@@ -2,41 +2,151 @@
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+ , RichTextConfig(..)
48+ , richText
49+ , text
50+ , display
51+ , BoxStyle(..)
52+ , hyphenBoxStyle
53+ , singleBoxStyle
54+ , roundedBoxStyle
55+ , thickBoxStyle
56+ , doubleBoxStyle
57+ , fill
58+ , hRule
59+ ) where
860
961import Control.Applicative (liftA2)
1062import 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
63+import Control.Monad.Trans (lift)
64+import Control.Monad.Trans.Reader (ReaderT, runReaderT, asks, ask)
65+import Control.Monad.Trans.Writer (WriterT, runWriterT, censor, tell)
66+import Control.Monad.Writer.Adjustable ()
67+import Data.Default (Default(..))
68+import Data.Text (Text)
69+import qualified Data.Text as T
70+import qualified Data.Text.Zipper as TZ
1971import Graphics.Vty (Image)
2072import qualified Graphics.Vty as V
2173import Reflex
22−import Reflex.Class ()
23−import Reflex.Host.Class (MonadReflexCreateTrigger)
74+import Reflex.Class.Switchable
75+import Reflex.NotReady.Class
76+import Reflex.NotReady.Class.Orphans ()
77+
2478import Reflex.Vty.Host
2579
26−-- * Running a vty application
80+-- | The context within which a 'VtyWidget' runs
81+data VtyWidgetCtx t = VtyWidgetCtx
82+ { _vtyWidgetCtx_size :: Dynamic t (Int,Int)
83+ -- ^ The width and height of the region allocated to the widget.
84+ , _vtyWidgetCtx_focus :: Dynamic t Bool
85+ -- ^ Whether the widget should behave as if it has focus for keyboard input.
86+ , _vtyWidgetCtx_input :: Event t VtyEvent
87+ -- ^ User input events that the widget's parent chooses to share. These will generally
88+ -- be filtered for relevance:
89+ -- * Keyboard inputs are restricted to focused widgets
90+ -- * Mouse inputs are restricted to the region in which the widget resides and are
91+ -- translated into its internal coordinates.
92+ }
93+
94+-- | The output of a 'VtyWidget'
95+data VtyWidgetOut t = VtyWidgetOut
96+ { _vtyWidgetOut_images :: Behavior t [Image]
97+ -- ^ The visual output of the 'VtyWidget'
98+ , _vtyWidgetOut_shutdown :: Event t ()
99+ }
100+
101+instance Reflex t => Semigroup (VtyWidgetOut t) where
102+ wo <> wo' = VtyWidgetOut
103+ { _vtyWidgetOut_images = _vtyWidgetOut_images wo <> _vtyWidgetOut_images wo'
104+ , _vtyWidgetOut_shutdown = _vtyWidgetOut_shutdown wo <> _vtyWidgetOut_shutdown wo'
105+ }
106+
107+instance (Reflex t) => Monoid (VtyWidgetOut t) where
108+ mempty = VtyWidgetOut mempty mempty
109+ mappend wo wo' = wo <> wo'
110+
111+instance Reflex t => Switchable t (VtyWidgetOut t) where
112+ switching e0 e = do
113+ shutdown <- switching (_vtyWidgetOut_shutdown e0) $ fmap _vtyWidgetOut_shutdown e
114+ images <- switching (_vtyWidgetOut_images e0) $ fmap _vtyWidgetOut_images e
115+ return $ VtyWidgetOut
116+ { _vtyWidgetOut_images = images
117+ , _vtyWidgetOut_shutdown = shutdown
118+ }
119+
120+-- | A widget that can read its context and produce image output
121+newtype VtyWidget t m a = VtyWidget
122+ { unVtyWidget :: WriterT (VtyWidgetOut t) (ReaderT (VtyWidgetCtx t) m) a
123+ }
124+ deriving (Functor, Applicative, Monad, MonadSample t, MonadHold t, MonadFix, NotReady t)
125+
126+instance (PostBuild t m, Reflex t) => PostBuild t (VtyWidget t m) where
127+ getPostBuild = VtyWidget $ lift getPostBuild
128+
129+instance (Adjustable t m, MonadHold t m, Reflex t) => Adjustable t (VtyWidget t m) where
130+ runWithReplace a0 a' = VtyWidget $ runWithReplace (unVtyWidget a0) $ fmap unVtyWidget a'
131+ traverseIntMapWithKeyWithAdjust f dm0 dm' = VtyWidget $
132+ traverseIntMapWithKeyWithAdjust (\k v -> unVtyWidget (f k v)) dm0 dm'
133+ traverseDMapWithKeyWithAdjust f dm0 dm' = VtyWidget $ do
134+ traverseDMapWithKeyWithAdjust (\k v -> unVtyWidget (f k v)) dm0 dm'
135+ traverseDMapWithKeyWithAdjustWithMove f dm0 dm' = VtyWidget $ do
136+ traverseDMapWithKeyWithAdjustWithMove (\k v -> unVtyWidget (f k v)) dm0 dm'
137+
138+-- | Runs a 'VtyWidget' with a given context
139+runVtyWidget
140+ :: Reflex t
141+ => VtyWidgetCtx t
142+ -> VtyWidget t m a
143+ -> m (a, VtyWidgetOut t)
