@@ -2,161 +2,41 @@
2Module: Reflex.Vty.Widget
2Module: Reflex.Vty.Widget
3Description: Basic set of widgets and building blocks for reflex-vty applications
3Description: Basic set of widgets and building blocks for reflex-vty applications
5−{-# LANGUAGE DefaultSignatures #-}
6−{-# LANGUAGE DeriveFunctor #-}
7−{-# LANGUAGE FlexibleContexts #-}
8−{-# LANGUAGE FlexibleInstances #-}
9−{-# LANGUAGE FunctionalDependencies #-}
10−{-# LANGUAGE GeneralizedNewtypeDeriving #-}
11−{-# LANGUAGE LambdaCase #-}
12−{-# LANGUAGE RankNTypes #-}
13−{-# LANGUAGE RecursiveDo #-}
14−{-# LANGUAGE ScopedTypeVariables #-}
15−{-# LANGUAGE StandaloneDeriving #-}
16−{-# LANGUAGE TupleSections #-}
17−{-# LANGUAGE TypeFamilies #-}
18−{-# LANGUAGE UndecidableInstances #-}
5+{-# Language UndecidableInstances #-}
20−module Reflex.Vty.Widget
7+module Reflex.Vty.Widget where
27− , mainWidgetWithHandle
42− , ScrollDirection(..)
72import Control.Applicative (liftA2)
9import Control.Applicative (liftA2)
73import Control.Monad.Fix (MonadFix)
10import Control.Monad.Fix (MonadFix)
74−import Control.Monad.Reader
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
75−import Control.Monad.Trans (lift)
16+import Control.Monad.Trans (MonadTrans, lift)
76−import Data.Default (Default(..))
77import Data.Set (Set)
17import Data.Set (Set)
78import qualified Data.Set as Set
18import qualified Data.Set as Set
79−import Data.Text (Text)
80−import qualified Data.Text as T
81−import qualified Data.Text.Zipper as TZ
82import Graphics.Vty (Image)
19import Graphics.Vty (Image)
83import qualified Graphics.Vty as V
20import qualified Graphics.Vty as V
84import Reflex
21import Reflex
85import Reflex.Class ()
22import Reflex.Class ()
86import Reflex.Host.Class (MonadReflexCreateTrigger)
23import Reflex.Host.Class (MonadReflexCreateTrigger)
88import Reflex.Vty.Host
24import Reflex.Vty.Host
90−import Control.Monad.NodeId
26+-- * Running a vty application
92−-- | The context within which a 'VtyWidget' runs
93−data VtyWidgetCtx t = VtyWidgetCtx
94− { _vtyWidgetCtx_width :: Dynamic t Int
95− -- ^ The width of the region allocated to the widget.
96− , _vtyWidgetCtx_height :: Dynamic t Int
97− -- ^ The height of the region allocated to the widget.
98− , _vtyWidgetCtx_focus :: Dynamic t Bool
99− -- ^ Whether the widget should behave as if it has focus for keyboard input.
100− , _vtyWidgetCtx_input :: Event t VtyEvent
101− -- ^ User input events that the widget's parent chooses to share. These will generally
102− -- be filtered for relevance:
103− -- * Keyboard inputs are restricted to focused widgets
104− -- * Mouse inputs are restricted to the region in which the widget resides and are
105− -- translated into its internal coordinates.
108−-- | The output of a 'VtyWidget'
109−data VtyWidgetOut t = VtyWidgetOut
110− { _vtyWidgetOut_shutdown :: Event t ()
113−instance (Adjustable t m, MonadHold t m, Reflex t) => Adjustable t (VtyWidget t m) where
114− runWithReplace a0 a' = VtyWidget $ runWithReplace (unVtyWidget a0) $ fmap unVtyWidget a'
115− traverseIntMapWithKeyWithAdjust f dm0 dm' = VtyWidget $
116− traverseIntMapWithKeyWithAdjust (\k v -> unVtyWidget (f k v)) dm0 dm'
117− traverseDMapWithKeyWithAdjust f dm0 dm' = VtyWidget $ do
118− traverseDMapWithKeyWithAdjust (\k v -> unVtyWidget (f k v)) dm0 dm'
119− traverseDMapWithKeyWithAdjustWithMove f dm0 dm' = VtyWidget $ do
120− traverseDMapWithKeyWithAdjustWithMove (\k v -> unVtyWidget (f k v)) dm0 dm'
122−-- | A widget that can read its context and produce image output
123−newtype VtyWidget t m a = VtyWidget
124− { unVtyWidget :: BehaviorWriterT t [Image] (ReaderT (VtyWidgetCtx t) m) a
136− , MonadReflexCreateTrigger t
140−deriving instance PerformEvent t m => PerformEvent t (VtyWidget t m)
141−instance MonadTrans (VtyWidget t) where
142− lift f = VtyWidget $ lift $ lift f
144−instance MonadNodeId m => MonadNodeId (VtyWidget t m) where
145− getNextNodeId = VtyWidget $ do
146− lift $ lift $ getNextNodeId
148−-- | Runs a 'VtyWidget' with a given context
150− :: (Reflex t, MonadNodeId m)
153− -> m (a, Behavior t [Image])
154−runVtyWidget ctx w = runReaderT (runBehaviorWriterT (unVtyWidget w)) ctx
156−-- | Sets up the top-level context for a 'VtyWidget' and runs it with that context
28+-- | Sets up the top-level context for a vty widget and runs it with that context
157mainWidgetWithHandle
29mainWidgetWithHandle
159− -> (forall t m. (MonadVtyApp t m, MonadNodeId m) => VtyWidget t m (Event t ()))
32+ ( MonadVtyApp t m
35+ , HasDisplayRegion t m
161mainWidgetWithHandle vty child =
41mainWidgetWithHandle vty child =
162 runVtyAppWithHandle vty $ \dr0 inp -> do
42 runVtyAppWithHandle vty $ \dr0 inp -> do
@@ -166,71 +46,178 @@ mainWidgetWithHandle vty child =
166 let inp' = fforMaybe inp $ \case
46 let inp' = fforMaybe inp $ \case
167 V.EvResize {} -> Nothing
47 V.EvResize {} -> Nothing
168 x -> Just x
48 x -> Just x
169− let ctx = VtyWidgetCtx
49+ (shutdown, images) <- runThemeReader (constant V.defAttr) $
170− { _vtyWidgetCtx_width = fmap fst size
50+ runFocusReader (pure True) $
171− , _vtyWidgetCtx_height = fmap snd size
51+ runDisplayRegion (fmap (\(w, h) -> Region 0 0 w h) size) $
172− , _vtyWidgetCtx_input = inp'
52+ runImageWriter $
