr) m a }
472− deriving
473− ( Functor
474− , Applicative
475− , Monad
476− , MonadFix
477− , MonadHold t
478− , MonadIO
479− , MonadRef
480− , MonadSample t
481− )
482−
483−instance (Monad m, Reflex t) => HasTheme t (ThemeReader t m) where
484− theme = ThemeReader ask
485− localTheme f = ThemeReader . local f . unThemeReader
486−
487−deriving instance MonadReflexCreateTrigger t m => MonadReflexCreateTrigger t (ThemeReader t m)
488−deriving instance NotReady t m => NotReady t (ThemeReader t m)
489−deriving instance PerformEvent t m => PerformEvent t (ThemeReader t m)
490−deriving instance PostBuild t m => PostBuild t (ThemeReader t m)
491−deriving instance TriggerEvent t m => TriggerEvent t (ThemeReader t m)
492−instance HasImageWriter t m => HasImageWriter t (ThemeReader t m)
493−
494−instance (Adjustable t m, MonadFix m, MonadHold t m) => Adjustable t (ThemeReader t m) where
495− runWithReplace (ThemeReader a) e = ThemeReader $ runWithReplace a $ fmap unThemeReader e
496− traverseIntMapWithKeyWithAdjust f m e = ThemeReader $ traverseIntMapWithKeyWithAdjust (\k v -> unThemeReader $ f k v) m e
497− traverseDMapWithKeyWithAdjust f m e = ThemeReader $ traverseDMapWithKeyWithAdjust (\k v -> unThemeReader $ f k v) m e
498− traverseDMapWithKeyWithAdjustWithMove f m e = ThemeReader $ traverseDMapWithKeyWithAdjustWithMove (\k v -> unThemeReader $ f k v) m e
499−
500−instance MonadTrans (ThemeReader t) where
501− lift = ThemeReader . lift
502−
503−instance MFunctor (ThemeReader t) where
504− hoist f = ThemeReader . hoist f . unThemeReader
505−
506−instance MonadNodeId m => MonadNodeId (ThemeReader t m)
507−
508−-- | Run a 'ThemeReader' action with the given focus value
509−runThemeReader
510− :: (Reflex t, Monad m)
511− => Behavior t V.Attr
512− -> ThemeReader t m a
513− -> m a
514−runThemeReader b = flip runReaderT b . unThemeReader
515−
516−
517−-- ** Manipulating images
236+regionBlankImage :: Region -> Image
237+regionBlankImage r@(Region _ _ width height) =
238+ withinImage r $ V.charFill V.defAttr ' ' width height
518239
519240-- | Translates and crops an 'Image' so that it is contained by
520241-- the given 'Region'.
@@ -526,17 +247,7 @@ withinImage (Region left top width height)
526247 | width < 0 || height < 0 = withinImage (Region left top 0 0)
527248 | otherwise = V.translate left top . V.crop width height
528249
529−-- | Crop a behavior of images to a behavior of regions. See 'withinImage'.
530−imagesInRegion
531− :: Reflex t
532− => Behavior t Region
533− -> Behavior t [Image]
534− -> Behavior t [Image]
535−imagesInRegion reg = liftA2 (\r is -> map (withinImage r) is) reg
536−
537−-- * Running sub-widgets
538−
539−-- | Low-level widget combinator that runs a child widget within
250+-- | Low-level widget combinator that runs a child 'VtyWidget' within
540251-- a given region and context. This widget filters and modifies the input
541252-- that the child widget receives such that:
542253-- * unfocused widgets receive no key events
@@ -544,18 +255,306 @@ imagesInRegion reg = liftA2 (\r is -> map (withinImage r) is) reg
544255-- * mouse inputs inside the region have their coordinates translated such
545256-- that (0,0) is the top-left corner of the region
546257pane
547− :: (Reflex t, Monad m, HasInput t m, HasImageWriter t m, HasDisplayRegion t m, HasFocusReader t m)
548− => Dynamic t Region
258+ :: (Reflex t, Monad m)
259+ => Dynamic t Region -- ^ Region into which we should draw the widget (in coordinates relative to our own)
549260 -> Dynamic t Bool -- ^ Whether the widget should be focused when the parent is.
