@@ -1,115 +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− , display
40− , hyphenBoxStyle
41− , singleBoxStyle
42− , roundedBoxStyle
43− , thickBoxStyle
44− , doubleBoxStyle
45− , fill
46− , hRule
47− , TextInputConfig(..)
48− , textInput
49− , multilineTextInput
50− , def
51− ) 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
528
539import Control.Applicative (liftA2)
5410import Control.Monad.Fix (MonadFix)
55−import Control.Monad.Trans (lift)
56−import Control.Monad.Trans.Reader (ReaderT, runReaderT, asks, ask)
57−import Control.Monad.Trans.Writer (WriterT, runWriterT, censor, tell)
58−import Data.Char
59−import Data.Default
60−import Data.Maybe (fromMaybe)
61−import Data.Text (Text)
62−import qualified Data.Text as T
63−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)
6420import qualified Graphics.Vty as V
6521import Reflex
66−
22+import Reflex.Class ()
23+import Reflex.Host.Class (MonadReflexCreateTrigger)
6724import Reflex.Vty.Host
6825
69−-- | The context within which a 'VtyWidget' runs
70−data VtyWidgetCtx t = VtyWidgetCtx
71− { _vtyWidgetCtx_size :: Dynamic t (Int,Int)
72− -- ^ The width and height of the region allocated to the widget.
73− , _vtyWidgetCtx_focus :: Dynamic t Bool
74− -- ^ Whether the widget should behave as if it has focus for keyboard input.
75− , _vtyWidgetCtx_input :: Event t VtyEvent
76− -- ^ User input events that the widget's parent chooses to share. These will generally
77− -- be filtered for relevance:
78− -- * Keyboard inputs are restricted to focused widgets
79− -- * Mouse inputs are restricted to the region in which the widget resides and are
80− -- translated into its internal coordinates.
81− }
82−
83−-- | The output of a 'VtyWidget'
84−data VtyWidgetOut t = VtyWidgetOut
85− { _vtyWidgetOut_images :: Behavior t [Image]
86− -- ^ The visual output of the 'VtyWidget'
87− , _vtyWidgetOut_shutdown :: Event t ()
88− }
89−
90−instance Reflex t => Semigroup (VtyWidgetOut t) where
91− wo <> wo' = VtyWidgetOut
92− { _vtyWidgetOut_images = _vtyWidgetOut_images wo <> _vtyWidgetOut_images wo'
93− , _vtyWidgetOut_shutdown = _vtyWidgetOut_shutdown wo <> _vtyWidgetOut_shutdown wo'
94− }
95−
96−instance (Reflex t) => Monoid (VtyWidgetOut t) where
97− mempty = VtyWidgetOut mempty mempty
98− mappend wo wo' = wo <> wo'
99−
100−newtype VtyWidget t m a = VtyWidget { unVtyWidget :: WriterT (VtyWidgetOut t) (ReaderT (VtyWidgetCtx t) m) a }
101− deriving (Functor, Applicative, Monad, MonadSample t, MonadHold t, MonadFix)
102−
103−-- | Runs a 'VtyWidget' with a given context
104−runVtyWidget
105− :: Reflex t
106− => VtyWidgetCtx t
107− -> VtyWidget t m a
108− -> m (a, VtyWidgetOut t)
109−runVtyWidget ctx w = runReaderT (runWriterT (unVtyWidget w)) ctx
110−
111−-- | Sets up the top-level context for a 'VtyWidget' and runs it with that context
112−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 ()
11341mainWidgetWithHandle vty child =
11442 runVtyAppWithHandle vty $ \dr0 inp -> do
11543 size <- holdDyn dr0 $ fforMaybe inp $ \case
@@ -118,59 +46,180 @@ mainWidgetWithHandle vty child =
11846 let inp' = fforMaybe inp $ \case
11947 V.EvResize {} -> Nothing
12048 x -> Just x
121− let ctx = VtyWidgetCtx
122− { _vtyWidgetCtx_size = size
