@@ -4,18 +4,71 @@ Description: Basic set of widgets and building blocks for reflex-vty application
5{-# Language UndecidableInstances #-}
5{-# Language UndecidableInstances #-}
7−module Reflex.Vty.Widget where
7+module Reflex.Vty.Widget
14+ , mainWidgetWithHandle
18+ , HasVtyWidgetCtx(..)
28+ , ScrollDirection(..)
9import Control.Applicative (liftA2)
59import Control.Applicative (liftA2)
10import Control.Monad.Fix (MonadFix)
60import Control.Monad.Fix (MonadFix)
11import Control.Monad.IO.Class (MonadIO)
61import Control.Monad.IO.Class (MonadIO)
12import Control.Monad.Morph
62import Control.Monad.Morph
13import Control.Monad.NodeId
63import Control.Monad.NodeId
14−import Control.Monad.Reader (ReaderT, ask, local, runReaderT)
64+import Control.Monad.Reader (ReaderT, ask, asks, local, runReaderT)
15−import Control.Monad.Ref
16import Control.Monad.Trans (MonadTrans, lift)
65import Control.Monad.Trans (MonadTrans, lift)
66+import Data.Default (Default(..))
17import Data.Set (Set)
67import Data.Set (Set)
18import qualified Data.Set as Set
68import qualified Data.Set as Set
69+import Data.Text (Text)
70+import qualified Data.Text as T
71+import qualified Data.Text.Zipper as TZ
19import Graphics.Vty (Image)
72import Graphics.Vty (Image)
20import qualified Graphics.Vty as V
73import qualified Graphics.Vty as V
21import Reflex
74import Reflex
@@ -23,20 +76,86 @@ import Reflex.Class ()
23import Reflex.Host.Class (MonadReflexCreateTrigger)
76import Reflex.Host.Class (MonadReflexCreateTrigger)
24import Reflex.Vty.Host
77import Reflex.Vty.Host
26−-- * Running a vty application
79+-- | The context within which a 'VtyWidget' runs
80+data VtyWidgetCtx t = VtyWidgetCtx
81+ { _vtyWidgetCtx_width :: Dynamic t Int
82+ -- ^ The width of the region allocated to the widget.
83+ , _vtyWidgetCtx_height :: Dynamic t Int
84+ -- ^ The height of the region allocated to the widget.
85+ , _vtyWidgetCtx_focus :: Dynamic t Bool
86+ -- ^ Whether the widget should behave as if it has focus for keyboard input.
89+-- | The output of a 'VtyWidget'
90+data VtyWidgetOut t = VtyWidgetOut
91+ { _vtyWidgetOut_shutdown :: Event t ()
94+instance (Adjustable t m, MonadHold t m, Reflex t) => Adjustable t (VtyWidget t m) where
95+ runWithReplace a0 a' = VtyWidget $ runWithReplace (unVtyWidget a0) $ fmap unVtyWidget a'
96+ traverseIntMapWithKeyWithAdjust f dm0 dm' = VtyWidget $
97+ traverseIntMapWithKeyWithAdjust (\k v -> unVtyWidget (f k v)) dm0 dm'
98+ traverseDMapWithKeyWithAdjust f dm0 dm' = VtyWidget $ do
99+ traverseDMapWithKeyWithAdjust (\k v -> unVtyWidget (f k v)) dm0 dm'
100+ traverseDMapWithKeyWithAdjustWithMove f dm0 dm' = VtyWidget $ do
101+ traverseDMapWithKeyWithAdjustWithMove (\k v -> unVtyWidget (f k v)) dm0 dm'
103+-- | A widget that can read its context and produce image output
104+newtype VtyWidget t m a = VtyWidget
105+ { unVtyWidget :: BehaviorWriterT t [Image]
106+ (ReaderT (VtyWidgetCtx t)
107+ (ReaderT (Event t VtyEvent) m)) a
119+ , MonadReflexCreateTrigger t
123+deriving instance PerformEvent t m => PerformEvent t (VtyWidget t m)
125+instance MonadTrans (VtyWidget t) where
126+ lift f = VtyWidget $ lift $ lift $ lift f
128+instance MFunctor (VtyWidget t) where
129+ hoist f = VtyWidget . hoist (hoist (hoist f)) . unVtyWidget
131+instance MonadNodeId m => MonadNodeId (VtyWidget t m) where
132+ getNextNodeId = VtyWidget $ do
133+ lift $ lift getNextNodeId
135+-- | A reader-like class for the vty widget context. Allows actions to be run in a sub-context.