550− -> m a
551− -> m a
552−pane dr foc child = localRegion (const dr) $
553− mapImages (imagesInRegion $ current dr) $
554− localFocus (const foc) $
555− inputInFocusedRegion >>= \e -> localInput (const e) child
556−
557−-- * Misc
558−
559−-- | A widget that draws nothing
560−blank :: Monad m => m ()
561−blank = return ()
261+ -> VtyWidget t m a
262+ -> VtyWidget t m a
263+pane reg foc child = VtyWidget $ do
264+ ctx <- lift ask
265+ let ctx' = VtyWidgetCtx
266+ { _vtyWidgetCtx_input = leftmost -- TODO: think about this leftmost more.
267+ [ fmapMaybe id $
268+ attachWith (\(r,f) e -> filterInput r f e)
269+ (liftA2 (,) (current reg) (current foc))
270+ (_vtyWidgetCtx_input ctx)
271+ ]
272+ , _vtyWidgetCtx_focus = liftA2 (&&) (_vtyWidgetCtx_focus ctx) foc
273+ , _vtyWidgetCtx_size = fmap regionSize reg }
274+ (result, wo) <- lift . lift $ runVtyWidget ctx' child
275+ let images = _vtyWidgetOut_images wo
276+ images' = liftA2 (\r is -> map (withinImage r) is) (current reg) images
277+ wo' = wo { _vtyWidgetOut_images = images' }
278+ tell wo'
279+ return result
280+ where
281+ filterInput :: Region -> Bool -> VtyEvent -> Maybe VtyEvent
282+ filterInput (Region l t w h) focused e = case e of
283+ V.EvKey _ _ | not focused -> Nothing
284+ V.EvMouseDown x y btn m -> mouse (\u v -> V.EvMouseDown u v btn m) x y
285+ V.EvMouseUp x y btn -> mouse (\u v -> V.EvMouseUp u v btn) x y
286+ _ -> Just e
287+ where
288+ mouse con x y
289+ | or [ x < l
290+ , y < t
291+ , x >= l + w
292+ , y >= t + h ] = Nothing
293+ | otherwise =
294+ Just (con (x - l) (y - t))
295+
296+-- | Information about a drag operation
297+data Drag = Drag
298+ { _drag_from :: (Int, Int) -- ^ Where the drag began
299+ , _drag_to :: (Int, Int) -- ^ Where the mouse currently is
300+ , _drag_button :: V.Button -- ^ Which mouse button is dragging
301+ , _drag_modifiers :: [V.Modifier] -- ^ What modifiers are held
302+ , _drag_end :: Bool -- ^ Whether the drag ended (the mouse button was released)
303+ }
304+ deriving (Eq, Ord, Show)
305+
306+-- | Converts raw vty mouse drag events into an event stream of 'Drag's
307+drag
308+ :: (Reflex t, MonadFix m, MonadHold t m)
309+ => V.Button
310+ -> VtyWidget t m (Event t Drag)
311+drag btn = do
312+ inp <- input
313+ let f :: Maybe Drag -> V.Event -> Maybe Drag
314+ f Nothing = \case
315+ V.EvMouseDown x y btn' mods
316+ | btn == btn' -> Just $ Drag (x,y) (x,y) btn' mods False
317+ | otherwise -> Nothing
318+ _ -> Nothing
319+ f (Just (Drag from _ _ mods end)) = \case
320+ V.EvMouseDown x y btn' mods'
321+ | end -> Just $ Drag (x,y) (x,y) btn' mods' False
322+ | btn == btn' -> Just $ Drag from (x,y) btn mods' False
323+ | otherwise -> Nothing -- Ignore other buttons.
