@@ -1,113 +1,43 @@
1−{-# LANGUAGE FlexibleContexts #-}
2−{-# LANGUAGE FlexibleInstances #-}
3−{-# LANGUAGE FunctionalDependencies #-}
4−{-# LANGUAGE GeneralizedNewtypeDeriving #-}
5−{-# LANGUAGE LambdaCase #-}
6−{-# LANGUAGE MultiParamTypeClasses #-}
7−{-# LANGUAGE OverloadedStrings #-}
8−{-# LANGUAGE RankNTypes #-}
9−{-# LANGUAGE RecursiveDo #-}
10−{-# LANGUAGE TypeFamilies #-}
11−module Reflex.Vty.Widget
12− ( VtyWidgetCtx(..)
13− , VtyWidget(..)
14− , VtyWidgetOut(..)
15− , runVtyWidget
16− , mainWidget
17− , mainWidgetWithHandle
18− , HasDisplaySize(..)
19− , displayWidth
20− , displayHeight
21− , HasFocus(..)
22− , HasVtyInput(..)
23− , Region(..)
24− , regionSize
25− , regionBlankImage
26− , Drag (..)
27− , drag
28− , mouseDown
29− , pane
30− , modifyImages
31− , tellImages
32− , tellShutdown
33− , wrapText
34− , splitV
35− , splitVDrag
36− , fractionSz
37− , box
38− , text
39− , hyphenBoxStyle
40− , singleBoxStyle
41− , roundedBoxStyle
42− , thickBoxStyle
43− , doubleBoxStyle
44− , fill
45− , hRule
46− , TextInputConfig(..)
47− , textInput
48− , multilineTextInput
49− , def
50− ) where
1+{-|
2+Module: Reflex.Vty.Widget
3+Description: Basic set of widgets and building blocks for reflex-vty applications
4+-}
5+{-# Language UndecidableInstances #-}
6+
7+module Reflex.Vty.Widget where
518
529import Control.Applicative (liftA2)
5310import Control.Monad.Fix (MonadFix)
54−import Control.Monad.Trans (lift)
55−import Control.Monad.Trans.Reader (ReaderT, runReaderT, asks, ask)
56−import Control.Monad.Trans.Writer (WriterT, runWriterT, censor, tell)
57−import Data.Char
58−import Data.Default
59−import Data.Maybe (fromMaybe)
60−import Data.Text (Text)
61−import qualified Data.Text as T
62−import Graphics.Vty (Image, Attr)
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
19+import Graphics.Vty (Image)
6320import qualified Graphics.Vty as V
6421import Reflex
65−
22+import Reflex.Class ()
23+import Reflex.Host.Class (MonadReflexCreateTrigger)
6624import Reflex.Vty.Host
6725
68−-- | The context within which a 'VtyWidget' runs
69−data VtyWidgetCtx t = VtyWidgetCtx
70− { _vtyWidgetCtx_size :: Dynamic t (Int,Int)
71− -- ^ The width and height of the region allocated to the widget.
72− , _vtyWidgetCtx_focus :: Dynamic t Bool
73− -- ^ Whether the widget should behave as if it has focus for keyboard input.
74− , _vtyWidgetCtx_input :: Event t VtyEvent
75− -- ^ User input events that the widget's parent chooses to share. These will generally
76− -- be filtered for relevance:
77− -- * Keyboard inputs are restricted to focused widgets
78− -- * Mouse inputs are restricted to the region in which the widget resides and are
79− -- translated into its internal coordinates.
