@@ -2,41 +2,136 @@
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 DeriveFunctor #-}
6+{-# LANGUAGE FlexibleContexts #-}
7+{-# LANGUAGE FlexibleInstances #-}
8+{-# LANGUAGE FunctionalDependencies #-}
9+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
10+{-# LANGUAGE LambdaCase #-}
11+{-# LANGUAGE MultiParamTypeClasses #-}
12+{-# LANGUAGE OverloadedStrings #-}
13+{-# LANGUAGE RankNTypes #-}
14+{-# LANGUAGE RecursiveDo #-}
15+{-# LANGUAGE ScopedTypeVariables #-}
16+{-# LANGUAGE StandaloneDeriving #-}
17+{-# LANGUAGE TupleSections #-}
18+{-# LANGUAGE TypeFamilies #-}
19+{-# LANGUAGE UndecidableInstances #-}
20+module Reflex.Vty.Widget
21+ ( VtyWidgetCtx(..)
22+ , VtyWidget(..)
23+ , VtyWidgetOut(..)
24+ , ImageWriter(..)
25+ , runVtyWidget
26+ , mainWidget
27+ , mainWidgetWithHandle
28+
29+ , StackWidget(..)
30+ , stack
31+ , Direction(..)
32+ , col
33+ , row
34+ , sized
35+
36+ , HasDisplaySize(..)
37+ , HasFocus(..)
38+ , HasVtyInput(..)
39+ , DynRegion(..)
40+ , currentRegion
41+ , Region(..)
42+ , regionSize
43+ , regionBlankImage
44+ , Drag(..)
45+ , drag
46+ , MouseDown(..)
47+ , MouseUp(..)
48+ , mouseDown
49+ , mouseUp
50+ , pane
51+ , splitV
52+ , splitVDrag
53+ , box
54+ , boxStatic
55+ , RichTextConfig(..)
56+ , richText
57+ , text
58+ , display
59+ , BoxStyle(..)
60+ , hyphenBoxStyle
61+ , singleBoxStyle
62+ , roundedBoxStyle
63+ , thickBoxStyle
64+ , doubleBoxStyle
65+ , fill
66+ , hRule
67+ ) where
868
969import Control.Applicative (liftA2)
70+import Control.Monad (ap)
1071import 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
72+import Control.Monad.Trans (lift)
73+import Control.Monad.Trans.Reader (ReaderT, runReaderT, asks, ask)
74+import Data.Default (Default(..))
75+import Data.Text (Text)
76+import qualified Data.Text as T
77+import qualified Data.Text.Zipper as TZ
1978import Graphics.Vty (Image)
2079import qualified Graphics.Vty as V
2180import Reflex
22−import Reflex.Class ()
23−import Reflex.Host.Class (MonadReflexCreateTrigger)
81+import Reflex.Class.Orphans ()
82+import Reflex.NotReady.Class
83+import Reflex.NotReady.Class.Orphans ()
84+
2485import Reflex.Vty.Host
2586
26−-- * Running a vty application
87+-- | The context within which a 'VtyWidget' runs
88+data VtyWidgetCtx t = VtyWidgetCtx
89+ { _vtyWidgetCtx_width :: Dynamic t Int
90+ -- ^ The width of the region allocated to the widget.
91+ , _vtyWidgetCtx_height :: Dynamic t Int
92+ -- ^ The height of the region allocated to the widget.
93+ , _vtyWidgetCtx_focus :: Dynamic t Bool
94+ -- ^ Whether the widget should behave as if it has focus for keyboard input.
95+ , _vtyWidgetCtx_input :: Event t VtyEvent
96+ -- ^ User input events that the widget's parent chooses to share. These will generally
97+ -- be filtered for relevance:
98+ -- * Keyboard inputs are restricted to focused widgets
99+ -- * Mouse inputs are restricted to the region in which the widget resides and are
100+ -- translated into its internal coordinates.
