@@ -2,125 +2,41 @@
22Module: Reflex.Vty.Widget
33Description: Basic set of widgets and building blocks for reflex-vty applications
44-}
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− , HasFocus(..)
27− , HasVtyInput(..)
28− , Region(..)
29− , regionSize
30− , regionBlankImage
31− , Drag(..)
32− , drag
33− , MouseDown(..)
34− , MouseUp(..)
35− , mouseDown
36− , mouseUp
37− , pane
38− , pane'
39− , tellImages
40− , splitV
41− -- , splitVDrag TODO
42− , box
43− , boxStatic
44− , RichTextConfig(..)
45− , richText
46− , text
47− , display
48− , BoxStyle(..)
49− , hyphenBoxStyle
50− , singleBoxStyle
51− , roundedBoxStyle
52− , thickBoxStyle
53− , doubleBoxStyle
54− , fill
55− , hRule
56− ) where
5+{-# Language UndecidableInstances #-}
6+
7+module Reflex.Vty.Widget where
578
589import Control.Applicative (liftA2)
5910import Control.Monad.Fix (MonadFix)
60−import Control.Monad.Trans (lift)
61−import Control.Monad.Trans.Reader (ReaderT, runReaderT, asks, ask)
62−import Data.Default (Default(..))
63−import Data.Text (Text)
64−import qualified Data.Text as T
65−import qualified Data.Text.Zipper as TZ
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
6619import Graphics.Vty (Image)
6720import qualified Graphics.Vty as V
6821import Reflex
69−import Reflex.NotReady.Class
70−import Reflex.NotReady.Class.Orphans ()
71−import Reflex.BehaviorWriter.Class (tellBehavior)
72−import Reflex.BehaviorWriter.Base (BehaviorWriterT, runBehaviorWriterT)
73−
22+import Reflex.Class ()
23+import Reflex.Host.Class (MonadReflexCreateTrigger)
7424import Reflex.Vty.Host
7525
76−-- | The context within which a 'VtyWidget' runs
77−data VtyWidgetCtx t = VtyWidgetCtx
78− { _vtyWidgetCtx_width :: Dynamic t Int
79− -- ^ The width of the region allocated to the widget.
80− , _vtyWidgetCtx_height :: Dynamic t Int
81− -- ^ The height of the region allocated to the widget.
82− , _vtyWidgetCtx_focus :: Dynamic t Bool
83− -- ^ Whether the widget should behave as if it has focus for keyboard input.
84− , _vtyWidgetCtx_input :: Event t VtyEvent
85− -- ^ User input events that the widget's parent chooses to share. These will generally
86− -- be filtered for relevance:
87− -- * Keyboard inputs are restricted to focused widgets
88− -- * Mouse inputs are restricted to the region in which the widget resides and are
89− -- translated into its internal coordinates.
90− }
91−
92−-- | The output of a 'VtyWidget'
93−data VtyWidgetOut t = VtyWidgetOut
94− { _vtyWidgetOut_shutdown :: Event t ()
95− }
96−
97−instance (Adjustable t m, MonadHold t m, Reflex t) => Adjustable t (VtyWidget t m) where
98− runWithReplace a0 a' = VtyWidget $ runWithReplace (unVtyWidget a0) $ fmap unVtyWidget a'
99− traverseIntMapWithKeyWithAdjust f dm0 dm' = VtyWidget $
100− traverseIntMapWithKeyWithAdjust (\k v -> unVtyWidget (f k v)) dm0 dm'
101− traverseDMapWithKeyWithAdjust f dm0 dm' = VtyWidget $ do
102− traverseDMapWithKeyWithAdjust (\k v -> unVtyWidget (f k v)) dm0 dm'
103− traverseDMapWithKeyWithAdjustWithMove f dm0 dm' = VtyWidget $ do
104− traverseDMapWithKeyWithAdjustWithMove (\k v -> unVtyWidget (f k v)) dm0 dm'
105−
106−-- | A widget that can read its context and produce image output
107−newtype VtyWidget t m a = VtyWidget
108− { unVtyWidget :: BehaviorWriterT t [Image] (ReaderT (VtyWidgetCtx t) m) a
109− }
110− deriving (Functor, Applicative, Monad, MonadSample t, MonadHold t, MonadFix, NotReady t, ImageWriter t)
111−
112−-- | Runs a 'VtyWidget' with a given context
113−runVtyWidget
114− :: (Reflex t, Monad m)
115− => VtyWidgetCtx t
116− -> VtyWidget t m a
117− -> m (a, Behavior t [Image])
118−runVtyWidget ctx w = runReaderT (runBehaviorWriterT (unVtyWidget w)) ctx
26+-- * Running a vty application
11927
120−-- | Sets up the top-level context for a 'VtyWidget' and runs it with that context
28+-- | Sets up the top-level context for a vty widget and runs it with that context