80− }
81−
82−-- | The output of a 'VtyWidget'
83−data VtyWidgetOut t = VtyWidgetOut
84− { _vtyWidgetOut_images :: Behavior t [Image]
85− -- ^ The visual output of the 'VtyWidget'
86− , _vtyWidgetOut_shutdown :: Event t ()
87− }
88−
89−instance Reflex t => Semigroup (VtyWidgetOut t) where
90− wo <> wo' = VtyWidgetOut
91− { _vtyWidgetOut_images = _vtyWidgetOut_images wo <> _vtyWidgetOut_images wo'
92− , _vtyWidgetOut_shutdown = _vtyWidgetOut_shutdown wo <> _vtyWidgetOut_shutdown wo'
93− }
94−
95−instance (Reflex t) => Monoid (VtyWidgetOut t) where
96− mempty = VtyWidgetOut mempty mempty
97− mappend wo wo' = wo <> wo'
98−
99−newtype VtyWidget t m a = VtyWidget { unVtyWidget :: WriterT (VtyWidgetOut t) (ReaderT (VtyWidgetCtx t) m) a }
100− deriving (Functor, Applicative, Monad, MonadSample t, MonadHold t, MonadFix)
101−
102−-- | Runs a 'VtyWidget' with a given context
103−runVtyWidget :: (Reflex t)
104− => VtyWidgetCtx t
105− -> VtyWidget t m a
106− -> m (a, VtyWidgetOut t)
107−runVtyWidget ctx w = runReaderT (runWriterT (unVtyWidget w)) ctx
108−
109−-- | Sets up the top-level context for a 'VtyWidget' and runs it with that context
110−mainWidgetWithHandle :: V.Vty -> (forall t m. MonadVtyApp t m => VtyWidget t m ()) -> IO ()
26+-- * Running a vty application
27+
28+-- | Sets up the top-level context for a vty widget and runs it with that context
29+mainWidgetWithHandle
30+ :: 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 ()))
40+ -> IO ()
11141mainWidgetWithHandle vty child =
11242 runVtyAppWithHandle vty $ \dr0 inp -> do
11343 size <- holdDyn dr0 $ fforMaybe inp $ \case
@@ -116,59 +46,180 @@ mainWidgetWithHandle vty child =
11646 let inp' = fforMaybe inp $ \case
11747 V.EvResize {} -> Nothing
11848 x -> Just x
119− let ctx = VtyWidgetCtx
120− { _vtyWidgetCtx_size = size
121− , _vtyWidgetCtx_input = inp'
122− , _vtyWidgetCtx_focus = constDyn True
123− }
124− ((), wo) <- runVtyWidget ctx 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
12557 return $ VtyResult
126− { _vtyResult_picture = fmap (V.picForLayers . reverse) (_vtyWidgetOut_images wo)
127− , _vtyResult_shutdown = _vtyWidgetOut_shutdown wo
58+ { _vtyResult_picture = fmap (V.picForLayers . reverse) images
59+ , _vtyResult_shutdown = shutdown
12860 }
12961
62+-- | The output of a vty widget
63+data VtyWidgetOut t = VtyWidgetOut
64+ { _vtyWidgetOut_shutdown :: Event t ()
65+ }
66+
13067-- | Like 'mainWidgetWithHandle', but uses a default vty configuration
131−mainWidget :: (forall t m. MonadVtyApp t m => VtyWidget t m ()) -> IO ()
68+mainWidget
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 ()))
78+ -> IO ()
13279mainWidget child = do
13380 vty <- getDefaultVty
13481 mainWidgetWithHandle vty child
13582
136−class (Reflex t, Monad m) => HasDisplaySize t m | m -> t where
137− displaySize :: m (Dynamic t (Int, Int))
138−
139−instance (Reflex t, Monad m) => HasDisplaySize t (VtyWidget t m) where
140− displaySize = VtyWidget . lift $ asks _vtyWidgetCtx_size
141−
142−displayWidth :: HasDisplaySize t m => m (Dynamic t Int)
143−displayWidth = fmap fst <$> displaySize
83+-- * Input Events
14484
145−displayHeight :: HasDisplaySize t m => m (Dynamic t Int)
146−displayHeight = fmap snd <$> displaySize
147−
148−class HasVtyInput t m | m -> t where
85+-- | A class for things that can receive vty events as input
86+class HasInput t m | m -> t where
14987 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
150180
151−instance (Reflex t, Monad m) => HasVtyInput t (VtyWidget t m) where
152− input = VtyWidget . lift $ asks _vtyWidgetCtx_input
153−
154−class HasFocus t m | m -> t where
155− focus :: m (Dynamic t Bool)
156−
157−instance (Reflex t, Monad m) => HasFocus t (VtyWidget t m) where
158− focus = VtyWidget . lift $ asks _vtyWidgetCtx_focus
159−
160−class (Reflex t, Monad m) => ImageWriter t m | m -> t where
161− tellImages :: Behavior t [Image] -> m ()
162−
163−instance (Reflex t, Monad m) => ImageWriter t (VtyWidget t m) where
164− tellImages imgs = VtyWidget $ tell (mempty { _vtyWidgetOut_images = imgs })
165−
166−class (Reflex t, Monad m) => Shutdown t m where
167− tellShutdown :: Event t () -> 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
168219
169−instance (Reflex t, Monad m) => Shutdown t (VtyWidget t m) where
170− tellShutdown sd = VtyWidget $ tell (mempty { _vtyWidgetOut_shutdown = sd })
220+-- * Getting and setting the display region
171221
222+-- | A chunk of the display area
172223data Region = Region
173224 { _region_left :: Int
174225 , _region_top :: Int
@@ -177,397 +228,334 @@ data Region = Region
177228 }
178229 deriving (Show, Read, Eq, Ord)
179230
231+-- | A region that occupies no space.