324+ V.EvMouseUp x y (Just btn')
325+ | end -> Nothing
326+ | btn == btn' -> Just $ Drag from (x,y) btn mods True
327+ | otherwise -> Nothing
328+ V.EvMouseUp x y Nothing -- Terminal doesn't specify mouse up button,
329+ -- assume it's the right one.
330+ | end -> Nothing
331+ | otherwise -> Just $ Drag from (x,y) btn mods True
332+ _ -> Nothing
333+ rec let newDrag = attachWithMaybe f (current dragD) inp
334+ dragD <- holdDyn Nothing $ Just <$> newDrag
335+ return (fmapMaybe id $ updated dragD)
336+
337+-- | Mouse down events for a particular mouse button
338+mouseDown
339+ :: (Reflex t, Monad m)
340+ => V.Button
341+ -> VtyWidget t m (Event t MouseDown)
342+mouseDown btn = do
343+ i <- input
344+ return $ fforMaybe i $ \case
345+ V.EvMouseDown x y btn' mods -> if btn == btn'
346+ then Just $ MouseDown btn' (x, y) mods
347+ else Nothing
348+ _ -> Nothing
349+
350+-- | Mouse up events for a particular mouse button
351+mouseUp
352+ :: (Reflex t, Monad m)
353+ => VtyWidget t m (Event t MouseUp)
354+mouseUp = do
355+ i <- input
356+ return $ fforMaybe i $ \case
357+ V.EvMouseUp x y btn' -> Just $ MouseUp btn' (x, y)
358+ _ -> Nothing
359+
360+-- | Information about a mouse down event
361+data MouseDown = MouseDown
362+ { _mouseDown_button :: V.Button
363+ , _mouseDown_coordinates :: (Int, Int)
364+ , _mouseDown_modifiers :: [V.Modifier]
365+ }
366+ deriving (Eq, Ord, Show)
367+
368+-- | Information about a mouse up event
369+data MouseUp = MouseUp
370+ { _mouseUp_button :: Maybe V.Button
371+ , _mouseUp_coordinates :: (Int, Int)
372+ }
373+ deriving (Eq, Ord, Show)
374+
375+-- | A plain split of the available space into vertically stacked panes.
376+-- No visual separator is built in here.
377+splitV :: (Reflex t, Monad m)
378+ => Dynamic t (Int -> Int)
379+ -- ^ Function used to determine size of first pane based on available size
380+ -> Dynamic t (Bool, Bool)
381+ -- ^ How to focus the two sub-panes, given that we are focused.
382+ -> VtyWidget t m a
383+ -- ^ Widget for first pane
384+ -> VtyWidget t m b
385+ -- ^ Widget for second pane
386+ -> VtyWidget t m (a,b)
387+splitV sizeFunD focD wA wB = do
388+ sz <- displaySize
389+ let regA = (\f (w,h) -> Region 0 0 w (f h)) <$> sizeFunD <*> sz
390+ regB = (\(w,h) (Region _ _ _ hA) -> Region 0 hA w (h - hA)) <$> sz <*> regA
391+ ra <- pane regA (fst <$> focD) wA
392+ rb <- pane regB (snd <$> focD) wB
393+ return (ra,rb)
394+
395+-- | A split of the available space into two parts with a draggable separator.
396+-- Starts with half the space allocated to each, and the first pane has focus.
397+-- Clicking in a pane switches focus.