12129mainWidgetWithHandle
12230 :: V.Vty
123− -> (forall t m. MonadVtyApp t m => VtyWidget t m (Event t ()))
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 ()))
12440 -> IO ()
12541mainWidgetWithHandle vty child =
12642 runVtyAppWithHandle vty $ \dr0 inp -> do
@@ -130,60 +46,178 @@ mainWidgetWithHandle vty child =
13046 let inp' = fforMaybe inp $ \case
13147 V.EvResize {} -> Nothing
13248 x -> Just x
133− let ctx = VtyWidgetCtx
134− { _vtyWidgetCtx_width = fmap fst size
135− , _vtyWidgetCtx_height = fmap snd size
136− , _vtyWidgetCtx_input = inp'
137− , _vtyWidgetCtx_focus = constDyn True
138− }
139− (shutdown, images) <- runVtyWidget ctx $ do
140− tellImages . ffor (current size) $ \(w, h) -> [V.charFill V.defAttr ' ' w h]
141− child
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
14257 return $ VtyResult
14358 { _vtyResult_picture = fmap (V.picForLayers . reverse) images
14459 , _vtyResult_shutdown = shutdown
14560 }
14661
62+-- | The output of a vty widget
63+data VtyWidgetOut t = VtyWidgetOut
64+ { _vtyWidgetOut_shutdown :: Event t ()
65+ }
66+
14767-- | Like 'mainWidgetWithHandle', but uses a default vty configuration
14868mainWidget
149− :: (forall t m. MonadVtyApp t m => VtyWidget t m (Event t ()))
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 ()))
15078 -> IO ()
15179mainWidget child = do
15280 vty <- getDefaultVty
15381 mainWidgetWithHandle vty child
15482
155−-- | A class for things that know their own display size dimensions
156−class (Reflex t, Monad m) => HasDisplaySize t m | m -> t where
157− -- | Retrieve the display width (columns)
158− displayWidth :: m (Dynamic t Int)
159− -- | Retrieve the display height (rows)
160− displayHeight :: m (Dynamic t Int)
161−
162−instance (Reflex t, Monad m) => HasDisplaySize t (VtyWidget t m) where
163− displayWidth = VtyWidget . lift $ asks _vtyWidgetCtx_width
164− displayHeight = VtyWidget . lift $ asks _vtyWidgetCtx_height
83+-- * Input Events
16584
16685-- | A class for things that can receive vty events as input
167−class HasVtyInput t m | m -> t where
86+class HasInput t m | m -> t where
16887 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
169180
170−instance (Reflex t, Monad m) => HasVtyInput t (VtyWidget t m) where
171− input = VtyWidget . lift $ asks _vtyWidgetCtx_input
172−
173−-- | A class for things that can dynamically gain and lose focus
174−class HasFocus t m | m -> t where
175− focus :: m (Dynamic t Bool)
176−
177−instance (Reflex t, Monad m) => HasFocus t (VtyWidget t m) where
178− focus = VtyWidget . lift $ asks _vtyWidgetCtx_focus
179−
180−-- | A class for widgets that can produce images to draw to the display
181−class (Reflex t, Monad m) => ImageWriter t m | m -> t where
182− -- | Send images upstream for rendering
183− tellImages :: Behavior t [Image] -> m ()
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
184219
185−instance (Monad m, Reflex t) => ImageWriter t (BehaviorWriterT t [Image] m) where
186− tellImages = tellBehavior
220+-- * Getting and setting the display region
187221
188222-- | A chunk of the display area
189223data Region = Region
@@ -194,14 +228,293 @@ data Region = Region
194228 }
195229 deriving (Show, Read, Eq, Ord)
196230
231+-- | A region that occupies no space.
232+nilRegion :: Region
233+nilRegion = Region 0 0 0 0
234+
197235-- | The width and height of a 'Region'
198236regionSize :: Region -> (Int, Int)
199237regionSize (Region _ _ w h) = (w, h)
200238
201239-- | Produces an 'Image' that fills a region with space characters
202−regionBlankImage :: Region -> Image
203−regionBlankImage r@(Region _ _ width height) =
204− withinImage r $ V.charFill V.defAttr ' ' width height
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
205518
206519-- | Translates and crops an 'Image' so that it is contained by
207520-- the given 'Region'.