136+class HasVtyWidgetCtx t m | m -> t where
137+ askCtx :: m (VtyWidgetCtx t)
138+ default askCtx :: (f m' ~ m, Monad m', MonadTrans f, HasVtyWidgetCtx t m') => m (VtyWidgetCtx t)
139+ askCtx = lift askCtx
140+ localCtx :: (VtyWidgetCtx t -> VtyWidgetCtx t) -> m a -> m a
142+instance (Monad m, Reflex t) => HasVtyWidgetCtx t (VtyWidget t m) where
143+ askCtx = VtyWidget $ lift ask
144+ localCtx f (VtyWidget x) = VtyWidget $ local f x
146+-- | Runs a 'VtyWidget' with a given context
148+ :: (Reflex t, MonadNodeId m)
152+ -> m (a, Behavior t [Image])
153+runVtyWidget e ctx w = runReaderT (runReaderT (runBehaviorWriterT (unVtyWidget w)) ctx) e
28−-- | Sets up the top-level context for a vty widget and runs it with that context
155+-- | Sets up the top-level context for a 'VtyWidget' and runs it with that context
29mainWidgetWithHandle
156mainWidgetWithHandle
32− ( MonadVtyApp t m
158+ -> (forall t m. (MonadVtyApp t m, MonadNodeId m) => VtyWidget t m (Event t ()))
35− , HasDisplayRegion t m
41mainWidgetWithHandle vty child =
160mainWidgetWithHandle vty child =
42 runVtyAppWithHandle vty $ \dr0 inp -> do
161 runVtyAppWithHandle vty $ \dr0 inp -> do
@@ -46,475 +165,109 @@ mainWidgetWithHandle vty child =
46 let inp' = fforMaybe inp $ \case
165 let inp' = fforMaybe inp $ \case
47 V.EvResize {} -> Nothing
166 V.EvResize {} -> Nothing
48 x -> Just x
167 x -> Just x
49− (shutdown, images) <- runThemeReader (constant V.defAttr) $
168+ let ctx = VtyWidgetCtx
50− runFocusReader (pure True) $
169+ { _vtyWidgetCtx_width = fmap fst size
51− runDisplayRegion (fmap (\(w, h) -> Region 0 0 w h) size) $
170+ , _vtyWidgetCtx_height = fmap snd size
52− runImageWriter $
171+ , _vtyWidgetCtx_focus = constDyn True
54− runInput inp' $ do
173+ (shutdown, images) <- runNodeIdT $ runVtyWidget inp' ctx $ do
55− tellImages . ffor (current size) $ \(w, h) -> [V.charFill V.defAttr ' ' w h]
174+ tellImages . ffor (current size) $ \(w, h) -> [V.charFill V.defAttr ' ' w h]
57 return $ VtyResult
176 return $ VtyResult
58 { _vtyResult_picture = fmap (V.picForLayers . reverse) images
177 { _vtyResult_picture = fmap (V.picForLayers . reverse) images
59 , _vtyResult_shutdown = shutdown
178 , _vtyResult_shutdown = shutdown
62−-- | The output of a vty widget
63−data VtyWidgetOut t = VtyWidgetOut
64− { _vtyWidgetOut_shutdown :: Event t ()
67-- | Like 'mainWidgetWithHandle', but uses a default vty configuration
181-- | Like 'mainWidgetWithHandle', but uses a default vty configuration
68mainWidget
182mainWidget
70− ( MonadVtyApp t m
183+ :: (forall t m. (MonadVtyApp t m, MonadNodeId m) => VtyWidget t m (Event t ()))
73− , HasDisplayRegion t m
79mainWidget child = do
185mainWidget child = do
80 vty <- getDefaultVty
186 vty <- getDefaultVty
81 mainWidgetWithHandle vty child
187 mainWidgetWithHandle vty child
83−-- * Input Events
189+-- | A class for things that know their own display size dimensions
190+class (Reflex t, Monad m) => HasDisplaySize t m | m -> t where
191+ -- | Retrieve the display width (columns)
192+ displayWidth :: m (Dynamic t Int)
193+ default displayWidth :: (f m' ~ m, MonadTrans f, HasDisplaySize t m') => m (Dynamic t Int)
194+ displayWidth = lift displayWidth
195+ -- | Retrieve the display height (rows)
196+ displayHeight :: m (Dynamic t Int)
197+ default displayHeight :: (f m' ~ m, MonadTrans f, HasDisplaySize t m') => m (Dynamic t Int)
198+ displayHeight = lift displayHeight
200+instance (Reflex t, Monad m) => HasDisplaySize t (VtyWidget t m) where
201+ displayWidth = VtyWidget . lift $ asks _vtyWidgetCtx_width
202+ displayHeight = VtyWidget . lift $ asks _vtyWidgetCtx_height
204+instance HasDisplaySize t m => HasDisplaySize t (ReaderT x m)
205+instance HasDisplaySize t m => HasDisplaySize t (BehaviorWriterT t x m)
206+instance HasDisplaySize t m => HasDisplaySize t (DynamicWriterT t x m)
207+instance HasDisplaySize t m => HasDisplaySize t (EventWriterT t x m)
208+instance HasDisplaySize t m => HasDisplaySize t (NodeIdT m)
85-- | A class for things that can receive vty events as input
210-- | A class for things that can receive vty events as input
86−class HasInput t m | m -> t where
211+class HasVtyInput t m | m -> t where
87 input :: m (Event t VtyEvent)
212 input :: m (Event t VtyEvent)
88− default input :: (f m' ~ m, Monad m', MonadTrans f, HasInput t m') => m (Event t VtyEvent)
213+ default input :: (f m' ~ m, Monad m', MonadTrans f, HasVtyInput t m') => m (Event t VtyEvent)
89 input = lift input
214 input = lift input
90 -- | User input events that the widget's parent chooses to share. These will generally
215 -- | User input events that the widget's parent chooses to share. These will generally
91 -- be filtered for relevance.