144+runVtyWidget ctx w = runReaderT (runWriterT (unVtyWidget w)) ctx
27145
28−-- | Sets up the top-level context for a vty widget and runs it with that context
146+-- | Sets up the top-level context for a 'VtyWidget' and runs it with that context
29147mainWidgetWithHandle
30148 :: 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 ()))
149+ -> (forall t m. MonadVtyApp t m => VtyWidget t m ())
40150 -> IO ()
41151mainWidgetWithHandle vty child =
42152 runVtyAppWithHandle vty $ \dr0 inp -> do
@@ -46,178 +156,71 @@ mainWidgetWithHandle vty child =
46156 let inp' = fforMaybe inp $ \case
47157 V.EvResize {} -> Nothing
48158 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
159+ let ctx = VtyWidgetCtx
160+ { _vtyWidgetCtx_size = size
161+ , _vtyWidgetCtx_input = inp'
162+ , _vtyWidgetCtx_focus = constDyn True
163+ }
164+ ((), wo) <- runVtyWidget ctx $ do
165+ tellImages . ffor (current size) $ \(w, h) -> [V.charFill V.defAttr ' ' w h]
166+ child
57167 return $ VtyResult
58− { _vtyResult_picture = fmap (V.picForLayers . reverse) images
59− , _vtyResult_shutdown = shutdown
168+ { _vtyResult_picture = fmap (V.picForLayers . reverse) (_vtyWidgetOut_images wo)
169+ , _vtyResult_shutdown = _vtyWidgetOut_shutdown wo
60170 }
61171
62−-- | The output of a vty widget
63−data VtyWidgetOut t = VtyWidgetOut
64− { _vtyWidgetOut_shutdown :: Event t ()
65− }
66−
67172-- | Like 'mainWidgetWithHandle', but uses a default vty configuration
68173mainWidget
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 ()))
174+ :: (forall t m. MonadVtyApp t m => VtyWidget t m ())
78175 -> IO ()
79176mainWidget child = do
80177 vty <- getDefaultVty
81178 mainWidgetWithHandle vty child
82179
83−-- * Input Events
180+-- | A class for things that know their own display size dimensions
181+class (Reflex t, Monad m) => HasDisplaySize t m | m -> t where
182+ displaySize :: m (Dynamic t (Int, Int))
183+
184+instance (Reflex t, Monad m) => HasDisplaySize t (VtyWidget t m) where
185+ displaySize = VtyWidget . lift $ asks _vtyWidgetCtx_size
186+
187+-- | Retrieve the display width (columns)
188+displayWidth :: HasDisplaySize t m => m (Dynamic t Int)
189+displayWidth = fmap fst <$> displaySize
190+
191+-- | Retrieve the display height (rows)
192+displayHeight :: HasDisplaySize t m => m (Dynamic t Int)
193+displayHeight = fmap snd <$> displaySize
84194
85195-- | A class for things that can receive vty events as input
86−class HasInput t m | m -> t where
196+class HasVtyInput t m | m -> t where
87197 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
180198
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
199+instance (Reflex t, Monad m) => HasVtyInput t (VtyWidget t m) where
200+ input = VtyWidget . lift $ asks _vtyWidgetCtx_input
201+
202+-- | A class for things that can dynamically gain and lose focus
203+class HasFocus t m | m -> t where
204+ focus :: m (Dynamic t Bool)
205+
206+instance (Reflex t, Monad m) => HasFocus t (VtyWidget t m) where
207+ focus = VtyWidget . lift $ asks _vtyWidgetCtx_focus
208+
209+-- | A class for widgets that can produce images to draw to the display
210+class (Reflex t, Monad m) => ImageWriter t m | m -> t where
211+ -- | Send images upstream for rendering
212+ tellImages :: Behavior t [Image] -> m ()
213+
214+instance (Reflex t, Monad m) => ImageWriter t (VtyWidget t m) where
215+ tellImages imgs = VtyWidget $ tell (mempty { _vtyWidgetOut_images = imgs })
216+
217+-- | A class for things that can shut down the vty application
218+class (Reflex t, Monad m) => Shutdown t m where
219+ -- | Signals that the vty application should shut down
220+ tellShutdown :: Event t () -> m ()
219221
220−-- * Getting and setting the display region
222+instance (Reflex t, Monad m) => Shutdown t (VtyWidget t m) where
223+ tellShutdown sd = VtyWidget $ tell (mempty { _vtyWidgetOut_shutdown = sd })
221224
222225-- | A chunk of the display area
223226data Region = Region
@@ -228,293 +231,14 @@ data Region = Region
228231 }
229232 deriving (Show, Read, Eq, Ord)
230233
231−-- | A region that occupies no space.