@@ -213,7 +526,17 @@ withinImage (Region left top width height)
213526 | width < 0 || height < 0 = withinImage (Region left top 0 0)
214527 | otherwise = V.translate left top . V.crop width height
215528
216−-- | Low-level widget combinator that runs a child 'VtyWidget' within
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
217540-- a given region and context. This widget filters and modifies the input
218541-- that the child widget receives such that:
219542-- * unfocused widgets receive no key events
@@ -221,363 +544,18 @@ withinImage (Region left top width height)
221544-- * mouse inputs inside the region have their coordinates translated such
222545-- that (0,0) is the top-left corner of the region
223546pane
224− :: (Reflex t, Monad m)
225− => Dynamic t Region -- ^ Region into which we should draw the widget (in coordinates relative to our own)
547+ :: (Reflex t, Monad m, HasInput t m, HasImageWriter t m, HasDisplayRegion t m, HasFocusReader t m)
548+ => Dynamic t Region
226549 -> Dynamic t Bool -- ^ Whether the widget should be focused when the parent is.
227− -> VtyWidget t m a
228− -> VtyWidget t m a
229−pane reg foc child = VtyWidget $ do
230− ctx <- lift ask
231− let ctx' = VtyWidgetCtx
232− { _vtyWidgetCtx_input = leftmost -- TODO: think about this leftmost more.
233− [ fmapMaybe id $
234− attachWith (\(r,f) e -> filterInput r f e)
235− (liftA2 (,) (current reg) (current foc))
236− (_vtyWidgetCtx_input ctx)
237− ]
238− , _vtyWidgetCtx_focus = liftA2 (&&) (_vtyWidgetCtx_focus ctx) foc
239− , _vtyWidgetCtx_width = fmap (fst . regionSize) reg
240− , _vtyWidgetCtx_height = fmap (snd . regionSize) reg
241− }
242− (result, images) <- lift . lift $ runVtyWidget ctx' child
243− let images' = liftA2 (\r is -> map (withinImage r) is) (current reg) images
244− tellImages images'
245− return result
246− where
247− filterInput :: Region -> Bool -> VtyEvent -> Maybe VtyEvent
248− filterInput (Region l t w h) focused e = case e of
249− V.EvKey _ _ | not focused -> Nothing
250− V.EvMouseDown x y btn m -> mouse (\u v -> V.EvMouseDown u v btn m) x y
251− V.EvMouseUp x y btn -> mouse (\u v -> V.EvMouseUp u v btn) x y
252− _ -> Just e
253− where
254− mouse con x y
255− | or [ x < l
256− , y < t
257− , x >= l + w
258− , y >= t + h ] = Nothing
259− | otherwise =
260− Just (con (x - l) (y - t))
261−
262−pane'
263− :: (Reflex t, Monad m)
264− => Dynamic t Int
265− -> Dynamic t Int
266− -> Dynamic t Int
267− -> Dynamic t Int
268− -> Dynamic t Bool -- ^ Whether the widget should be focused when the parent is.
269− -> VtyWidget t m a
270− -> VtyWidget t m a
271−pane' l t w h foc child = VtyWidget $ do
272− ctx <- lift ask
273− let reg = Region <$> l <*> t <*> w <*> h
274− let ctx' = VtyWidgetCtx
275− { _vtyWidgetCtx_input = leftmost -- TODO: think about this leftmost more.