216 -- be filtered for relevance.
92 localInput :: (Event t VtyEvent -> Event t VtyEvent) -> m a -> m a
217 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
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'
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
150−-- | Type synonym for a key and modifier combination
151−type KeyCombo = (V.Key, [V.Modifier])
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 . (,[])
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 (,[])
161−-- | Emit an event that fires whenever the provided key combination occurs
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
219-- | Filter the keyboard input that a child widget may receive
182−filterKeys :: (Reflex t, HasInput t m) => (KeyCombo -> Bool) -> m a -> m a
220+filterKeys :: (Reflex t, HasVtyInput t m) => (KeyCombo -> Bool) -> m a -> m a
183filterKeys f x = localInput (ffilter (\case
221filterKeys f x = localInput (ffilter (\case
184 V.EvKey k mods -> f (k, mods)
222 V.EvKey k mods -> f (k, mods)
185 _ -> True)) x
223 _ -> True)) x
187−-- | Filter mouse input events based on whether they target a particular region
225+instance (Reflex t, Monad m) => HasVtyInput t (VtyWidget t m) where
188−-- and translate them to the internal coordinate system of that region.
226+ input = VtyWidget . lift $ lift $ ask
189−--
227+ localInput f (VtyWidget m) = VtyWidget $ hoist (hoist (local f)) m
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
222−-- | A chunk of the display area
224− { _region_left :: Int
225− , _region_top :: Int
226− , _region_width :: Int
227− , _region_height :: Int
229− deriving (Show, Read, Eq, Ord)
231−-- | A region that occupies no space.
233−nilRegion = Region 0 0 0 0
235−-- | The width and height of a 'Region'
236−regionSize :: Region -> (Int, Int)
237−regionSize (Region _ _ w h) = (w, h)
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
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)
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 }
283−instance (Monad m, Reflex t) => HasDisplayRegion t (DisplayRegion t m) where
284− askRegion = DisplayRegion ask
285− localRegion f = DisplayRegion . local f . unDisplayRegion
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)
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
301−instance MonadTrans (DisplayRegion t) where
302− lift = DisplayRegion . lift
304−instance MFunctor (DisplayRegion t) where
305− hoist f = DisplayRegion . hoist f . unDisplayRegion
307−instance MonadNodeId m => MonadNodeId (DisplayRegion t m)
309−-- | Run a 'DisplayRegion' action with a given 'Region'
311− :: (Reflex t, Monad m)
313− -> DisplayRegion t m a
315−runDisplayRegion r = flip runReaderT r . unDisplayRegion
317−-- * Getting focus state
319-- | A class for things that can dynamically gain and lose focus
229-- | A class for things that can dynamically gain and lose focus
320−class (Reflex t, Monad m) => HasFocusReader t m | m -> t where
230+class HasFocus t m | m -> t where
321 focus :: m (Dynamic t Bool)
231 focus :: m (Dynamic t Bool)
322− default focus :: (f m' ~ m, Monad m', MonadTrans f, HasFocusReader t m') => m (Dynamic t Bool)
232+ default focus :: (f m' ~ m, Monad m', MonadTrans f, HasFocus t m') => m (Dynamic t Bool)
323 focus = lift focus
233 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)
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 }
348−instance (Monad m, Reflex t) => HasFocusReader t (FocusReader t m) where
349− focus = FocusReader ask
350− localFocus f = FocusReader . local f . unFocusReader
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)
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
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
375− :: (Reflex t, Monad m)
235+instance (Reflex t, Monad m) => HasFocus t (VtyWidget t m) where
376− => Dynamic t Bool
236+ focus = VtyWidget . lift $ asks _vtyWidgetCtx_focus
377− -> FocusReader t m a