123− , _vtyWidgetCtx_input = inp'
124− , _vtyWidgetCtx_focus = constDyn True
125− }
126− ((), 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
12757 return $ VtyResult
128− { _vtyResult_picture = fmap (V.picForLayers . reverse) (_vtyWidgetOut_images wo)
129− , _vtyResult_shutdown = _vtyWidgetOut_shutdown wo
58+ { _vtyResult_picture = fmap (V.picForLayers . reverse) images
59+ , _vtyResult_shutdown = shutdown
13060 }
13161
62+-- | The output of a vty widget
63+data VtyWidgetOut t = VtyWidgetOut
64+ { _vtyWidgetOut_shutdown :: Event t ()
65+ }
66+
13267-- | Like 'mainWidgetWithHandle', but uses a default vty configuration
133−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 ()
13479mainWidget child = do
13580 vty <- getDefaultVty
13681 mainWidgetWithHandle vty child
13782
138−class (Reflex t, Monad m) => HasDisplaySize t m | m -> t where
139− displaySize :: m (Dynamic t (Int, Int))
140−
141−instance (Reflex t, Monad m) => HasDisplaySize t (VtyWidget t m) where
142− displaySize = VtyWidget . lift $ asks _vtyWidgetCtx_size
83+-- * Input Events
14384
144−displayWidth :: HasDisplaySize t m => m (Dynamic t Int)
145−displayWidth = fmap fst <$> displaySize
146−
147−displayHeight :: HasDisplaySize t m => m (Dynamic t Int)
148−displayHeight = fmap snd <$> displaySize
149−
150−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
15187 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
152180
153−instance (Reflex t, Monad m) => HasVtyInput t (VtyWidget t m) where
154− input = VtyWidget . lift $ asks _vtyWidgetCtx_input
155−
156−class HasFocus t m | m -> t where
157− focus :: m (Dynamic t Bool)
158−
159−instance (Reflex t, Monad m) => HasFocus t (VtyWidget t m) where
160− focus = VtyWidget . lift $ asks _vtyWidgetCtx_focus
161−
162−class (Reflex t, Monad m) => ImageWriter t m | m -> t where
163− tellImages :: Behavior t [Image] -> m ()
164−
165−instance (Reflex t, Monad m) => ImageWriter t (VtyWidget t m) where
166− tellImages imgs = VtyWidget $ tell (mempty { _vtyWidgetOut_images = imgs })
167−
168−class (Reflex t, Monad m) => Shutdown t m where
169− 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
170219
171−instance (Reflex t, Monad m) => Shutdown t (VtyWidget t m) where
172− tellShutdown sd = VtyWidget $ tell (mempty { _vtyWidgetOut_shutdown = sd })
220+-- * Getting and setting the display region
173221
222+-- | A chunk of the display area
174223data Region = Region
175224 { _region_left :: Int
176225 , _region_top :: Int
@@ -179,432 +228,334 @@ data Region = Region
179228 }
180229 deriving (Show, Read, Eq, Ord)
181230
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'
182236regionSize :: Region -> (Int, Int)
183237regionSize (Region _ _ w h) = (w, h)
184238
185−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
186311 :: (Reflex t, Monad m)
187− => Dynamic t Region -- ^ Region into which we should draw the widget (in coordinates relative to our own)
188− -> Dynamic t Bool -- ^ Whether the widget should be focused when the parent is.
189− -> VtyWidget t m a
190− -> VtyWidget t m a
191−pane reg foc child = VtyWidget $ do
192− ctx <- lift ask
193− let ctx' = VtyWidgetCtx
194− { _vtyWidgetCtx_input = leftmost -- TODO: think about this leftmost more.