232−nilRegion :: Region
233−nilRegion = Region 0 0 0 0
234−
235234-- | The width and height of a 'Region'
236235regionSize :: Region -> (Int, Int)
237236regionSize (Region _ _ w h) = (w, h)
238237
239238-- | 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
239+regionBlankImage :: Region -> Image
240+regionBlankImage r@(Region _ _ width height) =
241+ withinImage r $ V.charFill V.defAttr ' ' width height
518242
519243-- | Translates and crops an 'Image' so that it is contained by
520244-- the given 'Region'.
@@ -526,17 +250,7 @@ withinImage (Region left top width height)
526250 | width < 0 || height < 0 = withinImage (Region left top 0 0)
527251 | otherwise = V.translate left top . V.crop width height
528252
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
253+-- | Low-level widget combinator that runs a child 'VtyWidget' within
540254-- a given region and context. This widget filters and modifies the input
541255-- that the child widget receives such that:
542256-- * unfocused widgets receive no key events
@@ -544,18 +258,323 @@ imagesInRegion reg = liftA2 (\r is -> map (withinImage r) is) reg
544258-- * mouse inputs inside the region have their coordinates translated such
545259-- that (0,0) is the top-left corner of the region
546260pane
547− :: (Reflex t, Monad m, HasInput t m, HasImageWriter t m, HasDisplayRegion t m, HasFocusReader t m)
548− => Dynamic t Region
261+ :: (Reflex t, Monad m)
262+ => Dynamic t Region -- ^ Region into which we should draw the widget (in coordinates relative to our own)
549263 -> 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 ()
264+ -> VtyWidget t m a
265+ -> VtyWidget t m a
266+pane reg foc child = VtyWidget $ do
267+ ctx <- lift ask
268+ let ctx' = VtyWidgetCtx
269+ { _vtyWidgetCtx_input = leftmost -- TODO: think about this leftmost more.
270+ [ fmapMaybe id $
271+ attachWith (\(r,f) e -> filterInput r f e)
272+ (liftA2 (,) (current reg) (current foc))
273+ (_vtyWidgetCtx_input ctx)
274+ ]
275+ , _vtyWidgetCtx_focus = liftA2 (&&) (_vtyWidgetCtx_focus ctx) foc
276+ , _vtyWidgetCtx_size = fmap regionSize reg }
277+ (result, wo) <- lift . lift $ runVtyWidget ctx' child
278+ let images = _vtyWidgetOut_images wo
279+ images' = liftA2 (\r is -> map (withinImage r) is) (current reg) images
280+ wo' = wo { _vtyWidgetOut_images = images' }
281+ tell wo'
282+ return result
283+ where
284+ filterInput :: Region -> Bool -> VtyEvent -> Maybe VtyEvent
285+ filterInput (Region l t w h) focused e = case e of
286+ V.EvKey _ _ | not focused -> Nothing
287+ V.EvMouseDown x y btn m -> mouse (\u v -> V.EvMouseDown u v btn m) x y
288+ V.EvMouseUp x y btn -> mouse (\u v -> V.EvMouseUp u v btn) x y
289+ _ -> Just e
290+ where
291+ mouse con x y
292+ | or [ x < l
293+ , y < t
294+ , x >= l + w
295+ , y >= t + h ] = Nothing
296+ | otherwise =
297+ Just (con (x - l) (y - t))
298+
299+-- | Information about a drag operation
300+data Drag = Drag
301+ { _drag_from :: (Int, Int) -- ^ Where the drag began
302+ , _drag_to :: (Int, Int) -- ^ Where the mouse currently is
303+ , _drag_button :: V.Button -- ^ Which mouse button is dragging
304+ , _drag_modifiers :: [V.Modifier] -- ^ What modifiers are held
305+ , _drag_end :: Bool -- ^ Whether the drag ended (the mouse button was released)
306+ }
307+ deriving (Eq, Ord, Show)
308+
309+-- | Converts raw vty mouse drag events into an event stream of 'Drag's
310+drag
311+ :: (Reflex t, MonadFix m, MonadHold t m)
312+ => V.Button
313+ -> VtyWidget t m (Event t Drag)
314+drag btn = do
315+ inp <- input
316+ let f :: Maybe Drag -> V.Event -> Maybe Drag
317+ f Nothing = \case
318+ V.EvMouseDown x y btn' mods
319+ | btn == btn' -> Just $ Drag (x,y) (x,y) btn' mods False
320+ | otherwise -> Nothing
321+ _ -> Nothing
322+ f (Just (Drag from _ _ mods end)) = \case
323+ V.EvMouseDown x y btn' mods'
324+ | end -> Just $ Drag (x,y) (x,y) btn' mods' False
325+ | btn == btn' -> Just $ Drag from (x,y) btn mods' False
326+ | otherwise -> Nothing -- Ignore other buttons.