232+nilRegion :: Region
233+nilRegion = Region 0 0 0 0
234+
235+-- | The width and height of a 'Region'
180236regionSize :: Region -> (Int, Int)
181237regionSize (Region _ _ w h) = (w, h)
182238
183−pane
239+-- | 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
184311 :: (Reflex t, Monad m)
185− => Dynamic t Region -- ^ Region into which we should draw the widget (in coordinates relative to our own)
186− -> Dynamic t Bool -- ^ Whether the widget should be focused when the parent is.
187− -> VtyWidget t m a
188− -> VtyWidget t m a
189−pane reg foc child = VtyWidget $ do
190− ctx <- lift ask
191− let ctx' = VtyWidgetCtx
192− { _vtyWidgetCtx_input = leftmost -- TODO: think about this leftmost more.
193− [ fmapMaybe id $
194− attachWith (\(r,f) e -> filterInput r f e)
195− (liftA2 (,) (current reg) (current foc))
196− (_vtyWidgetCtx_input ctx)
197− ]
198− , _vtyWidgetCtx_focus = liftA2 (&&) (_vtyWidgetCtx_focus ctx) foc
199− , _vtyWidgetCtx_size = fmap regionSize reg }
200− (result, wo) <- lift . lift $ runVtyWidget ctx' child
201− let images = _vtyWidgetOut_images wo
202− images' = liftA2 (\r is -> map (withinImage r) is) (current reg) images
203− wo' = wo { _vtyWidgetOut_images = images' }
204− tell wo'
205− return result
206− where
207− -- Filters input such that:
208− -- * unfocused widgets receive no key events
209− -- * mouse inputs outside the region are ignored
210− -- * mouse inputs inside the region have their coordinates translated
211− -- such that (0,0) is the top-left corner of the region
212− filterInput :: Region -> Bool -> VtyEvent -> Maybe VtyEvent
213− filterInput (Region l t w h) focused e = case e of
214− V.EvKey _ _ | not focused -> Nothing
215− V.EvMouseDown x y btn m -> mouse (\u v -> V.EvMouseDown u v btn m) x y
216− V.EvMouseUp x y btn -> mouse (\u v -> V.EvMouseUp u v btn) x y
217− _ -> Just e
218− where
219− mouse con x y
220− | or [ x < l
221− , y < t
222− , x >= l + w
223− , y >= t + h ] = Nothing
224− | otherwise =
225− Just (con (x - l) (y - t))
226−
227−data Drag = Drag
228− { _drag_from :: (Int, Int) -- ^ Where the drag began
229− , _drag_to :: (Int, Int) -- ^ Where the mouse currently is
230− , _drag_button :: V.Button -- ^ Which mouse button is dragging
231− , _drag_modifiers :: [V.Modifier] -- ^ What modifiers are held
232− , _drag_end :: Bool -- ^ Whether the drag ended (the mouse button was released)
233− }
234− deriving (Eq, Ord, Show)
312+ => Dynamic t Region
313+ -> DisplayRegion t m a
314+ -> m a
315+runDisplayRegion r = flip runReaderT r . unDisplayRegion
235316
236−drag
237− :: (Reflex t, MonadFix m, MonadHold t m)
238− => V.Button
239− -> VtyWidget t m (Event t Drag)
240−drag btn = do
241− inp <- input
242− let f :: Drag -> V.Event -> Maybe Drag
243− f (Drag from _ _ mods end) = \case
244− V.EvMouseDown x y btn' mods'
245− | end -> Just $ Drag (x,y) (x,y) btn' mods' False
246− | btn == btn' -> Just $ Drag from (x,y) btn mods' False
247− | otherwise -> Nothing -- Ignore other buttons.