379−runFocusReader b = flip runReaderT b . unFocusReader
383-- | A class for widgets that can produce images to draw to the display
238-- | 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
239+class (Reflex t, Monad m) => ImageWriter t m | m -> t where
385 -- | Send images upstream for rendering
240 -- | Send images upstream for rendering
386 tellImages :: Behavior t [Image] -> m ()
241 tellImages :: Behavior t [Image] -> m ()
387− default tellImages :: (f m' ~ m, Monad m', MonadTrans f, HasImageWriter t m') => Behavior t [Image] -> m ()
242+ default tellImages :: (f m' ~ m, Monad m', MonadTrans f, ImageWriter t m') => Behavior t [Image] -> m ()
388 tellImages = lift . tellImages
243 tellImages = lift . tellImages
389 -- | Apply a transformation to the images produced by the child actions
244 -- | Apply a transformation to the images produced by the child actions
390 mapImages :: (Behavior t [Image] -> Behavior t [Image]) -> m a -> m a
245 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)
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 }
405− , MonadReflexCreateTrigger t
413−instance MonadTrans (ImageWriter t) where
414− lift = ImageWriter . lift
416−instance MFunctor (ImageWriter t) where
417− hoist f = ImageWriter . (hoist f) . unImageWriter
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
425−instance HasImageWriter t m => HasImageWriter t (ReaderT x m)
247+instance (Monad m, Reflex t) => ImageWriter t (BehaviorWriterT t [Image] m) where
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)
431−instance (Monad m, Reflex t) => HasImageWriter t (ImageWriter t m) where
432− tellImages = ImageWriter . tellBehavior
248+ tellImages = tellBehavior
433− mapImages f (ImageWriter x) = ImageWriter $ do
249+ mapImages f x = do
434 (a, images) <- lift $ runBehaviorWriterT x
250 (a, images) <- lift $ runBehaviorWriterT x
435− tellBehavior $ f images
251+ tellImages $ f images
438−instance HasDisplayRegion t m => HasDisplayRegion t (ImageWriter t m)
254+-- | A chunk of the display area
439−instance HasFocusReader t m => HasFocusReader t (ImageWriter t m)
255+data Region = Region
440−
256+ { _region_left :: Int
441−-- | Run a widget that can produce images
257+ , _region_top :: Int
442−runImageWriter
258+ , _region_width :: Int
443− :: (Reflex t, Monad m)
259+ , _region_height :: Int
444− => ImageWriter t m a
260+ }
445− -> m (a, Behavior t [Image])
446−runImageWriter = runBehaviorWriterT . unImageWriter
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)
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)
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 }
472− deriving
261+ deriving (Show, Read, Eq, Ord)
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
503−instance MFunctor (ThemeReader t) where
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
510− :: (Reflex t, Monad m)
511− => Behavior t V.Attr
512− -> ThemeReader t m a
514−runThemeReader b = flip runReaderT b . unThemeReader
263+-- | The width and height of a 'Region'
264+regionSize :: Region -> (Int, Int)
265+regionSize (Region _ _ w h) = (w, h)
517−-- ** Manipulating images
267+-- | Produces an 'Image' that fills a region with space characters
268+regionBlankImage :: Region -> Image
269+regionBlankImage r@(Region _ _ width height) =
270+ withinImage r $ V.charFill V.defAttr ' ' width height
519-- | Translates and crops an 'Image' so that it is contained by
272-- | Translates and crops an 'Image' so that it is contained by
520-- the given 'Region'.
273-- the given 'Region'.
@@ -526,17 +279,7 @@ withinImage (Region left top width height)
526 | width < 0 || height < 0 = withinImage (Region left top 0 0)
279 | width < 0 || height < 0 = withinImage (Region left top 0 0)
527 | otherwise = V.translate left top . V.crop width height
280 | otherwise = V.translate left top . V.crop width height
529−-- | Crop a behavior of images to a behavior of regions. See 'withinImage'.