173− , _vtyWidgetCtx_focus = constDyn True
53+ runNodeIdT $
174− }
54+ runInput inp' $ do
175− (shutdown, images) <- runNodeIdT $ runVtyWidget ctx $ do
176− tellImages . ffor (current size) $ \(w, h) -> [V.charFill V.defAttr ' ' w h]
55+ tellImages . ffor (current size) $ \(w, h) -> [V.charFill V.defAttr ' ' w h]
178 return $ VtyResult
57 return $ VtyResult
179 { _vtyResult_picture = fmap (V.picForLayers . reverse) images
58 { _vtyResult_picture = fmap (V.picForLayers . reverse) images
180 , _vtyResult_shutdown = shutdown
59 , _vtyResult_shutdown = shutdown
62+-- | The output of a vty widget
63+data VtyWidgetOut t = VtyWidgetOut
64+ { _vtyWidgetOut_shutdown :: Event t ()
183-- | Like 'mainWidgetWithHandle', but uses a default vty configuration
67-- | Like 'mainWidgetWithHandle', but uses a default vty configuration
184mainWidget
68mainWidget
185− :: (forall t m. (MonadVtyApp t m, MonadNodeId m) => VtyWidget t m (Event t ()))
70+ ( MonadVtyApp t m
73+ , HasDisplayRegion t m
187mainWidget child = do
79mainWidget child = do
188 vty <- getDefaultVty
80 vty <- getDefaultVty
189 mainWidgetWithHandle vty child
81 mainWidgetWithHandle vty child
191−-- | A class for things that know their own display size dimensions
83+-- * Input Events
192−class (Reflex t, Monad m) => HasDisplaySize t m | m -> t where
193− -- | Retrieve the display width (columns)
194− displayWidth :: m (Dynamic t Int)
195− default displayWidth :: (f m' ~ m, MonadTrans f, HasDisplaySize t m') => m (Dynamic t Int)
196− displayWidth = lift displayWidth
197− -- | Retrieve the display height (rows)
198− displayHeight :: m (Dynamic t Int)
199− default displayHeight :: (f m' ~ m, MonadTrans f, HasDisplaySize t m') => m (Dynamic t Int)
200− displayHeight = lift displayHeight
202−instance (Reflex t, Monad m) => HasDisplaySize t (VtyWidget t m) where
203− displayWidth = VtyWidget . lift $ asks _vtyWidgetCtx_width
204− displayHeight = VtyWidget . lift $ asks _vtyWidgetCtx_height
206−instance HasDisplaySize t m => HasDisplaySize t (ReaderT x m)
207−instance HasDisplaySize t m => HasDisplaySize t (BehaviorWriterT t x m)
208−instance HasDisplaySize t m => HasDisplaySize t (DynamicWriterT t x m)
209−instance HasDisplaySize t m => HasDisplaySize t (EventWriterT t x m)
211−instance HasDisplaySize t m => HasDisplaySize t (NodeIdT m)
213-- | A class for things that can receive vty events as input
85-- | A class for things that can receive vty events as input
214−class HasVtyInput t m | m -> t where
86+class HasInput t m | m -> t where
215 input :: m (Event t VtyEvent)
87 input :: m (Event t VtyEvent)
88+ default input :: (f m' ~ m, Monad m', MonadTrans f, HasInput t m') => m (Event t VtyEvent)
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)
96+instance (Reflex t, Monad m) => HasInput t (Input t m) where
98+ localInput f (Input m) = Input $ local f m
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
217−instance (Reflex t, Monad m) => HasVtyInput t (VtyWidget t m) where
114+instance (Adjustable t m, MonadHold t m, Reflex t) => Adjustable t (Input t m) where
218− input = VtyWidget . lift $ asks _vtyWidgetCtx_input
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'
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)
132+instance MonadTrans (Input t) where
133+ lift f = Input $ lift f
135+instance MFunctor (Input t) where
136+ hoist f = Input . hoist f . unInput
138+instance MonadNodeId m => MonadNodeId (Input t m)
140+-- | Runs an 'Input' with a given context
146+runInput e w = runReaderT (unInput w) e
148+-- ** Filtering input
220−-- | A class for things that can dynamically gain and lose focus
150+-- | Type synonym for a key and modifier combination
221−class HasFocus t m | m -> t where
151+type KeyCombo = (V.Key, [V.Modifier])
222− focus :: m (Dynamic t Bool)
224−instance (Reflex t, Monad m) => HasFocus t (VtyWidget t m) where
153+-- | Emits an event that fires on a particular key press (without modifiers)
225− focus = VtyWidget . lift $ asks _vtyWidgetCtx_focus
154+key :: (Monad m, Reflex t, HasInput t m) => V.Key -> m (Event t KeyCombo)
155+key = keyCombos . Set.singleton . (,[])
227−-- | A class for widgets that can produce images to draw to the display
157+-- | Emits an event that fires on particular key presses (without modifiers)
228−class (Reflex t, Monad m) => ImageWriter t m | m -> t where
158+keys :: (Monad m, Reflex t, HasInput t m) => [V.Key] -> m (Event t KeyCombo)
229− -- | Send images upstream for rendering
159+keys = keyCombos . Set.fromList . fmap (,[])
230− tellImages :: Behavior t [Image] -> m ()
232−instance (Monad m, Reflex t) => ImageWriter t (BehaviorWriterT t [Image] m) where
161+-- | Emit an event that fires whenever the provided key combination occurs
233− tellImages = tellBehavior
162+keyCombo
163+ :: (Reflex t, Monad m, HasInput t m)
165+ -> m (Event t KeyCombo)
166+keyCombo = keyCombos . Set.singleton
168+-- | Emit an event that fires whenever any of the provided key combinations occur
170+ :: (Reflex t, Monad m, HasInput t m)
172+ -> m (Event t KeyCombo)
175+ return $ fforMaybe i $ \case
176+ V.EvKey k m -> if Set.member (k, m) ks
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)
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.