327+ V.EvMouseUp x y (Just btn')
328+ | end -> Nothing
329+ | btn == btn' -> Just $ Drag from (x,y) btn mods True
330+ | otherwise -> Nothing
331+ V.EvMouseUp x y Nothing -- Terminal doesn't specify mouse up button,
332+ -- assume it's the right one.
333+ | end -> Nothing
334+ | otherwise -> Just $ Drag from (x,y) btn mods True
335+ _ -> Nothing
336+ rec let newDrag = attachWithMaybe f (current dragD) inp
337+ dragD <- holdDyn Nothing $ Just <$> newDrag
338+ return (fmapMaybe id $ updated dragD)
339+
340+-- | Mouse down events for a particular mouse button
341+mouseDown
342+ :: (Reflex t, Monad m)
343+ => V.Button
344+ -> VtyWidget t m (Event t MouseDown)
345+mouseDown btn = do
346+ i <- input
347+ return $ fforMaybe i $ \case
348+ V.EvMouseDown x y btn' mods -> if btn == btn'
349+ then Just $ MouseDown btn' (x, y) mods
350+ else Nothing
351+ _ -> Nothing
352+
353+-- | Mouse up events for a particular mouse button
354+mouseUp
355+ :: (Reflex t, Monad m)
356+ => VtyWidget t m (Event t MouseUp)
357+mouseUp = do
358+ i <- input
359+ return $ fforMaybe i $ \case
360+ V.EvMouseUp x y btn' -> Just $ MouseUp btn' (x, y)
361+ _ -> Nothing
362+
363+-- | Information about a mouse down event
364+data MouseDown = MouseDown
365+ { _mouseDown_button :: V.Button
366+ , _mouseDown_coordinates :: (Int, Int)
367+ , _mouseDown_modifiers :: [V.Modifier]
368+ }
369+ deriving (Eq, Ord, Show)
370+
371+-- | Information about a mouse up event
372+data MouseUp = MouseUp
373+ { _mouseUp_button :: Maybe V.Button
374+ , _mouseUp_coordinates :: (Int, Int)
375+ }
376+ deriving (Eq, Ord, Show)
377+
378+-- | A plain split of the available space into vertically stacked panes.
379+-- No visual separator is built in here.
380+splitV :: (Reflex t, Monad m)
381+ => Dynamic t (Int -> Int)
382+ -- ^ Function used to determine size of first pane based on available size
383+ -> Dynamic t (Bool, Bool)
384+ -- ^ How to focus the two sub-panes, given that we are focused.
385+ -> VtyWidget t m a
386+ -- ^ Widget for first pane
387+ -> VtyWidget t m b
388+ -- ^ Widget for second pane
389+ -> VtyWidget t m (a,b)
390+splitV sizeFunD focD wA wB = do
391+ sz <- displaySize
392+ let regA = (\f (w,h) -> Region 0 0 w (f h)) <$> sizeFunD <*> sz
393+ regB = (\(w,h) (Region _ _ _ hA) -> Region 0 hA w (h - hA)) <$> sz <*> regA
394+ ra <- pane regA (fst <$> focD) wA
395+ rb <- pane regB (snd <$> focD) wB
396+ return (ra,rb)
397+
398+-- | A split of the available space into two parts with a draggable separator.
