Create Menu system. Similar to Brick.Forms

ghcup.cabal

@@ -331,6 +331,7 @@ library ghcup-tui
     GHCup.Brick.Widgets.Tutorial
     GHCup.Brick.Widgets.KeyInfo
     GHCup.Brick.Widgets.SectionList
+    GHCup.Brick.Widgets.Menu
     GHCup.Brick.Actions
     GHCup.Brick.App
     GHCup.Brick.BrickState

lib-tui/GHCup/Brick/Actions.hs

@@ -31,7 +31,6 @@ import           GHCup.Brick.Widgets.Navigation (BrickInternalState)
 import qualified Brick
 import qualified Brick.Widgets.List as L
 import qualified Brick.Focus as F
-import           Codec.Archive
 import           Control.Applicative
 import           Control.Exception.Safe
 #if !MIN_VERSION_base(4,13,0)

lib-tui/GHCup/Brick/Attributes.hs

@@ -40,6 +40,8 @@ defaultAttributes no_color = Brick.attrMap
   , (dayAttr                   , Vty.defAttr `withForeColor` Vty.blue)
   , (helpAttr                  , Vty.defAttr `withStyle`     Vty.italic)
   , (hoorayAttr                , Vty.defAttr `withForeColor` Vty.brightWhite)
+  , (helpMsgAttr               , Vty.defAttr `withForeColor` Vty.brightBlack)
+  , (errMsgAttr                , Vty.defAttr `withForeColor` Vty.red)
   ]
   where
     withForeColor | no_color  = const
@@ -53,7 +55,7 @@ defaultAttributes no_color = Brick.attrMap
 
 notInstalledAttr, setAttr, installedAttr, recommendedAttr, hlsPoweredAttr :: Brick.AttrName
 latestAttr, latestPrereleaseAttr, latestNightlyAttr, prereleaseAttr, nightlyAttr :: Brick.AttrName
-compiledAttr, strayAttr, dayAttr, helpAttr, hoorayAttr:: Brick.AttrName
+compiledAttr, strayAttr, dayAttr, helpAttr, hoorayAttr, helpMsgAttr, errMsgAttr :: Brick.AttrName
 
 notInstalledAttr = Brick.attrName "not-installed"
 setAttr = Brick.attrName "set"
@@ -70,6 +72,8 @@ strayAttr = Brick.attrName "stray"
 dayAttr = Brick.attrName "day"
 helpAttr = Brick.attrName "help"
 hoorayAttr = Brick.attrName "hooray"
+helpMsgAttr = Brick.attrName "helpMsg"
+errMsgAttr = Brick.attrName "errMsg"
 
 dimAttributes :: Bool -> AttrMap
 dimAttributes no_color = Brick.attrMap

lib-tui/GHCup/Brick/Common.hs

@@ -25,12 +25,15 @@ This module contains common values used across the library. Crucially it contain
 module GHCup.Brick.Common where
 
 import           GHCup.List ( ListResult )
-import           GHCup.Types ( Tool )
+import           GHCup.Types ( Tool, KeyCombination (KeyCombination) )
+import Data.List (intercalate)
 import           Prelude                 hiding ( appendFile )
 import qualified Graphics.Vty                  as Vty
 import           Optics.TH (makeLenses)
 import           Optics.Lens (toLensVL)
 import qualified Brick
+import qualified Brick.Widgets.Border as Border
+import Brick ((<+>))
 
 -- | Some verbosity. A FocusRing (to loop through advance options), needs an set of resource names to be able to 
 -- dtermine focus. See https://hackage.haskell.org/package/brick-2.1.1/docs/Brick-Focus.html#t:FocusRing
@@ -90,6 +93,13 @@ showKey key = tail (show key)
 showMod :: Vty.Modifier -> String
 showMod = tail . show
 
+-- | Given a KeyComb, produces a string widget with and user friendly text
+keyToWidget :: KeyCombination -> Brick.Widget n
+keyToWidget (KeyCombination key mods) = Brick.str $ intercalate "+" (showKey key : (showMod <$> mods))
+
+-- | A section separator with max width. Looks like this:    -------- o --------
+separator :: Brick.Widget n
+separator = Border.hBorder <+> Brick.str " o " <+> Border.hBorder
 
 -- I refuse to give this a type signature. 
 