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
201+ , y >= t + h ] = Nothing
203+ Just (con (x - l) (y - t))
205+-- | Filter mouse input outside the current display region and
206+-- all input if the region is not focused
208+ :: (HasDisplayRegion t m, HasFocusReader t m, HasInput t m)
209+ => m (Event t VtyEvent)
210+inputInFocusedRegion = do
212+ reg <- current <$> askRegion
213+ foc <- current <$> focus
214+ pure $ fmapMaybe id $ attachWith filterInput ((,) <$> reg <*> foc) inp
216+ filterInput (r, f) = \case
217+ V.EvKey {} | not f -> Nothing
218+ x -> mouseInRegion r x
220+-- * Getting and setting the display region
235-- | A chunk of the display area
222-- | A chunk of the display area
236data Region = Region
223data Region = Region
@@ -241,499 +228,334 @@ data Region = Region
242 deriving (Show, Read, Eq, Ord)
229 deriving (Show, Read, Eq, Ord)
244−-- | A dynamic chunk of the display area
231+-- | A region that occupies no space.
245−data DynRegion t = DynRegion
232+nilRegion :: Region
246− { _dynRegion_left :: Dynamic t Int
233+nilRegion = Region 0 0 0 0
247− , _dynRegion_top :: Dynamic t Int
248− , _dynRegion_width :: Dynamic t Int
249− , _dynRegion_height :: Dynamic t Int
252-- | The width and height of a 'Region'
235-- | The width and height of a 'Region'
253regionSize :: Region -> (Int, Int)
236regionSize :: Region -> (Int, Int)
254regionSize (Region _ _ w h) = (w, h)
237regionSize (Region _ _ w h) = (w, h)
256-- | Produces an 'Image' that fills a region with space characters
239-- | Produces an 'Image' that fills a region with space characters
257−regionBlankImage :: Region -> Image
240+regionBlankImage :: V.Attr -> Region -> Image
258−regionBlankImage r@(Region _ _ width height) =
241+regionBlankImage attr r@(Region _ _ width height) =
259− withinImage r $ V.charFill V.defAttr ' ' width height
242+ withinImage r $ V.charFill attr ' ' width height
261−-- | A behavior of the current display area represented by a 'DynRegion'
244+-- | A class for things that know their own display size dimensions
262−currentRegion :: Reflex t => DynRegion t -> Behavior t Region
245+class (Reflex t, Monad m) => HasDisplayRegion t m | m -> t where
263−currentRegion (DynRegion l t w h) = Region <$> current l <*> current t <*> current w <*> current h
246+ -- | Retrieve the display region
247+ askRegion :: m (Dynamic t Region)
248+ default askRegion :: (f m' ~ m, MonadTrans f, HasDisplayRegion t m') => m (Dynamic t Region)
249+ askRegion = lift askRegion
250+ -- | Run an action in a local region, by applying a transformation to the region
251+ localRegion :: (Dynamic t Region -> Dynamic t Region) -> m a -> m a
252+ default localRegion :: (f m' ~ m, Monad m', MFunctor f, HasDisplayRegion t m') => (Dynamic t Region -> Dynamic t Region) -> m a -> m a
253+ localRegion f = hoist (localRegion f)
255+-- | Retrieve the display width
256+displayWidth :: HasDisplayRegion t m => m (Dynamic t Int)
257+displayWidth = fmap _region_width <$> askRegion
259+-- | Retrieve the display height
260+displayHeight :: HasDisplayRegion t m => m (Dynamic t Int)
261+displayHeight = fmap _region_height <$> askRegion
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)
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 }
265−-- | Translates and crops an 'Image' so that it is contained by
283+instance (Monad m, Reflex t) => HasDisplayRegion t (DisplayRegion t m) where
266−-- the given 'Region'.