101+ }
102+
103+-- | The output of a 'VtyWidget'
104+data VtyWidgetOut t = VtyWidgetOut
105+ { _vtyWidgetOut_shutdown :: Event t ()
106+ }
107+
108+instance (Adjustable t m, MonadHold t m, Reflex t) => Adjustable t (VtyWidget t m) where
109+ runWithReplace a0 a' = VtyWidget $ runWithReplace (unVtyWidget a0) $ fmap unVtyWidget a'
110+ traverseIntMapWithKeyWithAdjust f dm0 dm' = VtyWidget $
111+ traverseIntMapWithKeyWithAdjust (\k v -> unVtyWidget (f k v)) dm0 dm'
112+ traverseDMapWithKeyWithAdjust f dm0 dm' = VtyWidget $ do
113+ traverseDMapWithKeyWithAdjust (\k v -> unVtyWidget (f k v)) dm0 dm'
114+ traverseDMapWithKeyWithAdjustWithMove f dm0 dm' = VtyWidget $ do
115+ traverseDMapWithKeyWithAdjustWithMove (\k v -> unVtyWidget (f k v)) dm0 dm'
116+
117+-- | A widget that can read its context and produce image output
118+newtype VtyWidget t m a = VtyWidget
119+ { unVtyWidget :: BehaviorWriterT t [Image] (ReaderT (VtyWidgetCtx t) m) a
120+ }
121+ deriving (Functor, Applicative, Monad, MonadSample t, MonadHold t, MonadFix, NotReady t, ImageWriter t)
122+
123+-- | Runs a 'VtyWidget' with a given context
124+runVtyWidget
125+ :: (Reflex t, Monad m)
126+ => VtyWidgetCtx t
127+ -> VtyWidget t m a
128+ -> m (a, Behavior t [Image])
129+runVtyWidget ctx w = runReaderT (runBehaviorWriterT (unVtyWidget w)) ctx
27130
28−-- | Sets up the top-level context for a vty widget and runs it with that context
131+-- | Sets up the top-level context for a 'VtyWidget' and runs it with that context
29132mainWidgetWithHandle
30133 :: 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 ()))
134+ -> (forall t m. MonadVtyApp t m => VtyWidget t m (Event t ()))
40135 -> IO ()
41136mainWidgetWithHandle vty child =
42137 runVtyAppWithHandle vty $ \dr0 inp -> do
@@ -46,178 +141,60 @@ mainWidgetWithHandle vty child =
46141 let inp' = fforMaybe inp $ \case
47142 V.EvResize {} -> Nothing
48143 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
144+ let ctx = VtyWidgetCtx
145+ { _vtyWidgetCtx_width = fmap fst size
146+ , _vtyWidgetCtx_height = fmap snd size
147+ , _vtyWidgetCtx_input = inp'
148+ , _vtyWidgetCtx_focus = constDyn True
149+ }
150+ (shutdown, images) <- runVtyWidget ctx $ do
151+ tellImages . ffor (current size) $ \(w, h) -> [V.charFill V.defAttr ' ' w h]
152+ child
57153 return $ VtyResult
58154 { _vtyResult_picture = fmap (V.picForLayers . reverse) images
59155 , _vtyResult_shutdown = shutdown
60156 }
61157
62−-- | The output of a vty widget
63−data VtyWidgetOut t = VtyWidgetOut
64− { _vtyWidgetOut_shutdown :: Event t ()
65− }
66−
67158-- | Like 'mainWidgetWithHandle', but uses a default vty configuration
68159mainWidget
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 ()))
160+ :: (forall t m. MonadVtyApp t m => VtyWidget t m (Event t ()))
78161 -> IO ()
79162mainWidget child = do
80163 vty <- getDefaultVty
81164 mainWidgetWithHandle vty child
82165
83−-- * Input Events
166+-- | A class for things that know their own display size dimensions
167+class (Reflex t, Monad m) => HasDisplaySize t m | m -> t where
168+ -- | Retrieve the display width (columns)
169+ displayWidth :: m (Dynamic t Int)
170+ -- | Retrieve the display height (rows)
171+ displayHeight :: m (Dynamic t Int)
172+
173+instance (Reflex t, Monad m) => HasDisplaySize t (VtyWidget t m) where
174+ displayWidth = VtyWidget . lift $ asks _vtyWidgetCtx_width
175+ displayHeight = VtyWidget . lift $ asks _vtyWidgetCtx_height
84176
85177-- | A class for things that can receive vty events as input
86−class HasInput t m | m -> t where