532− => Behavior t Region
533− -> Behavior t [Image]
534− -> Behavior t [Image]
535−imagesInRegion reg = liftA2 (\r is -> map (withinImage r) is) reg
537−-- * Running sub-widgets
539−-- | Low-level widget combinator that runs a child widget within
282+-- | Low-level widget combinator that runs a child 'VtyWidget' within
540-- a given region and context. This widget filters and modifies the input
283-- a given region and context. This widget filters and modifies the input
541-- that the child widget receives such that:
284-- that the child widget receives such that:
542-- * unfocused widgets receive no key events
285-- * unfocused widgets receive no key events
@@ -544,17 +287,433 @@ imagesInRegion reg = liftA2 (\r is -> map (withinImage r) is) reg
544-- * mouse inputs inside the region have their coordinates translated such
287-- * mouse inputs inside the region have their coordinates translated such
545-- that (0,0) is the top-left corner of the region
288-- 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)
290+ :: (Reflex t, Monad m, MonadNodeId m, HasVtyWidgetCtx t m, HasVtyInput t m, ImageWriter t m)
548 => Dynamic t Region
291 => Dynamic t Region
549 -> Dynamic t Bool -- ^ Whether the widget should be focused when the parent is.
292 -> Dynamic t Bool -- ^ Whether the widget should be focused when the parent is.
552−pane dr foc child = localRegion (const dr) $
295+pane dr foc child = do
553− mapImages (imagesInRegion $ current dr) $
296+ let reg = current dr
554− localFocus (const foc) $
297+ let subContext ctx = VtyWidgetCtx
555− inputInFocusedRegion >>= \e -> localInput (const e) child
298+ { _vtyWidgetCtx_focus = liftA2 (&&) (_vtyWidgetCtx_focus ctx) foc
299+ , _vtyWidgetCtx_width = _region_width <$> dr
300+ , _vtyWidgetCtx_height = _region_height <$> dr
302+ inputFilter = fmapMaybe id .
303+ attachWith (\(r,f) e -> filterInput r f e)
304+ (liftA2 (,) reg (current foc))
305+ let imagesWithinRegion images = liftA2 (\is r -> map (withinImage r) is) images reg
306+ mapImages imagesWithinRegion $ localInput inputFilter $ localCtx subContext child
308+ filterInput :: Region -> Bool -> VtyEvent -> Maybe VtyEvent
309+ filterInput (Region l t w h) focused e = case e of
310+ V.EvKey _ _ | not focused -> Nothing
311+ V.EvMouseDown x y btn m -> mouse (\u v -> V.EvMouseDown u v btn m) x y
312+ V.EvMouseUp x y btn -> mouse (\u v -> V.EvMouseUp u v btn) x y
319+ , y >= t + h ] = Nothing
321+ Just (con (x - l) (y - t))
323+-- | Information about a drag operation
325+ { _drag_from :: (Int, Int) -- ^ Where the drag began
326+ , _drag_to :: (Int, Int) -- ^ Where the mouse currently is
327+ , _drag_button :: V.Button -- ^ Which mouse button is dragging
328+ , _drag_modifiers :: [V.Modifier] -- ^ What modifiers are held
329+ , _drag_end :: Bool -- ^ Whether the drag ended (the mouse button was released)
331+ deriving (Eq, Ord, Show)
333+-- | Converts raw vty mouse drag events into an event stream of 'Drag's
335+ :: (Reflex t, MonadFix m, MonadHold t m, HasVtyInput t m)
340+ let f :: Maybe Drag -> V.Event -> Maybe Drag
342+ V.EvMouseDown x y btn' mods
343+ | btn == btn' -> Just $ Drag (x,y) (x,y) btn' mods False
344+ | otherwise -> Nothing
346+ f (Just (Drag from _ _ mods end)) = \case
347+ V.EvMouseDown x y btn' mods'
348+ | end && btn == btn' -> Just $ Drag (x,y) (x,y) btn' mods' False
349+ | btn == btn' -> Just $ Drag from (x,y) btn mods' False
350+ | otherwise -> Nothing -- Ignore other buttons.
351+ V.EvMouseUp x y (Just btn')
353+ | btn == btn' -> Just $ Drag from (x,y) btn mods True
354+ | otherwise -> Nothing
355+ V.EvMouseUp x y Nothing -- Terminal doesn't specify mouse up button,
356+ -- assume it's the right one.