284+ askRegion = DisplayRegion ask
267−withinImage
285+ localRegion f = DisplayRegion . local f . unDisplayRegion
271−withinImage (Region left top width height)
272− | width < 0 || height < 0 = withinImage (Region left top 0 0)
273− | otherwise = V.translate left top . V.crop width height
275−-- | Low-level widget combinator that runs a child 'VtyWidget' within
287+deriving instance MonadReflexCreateTrigger t m => MonadReflexCreateTrigger t (DisplayRegion t m)
276−-- a given region and context. This widget filters and modifies the input
288+deriving instance NotReady t m => NotReady t (DisplayRegion t m)
277−-- that the child widget receives such that:
289+deriving instance PerformEvent t m => PerformEvent t (DisplayRegion t m)
278−-- * unfocused widgets receive no key events
290+deriving instance PostBuild t m => PostBuild t (DisplayRegion t m)
279−-- * mouse inputs outside the region are ignored
291+deriving instance TriggerEvent t m => TriggerEvent t (DisplayRegion t m)
280−-- * mouse inputs inside the region have their coordinates translated such
292+instance HasImageWriter t m => HasImageWriter t (DisplayRegion t m)
281−-- that (0,0) is the top-left corner of the region
293+instance HasFocusReader t m => HasFocusReader t (DisplayRegion t m)
283− :: (Reflex t, Monad m, MonadNodeId m)
285− -> Dynamic t Bool -- ^ Whether the widget should be focused when the parent is.
288−pane dr foc child = VtyWidget $ do
290− let reg = currentRegion dr
291− let ctx' = VtyWidgetCtx
292− { _vtyWidgetCtx_input = leftmost -- TODO: think about this leftmost more.
294− attachWith (\(r,f) e -> filterInput r f e)
295− (liftA2 (,) reg (current foc))
296− (_vtyWidgetCtx_input ctx)
298− , _vtyWidgetCtx_focus = liftA2 (&&) (_vtyWidgetCtx_focus ctx) foc
299− , _vtyWidgetCtx_width = _dynRegion_width dr
300− , _vtyWidgetCtx_height = _dynRegion_height dr
302− (result, images) <- lift . lift $ runVtyWidget ctx' child
303− let images' = liftA2 (\r is -> map (withinImage r) is) reg images
307− filterInput :: Region -> Bool -> VtyEvent -> Maybe VtyEvent
308− filterInput (Region l t w h) focused e = case e of
309− V.EvKey _ _ | not focused -> Nothing
310− V.EvMouseDown x y btn m -> mouse (\u v -> V.EvMouseDown u v btn m) x y
311− V.EvMouseUp x y btn -> mouse (\u v -> V.EvMouseUp u v btn) x y
318− , y >= t + h ] = Nothing
320− Just (con (x - l) (y - t))
322−-- | Information about a drag operation
324− { _drag_from :: (Int, Int) -- ^ Where the drag began
325− , _drag_to :: (Int, Int) -- ^ Where the mouse currently is
326− , _drag_button :: V.Button -- ^ Which mouse button is dragging
327− , _drag_modifiers :: [V.Modifier] -- ^ What modifiers are held
328− , _drag_end :: Bool -- ^ Whether the drag ended (the mouse button was released)
330− deriving (Eq, Ord, Show)
332−-- | Converts raw vty mouse drag events into an event stream of 'Drag's
334− :: (Reflex t, MonadFix m, MonadHold t m)
336− -> VtyWidget t m (Event t Drag)
339− let f :: Maybe Drag -> V.Event -> Maybe Drag
341− V.EvMouseDown x y btn' mods
342− | btn == btn' -> Just $ Drag (x,y) (x,y) btn' mods False
343− | otherwise -> Nothing
345− f (Just (Drag from _ _ mods end)) = \case
346− V.EvMouseDown x y btn' mods'
347− | end && btn == btn' -> Just $ Drag (x,y) (x,y) btn' mods' False
348− | btn == btn' -> Just $ Drag from (x,y) btn mods' False
349− | otherwise -> Nothing -- Ignore other buttons.
350− V.EvMouseUp x y (Just btn')
352− | btn == btn' -> Just $ Drag from (x,y) btn mods True
353− | otherwise -> Nothing
354− V.EvMouseUp x y Nothing -- Terminal doesn't specify mouse up button,
355− -- assume it's the right one.
357− | otherwise -> Just $ Drag from (x,y) btn mods True
359− rec let newDrag = attachWithMaybe f (current dragD) inp
360− dragD <- holdDyn Nothing $ Just <$> newDrag
361− return (fmapMaybe id $ updated dragD)
363−-- | Mouse down events for a particular mouse button
365− :: (Reflex t, Monad m)
367− -> VtyWidget t m (Event t MouseDown)
370− return $ fforMaybe i $ \case
371− V.EvMouseDown x y btn' mods -> if btn == btn'
372− then Just $ MouseDown btn' (x, y) mods
376−-- | Mouse up events for a particular mouse button
295+instance (Adjustable t m, MonadFix m, MonadHold t m) => Adjustable t (DisplayRegion t m) where
377−mouseUp
296+ runWithReplace (DisplayRegion a) e = DisplayRegion $ runWithReplace a $ fmap unDisplayRegion e
378− :: (Reflex t, Monad m)
297+ traverseIntMapWithKeyWithAdjust f m e = DisplayRegion $ traverseIntMapWithKeyWithAdjust (\k v -> unDisplayRegion $ f k v) m e
379− => VtyWidget t m (Event t MouseUp)
298+ traverseDMapWithKeyWithAdjust f m e = DisplayRegion $ traverseDMapWithKeyWithAdjust (\k v -> unDisplayRegion $ f k v) m e
380−mouseUp = do
299+ traverseDMapWithKeyWithAdjustWithMove f m e = DisplayRegion $ traverseDMapWithKeyWithAdjustWithMove (\k v -> unDisplayRegion $ f k v) m e
382− return $ fforMaybe i $ \case
383− V.EvMouseUp x y btn' -> Just $ MouseUp btn' (x, y)
386−-- | Information about a mouse down event
301+instance MonadTrans (DisplayRegion t) where