195− [ fmapMaybe id $
196− attachWith (\(r,f) e -> filterInput r f e)
197− (liftA2 (,) (current reg) (current foc))
198− (_vtyWidgetCtx_input ctx)
199− ]
200− , _vtyWidgetCtx_focus = liftA2 (&&) (_vtyWidgetCtx_focus ctx) foc
201− , _vtyWidgetCtx_size = fmap regionSize reg }
202− (result, wo) <- lift . lift $ runVtyWidget ctx' child
203− let images = _vtyWidgetOut_images wo
204− images' = liftA2 (\r is -> map (withinImage r) is) (current reg) images
205− wo' = wo { _vtyWidgetOut_images = images' }
206− tell wo'
207− return result
208− where
209− -- Filters input such that:
210− -- * unfocused widgets receive no key events
211− -- * mouse inputs outside the region are ignored
212− -- * mouse inputs inside the region have their coordinates translated
213− -- such that (0,0) is the top-left corner of the region
214− filterInput :: Region -> Bool -> VtyEvent -> Maybe VtyEvent
215− filterInput (Region l t w h) focused e = case e of
216− V.EvKey _ _ | not focused -> Nothing
217− V.EvMouseDown x y btn m -> mouse (\u v -> V.EvMouseDown u v btn m) x y
218− V.EvMouseUp x y btn -> mouse (\u v -> V.EvMouseUp u v btn) x y
219− _ -> Just e
220− where
221− mouse con x y
222− | or [ x < l
223− , y < t
224− , x >= l + w
225− , y >= t + h ] = Nothing
226− | otherwise =
227− Just (con (x - l) (y - t))
228−
229−data Drag = Drag
230− { _drag_from :: (Int, Int) -- ^ Where the drag began
231− , _drag_to :: (Int, Int) -- ^ Where the mouse currently is
232− , _drag_button :: V.Button -- ^ Which mouse button is dragging
233− , _drag_modifiers :: [V.Modifier] -- ^ What modifiers are held
234− , _drag_end :: Bool -- ^ Whether the drag ended (the mouse button was released)
235− }
236− deriving (Eq, Ord, Show)
312+ => Dynamic t Region
313+ -> DisplayRegion t m a
314+ -> m a
315+runDisplayRegion r = flip runReaderT r . unDisplayRegion
237316
238−drag
239− :: (Reflex t, MonadFix m, MonadHold t m)
240− => V.Button
241− -> VtyWidget t m (Event t Drag)
242−drag btn = do
243− inp <- input
244− let f :: Drag -> V.Event -> Maybe Drag
245− f (Drag from _ _ mods end) = \case
246− V.EvMouseDown x y btn' mods'
247− | end -> Just $ Drag (x,y) (x,y) btn' mods' False
248− | btn == btn' -> Just $ Drag from (x,y) btn mods' False
249− | otherwise -> Nothing -- Ignore other buttons.
250− V.EvMouseUp x y (Just btn')
251− | end -> Nothing
252− | btn == btn' -> Just $ Drag from (x,y) btn mods True
253− | otherwise -> Nothing
254− V.EvMouseUp x y Nothing -- Terminal doesn't specify mouse up button,
255− -- assume it's the right one.
256− | end -> Nothing
257− | otherwise -> Just $ Drag from (x,y) btn mods True
258− _ -> Nothing
259− rec let newDrag = attachWithMaybe f (current dragD) inp
260− dragD <- holdDyn (Drag (0,0) (0,0) btn [] True) -- gross, but ok because it'll never be produced.
261− newDrag
262− return (updated dragD)
263−
264−mouseDown
265− :: (Reflex t, Monad m)
266− => V.Button
267− -> VtyWidget t m (Event t VtyEvent)
268−mouseDown btn = do
269− i <- input
270− return $ fforMaybe i $ \x -> case x of
271− V.EvMouseDown _ _ btn' _ -> if btn == btn' then Just x else Nothing
272− _ -> Nothing
273−
274−-- | A plain split of the available space into vertically stacked panes.
275−-- No visual separator is built in here.
276−splitV :: (Reflex t, Monad m)
277− => Dynamic t (Int -> Int)
278− -- ^ Function used to determine size of first pane based on available size
279− -> Dynamic t (Bool, Bool)
280− -- ^ How to focus the two sub-panes, given that we are focused.