178+class HasVtyInput t m | m -> t where
87179 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
180180
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
181+instance (Reflex t, Monad m) => HasVtyInput t (VtyWidget t m) where
182+ input = VtyWidget . lift $ asks _vtyWidgetCtx_input
183+
184+-- | A class for things that can dynamically gain and lose focus
185+class HasFocus t m | m -> t where
186+ focus :: m (Dynamic t Bool)
187+
188+instance (Reflex t, Monad m) => HasFocus t (VtyWidget t m) where
189+ focus = VtyWidget . lift $ asks _vtyWidgetCtx_focus
190+
191+-- | A class for widgets that can produce images to draw to the display
192+class (Reflex t, Monad m) => ImageWriter t m | m -> t where
193+ -- | Send images upstream for rendering
194+ tellImages :: Behavior t [Image] -> m ()
219195
220−-- * Getting and setting the display region
196+instance (Monad m, Reflex t) => ImageWriter t (BehaviorWriterT t [Image] m) where
197+ tellImages = tellBehavior
221198
222199-- | A chunk of the display area
223200data Region = Region
@@ -228,293 +205,26 @@ data Region = Region
228205 }
229206 deriving (Show, Read, Eq, Ord)
230207
231−-- | A region that occupies no space.
232−nilRegion :: Region
233−nilRegion = Region 0 0 0 0
208+-- | A dynamic chunk of the display area
209+data DynRegion t = DynRegion
210+ { _dynRegion_left :: Dynamic t Int
211+ , _dynRegion_top :: Dynamic t Int
212+ , _dynRegion_width :: Dynamic t Int
213+ , _dynRegion_height :: Dynamic t Int
214+ }
234215
235216-- | The width and height of a 'Region'
236217regionSize :: Region -> (Int, Int)
237218regionSize (Region _ _ w h) = (w, h)
238219
239220-- | 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
221+regionBlankImage :: Region -> Image
222+regionBlankImage r@(Region _ _ width height) =
223+ withinImage r $ V.charFill V.defAttr ' ' width height
318224
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
225+-- | A behavior of the current display area represented by a 'DynRegion'
226+currentRegion :: Reflex t => DynRegion t -> Behavior t Region
227+currentRegion (DynRegion l t w h) = Region <$> current l <*> current t <*> current w <*> current h
518228
519229-- | Translates and crops an 'Image' so that it is contained by
520230-- the given 'Region'.
@@ -526,17 +236,7 @@ withinImage (Region left top width height)
526236 | width < 0 || height < 0 = withinImage (Region left top 0 0)
527237 | otherwise = V.translate left top . V.crop width height
528238
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
239+-- | Low-level widget combinator that runs a child 'VtyWidget' within
540240-- a given region and context. This widget filters and modifies the input
541241-- that the child widget receives such that:
542242-- * unfocused widgets receive no key events
@@ -544,18 +244,388 @@ imagesInRegion reg = liftA2 (\r is -> map (withinImage r) is) reg
544244-- * mouse inputs inside the region have their coordinates translated such
545245-- that (0,0) is the top-left corner of the region
546246pane
547− :: (Reflex t, Monad m, HasInput t m, HasImageWriter t m, HasDisplayRegion t m, HasFocusReader t m)
548− => Dynamic t Region
247+ :: (Reflex t, Monad m)
248+ => DynRegion t
549249 -> 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 ()
250+ -> VtyWidget t m a
251+ -> VtyWidget t m a
252+pane dr foc child = VtyWidget $ do
253+ ctx <- lift ask
254+ let reg = currentRegion dr
255+ let ctx' = VtyWidgetCtx
256+ { _vtyWidgetCtx_input = leftmost -- TODO: think about this leftmost more.