248− V.EvMouseUp x y (Just btn')
249− | end -> Nothing
250− | btn == btn' -> Just $ Drag from (x,y) btn mods True
251− | otherwise -> Nothing
252− V.EvMouseUp x y Nothing -- Terminal doesn't specify mouse up button,
253− -- assume it's the right one.
254− | end -> Nothing
255− | otherwise -> Just $ Drag from (x,y) btn mods True
256− _ -> Nothing
257− rec let newDrag = attachWithMaybe f (current dragD) inp
258− dragD <- holdDyn (Drag (0,0) (0,0) btn [] True) -- gross, but ok because it'll never be produced.
259− newDrag
260− return (updated dragD)
261−
262−mouseDown
263− :: (Reflex t, Monad m)
264− => V.Button
265− -> VtyWidget t m (Event t VtyEvent)
266−mouseDown btn = do
267− i <- input
268− return $ fforMaybe i $ \x -> case x of
269− V.EvMouseDown _ _ btn' _ -> if btn == btn' then Just x else Nothing
270− _ -> Nothing
317+-- * Getting focus state
271318
272−-- | A plain split of the available space into vertically stacked panes.
273−-- No visual separator is built in here.
274−splitV :: (Reflex t, Monad m)
275− => Dynamic t (Int -> Int)
276− -- ^ Function used to determine size of first pane based on available size
277− -> Dynamic t (Bool, Bool)
278− -- ^ How to focus the two sub-panes, given that we are focused.
279− -> VtyWidget t m a
280− -- ^ Widget for first pane
281− -> VtyWidget t m b
282− -- ^ Widget for second pane
283− -> VtyWidget t m (a,b)
284−splitV sizeFunD focD wA wB = do
285− sz <- displaySize
286− let regA = (\f (w,h) -> Region 0 0 w (f h)) <$> sizeFunD <*> sz
287− regB = (\(w,h) (Region _ _ _ hA) -> Region 0 hA w (h - hA)) <$> sz <*> regA
288− ra <- pane regA (fst <$> focD) wA
289− rb <- pane regB (snd <$> focD) wB
290− return (ra,rb)
291−
292−-- | A split of the available space into two parts with a draggable separator.
293−-- Starts with half the space allocated to each, and the first pane has focus.
294−-- Clicking in a pane switches focus.
295−splitVDrag :: (Reflex t, MonadFix m, MonadHold t m)
296− => VtyWidget t m ()
297− -> VtyWidget t m a
298− -> VtyWidget t m b
299− -> VtyWidget t m (a,b)
300−splitVDrag wS wA wB = do
301− sz <- displaySize
302− (_, h0) <- sample $ current sz
303− dragE <- drag V.BLeft
304− let splitter0 = h0 `div` 2
305− rec splitterCheckpoint <- holdDyn splitter0 $ leftmost [fst <$> ffilter snd dragSplitter, resizeSplitter]
306− splitterPos <- holdDyn splitter0 $ leftmost [fst <$> dragSplitter, resizeSplitter]
307− splitterFrac <- holdDyn ((1::Double) / 2) $ ffor (attach (current sz) (fst <$> dragSplitter)) $ \((_,h),x) ->
308− fromIntegral x / fromIntegral h
309− let dragSplitter = fforMaybe (attach (current splitterCheckpoint) dragE) $
310− \(splitterY, Drag (_, fromY) (_, toY) _ _ end) ->
311− if splitterY == fromY then Just (toY, end) else Nothing
312− regA = (\(w,_) sp -> Region 0 0 w sp) <$> sz <*> splitterPos
313− regS = (\(w,_) sp -> Region 0 sp w 1) <$> sz <*> splitterPos
314− regB = (\(w,h) sp -> Region 0 (sp + 1) w (h - sp - 1)) <$> sz <*> splitterPos
315− resizeSplitter = ffor (attach (current splitterFrac) (updated sz)) $
316− \(frac, (_,h)) -> round (frac * fromIntegral h)
317− focA <- holdDyn True $ leftmost
318− [ True <$ mA
319− , False <$ mB
320− ]
321− (mA, rA) <- pane regA focA $ withMouseDown wA
322− pane regS (pure False) wS
323− (mB, rB) <- pane regB (not <$> focA) $ withMouseDown wB
324− return (rA, rB)
325− where
326− withMouseDown x = do
327− m <- mouseDown V.BLeft
328− x' <- x
329− return (m, x')
330−
331−-- | Fill the background with a particular character.