276− [ fmapMaybe id $
277− attachWith (\(r,f) e -> filterInput r f e)
278− (liftA2 (,) (current reg) (current foc))
279− (_vtyWidgetCtx_input ctx)
280− ]
281− , _vtyWidgetCtx_focus = liftA2 (&&) (_vtyWidgetCtx_focus ctx) foc
282− , _vtyWidgetCtx_width = w
283− , _vtyWidgetCtx_height = h
284− }
285− (result, images) <- lift . lift $ runVtyWidget ctx' child
286− let images' = liftA2 (\r is -> map (withinImage r) is) (current reg) images
287− tellImages images'
288− return result
289− where
290− filterInput :: Region -> Bool -> VtyEvent -> Maybe VtyEvent
291− filterInput (Region l t w h) focused e = case e of
292− V.EvKey _ _ | not focused -> Nothing
293− V.EvMouseDown x y btn m -> mouse (\u v -> V.EvMouseDown u v btn m) x y
294− V.EvMouseUp x y btn -> mouse (\u v -> V.EvMouseUp u v btn) x y
295− _ -> Just e
296− where
297− mouse con x y
298− | or [ x < l
299− , y < t
300− , x >= l + w
301− , y >= t + h ] = Nothing
302− | otherwise =
303− Just (con (x - l) (y - t))
304−
305−
306−
307−-- | Information about a drag operation
308−data Drag = Drag
309− { _drag_from :: (Int, Int) -- ^ Where the drag began
310− , _drag_to :: (Int, Int) -- ^ Where the mouse currently is
311− , _drag_button :: V.Button -- ^ Which mouse button is dragging
312− , _drag_modifiers :: [V.Modifier] -- ^ What modifiers are held
313− , _drag_end :: Bool -- ^ Whether the drag ended (the mouse button was released)
314− }
315− deriving (Eq, Ord, Show)
316−
317−-- | Converts raw vty mouse drag events into an event stream of 'Drag's
318−drag
319− :: (Reflex t, MonadFix m, MonadHold t m)
320− => V.Button
321− -> VtyWidget t m (Event t Drag)
322−drag btn = do
323− inp <- input
324− let f :: Maybe Drag -> V.Event -> Maybe Drag
325− f Nothing = \case
326− V.EvMouseDown x y btn' mods
327− | btn == btn' -> Just $ Drag (x,y) (x,y) btn' mods False
328− | otherwise -> Nothing
329− _ -> Nothing
330− f (Just (Drag from _ _ mods end)) = \case
331− V.EvMouseDown x y btn' mods'
332− | end -> Just $ Drag (x,y) (x,y) btn' mods' False
333− | btn == btn' -> Just $ Drag from (x,y) btn mods' False
334− | otherwise -> Nothing -- Ignore other buttons.
335− V.EvMouseUp x y (Just btn')
336− | end -> Nothing
337− | btn == btn' -> Just $ Drag from (x,y) btn mods True
338− | otherwise -> Nothing
339− V.EvMouseUp x y Nothing -- Terminal doesn't specify mouse up button,
340− -- assume it's the right one.
341− | end -> Nothing
342− | otherwise -> Just $ Drag from (x,y) btn mods True
343− _ -> Nothing
344− rec let newDrag = attachWithMaybe f (current dragD) inp
345− dragD <- holdDyn Nothing $ Just <$> newDrag
346− return (fmapMaybe id $ updated dragD)
347−
348−-- | Mouse down events for a particular mouse button
349−mouseDown
350− :: (Reflex t, Monad m)
351− => V.Button
352− -> VtyWidget t m (Event t MouseDown)
353−mouseDown btn = do
354− i <- input
355− return $ fforMaybe i $ \case
356− V.EvMouseDown x y btn' mods -> if btn == btn'
357− then Just $ MouseDown btn' (x, y) mods
358− else Nothing
359− _ -> Nothing
360−
361−-- | Mouse up events for a particular mouse button
362−mouseUp
363− :: (Reflex t, Monad m)
364− => VtyWidget t m (Event t MouseUp)
365−mouseUp = do
366− i <- input
367− return $ fforMaybe i $ \case
368− V.EvMouseUp x y btn' -> Just $ MouseUp btn' (x, y)
369− _ -> Nothing
370−
371−-- | Information about a mouse down event
372−data MouseDown = MouseDown
373− { _mouseDown_button :: V.Button
374− , _mouseDown_coordinates :: (Int, Int)
375− , _mouseDown_modifiers :: [V.Modifier]
376− }
377− deriving (Eq, Ord, Show)
378−
379−-- | Information about a mouse up event
380−data MouseUp = MouseUp
381− { _mouseUp_button :: Maybe V.Button
382− , _mouseUp_coordinates :: (Int, Int)
383− }
384− deriving (Eq, Ord, Show)
385−
386−-- | A plain split of the available space into vertically stacked panes.
387−-- No visual separator is built in here.
388−splitV :: (Reflex t, Monad m)
389− => Dynamic t (Int -> Int)
390− -- ^ Function used to determine size of first pane based on available size
391− -> Dynamic t (Bool, Bool)
392− -- ^ How to focus the two sub-panes, given that we are focused.