257+ [ fmapMaybe id $
258+ attachWith (\(r,f) e -> filterInput r f e)
259+ (liftA2 (,) reg (current foc))
260+ (_vtyWidgetCtx_input ctx)
261+ ]
262+ , _vtyWidgetCtx_focus = liftA2 (&&) (_vtyWidgetCtx_focus ctx) foc
263+ , _vtyWidgetCtx_width = _dynRegion_width dr
264+ , _vtyWidgetCtx_height = _dynRegion_height dr
265+ }
266+ (result, images) <- lift . lift $ runVtyWidget ctx' child
267+ let images' = liftA2 (\r is -> map (withinImage r) is) reg images
268+ tellImages images'
269+ return result
270+ where
271+ filterInput :: Region -> Bool -> VtyEvent -> Maybe VtyEvent
272+ filterInput (Region l t w h) focused e = case e of
273+ V.EvKey _ _ | not focused -> Nothing
274+ V.EvMouseDown x y btn m -> mouse (\u v -> V.EvMouseDown u v btn m) x y
275+ V.EvMouseUp x y btn -> mouse (\u v -> V.EvMouseUp u v btn) x y
276+ _ -> Just e
277+ where
278+ mouse con x y
279+ | or [ x < l
280+ , y < t
281+ , x >= l + w
282+ , y >= t + h ] = Nothing
283+ | otherwise =
284+ Just (con (x - l) (y - t))
285+
286+
287+
288+-- | Information about a drag operation
289+data Drag = Drag
290+ { _drag_from :: (Int, Int) -- ^ Where the drag began
291+ , _drag_to :: (Int, Int) -- ^ Where the mouse currently is
292+ , _drag_button :: V.Button -- ^ Which mouse button is dragging
293+ , _drag_modifiers :: [V.Modifier] -- ^ What modifiers are held
294+ , _drag_end :: Bool -- ^ Whether the drag ended (the mouse button was released)
295+ }
296+ deriving (Eq, Ord, Show)
297+
298+-- | Converts raw vty mouse drag events into an event stream of 'Drag's
299+drag
300+ :: (Reflex t, MonadFix m, MonadHold t m)
301+ => V.Button
302+ -> VtyWidget t m (Event t Drag)
303+drag btn = do
304+ inp <- input
305+ let f :: Maybe Drag -> V.Event -> Maybe Drag
306+ f Nothing = \case
307+ V.EvMouseDown x y btn' mods
308+ | btn == btn' -> Just $ Drag (x,y) (x,y) btn' mods False
309+ | otherwise -> Nothing
310+ _ -> Nothing
311+ f (Just (Drag from _ _ mods end)) = \case
312+ V.EvMouseDown x y btn' mods'
313+ | end -> Just $ Drag (x,y) (x,y) btn' mods' False
314+ | btn == btn' -> Just $ Drag from (x,y) btn mods' False
315+ | otherwise -> Nothing -- Ignore other buttons.
316+ V.EvMouseUp x y (Just btn')
317+ | end -> Nothing
318+ | btn == btn' -> Just $ Drag from (x,y) btn mods True
319+ | otherwise -> Nothing
320+ V.EvMouseUp x y Nothing -- Terminal doesn't specify mouse up button,
321+ -- assume it's the right one.
322+ | end -> Nothing
323+ | otherwise -> Just $ Drag from (x,y) btn mods True
324+ _ -> Nothing
325+ rec let newDrag = attachWithMaybe f (current dragD) inp
326+ dragD <- holdDyn Nothing $ Just <$> newDrag
327+ return (fmapMaybe id $ updated dragD)
328+
329+-- | Mouse down events for a particular mouse button
330+mouseDown
331+ :: (Reflex t, Monad m)
332+ => V.Button
333+ -> VtyWidget t m (Event t MouseDown)
334+mouseDown btn = do
335+ i <- input
336+ return $ fforMaybe i $ \case
337+ V.EvMouseDown x y btn' mods -> if btn == btn'
338+ then Just $ MouseDown btn' (x, y) mods
339+ else Nothing
340+ _ -> Nothing
341+
342+-- | Mouse up events for a particular mouse button
343+mouseUp
344+ :: (Reflex t, Monad m)
345+ => VtyWidget t m (Event t MouseUp)
346+mouseUp = do
347+ i <- input
348+ return $ fforMaybe i $ \case
349+ V.EvMouseUp x y btn' -> Just $ MouseUp btn' (x, y)
350+ _ -> Nothing
351+
352+-- | Information about a mouse down event
353+data MouseDown = MouseDown
354+ { _mouseDown_button :: V.Button
355+ , _mouseDown_coordinates :: (Int, Int)
356+ , _mouseDown_modifiers :: [V.Modifier]
357+ }
358+ deriving (Eq, Ord, Show)
359+
360+-- | Information about a mouse up event
361+data MouseUp = MouseUp
362+ { _mouseUp_button :: Maybe V.Button
363+ , _mouseUp_coordinates :: (Int, Int)
364+ }
365+ deriving (Eq, Ord, Show)
366+
367+-- | A plain split of the available space into vertically stacked panes.