358+ | otherwise -> Just $ Drag from (x,y) btn mods True
360+ rec let newDrag = attachWithMaybe f (current dragD) inp
361+ dragD <- holdDyn Nothing $ Just <$> newDrag
362+ return (fmapMaybe id $ updated dragD)
364+-- | Mouse down events for a particular mouse button
366+ :: (Reflex t, Monad m, HasVtyInput t m)
368+ -> m (Event t MouseDown)
371+ return $ fforMaybe i $ \case
372+ V.EvMouseDown x y btn' mods -> if btn == btn'
373+ then Just $ MouseDown btn' (x, y) mods
377+-- | Mouse up events for a particular mouse button
379+ :: (Reflex t, Monad m, HasVtyInput t m)
380+ => m (Event t MouseUp)
383+ return $ fforMaybe i $ \case
384+ V.EvMouseUp x y btn' -> Just $ MouseUp btn' (x, y)
387+-- | Information about a mouse down event
388+data MouseDown = MouseDown
389+ { _mouseDown_button :: V.Button
390+ , _mouseDown_coordinates :: (Int, Int)
391+ , _mouseDown_modifiers :: [V.Modifier]
393+ deriving (Eq, Ord, Show)
395+-- | Information about a mouse up event
396+data MouseUp = MouseUp
397+ { _mouseUp_button :: Maybe V.Button
398+ , _mouseUp_coordinates :: (Int, Int)
400+ deriving (Eq, Ord, Show)
402+-- | Mouse scroll direction
403+data ScrollDirection = ScrollDirection_Up | ScrollDirection_Down
404+ deriving (Eq, Ord, Show)
406+-- | Produce an event that fires when the mouse wheel is scrolled
408+ :: (Reflex t, Monad m, HasVtyInput t m)
409+ => m (Event t ScrollDirection)
411+ up <- mouseDown V.BScrollUp
412+ down <- mouseDown V.BScrollDown
414+ [ ScrollDirection_Up <$ up
415+ , ScrollDirection_Down <$ down
418+-- | Type synonym for a key and modifier combination
419+type KeyCombo = (V.Key, [V.Modifier])
421+-- | Emits an event that fires on a particular key press (without modifiers)
422+key :: (Monad m, Reflex t, HasVtyInput t m) => V.Key -> m (Event t KeyCombo)
423+key = keyCombos . Set.singleton . (,[])
425+-- | Emits an event that fires on particular key presses (without modifiers)
426+keys :: (Monad m, Reflex t, HasVtyInput t m) => [V.Key] -> m (Event t KeyCombo)
427+keys = keyCombos . Set.fromList . fmap (,[])
429+-- | Emit an event that fires whenever the provided key combination occurs
431+ :: (Reflex t, Monad m, HasVtyInput t m)
433+ -> m (Event t KeyCombo)
434+keyCombo = keyCombos . Set.singleton
436+-- | Emit an event that fires whenever any of the provided key combinations occur
438+ :: (Reflex t, Monad m, HasVtyInput t m)
440+ -> m (Event t KeyCombo)
443+ return $ fforMaybe i $ \case
444+ V.EvKey k m -> if Set.member (k, m) ks
449+-- | A plain split of the available space into vertically stacked panes.
450+-- No visual separator is built in here.
451+splitV :: (Reflex t, Monad m, MonadNodeId m, HasVtyWidgetCtx t m, HasDisplaySize t m, HasVtyInput t m, ImageWriter t m)
452+ => Dynamic t (Int -> Int)
453+ -- ^ Function used to determine size of first pane based on available size
454+ -> Dynamic t (Bool, Bool)
455+ -- ^ How to focus the two sub-panes, given that we are focused.
457+ -- ^ Widget for first pane
459+ -- ^ Widget for second pane
461+splitV sizeFunD focD wA wB = do
464+ let regA = Region 0 0 <$> dw <*> (sizeFunD <*> dh)
465+ regB = Region 0 <$> (_region_height <$> regA) <*> dw <*> liftA2 (-) dh (_region_height <$> regA)
466+ ra <- pane regA (fst <$> focD) wA
467+ rb <- pane regB (snd <$> focD) wB
470+-- | A plain split of the available space into horizontally stacked panes.
471+-- No visual separator is built in here.
472+splitH :: (Reflex t, Monad m, MonadNodeId m, HasDisplaySize t m, HasVtyWidgetCtx t m, HasVtyInput t m, ImageWriter t m)
473+ => Dynamic t (Int -> Int)
474+ -- ^ Function used to determine size of first pane based on available size
475+ -> Dynamic t (Bool, Bool)
476+ -- ^ How to focus the two sub-panes, given that we are focused.
478+ -- ^ Widget for first pane
480+ -- ^ Widget for second pane
482+splitH sizeFunD focD wA wB = do
485+ let regA = Region 0 0 <$> (sizeFunD <*> dw) <*> dh
486+ regB = Region <$> (_region_width <$> regA) <*> 0 <*> liftA2 (-) dw (_region_width <$> regA) <*> dh
487+ liftA2 (,) (pane regA (fmap fst focD) wA) (pane regB (fmap snd focD) wB)
489+-- | A split of the available space into two parts with a draggable separator.
490+-- Starts with half the space allocated to each, and the first pane has focus.
491+-- Clicking in a pane switches focus.