398+splitVDrag :: (Reflex t, MonadFix m, MonadHold t m)
399+ => VtyWidget t m ()
400+ -> VtyWidget t m a
401+ -> VtyWidget t m b
402+ -> VtyWidget t m (a,b)
403+splitVDrag wS wA wB = do
404+ sz <- displaySize
405+ (_, h0) <- sample $ current sz
406+ dragE <- drag V.BLeft
407+ let splitter0 = h0 `div` 2
408+ rec splitterCheckpoint <- holdDyn splitter0 $ leftmost [fst <$> ffilter snd dragSplitter, resizeSplitter]
409+ splitterPos <- holdDyn splitter0 $ leftmost [fst <$> dragSplitter, resizeSplitter]
410+ splitterFrac <- holdDyn ((1::Double) / 2) $ ffor (attach (current sz) (fst <$> dragSplitter)) $ \((_,h),x) ->
411+ fromIntegral x / fromIntegral h
412+ let dragSplitter = fforMaybe (attach (current splitterCheckpoint) dragE) $
413+ \(splitterY, Drag (_, fromY) (_, toY) _ _ end) ->
414+ if splitterY == fromY then Just (toY, end) else Nothing
415+ regA = (\(w,_) sp -> Region 0 0 w sp) <$> sz <*> splitterPos
416+ regS = (\(w,_) sp -> Region 0 sp w 1) <$> sz <*> splitterPos
417+ regB = (\(w,h) sp -> Region 0 (sp + 1) w (h - sp - 1)) <$> sz <*> splitterPos
418+ resizeSplitter = ffor (attach (current splitterFrac) (updated sz)) $
419+ \(frac, (_,h)) -> round (frac * fromIntegral h)
420+ focA <- holdDyn True $ leftmost
421+ [ True <$ mA
422+ , False <$ mB
423+ ]
424+ (mA, rA) <- pane regA focA $ withMouseDown wA
425+ pane regS (pure False) wS
426+ (mB, rB) <- pane regB (not <$> focA) $ withMouseDown wB
427+ return (rA, rB)
428+ where
429+ withMouseDown x = do
430+ m <- mouseDown V.BLeft
431+ x' <- x
432+ return (m, x')
433+
434+-- | Fill the background with a particular character.
435+fill :: (Reflex t, Monad m) => Char -> VtyWidget t m ()
436+fill c = do
437+ sz <- displaySize
438+ let fillImg = ffor (current sz) $ \(w,h) -> [V.charFill V.defAttr c w h]
439+ tellImages fillImg
440+
441+-- | Fill the background with the bottom
442+hRule :: (Reflex t, Monad m) => BoxStyle -> VtyWidget t m ()
443+hRule boxStyle = fill (_boxStyle_s boxStyle)
444+
445+-- | Transform the images produces by a widget
446+modifyImages
447+ :: (Reflex t, MonadHold t m, MonadFix m)
448+ => Behavior t ([Image] -> [Image])
449+ -> VtyWidget t m a
450+ -> VtyWidget t m a
451+modifyImages f (VtyWidget w) = VtyWidget $ flip censor w $ \wo ->
452+ wo { _vtyWidgetOut_images = f <*> (_vtyWidgetOut_images wo) }
453+
454+-- | Defines a set of symbols to use to draw the outlines of boxes
455+-- C.f. https://en.wikipedia.org/wiki/Box-drawing_character
456+data BoxStyle = BoxStyle
457+ { _boxStyle_nw :: Char
458+ , _boxStyle_n :: Char
459+ , _boxStyle_ne :: Char
460+ , _boxStyle_e :: Char
461+ , _boxStyle_se :: Char
462+ , _boxStyle_s :: Char
463+ , _boxStyle_sw :: Char
464+ , _boxStyle_w :: Char
465+ }
466+
467+instance Default BoxStyle where
468+ def = singleBoxStyle
469+
470+-- | A box style that uses hyphens and pipe characters. Doesn't handle
471+-- corners very well.