281− -> VtyWidget t m a
282− -- ^ Widget for first pane
283− -> VtyWidget t m b
284− -- ^ Widget for second pane
285− -> VtyWidget t m (a,b)
286−splitV sizeFunD focD wA wB = do
287− sz <- displaySize
288− let regA = (\f (w,h) -> Region 0 0 w (f h)) <$> sizeFunD <*> sz
289− regB = (\(w,h) (Region _ _ _ hA) -> Region 0 hA w (h - hA)) <$> sz <*> regA
290− ra <- pane regA (fst <$> focD) wA
291− rb <- pane regB (snd <$> focD) wB
292− return (ra,rb)
293−
294−-- | A split of the available space into two parts with a draggable separator.
295−-- Starts with half the space allocated to each, and the first pane has focus.
296−-- Clicking in a pane switches focus.
297−splitVDrag :: (Reflex t, MonadFix m, MonadHold t m)
298− => VtyWidget t m ()
299− -> VtyWidget t m a
300− -> VtyWidget t m b
301− -> VtyWidget t m (a,b)
302−splitVDrag wS wA wB = do
303− sz <- displaySize
304− (_, h0) <- sample $ current sz
305− dragE <- drag V.BLeft
306− let splitter0 = h0 `div` 2
307− rec splitterCheckpoint <- holdDyn splitter0 $ leftmost [fst <$> ffilter snd dragSplitter, resizeSplitter]
308− splitterPos <- holdDyn splitter0 $ leftmost [fst <$> dragSplitter, resizeSplitter]
309− splitterFrac <- holdDyn ((1::Double) / 2) $ ffor (attach (current sz) (fst <$> dragSplitter)) $ \((_,h),x) ->
310− fromIntegral x / fromIntegral h
311− let dragSplitter = fforMaybe (attach (current splitterCheckpoint) dragE) $
312− \(splitterY, Drag (_, fromY) (_, toY) _ _ end) ->
313− if splitterY == fromY then Just (toY, end) else Nothing
314− regA = (\(w,_) sp -> Region 0 0 w sp) <$> sz <*> splitterPos
315− regS = (\(w,_) sp -> Region 0 sp w 1) <$> sz <*> splitterPos
316− regB = (\(w,h) sp -> Region 0 (sp + 1) w (h - sp - 1)) <$> sz <*> splitterPos
317− resizeSplitter = ffor (attach (current splitterFrac) (updated sz)) $
318− \(frac, (_,h)) -> round (frac * fromIntegral h)
319− focA <- holdDyn True $ leftmost
320− [ True <$ mA
321− , False <$ mB
322− ]
323− (mA, rA) <- pane regA focA $ withMouseDown wA
324− pane regS (pure False) wS
325− (mB, rB) <- pane regB (not <$> focA) $ withMouseDown wB
326− return (rA, rB)
327− where
328− withMouseDown x = do
329− m <- mouseDown V.BLeft
330− x' <- x
331− return (m, x')
332−
333−-- | Fill the background with a particular character.
334−fill :: (Reflex t, Monad m) => Char -> VtyWidget t m ()
335−fill c = do
336− sz <- displaySize
337− let fillImg = ffor (current sz) $ \(w,h) -> [V.charFill V.defAttr c w h]
338− tellImages fillImg
339−
340−-- | Fill the background with the bottom
341−hRule :: (Reflex t, Monad m) => BoxStyle -> VtyWidget t m ()
342−hRule boxStyle = fill (_boxStyle_s boxStyle)
343−
344−fractionSz :: Double -> Int -> Int
345−fractionSz x h = round (fromIntegral h * x)
346−
347−modifyImages
348− :: (Reflex t, MonadHold t m, MonadFix m)
349− => Behavior t ([Image] -> [Image])
350− -> VtyWidget t m a
351− -> VtyWidget t m a
352−modifyImages f (VtyWidget w) = VtyWidget $ flip censor w $ \wo ->
353− wo { _vtyWidgetOut_images = f <*> (_vtyWidgetOut_images wo) }
354−
355−data BoxStyle = BoxStyle
356− { _boxStyle_nw :: Char
357− , _boxStyle_n :: Char
358− , _boxStyle_ne :: Char
359− , _boxStyle_e :: Char
360− , _boxStyle_se :: Char
361− , _boxStyle_s :: Char
362− , _boxStyle_sw :: Char
363− , _boxStyle_w :: Char
364− }