393− -> VtyWidget t m a
394− -- ^ Widget for first pane
395− -> VtyWidget t m b
396− -- ^ Widget for second pane
397− -> VtyWidget t m (a,b)
398−splitV sizeFunD focD wA wB = do
399− dw <- displayWidth
400− dh <- displayHeight
401− let regA = (\f w h -> Region 0 0 w (f h)) <$> sizeFunD <*> dw <*> dh
402− regB = (\w h (Region _ _ _ hA) -> Region 0 hA w (h - hA)) <$> dw <*> dh <*> regA
403− ra <- pane regA (fst <$> focD) wA
404− rb <- pane regB (snd <$> focD) wB
405− return (ra,rb)
406−
407−{-
408−-- | A split of the available space into two parts with a draggable separator.
409−-- Starts with half the space allocated to each, and the first pane has focus.
410−-- Clicking in a pane switches focus.
411−splitVDrag :: (Reflex t, MonadFix m, MonadHold t m)
412− => VtyWidget t m ()
413− -> VtyWidget t m a
414− -> VtyWidget t m b
415− -> VtyWidget t m (a,b)
416−splitVDrag wS wA wB = do
417− sz <- displaySize
418− (_, h0) <- sample $ current sz
419− dragE <- drag V.BLeft
420− let splitter0 = h0 `div` 2
421− rec splitterCheckpoint <- holdDyn splitter0 $ leftmost [fst <$> ffilter snd dragSplitter, resizeSplitter]
422− splitterPos <- holdDyn splitter0 $ leftmost [fst <$> dragSplitter, resizeSplitter]
423− splitterFrac <- holdDyn ((1::Double) / 2) $ ffor (attach (current sz) (fst <$> dragSplitter)) $ \((_,h),x) ->
424− fromIntegral x / fromIntegral h
425− let dragSplitter = fforMaybe (attach (current splitterCheckpoint) dragE) $
426− \(splitterY, Drag (_, fromY) (_, toY) _ _ end) ->
427− if splitterY == fromY then Just (toY, end) else Nothing
428− regA = (\(w,_) sp -> Region 0 0 w sp) <$> sz <*> splitterPos
429− regS = (\(w,_) sp -> Region 0 sp w 1) <$> sz <*> splitterPos
430− regB = (\(w,h) sp -> Region 0 (sp + 1) w (h - sp - 1)) <$> sz <*> splitterPos
431− resizeSplitter = ffor (attach (current splitterFrac) (updated sz)) $
432− \(frac, (_,h)) -> round (frac * fromIntegral h)
433− focA <- holdDyn True $ leftmost
434− [ True <$ mA
435− , False <$ mB
436− ]
437− (mA, rA) <- pane regA focA $ withMouseDown wA
438− pane regS (pure False) wS
439− (mB, rB) <- pane regB (not <$> focA) $ withMouseDown wB
440− return (rA, rB)
441− where
442− withMouseDown x = do
443− m <- mouseDown V.BLeft
444− x' <- x
445− return (m, x')
446−-}
447−-- | Fill the background with a particular character.
448−fill :: (Reflex t, Monad m) => Char -> VtyWidget t m ()
449−fill c = do
450− dw <- displayWidth
451− dh <- displayHeight
452− let fillImg = current $ liftA2 (\w h -> [V.charFill V.defAttr c w h]) dw dh
453− tellImages fillImg
454−
455−-- | Fill the background with the bottom
456−hRule :: (Reflex t, Monad m) => BoxStyle -> VtyWidget t m ()
457−hRule boxStyle = fill (_boxStyle_s boxStyle)
458−
459−-- | Defines a set of symbols to use to draw the outlines of boxes
460−-- C.f. https://en.wikipedia.org/wiki/Box-drawing_character
461−data BoxStyle = BoxStyle
462− { _boxStyle_nw :: Char
463− , _boxStyle_n :: Char
464− , _boxStyle_ne :: Char
465− , _boxStyle_e :: Char
466− , _boxStyle_se :: Char
467− , _boxStyle_s :: Char
468− , _boxStyle_sw :: Char
469− , _boxStyle_w :: Char
470− }
471−
472−instance Default BoxStyle where
473− def = singleBoxStyle
474−
475−-- | A box style that uses hyphens and pipe characters. Doesn't handle
476−-- corners very well.