332−fill :: (Reflex t, Monad m) => Char -> VtyWidget t m ()
333−fill c = do
334− sz <- displaySize
335− let fillImg = ffor (current sz) $ \(w,h) -> [V.charFill V.defAttr c w h]
336− tellImages fillImg
337−
338−-- | Fill the background with the bottom
339−hRule :: (Reflex t, Monad m) => BoxStyle -> VtyWidget t m ()
340−hRule boxStyle = fill (_boxStyle_s boxStyle)
341−
342−fractionSz :: Double -> Int -> Int
343−fractionSz x h = round (fromIntegral h * x)
344−
345−modifyImages
346− :: (Reflex t, MonadHold t m, MonadFix m)
347− => Behavior t ([Image] -> [Image])
348− -> VtyWidget t m a
349− -> VtyWidget t m a
350−modifyImages f (VtyWidget w) = VtyWidget $ flip censor w $ \wo ->
351− wo { _vtyWidgetOut_images = f <*> (_vtyWidgetOut_images wo) }
352−
353−data BoxStyle = BoxStyle
354− { _boxStyle_nw :: Char
355− , _boxStyle_n :: Char
356− , _boxStyle_ne :: Char
357− , _boxStyle_e :: Char
358− , _boxStyle_se :: Char
359− , _boxStyle_s :: Char
360− , _boxStyle_sw :: Char
361− , _boxStyle_w :: Char
362− }
363−
364−instance Default BoxStyle where
365− def = singleBoxStyle
366−
367−hyphenBoxStyle :: BoxStyle
368−hyphenBoxStyle = BoxStyle '-' '-' '-' '|' '-' '-' '-' '|'
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
369380
370−singleBoxStyle :: BoxStyle
371−singleBoxStyle = BoxStyle '┌' '─' '┐' '│' '┘' '─' '└' '│'
381+-- * "Image" output
372382
373−thickBoxStyle :: BoxStyle
374−thickBoxStyle = BoxStyle '┏' '━' '┓' '┃' '┛' '━' '┗' '┃'
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
375515
376−doubleBoxStyle :: BoxStyle
377−doubleBoxStyle = BoxStyle '╔' '═' '╗' '║' '╝' '═' '╚' '║'
378516
379−roundedBoxStyle :: BoxStyle
380−roundedBoxStyle = BoxStyle '╭' '─' '╮' '│' '╯' '─' '╰' '│'
517+-- ** Manipulating images
381518
382−box :: (Monad m, Reflex t)
383− => BoxStyle
384− -> VtyWidget t m a
385− -> VtyWidget t m a
386−box style child = do
387− sz <- displaySize
388− let boxReg = ffor (current sz) $ \(w,h) -> Region 0 0 w h
389− innerReg = ffor sz $ \(w,h) -> Region 1 1 (w - 2) (h - 2)
390− tellImages (fmap boxImages boxReg)
391− tellImages (fmap (\r -> [regionBlankImage r]) (current innerReg))
392− pane innerReg (pure True) child
393− where
394− boxImages :: Region -> [Image]
395− boxImages (Region left top width height) =
396− let right = left + width - 1
397− bottom = top + height - 1
398− sides =
399− [ withinImage (Region (left + 1) top (width - 2) 1) $
400− V.charFill V.defAttr (_boxStyle_n style) (width - 2) 1
401− , withinImage (Region right (top + 1) 1 (height - 2)) $
402− V.charFill V.defAttr (_boxStyle_e style) 1 (height - 2)
403− , withinImage (Region (left + 1) bottom (width - 2) 1) $
404− V.charFill V.defAttr (_boxStyle_s style) (width - 2) 1
405− , withinImage (Region left (top + 1) 1 (height - 2)) $
406− V.charFill V.defAttr (_boxStyle_w style) 1 (height - 2)
407− ]
408− corners =
409− [ withinImage (Region left top 1 1) $
410− V.char V.defAttr (_boxStyle_nw style)
411− , withinImage (Region right top 1 1) $
412− V.char V.defAttr (_boxStyle_ne style)
413− , withinImage (Region right bottom 1 1) $
414− V.char V.defAttr (_boxStyle_se style)
415− , withinImage (Region left bottom 1 1) $
416− V.char V.defAttr (_boxStyle_sw style)
417− ]
418− in sides ++ if width > 1 && height > 1 then corners else []
419−
420−text :: (Reflex t, Monad m) => Behavior t Text -> VtyWidget t m ()
421−text msg = do
422− dw <- displayWidth
423− let img = (\w s -> [wrapText w V.defAttr s]) <$> current dw <*> msg
424− tellImages img
425−
426−regionBlankImage :: Region -> Image
427−regionBlankImage r@(Region _ _ width height) =
428− withinImage r $ V.charFill V.defAttr ' ' width height
429−
430−withinImage :: Region -> Image -> Image
519+-- | Translates and crops an 'Image' so that it is contained by
520+-- the given 'Region'.