317+-- * Getting focus state
365318
366−instance Default BoxStyle where
367− def = singleBoxStyle
368−
369−hyphenBoxStyle :: BoxStyle
370−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
371380
372−singleBoxStyle :: BoxStyle
373−singleBoxStyle = BoxStyle '┌' '─' '┐' '│' '┘' '─' '└' '│'
381+-- * "Image" output
374382
375−thickBoxStyle :: BoxStyle
376−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
377515
378−doubleBoxStyle :: BoxStyle
379−doubleBoxStyle = BoxStyle '╔' '═' '╗' '║' '╝' '═' '╚' '║'
380516
381−roundedBoxStyle :: BoxStyle
382−roundedBoxStyle = BoxStyle '╭' '─' '╮' '│' '╯' '─' '╰' '│'
517+-- ** Manipulating images
383518
384−box :: (Monad m, Reflex t)
385− => BoxStyle
386− -> VtyWidget t m a
387− -> VtyWidget t m a
388−box style child = do
389− sz <- displaySize
390− let boxReg = ffor (current sz) $ \(w,h) -> Region 0 0 w h
391− innerReg = ffor sz $ \(w,h) -> Region 1 1 (w - 2) (h - 2)
392− tellImages (fmap boxImages boxReg)
393− tellImages (fmap (\r -> [regionBlankImage r]) (current innerReg))
394− pane innerReg (pure True) child
395− where
396− boxImages :: Region -> [Image]
397− boxImages (Region left top width height) =
398− let right = left + width - 1
399− bottom = top + height - 1
400− sides =
401− [ withinImage (Region (left + 1) top (width - 2) 1) $
402− V.charFill V.defAttr (_boxStyle_n style) (width - 2) 1
403− , withinImage (Region right (top + 1) 1 (height - 2)) $
404− V.charFill V.defAttr (_boxStyle_e style) 1 (height - 2)
405− , withinImage (Region (left + 1) bottom (width - 2) 1) $
406− V.charFill V.defAttr (_boxStyle_s style) (width - 2) 1
407− , withinImage (Region left (top + 1) 1 (height - 2)) $
408− V.charFill V.defAttr (_boxStyle_w style) 1 (height - 2)
409− ]
410− corners =
411− [ withinImage (Region left top 1 1) $
412− V.char V.defAttr (_boxStyle_nw style)
413− , withinImage (Region right top 1 1) $
414− V.char V.defAttr (_boxStyle_ne style)
415− , withinImage (Region right bottom 1 1) $
416− V.char V.defAttr (_boxStyle_se style)
417− , withinImage (Region left bottom 1 1) $
418− V.char V.defAttr (_boxStyle_sw style)
419− ]
420− in sides ++ if width > 1 && height > 1 then corners else []
421−
422−text :: (Reflex t, Monad m) => Behavior t Text -> VtyWidget t m ()
423−text msg = do
424− dw <- displayWidth
425− let img = (\w s -> [wrapText w V.defAttr s]) <$> current dw <*> msg
426− tellImages img
427−
428−display :: (Reflex t, Monad m, Show a) => Behavior t a -> VtyWidget t m ()
429−display a = text $ T.pack . show <$> a
430−
431−regionBlankImage :: Region -> Image
432−regionBlankImage r@(Region _ _ width height) =
433− withinImage r $ V.charFill V.defAttr ' ' width height
434−
435−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
436525withinImage (Region left top width height)
437526 | width < 0 || height < 0 = withinImage (Region left top 0 0)
438527 | otherwise = V.translate left top . V.crop width height
439528
440−wrapText :: Int -> Attr -> Text -> Image
441−wrapText maxWidth attrs = V.vertCat
442− . concatMap (fmap (V.string attrs . T.unpack) . wrapWithOffset maxWidth 0)
443− . T.split (=='\n')
444−
445−wrapWithOffset :: Int -> Int -> Text -> [Text]
446−wrapWithOffset maxWidth n xs =
447− let (firstLine, rest) = T.splitAt (maxWidth - n) xs