368+-- No visual separator is built in here.
369+splitV :: (Reflex t, Monad m)
370+ => Dynamic t (Int -> Int)
371+ -- ^ Function used to determine size of first pane based on available size
372+ -> Dynamic t (Bool, Bool)
373+ -- ^ How to focus the two sub-panes, given that we are focused.
374+ -> VtyWidget t m a
375+ -- ^ Widget for first pane
376+ -> VtyWidget t m b
377+ -- ^ Widget for second pane
378+ -> VtyWidget t m (a,b)
379+splitV sizeFunD focD wA wB = do
380+ dw <- displayWidth
381+ dh <- displayHeight
382+ let regA = DynRegion
383+ { _dynRegion_left = pure 0
384+ , _dynRegion_top = pure 0
385+ , _dynRegion_width = dw
386+ , _dynRegion_height = sizeFunD <*> dh
387+ }
388+ regB = DynRegion
389+ { _dynRegion_left = pure 0
390+ , _dynRegion_top = _dynRegion_height regA
391+ , _dynRegion_width = dw
392+ , _dynRegion_height = liftA2 (-) dh (_dynRegion_height regA)
393+ }
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+ dh <- displayHeight
408+ dw <- displayWidth
409+ h0 <- sample $ current dh -- TODO
410+ dragE <- drag V.BLeft
411+ let splitter0 = h0 `div` 2
412+ rec splitterCheckpoint <- holdDyn splitter0 $ leftmost [fst <$> ffilter snd dragSplitter, resizeSplitter]
413+ splitterPos <- holdDyn splitter0 $ leftmost [fst <$> dragSplitter, resizeSplitter]
414+ splitterFrac <- holdDyn ((1::Double) / 2) $ ffor (attach (current dh) (fst <$> dragSplitter)) $ \(h, x) ->
415+ fromIntegral x / fromIntegral h
416+ let dragSplitter = fforMaybe (attach (current splitterCheckpoint) dragE) $
417+ \(splitterY, Drag (_, fromY) (_, toY) _ _ end) ->
418+ if splitterY == fromY then Just (toY, end) else Nothing
419+ regA = DynRegion 0 0 dw splitterPos
420+ regS = DynRegion 0 splitterPos dw 1
421+ regB = DynRegion 0 (splitterPos + 1) dw (dh - splitterPos - 1)
422+ resizeSplitter = ffor (attach (current splitterFrac) (updated dh)) $
423+ \(frac, h) -> round (frac * fromIntegral h)
424+ focA <- holdDyn True $ leftmost
425+ [ True <$ mA
426+ , False <$ mB
427+ ]
428+ (mA, rA) <- pane regA focA $ withMouseDown wA
429+ pane regS (pure False) wS
430+ (mB, rB) <- pane regB (not <$> focA) $ withMouseDown wB
431+ return (rA, rB)
432+ where
433+ withMouseDown x = do
434+ m <- mouseDown V.BLeft
435+ x' <- x
436+ return (m, x')
437+
438+-- | Fill the background with a particular character.