521+withinImage
522+ :: Region
523+ -> Image
524+ -> Image
431525withinImage (Region left top width height)
432526 | width < 0 || height < 0 = withinImage (Region left top 0 0)
433527 | otherwise = V.translate left top . V.crop width height
434528
435−wrapText :: Int -> Attr -> Text -> Image
436−wrapText maxWidth attrs = V.vertCat
437− . concatMap (fmap (V.string attrs . T.unpack) . wrapWithOffset maxWidth 0)
438− . T.split (=='\n')
439−
440−wrapWithOffset :: Int -> Int -> Text -> [Text]
441−wrapWithOffset maxWidth n xs =
442− let (firstLine, rest) = T.splitAt (maxWidth - n) xs
443− in firstLine : (fmap (T.take maxWidth) . takeWhile (not . T.null) . iterate (T.drop maxWidth) $ rest)
444−
445−wrapInputState
446− :: Int -- ^ Maximum line length
447− -> Attr -- ^ Normal string attributes
448− -> Attr -- ^ Cursor character attributes
449− -> InputState -- ^ The input to render
450− -> Image
451−wrapInputState maxWidth attrs cursorAttrs (InputState before after) =
452− let -- Break up the InputState into:
453− -- * A top section of lines before the line containing the cursor
454− -- * A part of the line containing the cursor that comes immediately before the cursor
455− -- * The cursor character (i.e., the character the cursor is on top of)
456− -- * The remainder of the line containing the cursor
457− -- * The bottom section of lines after the line containing the cursor
458− (top, midBefore, cursorChar, midAfter, bottom) = case (initLast before', headTail after') of
459− (Nothing, Nothing) -> ([], "", ' ', "", [])
460− (Just (top', mid), Nothing) -> (top', mid, ' ', "", [])
461− (Nothing, Just (mid, bottom')) -> case T.uncons mid of
462− Nothing -> ([], "", ' ', "", bottom')
463− Just (c, rest) -> ([], "", c, rest, bottom')
464− (Just (top', midB), Just (midA, bottom')) -> case T.uncons midA of
465− Nothing -> (top', midB, ' ', "", bottom')
466− Just (c, rest) -> (top', midB, c, rest, bottom')
467− (midBeforeTop, midBefore') = fromMaybe ([], "") $ initLast $ wrap [midBefore]
468− (midAfter', midAfterBottom) =
469− let offset = if T.length midBefore' == maxWidth then 1 else T.length midBefore' + 1
470− in case wrapWithOffset maxWidth offset midAfter of
471− [] -> ("", [])
472− x:xs -> (x, xs)
473− cursor = V.char cursorAttrs cursorChar
474− in V.vertCat $ mconcat
475− [ vstring <$> wrap top
476− , vstring <$> midBeforeTop
477− , if T.length midBefore' == maxWidth
478− then
479− [ vstring midBefore'
480− , V.horizCat
481− [ cursor
482− , vstring midAfter'
483− ]
484− ]
485− else
486− [ V.horizCat
487− [ vstring midBefore'
488− , cursor
489− , vstring midAfter'
490− ]
491− ]
492− , vstring <$> midAfterBottom
493− , vstring <$> bottom
494− ]
495− where
496− before' = T.split (=='\n') before
497− after' = T.split (=='\n') after
498− vstring = V.string attrs . T.unpack
499− wrap :: [Text] -> [Text]
500− wrap = concatMap (wrapWithOffset maxWidth 0)
501− headTail :: [a] -> Maybe (a, [a])
502− headTail = \case
503− [] -> Nothing
504− x:xs -> Just (x, xs)
505− initLast :: [a] -> Maybe ([a], a)
506− initLast = \case
507− [] -> Nothing
508− (x:xs) -> case initLast xs of