448− in firstLine : (fmap (T.take maxWidth) . takeWhile (not . T.null) . iterate (T.drop maxWidth) $ rest)
449−
450−wrapInputState
451− :: Int -- ^ Maximum line length
452− -> Attr -- ^ Normal string attributes
453− -> Attr -- ^ Cursor character attributes
454− -> InputState -- ^ The input to render
455− -> ([Image], Int)
456−wrapInputState maxWidth attrs cursorAttrs (InputState before after) =
457− let -- Break up the InputState into:
458− -- * A top section of lines before the line containing the cursor
459− -- * A part of the line containing the cursor that comes immediately before the cursor
460− -- * The cursor character (i.e., the character the cursor is on top of)
461− -- * The remainder of the line containing the cursor
462− -- * The bottom section of lines after the line containing the cursor
463− (top, midBefore, cursorChar, midAfter, bottom) = case (initLast before', headTail after') of
464− (Nothing, Nothing) -> ([], "", ' ', "", [])
465− (Just (top', mid), Nothing) -> (top', mid, ' ', "", [])
466− (Nothing, Just (mid, bottom')) -> case T.uncons mid of
467− Nothing -> ([], "", ' ', "", bottom')
468− Just (c, rest) -> ([], "", c, rest, bottom')
469− (Just (top', midB), Just (midA, bottom')) -> case T.uncons midA of
470− Nothing -> (top', midB, ' ', "", bottom')
471− Just (c, rest) -> (top', midB, c, rest, bottom')
472− (midBeforeTop, midBefore') = fromMaybe ([], "") $ initLast $ wrap [midBefore]
473− cursorAfterEOL = T.length midBefore' == maxWidth
474− (midAfter', midAfterBottom) =
475− let offset = if cursorAfterEOL then 1 else T.length midBefore' + 1
476− in case wrapWithOffset maxWidth offset midAfter of
477− [] -> ("", [])
478− x:xs -> (x, xs)
479− cursor = V.char cursorAttrs cursorChar
480− images = mconcat
481− [ vstring <$> wrap top
482− , vstring <$> midBeforeTop
483− , if cursorAfterEOL
484− then
485− [ vstring midBefore'
486− , V.horizCat
487− [ cursor
488− , vstring midAfter'
489− ]
490− ]
491− else
492− [ V.horizCat
493− [ vstring midBefore'
494− , cursor
495− , vstring midAfter'
496− ]
497− ]
498− , vstring <$> midAfterBottom
499− , vstring <$> bottom
500− ]
501− cursorY = length top + length midBeforeTop + if cursorAfterEOL then 1 else 0
502− in (images, cursorY)
503− where
504− before' = T.split (=='\n') before
505− after' = T.split (=='\n') after
506− vstring = V.string attrs . T.unpack
507− wrap :: [Text] -> [Text]
508− wrap = concatMap (wrapWithOffset maxWidth 0)
509− headTail :: [a] -> Maybe (a, [a])
510− headTail = \case
511− [] -> Nothing
512− x:xs -> Just (x, xs)
513− initLast :: [a] -> Maybe ([a], a)
514− initLast = \case
515− [] -> Nothing
516− (x:xs) -> case initLast xs of
517− Nothing -> Just ([], x)
518− Just (ys, y) -> Just (x:ys, y)
519−
520−data InputState = InputState
521− { _inputState_beforeCursor :: Text
522− , _inputState_afterCursor :: Text
523− }
524−
525−inputValue :: InputState -> Text
526−inputValue (InputState a b) = a <> b
527−
528−updateInputState :: V.Event -> InputState -> InputState
529−updateInputState ev i@(InputState before after) = case ev of
530− -- Regular characters
531− V.EvKey (V.KChar k) [] -> InputState (T.snoc before k) after
532− -- Deletion buttons
533− V.EvKey V.KBS [] -> InputState (if T.null before then T.empty else T.init before) after