439+fill :: (Reflex t, Monad m) => Char -> VtyWidget t m ()
440+fill c = do
441+ dw <- displayWidth
442+ dh <- displayHeight
443+ let fillImg = current $ liftA2 (\w h -> [V.charFill V.defAttr c w h]) dw dh
444+ tellImages fillImg
445+
446+-- | Fill the background with the bottom
447+hRule :: (Reflex t, Monad m) => BoxStyle -> VtyWidget t m ()
448+hRule boxStyle = fill (_boxStyle_s boxStyle)
449+
450+-- | Defines a set of symbols to use to draw the outlines of boxes
451+-- C.f. https://en.wikipedia.org/wiki/Box-drawing_character
452+data BoxStyle = BoxStyle
453+ { _boxStyle_nw :: Char
454+ , _boxStyle_n :: Char
455+ , _boxStyle_ne :: Char
456+ , _boxStyle_e :: Char
457+ , _boxStyle_se :: Char
458+ , _boxStyle_s :: Char
459+ , _boxStyle_sw :: Char
460+ , _boxStyle_w :: Char
461+ }
462+
463+instance Default BoxStyle where
464+ def = singleBoxStyle
465+
466+-- | A box style that uses hyphens and pipe characters. Doesn't handle
467+-- corners very well.
468+hyphenBoxStyle :: BoxStyle
469+hyphenBoxStyle = BoxStyle '-' '-' '-' '|' '-' '-' '-' '|'
470+
471+-- | A single line box style
472+singleBoxStyle :: BoxStyle
473+singleBoxStyle = BoxStyle '┌' '─' '┐' '│' '┘' '─' '└' '│'
474+
475+-- | A thick single line box style
476+thickBoxStyle :: BoxStyle
477+thickBoxStyle = BoxStyle '┏' '━' '┓' '┃' '┛' '━' '┗' '┃'
478+
479+-- | A double line box style
480+doubleBoxStyle :: BoxStyle
481+doubleBoxStyle = BoxStyle '╔' '═' '╗' '║' '╝' '═' '╚' '║'
482+
483+-- | A single line box style with rounded corners
484+roundedBoxStyle :: BoxStyle
485+roundedBoxStyle = BoxStyle '╭' '─' '╮' '│' '╯' '─' '╰' '│'
486+
487+-- | Draws a box in the provided style and a child widget inside of that box
488+box :: (Monad m, Reflex t)
489+ => Behavior t BoxStyle
490+ -> VtyWidget t m a
491+ -> VtyWidget t m a
492+box boxStyle child = do
493+ dh <- displayHeight
494+ dw <- displayWidth
495+ let boxReg = DynRegion (pure 0) (pure 0) dw dh
496+ innerReg = DynRegion (pure 1) (pure 1) (subtract 2 <$> dw) (subtract 2 <$> dh)
497+ tellImages (boxImages <$> boxStyle <*> currentRegion boxReg)
498+ tellImages (fmap (\r -> [regionBlankImage r]) (currentRegion innerReg))
499+ pane innerReg (pure True) child
500+ where
501+ boxImages :: BoxStyle -> Region -> [Image]
502+ boxImages style (Region left top width height) =
503+ let right = left + width - 1
504+ bottom = top + height - 1
505+ sides =
506+ [ withinImage (Region (left + 1) top (width - 2) 1) $
507+ V.charFill V.defAttr (_boxStyle_n style) (width - 2) 1
508+ , withinImage (Region right (top + 1) 1 (height - 2)) $
509+ V.charFill V.defAttr (_boxStyle_e style) 1 (height - 2)
510+ , withinImage (Region (left + 1) bottom (width - 2) 1) $
511+ V.charFill V.defAttr (_boxStyle_s style) (width - 2) 1
512+ , withinImage (Region left (top + 1) 1 (height - 2)) $
513+ V.charFill V.defAttr (_boxStyle_w style) 1 (height - 2)
514+ ]
515+ corners =
516+ [ withinImage (Region left top 1 1) $
517+ V.char V.defAttr (_boxStyle_nw style)
518+ , withinImage (Region right top 1 1) $
519+ V.char V.defAttr (_boxStyle_ne style)
520+ , withinImage (Region right bottom 1 1) $
521+ V.char V.defAttr (_boxStyle_se style)
522+ , withinImage (Region left bottom 1 1) $