399+-- Starts with half the space allocated to each, and the first pane has focus.
400+-- Clicking in a pane switches focus.
401+splitVDrag :: (Reflex t, MonadFix m, MonadHold t m)
402+ => VtyWidget t m ()
403+ -> VtyWidget t m a
404+ -> VtyWidget t m b
405+ -> VtyWidget t m (a,b)
406+splitVDrag wS wA wB = do
407+ sz <- displaySize
408+ (_, h0) <- sample $ current sz
409+ dragE <- drag V.BLeft
410+ let splitter0 = h0 `div` 2
411+ rec splitterCheckpoint <- holdDyn splitter0 $ leftmost [fst <$> ffilter snd dragSplitter, resizeSplitter]
412+ splitterPos <- holdDyn splitter0 $ leftmost [fst <$> dragSplitter, resizeSplitter]
413+ splitterFrac <- holdDyn ((1::Double) / 2) $ ffor (attach (current sz) (fst <$> dragSplitter)) $ \((_,h),x) ->
414+ fromIntegral x / fromIntegral h
415+ let dragSplitter = fforMaybe (attach (current splitterCheckpoint) dragE) $
416+ \(splitterY, Drag (_, fromY) (_, toY) _ _ end) ->
417+ if splitterY == fromY then Just (toY, end) else Nothing
418+ regA = (\(w,_) sp -> Region 0 0 w sp) <$> sz <*> splitterPos
419+ regS = (\(w,_) sp -> Region 0 sp w 1) <$> sz <*> splitterPos
420+ regB = (\(w,h) sp -> Region 0 (sp + 1) w (h - sp - 1)) <$> sz <*> splitterPos
421+ resizeSplitter = ffor (attach (current splitterFrac) (updated sz)) $
422+ \(frac, (_,h)) -> round (frac * fromIntegral h)
423+ focA <- holdDyn True $ leftmost
424+ [ True <$ mA
425+ , False <$ mB
426+ ]
427+ (mA, rA) <- pane regA focA $ withMouseDown wA
428+ pane regS (pure False) wS
429+ (mB, rB) <- pane regB (not <$> focA) $ withMouseDown wB
430+ return (rA, rB)
431+ where
432+ withMouseDown x = do
433+ m <- mouseDown V.BLeft
434+ x' <- x
435+ return (m, x')
436+
437+-- | Fill the background with a particular character.
438+fill :: (Reflex t, Monad m) => Char -> VtyWidget t m ()
439+fill c = do
440+ sz <- displaySize
441+ let fillImg = ffor (current sz) $ \(w,h) -> [V.charFill V.defAttr c w h]
442+ tellImages fillImg
443+
444+-- | Fill the background with the bottom
445+hRule :: (Reflex t, Monad m) => BoxStyle -> VtyWidget t m ()
446+hRule boxStyle = fill (_boxStyle_s boxStyle)
447+
448+-- | Transform the images produces by a widget
449+modifyImages
450+ :: (Reflex t, MonadHold t m, MonadFix m)
451+ => Behavior t ([Image] -> [Image])
452+ -> VtyWidget t m a
453+ -> VtyWidget t m a
454+modifyImages f (VtyWidget w) = VtyWidget $ flip censor w $ \wo ->
455+ wo { _vtyWidgetOut_images = f <*> (_vtyWidgetOut_images wo) }
456+
457+-- | Defines a set of symbols to use to draw the outlines of boxes
458+-- C.f. https://en.wikipedia.org/wiki/Box-drawing_character
459+data BoxStyle = BoxStyle
460+ { _boxStyle_nw :: Char
461+ , _boxStyle_n :: Char
462+ , _boxStyle_ne :: Char
463+ , _boxStyle_e :: Char
464+ , _boxStyle_se :: Char
465+ , _boxStyle_s :: Char
466+ , _boxStyle_sw :: Char
467+ , _boxStyle_w :: Char
468+ }
469+
470+instance Default BoxStyle where
471+ def = singleBoxStyle
472+
473+-- | A box style that uses hyphens and pipe characters. Doesn't handle
474+-- corners very well.