492+splitVDrag :: (Reflex t, MonadFix m, MonadHold t m, MonadNodeId m, HasDisplaySize t m, HasVtyInput t m, HasVtyWidgetCtx t m, ImageWriter t m)
497+splitVDrag wS wA wB = do
500+ h0 <- sample $ current dh -- TODO
501+ dragE <- drag V.BLeft
502+ let splitter0 = h0 `div` 2
503+ rec splitterCheckpoint <- holdDyn splitter0 $ leftmost [fst <$> ffilter snd dragSplitter, resizeSplitter]
504+ splitterPos <- holdDyn splitter0 $ leftmost [fst <$> dragSplitter, resizeSplitter]
505+ splitterFrac <- holdDyn ((1::Double) / 2) $ ffor (attach (current dh) (fst <$> dragSplitter)) $ \(h, x) ->
506+ fromIntegral x / max 1 (fromIntegral h)
507+ let dragSplitter = fforMaybe (attach (current splitterCheckpoint) dragE) $
508+ \(splitterY, Drag (_, fromY) (_, toY) _ _ end) ->
509+ if splitterY == fromY then Just (toY, end) else Nothing
510+ regA = Region 0 0 <$> dw <*> splitterPos
511+ regS = Region 0 <$> splitterPos <*> dw <*> 1
512+ regB = Region 0 <$> (splitterPos + 1) <*> dw <*> (dh - splitterPos - 1)
513+ resizeSplitter = ffor (attach (current splitterFrac) (updated dh)) $
514+ \(frac, h) -> round (frac * fromIntegral h)
515+ focA <- holdDyn True $ leftmost
519+ (mA, rA) <- pane regA focA $ withMouseDown wA
520+ pane regS (pure False) wS
521+ (mB, rB) <- pane regB (not <$> focA) $ withMouseDown wB
524+ withMouseDown x = do
525+ m <- mouseDown V.BLeft
529+-- | Fill the background with a particular character.
530+fill :: (HasDisplaySize t m, ImageWriter t m) => Char -> m ()
534+ let fillImg = current $ liftA2 (\w h -> [V.charFill V.defAttr c w h]) dw dh
537+-- | Fill the background with the bottom
538+hRule :: (HasDisplaySize t m, ImageWriter t m) => BoxStyle -> m ()
539+hRule boxStyle = fill (_boxStyle_s boxStyle)
541+-- | Defines a set of symbols to use to draw the outlines of boxes
542+-- C.f. https://en.wikipedia.org/wiki/Box-drawing_character
543+data BoxStyle = BoxStyle
544+ { _boxStyle_nw :: Char
545+ , _boxStyle_n :: Char
546+ , _boxStyle_ne :: Char
547+ , _boxStyle_e :: Char
548+ , _boxStyle_se :: Char
549+ , _boxStyle_s :: Char
550+ , _boxStyle_sw :: Char
551+ , _boxStyle_w :: Char
554+instance Default BoxStyle where
555+ def = singleBoxStyle
557+-- | A box style that uses hyphens and pipe characters. Doesn't handle
558+-- corners very well.
559+hyphenBoxStyle :: BoxStyle
560+hyphenBoxStyle = BoxStyle '-' '-' '-' '|' '-' '-' '-' '|'
562+-- | A single line box style
563+singleBoxStyle :: BoxStyle
564+singleBoxStyle = BoxStyle '┌' '─' '┐' '│' '┘' '─' '└' '│'
566+-- | A thick single line box style
567+thickBoxStyle :: BoxStyle
568+thickBoxStyle = BoxStyle '┏' '━' '┓' '┃' '┛' '━' '┗' '┃'
570+-- | A double line box style
571+doubleBoxStyle :: BoxStyle
572+doubleBoxStyle = BoxStyle '╔' '═' '╗' '║' '╝' '═' '╚' '║'
574+-- | A single line box style with rounded corners
575+roundedBoxStyle :: BoxStyle
576+roundedBoxStyle = BoxStyle '╭' '─' '╮' '│' '╯' '─' '╰' '│'
578+-- | Draws a titled box in the provided style and a child widget inside of that box
579+boxTitle :: (Monad m, Reflex t, MonadNodeId m, HasDisplaySize t m, ImageWriter t m, HasVtyWidgetCtx t m, HasVtyInput t m)
580+ => Behavior t BoxStyle
584+boxTitle boxStyle title child = do
587+ let boxReg = Region 0 0 <$> dw <*> dh
588+ innerReg = Region 1 1 <$> (subtract 2 <$> dw) <*> (subtract 2 <$> dh)
589+ tellImages (boxImages <$> boxStyle <*> current boxReg)
590+ tellImages (fmap (\r -> [regionBlankImage r]) (current innerReg))
591+ pane innerReg (pure True) child
593+ boxImages :: BoxStyle -> Region -> [Image]
594+ boxImages style (Region left top width height) =
595+ let right = left + width - 1
596+ bottom = top + height - 1