523+ V.char V.defAttr (_boxStyle_sw style)
524+ ]
525+ in sides ++ if width > 1 && height > 1 then corners else []
526+
527+-- | A box whose style is static
528+boxStatic
529+ :: (Reflex t, Monad m)
530+ => BoxStyle
531+ -> VtyWidget t m a
532+ -> VtyWidget t m a
533+boxStatic = box . pure
534+
535+-- | Configuration options for displaying "rich" text
536+data RichTextConfig t = RichTextConfig
537+ { _richTextConfig_attributes :: Behavior t V.Attr
538+ }
539+
540+instance Reflex t => Default (RichTextConfig t) where
541+ def = RichTextConfig $ pure V.defAttr
542+
543+-- | A widget that displays text with custom time-varying attributes
544+richText
545+ :: (Reflex t, Monad m)
546+ => RichTextConfig t
547+ -> Behavior t Text
548+ -> VtyWidget t m ()
549+richText cfg t = do
550+ dw <- displayWidth
551+ let img = (\w a s -> [wrapText w a s])
552+ <$> current dw
553+ <*> _richTextConfig_attributes cfg
554+ <*> t
555+ tellImages img
556+ where
557+ wrapText maxWidth attrs = V.vertCat
558+ . concatMap (fmap (V.string attrs . T.unpack) . TZ.wrapWithOffset maxWidth 0)
559+ . T.split (=='\n')
560+
561+-- | Renders text, wrapped to the container width
562+text
563+ :: (Reflex t, Monad m)
564+ => Behavior t Text
565+ -> VtyWidget t m ()
566+text = richText def
567+
568+-- | Renders any behavior whose value can be converted to
569+-- 'String' as text
570+display
571+ :: (Reflex t, Monad m, Show a)
572+ => Behavior t a
573+ -> VtyWidget t m ()
574+display a = text $ T.pack . show <$> a
575+
576+data Direction = Direction_Column
577+ | Direction_Row
578+ deriving (Show, Read, Eq, Ord)
579+
580+newtype StackWidget t m a = StackWidget { unStackWidget :: Direction -> VtyWidget t m (Dynamic t Int, a) }
581+ deriving (Functor)
582+
583+instance (Reflex t, MonadFix m) => Applicative (StackWidget t m) where
584+ pure = return
585+ (<*>) = ap
586+
587+instance (MonadFix m, Reflex t) => Monad (StackWidget t m) where
588+ w >>= g = StackWidget $ \dir -> do
589+ (sz, r) <- runStackWidget dir 0 w
590+ (sz', r') <- runStackWidget dir sz (g r)
591+ return (sz + sz', r')
592+ return x = StackWidget $ \_ -> return (0, x)
593+
594+runStackWidget
595+ :: (Reflex t, MonadFix m)
596+ => Direction
597+ -> Dynamic t Int
598+ -> StackWidget t m a
599+ -> VtyWidget t m (Dynamic t Int, a)
600+runStackWidget dir offset x = do
601+ mkRegion <- case dir of
602+ Direction_Column -> (\w sz -> DynRegion 0 offset w sz) <$> displayWidth
603+ Direction_Row -> (\h sz -> DynRegion offset 0 sz h) <$> displayHeight
604+ rec (h, a) <- pane (mkRegion h) (pure True) $ unStackWidget x dir
605+ return (h, a)
606+
607+stack
608+ :: (Reflex t, MonadFix m)
609+ => Direction
610+ -> StackWidget t m a
611+ -> VtyWidget t m a
612+stack dir w = fmap snd $ runStackWidget dir 0 w
613+
614+col
615+ :: (Reflex t, MonadFix m)
616+ => StackWidget t m a
617+ -> VtyWidget t m a
618+col = stack Direction_Column
619+
620+row
621+ :: (Reflex t, MonadFix m)
622+ => StackWidget t m a
623+ -> VtyWidget t m a
624+row = stack Direction_Row
625+
626+sized
627+ :: (Reflex t, MonadFix m)
628+ => Dynamic t Int
629+ -> VtyWidget t m a
630+ -> StackWidget t m a
631+sized sz w = StackWidget $ \_ -> (sz,) <$> w