475+hyphenBoxStyle :: BoxStyle
476+hyphenBoxStyle = BoxStyle '-' '-' '-' '|' '-' '-' '-' '|'
477+
478+-- | A single line box style
479+singleBoxStyle :: BoxStyle
480+singleBoxStyle = BoxStyle '┌' '─' '┐' '│' '┘' '─' '└' '│'
481+
482+-- | A thick single line box style
483+thickBoxStyle :: BoxStyle
484+thickBoxStyle = BoxStyle '┏' '━' '┓' '┃' '┛' '━' '┗' '┃'
485+
486+-- | A double line box style
487+doubleBoxStyle :: BoxStyle
488+doubleBoxStyle = BoxStyle '╔' '═' '╗' '║' '╝' '═' '╚' '║'
489+
490+-- | A single line box style with rounded corners
491+roundedBoxStyle :: BoxStyle
492+roundedBoxStyle = BoxStyle '╭' '─' '╮' '│' '╯' '─' '╰' '│'
493+
494+-- | Draws a box in the provided style and a child widget inside of that box
495+box :: (Monad m, Reflex t)
496+ => Behavior t BoxStyle
497+ -> VtyWidget t m a
498+ -> VtyWidget t m a
499+box boxStyle child = do
500+ sz <- displaySize
501+ let boxReg = ffor (current sz) $ \(w,h) -> Region 0 0 w h
502+ innerReg = ffor sz $ \(w,h) -> Region 1 1 (w - 2) (h - 2)
503+ tellImages (boxImages <$> boxStyle <*> boxReg)
504+ tellImages (fmap (\r -> [regionBlankImage r]) (current innerReg))
505+ pane innerReg (pure True) child
506+ where
507+ boxImages :: BoxStyle -> Region -> [Image]
508+ boxImages style (Region left top width height) =
509+ let right = left + width - 1
510+ bottom = top + height - 1
511+ sides =
512+ [ withinImage (Region (left + 1) top (width - 2) 1) $
513+ V.charFill V.defAttr (_boxStyle_n style) (width - 2) 1
514+ , withinImage (Region right (top + 1) 1 (height - 2)) $
515+ V.charFill V.defAttr (_boxStyle_e style) 1 (height - 2)
516+ , withinImage (Region (left + 1) bottom (width - 2) 1) $
517+ V.charFill V.defAttr (_boxStyle_s style) (width - 2) 1
518+ , withinImage (Region left (top + 1) 1 (height - 2)) $
519+ V.charFill V.defAttr (_boxStyle_w style) 1 (height - 2)
520+ ]
521+ corners =
522+ [ withinImage (Region left top 1 1) $
523+ V.char V.defAttr (_boxStyle_nw style)
524+ , withinImage (Region right top 1 1) $
525+ V.char V.defAttr (_boxStyle_ne style)
526+ , withinImage (Region right bottom 1 1) $
527+ V.char V.defAttr (_boxStyle_se style)
528+ , withinImage (Region left bottom 1 1) $
529+ V.char V.defAttr (_boxStyle_sw style)
530+ ]
531+ in sides ++ if width > 1 && height > 1 then corners else []
532+
533+-- | A box whose style is static
534+boxStatic
535+ :: (Reflex t, Monad m)
536+ => BoxStyle
537+ -> VtyWidget t m a
538+ -> VtyWidget t m a
539+boxStatic = box . pure
540+
541+-- | Configuration options for displaying "rich" text
542+data RichTextConfig t = RichTextConfig
543+ { _richTextConfig_attributes :: Behavior t V.Attr
544+ }
545+
546+instance Reflex t => Default (RichTextConfig t) where
547+ def = RichTextConfig $ pure V.defAttr
548+
549+-- | A widget that displays text with custom time-varying attributes
550+richText
551+ :: (Reflex t, Monad m)
552+ => RichTextConfig t
553+ -> Behavior t Text
554+ -> VtyWidget t m ()
555+richText cfg t = do
556+ dw <- displayWidth
557+ let img = (\w a s -> [wrapText w a s])
558+ <$> current dw
559+ <*> _richTextConfig_attributes cfg
560+ <*> t
561+ tellImages img
562+ where
563+ wrapText maxWidth attrs = V.vertCat
564+ . concatMap (fmap (V.string attrs . T.unpack) . TZ.wrapWithOffset maxWidth 0)
565+ . T.split (=='\n')
566+
567+-- | Renders text, wrapped to the container width
568+text
569+ :: (Reflex t, Monad m)
570+ => Behavior t Text
571+ -> VtyWidget t m ()
572+text = richText def
573+
574+-- | Renders any behavior whose value can be converted to
575+-- 'String' as text
576+display
577+ :: (Reflex t, Monad m, Show a)
578+ => Behavior t a
579+ -> VtyWidget t m ()
580+display a = text $ T.pack . show <$> a