509− Nothing -> Just ([], x)
510− Just (ys, y) -> Just (x:ys, y)
511−
512−data InputState = InputState
513− { _inputState_beforeCursor :: Text
514− , _inputState_afterCursor :: Text
515− }
516−
517−inputValue :: InputState -> Text
518−inputValue (InputState a b) = a <> b
519−
520−updateInputState :: V.Event -> InputState -> InputState
521−updateInputState ev i@(InputState before after) = case ev of
522− -- Regular characters
523− V.EvKey (V.KChar k) [] -> InputState (T.snoc before k) after
524− -- Deletion buttons
525− V.EvKey V.KBS [] -> InputState (if T.null before then T.empty else T.init before) after
526− V.EvKey V.KDel [] -> case T.uncons after of
527− Nothing -> i
528− Just (_, a) -> InputState before a
529− -- Key combinations
530− V.EvKey (V.KChar 'u') [V.MCtrl] -> InputState mempty mempty
531− V.EvKey (V.KChar 'w') [V.MCtrl] -> InputState (T.dropWhileEnd (not . isSpace) $ T.dropWhileEnd isSpace $ before) after
532− -- Navigation
533− V.EvKey V.KRight [] -> case T.uncons after of
534− Nothing -> i
535− Just (a, as) -> InputState (T.snoc before a) as
536− V.EvKey V.KLeft [] -> case T.unsnoc before of
537− Nothing -> i
538− Just (bs, b) -> InputState bs (T.cons b after)
539− _ -> i
540−
541−data TextInputConfig t = TextInputConfig
542− { _textInputConfig_initialValue :: Text
543− , _textInputConfig_modifyInputState :: Event t (InputState -> InputState)
544− }
545−
546−instance Reflex t => Default (TextInputConfig t) where
547− def = TextInputConfig "" never
548−
549−textInput :: (Reflex t, MonadHold t m, MonadFix m) => TextInputConfig t -> VtyWidget t m (Dynamic t Text)
550−textInput cfg = do
551− i <- input
552− v <- foldDyn ($) (InputState (_textInputConfig_initialValue cfg) mempty) $ mergeWith (.)
553− [ updateInputState <$> i
554− , _textInputConfig_modifyInputState cfg
555− ]
556− dw <- displayWidth
557− let img = (\w s -> [wrapInputState w V.defAttr (V.withStyle V.defAttr V.reverseVideo) s]) -- TODO cursor ought to blink
558− <$> current dw
559− <*> current v
560− tellImages img
561− return $ inputValue <$> v
562−
563−multilineTextInput :: (Reflex t, MonadHold t m, MonadFix m) => TextInputConfig t -> VtyWidget t m (Dynamic t Text)
564−multilineTextInput cfg = do
565− i <- input
566− textInput $ cfg
567− { _textInputConfig_modifyInputState = mergeWith (.)
568− [ fforMaybe i $ \case
569− V.EvKey V.KEnter [] -> Just $ \(InputState before after) -> InputState (T.snoc before '\n') after
570− _ -> Nothing
571− , _textInputConfig_modifyInputState cfg
572− ]
573− }
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
540+-- a given region and context. This widget filters and modifies the input
541+-- that the child widget receives such that:
542+-- * unfocused widgets receive no key events
543+-- * mouse inputs outside the region are ignored
544+-- * mouse inputs inside the region have their coordinates translated such
545+-- that (0,0) is the top-left corner of the region
546+pane
547+ :: (Reflex t, Monad m, HasInput t m, HasImageWriter t m, HasDisplayRegion t m, HasFocusReader t m)
548+ => Dynamic t Region
549+ -> 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 ()