387−data MouseDown = MouseDown
302+ lift = DisplayRegion . lift
388− { _mouseDown_button :: V.Button
389− , _mouseDown_coordinates :: (Int, Int)
390− , _mouseDown_modifiers :: [V.Modifier]
392− deriving (Eq, Ord, Show)
394−-- | Information about a mouse up event
304+instance MFunctor (DisplayRegion t) where
395−data MouseUp = MouseUp
305+ hoist f = DisplayRegion . hoist f . unDisplayRegion
396− { _mouseUp_button :: Maybe V.Button
397− , _mouseUp_coordinates :: (Int, Int)
399− deriving (Eq, Ord, Show)
401−-- | Mouse scroll direction
307+instance MonadNodeId m => MonadNodeId (DisplayRegion t m)
402−data ScrollDirection = ScrollDirection_Up | ScrollDirection_Down
403− deriving (Eq, Ord, Show)
405−-- | Produce an event that fires when the mouse wheel is scrolled
309+-- | Run a 'DisplayRegion' action with a given 'Region'
406−mouseScroll
310+runDisplayRegion
407 :: (Reflex t, Monad m)
311 :: (Reflex t, Monad m)
408− => VtyWidget t m (Event t ScrollDirection)
312+ => Dynamic t Region
409−mouseScroll = do
313+ -> DisplayRegion t m a
410− up <- mouseDown V.BScrollUp
314+ -> m a
411− down <- mouseDown V.BScrollDown
315+runDisplayRegion r = flip runReaderT r . unDisplayRegion
413− [ ScrollDirection_Up <$ up
414− , ScrollDirection_Down <$ down
417−-- | Type synonym for a key and modifier combination
317+-- * Getting focus state
418−type KeyCombo = (V.Key, [V.Modifier])
420−-- | Emits an event that fires on a particular key press (without modifiers)
319+-- | A class for things that can dynamically gain and lose focus
421−key :: (Monad m, Reflex t) => V.Key -> VtyWidget t m (Event t KeyCombo)
320+class (Reflex t, Monad m) => HasFocusReader t m | m -> t where
422−key = keyCombos . Set.singleton . (,[])
321+ focus :: m (Dynamic t Bool)
322+ default focus :: (f m' ~ m, Monad m', MonadTrans f, HasFocusReader t m') => m (Dynamic t Bool)
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)
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)
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 }
424−-- | Emits an event that fires on particular key presses (without modifiers)
348+instance (Monad m, Reflex t) => HasFocusReader t (FocusReader t m) where
425−keys :: (Monad m, Reflex t) => [V.Key] -> VtyWidget t m (Event t KeyCombo)
349+ focus = FocusReader ask
426−keys = keyCombos . Set.fromList . fmap (,[])
350+ localFocus f = FocusReader . local f . unFocusReader
428−-- | Emit an event that fires whenever the provided key combination occurs
352+deriving instance MonadReflexCreateTrigger t m => MonadReflexCreateTrigger t (FocusReader t m)
429−keyCombo
353+deriving instance NotReady t m => NotReady t (FocusReader t m)
430− :: (Reflex t, Monad m)
354+deriving instance PerformEvent t m => PerformEvent t (FocusReader t m)
431− => KeyCombo
355+deriving instance PostBuild t m => PostBuild t (FocusReader t m)
432− -> VtyWidget t m (Event t KeyCombo)
356+deriving instance TriggerEvent t m => TriggerEvent t (FocusReader t m)
433−keyCombo = keyCombos . Set.singleton
357+instance HasImageWriter t m => HasImageWriter t (FocusReader t m)
435−-- | Emit an event that fires whenever any of the provided key combinations occur
359+instance (Adjustable t m, MonadFix m, MonadHold t m) => Adjustable t (FocusReader t m) where
436−keyCombos
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
365+instance MonadTrans (FocusReader t) where
366+ lift = FocusReader . lift
368+instance MFunctor (FocusReader t) where
369+ hoist f = FocusReader . hoist f . unFocusReader
371+instance MonadNodeId m => MonadNodeId (FocusReader t m)
373+-- | Run a 'FocusReader' action with the given focus value
437 :: (Reflex t, Monad m)
375 :: (Reflex t, Monad m)
438− => Set KeyCombo
376+ => Dynamic t Bool
439− -> VtyWidget t m (Event t KeyCombo)
377+ -> FocusReader t m a
440−keyCombos ks = do
378+ -> m a
441− i <- input
379+runFocusReader b = flip runReaderT b . unFocusReader
442− return $ fforMaybe i $ \case
443− V.EvKey k m -> if Set.member (k, m) ks
448−-- | A plain split of the available space into vertically stacked panes.
381+-- * "Image" output
449−-- No visual separator is built in here.
450−splitV :: (Reflex t, Monad m, MonadNodeId m)
451− => Dynamic t (Int -> Int)
452− -- ^ Function used to determine size of first pane based on available size
453− -> Dynamic t (Bool, Bool)
454− -- ^ How to focus the two sub-panes, given that we are focused.
456− -- ^ Widget for first pane
458− -- ^ Widget for second pane
459− -> VtyWidget t m (a,b)
460−splitV sizeFunD focD wA wB = do
463− let regA = DynRegion
464− { _dynRegion_left = pure 0
465− , _dynRegion_top = pure 0
466− , _dynRegion_width = dw
467− , _dynRegion_height = sizeFunD <*> dh
470− { _dynRegion_left = pure 0
471− , _dynRegion_top = _dynRegion_height regA
472− , _dynRegion_width = dw
473− , _dynRegion_height = liftA2 (-) dh (_dynRegion_height regA)
475− ra <- pane regA (fst <$> focD) wA
476− rb <- pane regB (snd <$> focD) wB
479−-- | A plain split of the available space into horizontally stacked panes.