534− V.EvKey V.KDel [] -> case T.uncons after of
535− Nothing -> i
536− Just (_, a) -> InputState before a
537− -- Key combinations
538− V.EvKey (V.KChar 'u') [V.MCtrl] -> InputState mempty mempty
539− V.EvKey (V.KChar 'w') [V.MCtrl] -> InputState (T.dropWhileEnd (not . isSpace) $ T.dropWhileEnd isSpace $ before) after
540− -- Arrow keys
541− V.EvKey V.KRight [] -> case T.uncons after of
542− Nothing -> i
543− Just (a, as) -> InputState (T.snoc before a) as
544− V.EvKey V.KLeft [] -> case T.unsnoc before of
545− Nothing -> i
546− Just (bs, b) -> InputState bs (T.cons b after)
547− V.EvKey V.KUp [] ->
548− let (pre, post) = T.breakOnEnd "\n" before
549− (top, previousLine) = T.breakOnEnd "\n" (T.dropEnd 1 pre)
550− (previousLineBefore, previousLineAfter) = T.splitAt (T.length post) previousLine
551− in if T.null pre
552− then i
553− else InputState (top <> previousLineBefore) (previousLineAfter <> "\n" <> post <> after)
554− V.EvKey V.KDown [] ->
555− let offset = T.length $ T.takeWhileEnd (/='\n') before
556− (pre, post) = T.breakOn "\n" after
557− (nextLine, rest) = T.breakOn "\n" (T.drop 1 post)
558− (nextLineBefore, nextLineAfter) = T.splitAt offset nextLine
559− in if T.null post
560− then i
561− else InputState (before <> pre <> "\n" <> nextLineBefore) (nextLineAfter <> rest)
562− V.EvKey V.KHome [] ->
563− let (pre, post) = T.breakOnEnd "\n" before
564− in InputState pre (post <> after)
565− V.EvKey V.KEnd [] ->
566− let (pre, post) = T.breakOn "\n" after
567− in InputState (before <> pre) post
568− _ -> i
569−
570−data TextInputConfig t = TextInputConfig
571− { _textInputConfig_initialValue :: Text
572− , _textInputConfig_modifyInputState :: Event t (InputState -> InputState)
573− }
574−
575−instance Reflex t => Default (TextInputConfig t) where
576− def = TextInputConfig "" never
577−
578−textInput :: (Reflex t, MonadHold t m, MonadFix m) => TextInputConfig t -> VtyWidget t m (Dynamic t Text)
579−textInput cfg = do
580− i <- input
581− v <- foldDyn ($) (InputState (_textInputConfig_initialValue cfg) mempty) $ mergeWith (.)
582− [ updateInputState <$> i
583− , _textInputConfig_modifyInputState cfg
584− ]
585− dw <- displayWidth
586− dh <- displayHeight
587− let img = (\w s -> wrapInputState w V.defAttr (V.withStyle V.defAttr V.reverseVideo) s) -- TODO cursor ought to blink
588− <$> dw
589− <*> v
590− y <- holdUniqDyn $ snd <$> img
591− let newScrollTop st (h, cursorY)
592− | cursorY < st = cursorY
593− | cursorY >= st + h = cursorY - h + 1
594− | otherwise = st
595− rec let hy = attachWith newScrollTop (current scrollTop) $ updated $ zipDyn dh y
596− scrollTop <- holdDyn 0 hy
597− tellImages $ (\(imgs, _) st -> (:[]) . V.vertCat $ drop st imgs) <$> current img <*> current scrollTop
598− return $ inputValue <$> v
599−
600−multilineTextInput :: (Reflex t, MonadHold t m, MonadFix m) => TextInputConfig t -> VtyWidget t m (Dynamic t Text)
601−multilineTextInput cfg = do
602− i <- input
603− textInput $ cfg
604− { _textInputConfig_modifyInputState = mergeWith (.)
605− [ fforMaybe i $ \case
606− V.EvKey V.KEnter [] -> Just $ \(InputState before after) -> InputState (T.snoc before '\n') after
607− _ -> Nothing
608− , _textInputConfig_modifyInputState cfg
609− ]
610− }
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 ()