472+hyphenBoxStyle :: BoxStyle
473+hyphenBoxStyle = BoxStyle '-' '-' '-' '|' '-' '-' '-' '|'
474+
475+-- | A single line box style
476+singleBoxStyle :: BoxStyle
477+singleBoxStyle = BoxStyle '┌' '─' '┐' '│' '┘' '─' '└' '│'
478+
479+-- | A thick single line box style
480+thickBoxStyle :: BoxStyle
481+thickBoxStyle = BoxStyle '┏' '━' '┓' '┃' '┛' '━' '┗' '┃'
482+
483+-- | A double line box style
484+doubleBoxStyle :: BoxStyle
485+doubleBoxStyle = BoxStyle '╔' '═' '╗' '║' '╝' '═' '╚' '║'
486+
487+-- | A single line box style with rounded corners
488+roundedBoxStyle :: BoxStyle
489+roundedBoxStyle = BoxStyle '╭' '─' '╮' '│' '╯' '─' '╰' '│'
490+
491+-- | Draws a box in the provided style and a child widget inside of that box
492+box :: (Monad m, Reflex t)
493+ => Behavior t BoxStyle
494+ -> VtyWidget t m a
495+ -> VtyWidget t m a
496+box boxStyle child = do
497+ sz <- displaySize
498+ let boxReg = ffor (current sz) $ \(w,h) -> Region 0 0 w h
499+ innerReg = ffor sz $ \(w,h) -> Region 1 1 (w - 2) (h - 2)
500+ tellImages (boxImages <$> boxStyle <*> boxReg)
501+ tellImages (fmap (\r -> [regionBlankImage r]) (current innerReg))
502+ pane innerReg (pure True) child
503+ where
504+ boxImages :: BoxStyle -> Region -> [Image]
505+ boxImages style (Region left top width height) =
506+ let right = left + width - 1
507+ bottom = top + height - 1
508+ sides =
509+ [ withinImage (Region (left + 1) top (width - 2) 1) $
510+ V.charFill V.defAttr (_boxStyle_n style) (width - 2) 1
511+ , withinImage (Region right (top + 1) 1 (height - 2)) $
512+ V.charFill V.defAttr (_boxStyle_e style) 1 (height - 2)
513+ , withinImage (Region (left + 1) bottom (width - 2) 1) $
514+ V.charFill V.defAttr (_boxStyle_s style) (width - 2) 1
515+ , withinImage (Region left (top + 1) 1 (height - 2)) $
516+ V.charFill V.defAttr (_boxStyle_w style) 1 (height - 2)
517+ ]
518+ corners =
519+ [ withinImage (Region left top 1 1) $
520+ V.char V.defAttr (_boxStyle_nw style)
521+ , withinImage (Region right top 1 1) $
522+ V.char V.defAttr (_boxStyle_ne style)
523+ , withinImage (Region right bottom 1 1) $
524+ V.char V.defAttr (_boxStyle_se style)
525+ , withinImage (Region left bottom 1 1) $
526+ V.char V.defAttr (_boxStyle_sw style)
527+ ]
528+ in sides ++ if width > 1 && height > 1 then corners else []
529+
530+-- | A box whose style is static
531+boxStatic
532+ :: (Reflex t, Monad m)
533+ => BoxStyle
534+ -> VtyWidget t m a
535+ -> VtyWidget t m a
536+boxStatic = box . pure
537+
538+-- | Renders text, wrapped to the container width
539+text
540+ :: (Reflex t, Monad m)
541+ => Behavior t Text
542+ -> VtyWidget t m ()
543+text msg = do
544+ dw <- displayWidth
545+ let img = (\w s -> [wrapText w V.defAttr s]) <$> current dw <*> msg
546+ tellImages img
547+ where
548+ wrapText maxWidth attrs = V.vertCat
549+ . concatMap (fmap (V.string attrs . T.unpack) . TZ.wrapWithOffset maxWidth 0)
550+ . T.split (=='\n')
551+
552+-- | Renders any behavior whose value can be converted to
553+-- 'String' as text
554+display
555+ :: (Reflex t, Monad m, Show a)
556+ => Behavior t a
557+ -> VtyWidget t m ()
558+display a = text $ T.pack . show <$> a
559+
560+