480−-- No visual separator is built in here.
481−splitH :: (Reflex t, Monad m, MonadNodeId m)
482− => Dynamic t (Int -> Int)
483− -- ^ Function used to determine size of first pane based on available size
484− -> Dynamic t (Bool, Bool)
485− -- ^ How to focus the two sub-panes, given that we are focused.
487− -- ^ Widget for first pane
489− -- ^ Widget for second pane
490− -> VtyWidget t m (a,b)
491−splitH sizeFunD focD wA wB = do
494− let regA = DynRegion
495− { _dynRegion_left = pure 0
496− , _dynRegion_top = pure 0
497− , _dynRegion_width = sizeFunD <*> dw
498− , _dynRegion_height = dh
501− { _dynRegion_left = _dynRegion_width regA
502− , _dynRegion_top = pure 0
503− , _dynRegion_width = liftA2 (-) dw (_dynRegion_width regA)
504− , _dynRegion_height = dh
506− liftA2 (,) (pane regA (fmap fst focD) wA) (pane regB (fmap snd focD) wB)
508−-- | A split of the available space into two parts with a draggable separator.
509−-- Starts with half the space allocated to each, and the first pane has focus.
510−-- Clicking in a pane switches focus.
511−splitVDrag :: (Reflex t, MonadFix m, MonadHold t m, MonadNodeId m)
515− -> VtyWidget t m (a,b)
516−splitVDrag wS wA wB = do
519− h0 <- sample $ current dh -- TODO
520− dragE <- drag V.BLeft
521− let splitter0 = h0 `div` 2
522− rec splitterCheckpoint <- holdDyn splitter0 $ leftmost [fst <$> ffilter snd dragSplitter, resizeSplitter]
523− splitterPos <- holdDyn splitter0 $ leftmost [fst <$> dragSplitter, resizeSplitter]
524− splitterFrac <- holdDyn ((1::Double) / 2) $ ffor (attach (current dh) (fst <$> dragSplitter)) $ \(h, x) ->
525− fromIntegral x / (max 1 (fromIntegral h))
526− let dragSplitter = fforMaybe (attach (current splitterCheckpoint) dragE) $
527− \(splitterY, Drag (_, fromY) (_, toY) _ _ end) ->
528− if splitterY == fromY then Just (toY, end) else Nothing
529− regA = DynRegion 0 0 dw splitterPos
530− regS = DynRegion 0 splitterPos dw 1
531− regB = DynRegion 0 (splitterPos + 1) dw (dh - splitterPos - 1)
532− resizeSplitter = ffor (attach (current splitterFrac) (updated dh)) $
533− \(frac, h) -> round (frac * fromIntegral h)
534− focA <- holdDyn True $ leftmost
538− (mA, rA) <- pane regA focA $ withMouseDown wA
539− pane regS (pure False) wS
540− (mB, rB) <- pane regB (not <$> focA) $ withMouseDown wB
543− withMouseDown x = do
544− m <- mouseDown V.BLeft
548−-- | Fill the background with a particular character.
549−fill :: (Reflex t, Monad m) => Char -> VtyWidget t m ()
553− let fillImg = current $ liftA2 (\w h -> [V.charFill V.defAttr c w h]) dw dh
556−-- | Fill the background with the bottom
557−hRule :: (Reflex t, Monad m) => BoxStyle -> VtyWidget t m ()
558−hRule boxStyle = fill (_boxStyle_s boxStyle)
560−-- | Defines a set of symbols to use to draw the outlines of boxes
561−-- C.f. https://en.wikipedia.org/wiki/Box-drawing_character
562−data BoxStyle = BoxStyle
563− { _boxStyle_nw :: Char
564− , _boxStyle_n :: Char
565− , _boxStyle_ne :: Char
566− , _boxStyle_e :: Char
567− , _boxStyle_se :: Char
568− , _boxStyle_s :: Char
569− , _boxStyle_sw :: Char
570− , _boxStyle_w :: Char
573−instance Default BoxStyle where
383+-- | A class for widgets that can produce images to draw to the display
574− def = singleBoxStyle
384+class (Reflex t, Monad m) => HasImageWriter t m | m -> t where
575−
385+ -- | Send images upstream for rendering
576−-- | A box style that uses hyphens and pipe characters. Doesn't handle
386+ tellImages :: Behavior t [Image] -> m ()
577−-- corners very well.