598+ [ withinImage (Region (left + 1) top (width - 2) 1) $
600+ hPadText title (_boxStyle_n style) (width - 2)
601+ , withinImage (Region right (top + 1) 1 (height - 2)) $
602+ V.charFill V.defAttr (_boxStyle_e style) 1 (height - 2)
603+ , withinImage (Region (left + 1) bottom (width - 2) 1) $
604+ V.charFill V.defAttr (_boxStyle_s style) (width - 2) 1
605+ , withinImage (Region left (top + 1) 1 (height - 2)) $
606+ V.charFill V.defAttr (_boxStyle_w style) 1 (height - 2)
609+ [ withinImage (Region left top 1 1) $
610+ V.char V.defAttr (_boxStyle_nw style)
611+ , withinImage (Region right top 1 1) $
612+ V.char V.defAttr (_boxStyle_ne style)
613+ , withinImage (Region right bottom 1 1) $
614+ V.char V.defAttr (_boxStyle_se style)
615+ , withinImage (Region left bottom 1 1) $
616+ V.char V.defAttr (_boxStyle_sw style)
618+ in sides ++ if width > 1 && height > 1 then corners else []
619+ hPadText :: T.Text -> Char -> Int -> T.Text
620+ hPadText t c l = if lt >= l
622+ else left <> t <> right
626+ mkHalf n = T.replicate (n `div` 2) (T.singleton c)
627+ left = mkHalf $ delta + 1
628+ right = mkHalf delta
630+-- | A box without a title
631+box :: (Monad m, Reflex t, MonadNodeId m, HasDisplaySize t m, ImageWriter t m, HasVtyWidgetCtx t m, HasVtyInput t m)
632+ => Behavior t BoxStyle
635+box boxStyle = boxTitle boxStyle mempty
637+-- | A box whose style is static
639+ :: (Monad m, Reflex t, MonadNodeId m, HasDisplaySize t m, ImageWriter t m, HasVtyWidgetCtx t m, HasVtyInput t m)
643+boxStatic = box . pure
557−-- * Misc
645+-- | Configuration options for displaying "rich" text
646+data RichTextConfig t = RichTextConfig
647+ { _richTextConfig_attributes :: Behavior t V.Attr
650+instance Reflex t => Default (RichTextConfig t) where
651+ def = RichTextConfig $ pure V.defAttr
653+-- | A widget that displays text with custom time-varying attributes
655+ :: (Reflex t, Monad m, HasDisplaySize t m, ImageWriter t m)
661+ let img = (\w a s -> [wrapText w a s])
663+ <*> _richTextConfig_attributes cfg
667+ wrapText maxWidth attrs = V.vertCat
668+ . concatMap (fmap (V.string attrs . T.unpack) . TZ.wrapWithOffset maxWidth 0)
671+-- | Renders text, wrapped to the container width
673+ :: (Reflex t, Monad m, HasDisplaySize t m, ImageWriter t m)
678+-- | Scrollable text widget. The output pair exposes the current scroll position and total number of lines (including those
681+ :: forall t m. (Reflex t, MonadHold t m, MonadFix m, HasDisplaySize t m, HasVtyInput t m, ImageWriter t m)
683+ -- ^ Number of lines to scroll by
685+ -> m (Behavior t (Int, Int))
686+ -- ^ (Current scroll position, total number of lines)
687+scrollableText scrollBy t = do
689+ let imgs = wrap <$> current dw <*> t
691+ kdown <- key V.KDown
693+ let requestedScroll :: Event t Int
694+ requestedScroll = leftmost
698+ ScrollDirection_Up -> (-1)
699+ ScrollDirection_Down -> 1
702+ updateLine maxN delta ix = min (max 0 (ix + delta)) maxN
703+ lineIndex :: Dynamic t Int <- foldDyn (\(maxN, delta) ix -> updateLine (maxN - 1) delta ix) 0 $
704+ attach (length <$> imgs) requestedScroll
705+ tellImages $ fmap ((:[]) . V.vertCat) $ drop <$> current lineIndex <*> imgs
706+ return $ (,) <$> ((+) <$> current lineIndex <*> pure 1) <*> (length <$> imgs)
708+ wrap maxWidth = concatMap (fmap (V.string V.defAttr . T.unpack) . TZ.wrapWithOffset maxWidth 0) . T.split (=='\n')
710+-- | Renders any behavior whose value can be converted to
713+ :: (Reflex t, Monad m, Show a, HasDisplaySize t m, ImageWriter t m)
716+display a = text $ T.pack . show <$> a
559-- | A widget that draws nothing
718-- | A widget that draws nothing
560blank :: Monad m => m ()
719blank :: Monad m => m ()