477−hyphenBoxStyle :: BoxStyle
478−hyphenBoxStyle = BoxStyle '-' '-' '-' '|' '-' '-' '-' '|'
479−
480−-- | A single line box style
481−singleBoxStyle :: BoxStyle
482−singleBoxStyle = BoxStyle '┌' '─' '┐' '│' '┘' '─' '└' '│'
483−
484−-- | A thick single line box style
485−thickBoxStyle :: BoxStyle
486−thickBoxStyle = BoxStyle '┏' '━' '┓' '┃' '┛' '━' '┗' '┃'
487−
488−-- | A double line box style
489−doubleBoxStyle :: BoxStyle
490−doubleBoxStyle = BoxStyle '╔' '═' '╗' '║' '╝' '═' '╚' '║'
491−
492−-- | A single line box style with rounded corners
493−roundedBoxStyle :: BoxStyle
494−roundedBoxStyle = BoxStyle '╭' '─' '╮' '│' '╯' '─' '╰' '│'
495−
496−-- | Draws a box in the provided style and a child widget inside of that box
497−box :: (Monad m, Reflex t)
498− => Behavior t BoxStyle
499− -> VtyWidget t m a
500− -> VtyWidget t m a
501−box boxStyle child = do
502− dh <- displayHeight
503− dw <- displayWidth
504− let boxReg = liftA2 (\w h -> Region 0 0 w h) dw dh
505− innerReg = liftA2 (\w h -> Region 1 1 (w - 2) (h - 2)) dw dh
506− tellImages (boxImages <$> boxStyle <*> current boxReg)
507− tellImages (fmap (\r -> [regionBlankImage r]) (current innerReg))
508− pane innerReg (pure True) child
509− where
510− boxImages :: BoxStyle -> Region -> [Image]
511− boxImages style (Region left top width height) =
512− let right = left + width - 1
513− bottom = top + height - 1
514− sides =
515− [ withinImage (Region (left + 1) top (width - 2) 1) $
516− V.charFill V.defAttr (_boxStyle_n style) (width - 2) 1
517− , withinImage (Region right (top + 1) 1 (height - 2)) $
518− V.charFill V.defAttr (_boxStyle_e style) 1 (height - 2)
519− , withinImage (Region (left + 1) bottom (width - 2) 1) $
520− V.charFill V.defAttr (_boxStyle_s style) (width - 2) 1
521− , withinImage (Region left (top + 1) 1 (height - 2)) $
522− V.charFill V.defAttr (_boxStyle_w style) 1 (height - 2)
523− ]
524− corners =
525− [ withinImage (Region left top 1 1) $
526− V.char V.defAttr (_boxStyle_nw style)
527− , withinImage (Region right top 1 1) $
528− V.char V.defAttr (_boxStyle_ne style)
529− , withinImage (Region right bottom 1 1) $
530− V.char V.defAttr (_boxStyle_se style)
531− , withinImage (Region left bottom 1 1) $
532− V.char V.defAttr (_boxStyle_sw style)
533− ]
534− in sides ++ if width > 1 && height > 1 then corners else []
535−
536−-- | A box whose style is static
537−boxStatic
538− :: (Reflex t, Monad m)
539− => BoxStyle
540− -> VtyWidget t m a
541− -> VtyWidget t m a
542−boxStatic = box . pure
543−
544−-- | Configuration options for displaying "rich" text
545−data RichTextConfig t = RichTextConfig
546− { _richTextConfig_attributes :: Behavior t V.Attr
547− }
548−
549−instance Reflex t => Default (RichTextConfig t) where
550− def = RichTextConfig $ pure V.defAttr
551−
552−-- | A widget that displays text with custom time-varying attributes
553−richText
554− :: (Reflex t, Monad m)
555− => RichTextConfig t
556− -> Behavior t Text
557− -> VtyWidget t m ()
558−richText cfg t = do
559− dw <- displayWidth
560− let img = (\w a s -> [wrapText w a s])
561− <$> current dw
562− <*> _richTextConfig_attributes cfg
563− <*> t
564− tellImages img
565− where
566− wrapText maxWidth attrs = V.vertCat
567− . concatMap (fmap (V.string attrs . T.unpack) . TZ.wrapWithOffset maxWidth 0)
568− . T.split (=='\n')
569−
570−-- | Renders text, wrapped to the container width
571−text
572− :: (Reflex t, Monad m)
573− => Behavior t Text
574− -> VtyWidget t m ()
575−text = richText def
576−
577−-- | Renders any behavior whose value can be converted to
578−-- 'String' as text
579−display
580− :: (Reflex t, Monad m, Show a)
581− => Behavior t a
582− -> VtyWidget t m ()
583−display a = text $ T.pack . show <$> a
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 ()