387+ default tellImages :: (f m' ~ m, Monad m', MonadTrans f, HasImageWriter t m') => Behavior t [Image] -> m ()
578−hyphenBoxStyle :: BoxStyle
388+ tellImages = lift . tellImages
579−hyphenBoxStyle = BoxStyle '-' '-' '-' '|' '-' '-' '-' '|'
389+ -- | Apply a transformation to the images produced by the child actions
580−
390+ mapImages :: (Behavior t [Image] -> Behavior t [Image]) -> m a -> m a
581−-- | A single line box style
391+ default mapImages :: (f m' ~ m, Monad m', MFunctor f, HasImageWriter t m') => (Behavior t [Image] -> Behavior t [Image]) -> m a -> m a
582−singleBoxStyle :: BoxStyle
392+ mapImages f = hoist (mapImages f)
583−singleBoxStyle = BoxStyle '┌' '─' '┐' '│' '┘' '─' '└' '│'
393+
584−
394+-- | A widget that can produce images to draw onto the display
585−-- | A thick single line box style
395+newtype ImageWriter t m a = ImageWriter
586−thickBoxStyle :: BoxStyle
396+ { unImageWriter :: BehaviorWriterT t [Image] m a }
587−thickBoxStyle = BoxStyle '┏' '━' '┓' '┃' '┛' '━' '┗' '┃'
397+ deriving
589−-- | A double line box style
399+ , Applicative
590−doubleBoxStyle :: BoxStyle
400+ , Monad
591−doubleBoxStyle = BoxStyle '╔' '═' '╗' '║' '╝' '═' '╚' '║'
401+ , MonadFix
593−-- | A single line box style with rounded corners
403+ , MonadIO
594−roundedBoxStyle :: BoxStyle
404+ , MonadRef
595−roundedBoxStyle = BoxStyle '╭' '─' '╮' '│' '╯' '─' '╰' '│'
405+ , MonadReflexCreateTrigger t
597−-- | Draws a titled box in the provided style and a child widget inside of that box
407+ , NotReady t
598−boxTitle :: (Monad m, Reflex t, MonadNodeId m)
408+ , PerformEvent t
599− => Behavior t BoxStyle
409+ , PostBuild t
600− -> Text
410+ , TriggerEvent t
601− -> VtyWidget t m a
411+ )
602− -> VtyWidget t m a
412+
603−boxTitle boxStyle title child = do
413+instance MonadTrans (ImageWriter t) where
604− dh <- displayHeight
414+ lift = ImageWriter . lift
605− dw <- displayWidth
415+
606− let boxReg = DynRegion (pure 0) (pure 0) dw dh
416+instance MFunctor (ImageWriter t) where
607− innerReg = DynRegion (pure 1) (pure 1) (subtract 2 <$> dw) (subtract 2 <$> dh)
417+ hoist f = ImageWriter . (hoist f) . unImageWriter
608− tellImages (boxImages <$> boxStyle <*> currentRegion boxReg)
418+
609− tellImages (fmap (\r -> [regionBlankImage r]) (currentRegion innerReg))
419+instance (Adjustable t m, MonadFix m, MonadHold t m) => Adjustable t (ImageWriter t m) where
610− pane innerReg (pure True) child
420+ runWithReplace (ImageWriter a) e = ImageWriter $ runWithReplace a $ fmap unImageWriter e
611− where
421+ traverseIntMapWithKeyWithAdjust f m e = ImageWriter $ traverseIntMapWithKeyWithAdjust (\k v -> unImageWriter $ f k v) m e
612− boxImages :: BoxStyle -> Region -> [Image]
422+ traverseDMapWithKeyWithAdjust f m e = ImageWriter $ traverseDMapWithKeyWithAdjust (\k v -> unImageWriter $ f k v) m e
613− boxImages style (Region left top width height) =
423+ traverseDMapWithKeyWithAdjustWithMove f m e = ImageWriter $ traverseDMapWithKeyWithAdjustWithMove (\k v -> unImageWriter $ f k v) m e
614− let right = left + width - 1
615− bottom = top + height - 1
617− [ withinImage (Region (left + 1) top (width - 2) 1) $
619− hPadText title (_boxStyle_n style) (width - 2)
620− , withinImage (Region right (top + 1) 1 (height - 2)) $
621− V.charFill V.defAttr (_boxStyle_e style) 1 (height - 2)
622− , withinImage (Region (left + 1) bottom (width - 2) 1) $
623− V.charFill V.defAttr (_boxStyle_s style) (width - 2) 1
624− , withinImage (Region left (top + 1) 1 (height - 2)) $
625− V.charFill V.defAttr (_boxStyle_w style) 1 (height - 2)
628− [ withinImage (Region left top 1 1) $
629− V.char V.defAttr (_boxStyle_nw style)
630− , withinImage (Region right top 1 1) $
631− V.char V.defAttr (_boxStyle_ne style)
632− , withinImage (Region right bottom 1 1) $
633− V.char V.defAttr (_boxStyle_se style)
634− , withinImage (Region left bottom 1 1) $
635− V.char V.defAttr (_boxStyle_sw style)
637− in sides ++ if width > 1 && height > 1 then corners else []
638− hPadText :: T.Text -> Char -> Int -> T.Text
639− hPadText t c l = if lt >= l
641− else left <> t <> right
645− mkHalf n = T.replicate (n `div` 2) (T.singleton c)
646− left = mkHalf $ delta + 1
647− right = mkHalf delta
649−-- | A box without a title
650−box :: (Monad m, Reflex t, MonadNodeId m)
651− => Behavior t BoxStyle
654−box boxStyle = boxTitle boxStyle mempty
656−-- | A box whose style is static
658− :: (Reflex t, Monad m, MonadNodeId m)
662−boxStatic = box . pure
664−-- | Configuration options for displaying "rich" text
665−data RichTextConfig t = RichTextConfig
666− { _richTextConfig_attributes :: Behavior t V.Attr
669−instance Reflex t => Default (RichTextConfig t) where
425+instance HasImageWriter t m => HasImageWriter t (ReaderT x m)
670− def = RichTextConfig $ pure V.defAttr
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)
672−-- | A widget that displays text with custom time-varying attributes
431+instance (Monad m, Reflex t) => HasImageWriter t (ImageWriter t m) where
673−richText
432+ tellImages = ImageWriter . tellBehavior
433+ mapImages f (ImageWriter x) = ImageWriter $ do
434+ (a, images) <- lift $ runBehaviorWriterT x
435+ tellBehavior $ f images
438+instance HasDisplayRegion t m => HasDisplayRegion t (ImageWriter t m)
439+instance HasFocusReader t m => HasFocusReader t (ImageWriter t m)
441+-- | Run a widget that can produce images
674 :: (Reflex t, Monad m)
443 :: (Reflex t, Monad m)
675− => RichTextConfig t
444+ => ImageWriter t m a
676− -> Behavior t Text
445+ -> m (a, Behavior t [Image])
677− -> VtyWidget t m ()
446+runImageWriter = runBehaviorWriterT . unImageWriter
678−richText cfg t = do
447+
679− dw <- displayWidth
448+-- * Theming
680− let img = (\w a s -> [wrapText w a s])
449+
681− <$> current dw
450+-- | A class for things that can be visually styled
682− <*> _richTextConfig_attributes cfg
451+class (Reflex t, Monad m) => HasTheme t m | m -> t where
683− <*> t
452+ theme :: m (Behavior t V.Attr)
684− tellImages img
453+ default theme :: (f m' ~ m, Monad m', MonadTrans f, HasTheme t m') => m (Behavior t V.Attr)
685− where
454+ theme = lift theme
686− wrapText maxWidth attrs = V.vertCat
455+ localTheme :: (Behavior t V.Attr -> Behavior t V.Attr) -> m a -> m a
687− . concatMap (fmap (V.string attrs . T.unpack) . TZ.wrapWithOffset maxWidth 0)
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
688− . T.split (=='\n')
457+ localTheme f = hoist (localTheme f)
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)
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 }
483+instance (Monad m, Reflex t) => HasTheme t (ThemeReader t m) where
484+ theme = ThemeReader ask
485+ localTheme f = ThemeReader . local f . unThemeReader
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)
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
500+instance MonadTrans (ThemeReader t) where
501+ lift = ThemeReader . lift
690−-- | Renders text, wrapped to the container width
503+instance MFunctor (ThemeReader t) where
691−text
504+ hoist f = ThemeReader . hoist f . unThemeReader
506+instance MonadNodeId m => MonadNodeId (ThemeReader t m)
508+-- | Run a 'ThemeReader' action with the given focus value
692 :: (Reflex t, Monad m)
510 :: (Reflex t, Monad m)
693− => Behavior t Text
511+ => Behavior t V.Attr
694− -> VtyWidget t m ()
512+ -> ThemeReader t m a
695−text = richText def
513+ -> m a
696−
514+runThemeReader b = flip runReaderT b . unThemeReader
697−-- | Scrollable text widget. The output pair exposes the current scroll position and total number of lines (including those
515+
698−-- that are hidden)
516+
699−scrollableText
517+-- ** Manipulating images
700− :: forall t m. (Reflex t, MonadHold t m, MonadFix m)
518+
701− => Event t Int
519+-- | Translates and crops an 'Image' so that it is contained by
702− -- ^ Number of lines to scroll by
520+-- the given 'Region'.
703− -> Behavior t Text
521+withinImage
704− -> VtyWidget t m (Behavior t (Int, Int))
522+ :: Region
705− -- ^ (Current scroll position, total number of lines)
523+ -> Image
706−scrollableText scrollBy t = do
524+ -> Image
707− dw <- displayWidth
525+withinImage (Region left top width height)
708− let imgs = wrap <$> current dw <*> t
526+ | width < 0 || height < 0 = withinImage (Region left top 0 0)
709− kup <- key V.KUp
527+ | otherwise = V.translate left top . V.crop width height
710− kdown <- key V.KDown
528+
711− m <- mouseScroll
529+-- | Crop a behavior of images to a behavior of regions. See 'withinImage'.
712− let requestedScroll :: Event t Int
530+imagesInRegion
713− requestedScroll = leftmost
531+ :: Reflex t
714− [ 1 <$ kdown
532+ => Behavior t Region
715− , (-1) <$ kup
533+ -> Behavior t [Image]
716− , ffor m $ \case
534+ -> Behavior t [Image]
717− ScrollDirection_Up -> (-1)
535+imagesInRegion reg = liftA2 (\r is -> map (withinImage r) is) reg
718− ScrollDirection_Down -> 1
536+
719− , scrollBy
537+-- * Running sub-widgets
721− updateLine maxN delta ix = min (max 0 (ix + delta)) maxN
539+-- | Low-level widget combinator that runs a child widget within
722− lineIndex :: Dynamic t Int <- foldDyn (\(maxN, delta) ix -> updateLine (maxN - 1) delta ix) 0 $
540+-- a given region and context. This widget filters and modifies the input
723− attach (length <$> imgs) requestedScroll
541+-- that the child widget receives such that:
724− tellImages $ fmap ((:[]) . V.vertCat) $ drop <$> current lineIndex <*> imgs
542+-- * unfocused widgets receive no key events
725− return $ (,) <$> ((+) <$> current lineIndex <*> pure 1) <*> (length <$> imgs)
543+-- * mouse inputs outside the region are ignored
726− where
544+-- * mouse inputs inside the region have their coordinates translated such
727− wrap maxWidth = concatMap (fmap (V.string V.defAttr . T.unpack) . TZ.wrapWithOffset maxWidth 0) . T.split (=='\n')
545+-- that (0,0) is the top-left corner of the region
547+ :: (Reflex t, Monad m, HasInput t m, HasImageWriter t m, HasDisplayRegion t m, HasFocusReader t m)
549+ -> Dynamic t Bool -- ^ Whether the widget should be focused when the parent is.
552+pane dr foc child = localRegion (const dr) $
553+ mapImages (imagesInRegion $ current dr) $
554+ localFocus (const foc) $
555+ inputInFocusedRegion >>= \e -> localInput (const e) child
729−-- | Renders any behavior whose value can be converted to
557+-- * Misc
732− :: (Reflex t, Monad m, Show a)
735−display a = text $ T.pack . show <$> a
737-- | A widget that draws nothing
559-- | A widget that draws nothing
738−blank :: Monad m => VtyWidget t m ()
560+blank :: Monad m => m ()
739blank = return ()
561blank = return ()