lib-tui/GHCup/Brick/Widgets/Menu.hs

@@ -0,0 +1,359 @@
+{-# LANGUAGE CPP               #-}
+{-# LANGUAGE DataKinds         #-}
+{-# LANGUAGE FlexibleContexts  #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TypeApplications  #-}
+{-# LANGUAGE RankNTypes        #-}
+{-# LANGUAGE ViewPatterns      #-}
+{-# OPTIONS_GHC -Wno-unused-record-wildcards #-}
+{-# OPTIONS_GHC -Wno-unused-matches #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE TemplateHaskell   #-}
+{-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE InstanceSigs #-}
+{-# LANGUAGE GADTs #-}
+
+
+{- **************
+
+A general system inspired by Brick.Form. It uses optics instead of microlenses and it is less generic than
+Brick.Form, but generic enough to serve our purpose.
+
+A Menu consists in
+  a) A state value
+  b) A list of fields. Each field is capable of modifying a part of the state
+  c) some metadata
+
+A field (type MenuField) consists in
+  a) a Lens to a part of the Menu state, so the Menu can call that lens to modify its own state
+  b) an input widget
+
+An input (type FieldInput) consist in
+  a) some state
+  b) a validator function
+  c) a handler and a renderer
+
+We have to use existential types to achive a composable API since every FieldInput has a different 
+internal type, and every MenuField has a different Lens. For example: 
+  - The menu state is a record (MyRecord {uri: URI, flag : Bool}) 
+  - Then, there are two MenuField:
+    - One MenuField has (Lens' MyRecord URI) and the other has (Lens' MyRecord Bool)
+    - The MenuFields has FieldInputs with internal state Text and Bool, respectively
+  - Obviously, the MenuField has to be polimorphic in the Lens' and in the Input internal state,
+    But we must hide that polimorphisim (existential), in order to store all MenuField in a List
+
+************** -}
+
+module GHCup.Brick.Widgets.Menu where
+
+import qualified GHCup.Brick.Attributes as Attributes
+import qualified GHCup.Brick.Common as Common
+
+import Brick
+    ( BrickEvent(..),
+      EventM,
+      Widget(..),
+      (<+>))
+import qualified Brick
+import qualified Brick.Widgets.Border as Border
+import qualified Brick.Widgets.List as L
+import qualified Brick.Widgets.Edit as Edit
+import           Brick.Focus (FocusRing)
+import qualified Brick.Focus as F
+import           Data.Function ( (&))
+import           Prelude             hiding ( appendFile )
+
+import qualified Data.Text                     as T
+
+
+import           Optics.TH (makeLensesFor)
+import qualified Graphics.Vty as Vty
+import Optics.State.Operators ((%=), (.=))
+import Optics.Optic ((%))
+import Optics.State (use)
+import GHCup.Types (KeyCombination)
+import Optics (Lens', to, lens)
+import Optics.Operators ( (^.), (.~) )
+import Data.Foldable (foldl')
+
+
+-- | Just some type synonym to make things explicit
+type Formatter n = Bool -> Widget n -> Widget n
+-- | A label
+type Label = T.Text
+-- | A help message of an entry
+type HelpMessage = T.Text
+-- | A button name
+type ButtonName n = n
+
+idFormatter :: Formatter n
+idFormatter = const id
+
+
+-- | An error message
+type ErrorMessage = T.Text
+data ErrorStatus = Valid | Invalid ErrorMessage
+
+-- | A lens which does nothing. Usefull to defined no-op fields
+emptyLens :: Lens' s ()
+emptyLens = lens (const ()) (\s _ -> s)
+
+-- | A FieldInput is a pair label-content
+--   a - is the type of the field it manipulates
+--   b - is its internal state (modified in the gui)
+--   n - your application's resource name type
+data FieldInput a b n =
+  FieldInput
+    { inputState :: b                                     -- ^ The state of the input field (what's rendered in the screen)
+    , inputValidator :: b -> Either ErrorMessage a        -- ^ A validator function
+    , inputHelp   :: HelpMessage                          -- ^ The input helpMessage
+    , inputRender :: Bool
+                  -> ErrorStatus
+                  -> HelpMessage
+                  -> b
+                  -> (Widget n -> Widget n)
+                  -> Widget n                             -- ^ How to draw the input, with focus a help message and input. 
+                                                          --   A extension function can be applied too
+    , inputHandler :: BrickEvent n () -> EventM n b ()    -- ^ The handler
+    }
+
+makeLensesFor
+  [ ("inputState", "inputStateL")
+  , ("inputValidator", "inputValidatorL")
+  , ("inputName", "inputNameL")
+  , ("inputHelp", "inputHelpL")
+  ]
+  ''FieldInput
+
+-- | The MenuField is an existential type which stores a Lens' to a part of the Menu state.
+--   In also contains a Field input which internal state is hidden
+data MenuField s n where
+  MenuField ::
+      { fieldAccesor   :: Lens' s a                   -- ^ A Lens pointing to some part of the state
+      , fieldInput     :: FieldInput a b n            -- ^ The input which modifies the state
+      , fieldLabel     :: Label                       -- ^ The label
+      , fieldStatus    :: ErrorStatus                 -- ^ Whether the current is valid or not.
+      , fieldName      :: n
+      } -> MenuField s n
+
+
+makeLensesFor
+  [ ("fieldLabel", "fieldLabelL")
+  , ("fieldStatus", "fieldStatusL")
+  ]
+  ''MenuField
+
+-- | A fancy lens to the help message
+fieldHelpMsgL :: Lens' (MenuField s n) HelpMessage
+fieldHelpMsgL = lens g s
+  where g (MenuField {..})= fieldInput ^. inputHelpL
+        s (MenuField{..}) msg = MenuField {fieldInput = fieldInput & inputHelpL .~ msg , ..}
+
+instance Brick.Named (MenuField s n) n where
+  getName :: MenuField s n -> n
+  getName entry = entry & fieldName
+
+
+{- *****************
+  CheckBox widget
+***************** -}
+
+type CheckBoxField = MenuField
+
+createCheckBoxInput :: FieldInput Bool Bool n
+createCheckBoxInput = FieldInput False Right "" checkBoxRender checkBoxHandler
+  where
+    border = Border.border . Brick.padRight (Brick.Pad 1) . Brick.padLeft (Brick.Pad 2)
+    drawBool b =
+        if b
+          then border . Brick.withAttr Attributes.installedAttr    $ Brick.str Common.installedSign
+          else border . Brick.withAttr Attributes.notInstalledAttr $ Brick.str Common.notInstalledSign
+    checkBoxRender focus _ help check f =
+      let core = f $ drawBool check
+      in if focus 
+        then core
+        else core <+> (Brick.padLeft (Brick.Pad 1) . centerV . renderAsHelpMsg $ help)
+    checkBoxHandler = \case
+        VtyEvent (Vty.EvKey Vty.KEnter []) -> Brick.modify not
+        _ -> pure ()
+
+createCheckBoxField :: n -> Lens' s Bool -> CheckBoxField s n
+createCheckBoxField name access = MenuField access createCheckBoxInput "" Valid name
+
+{- *****************
+  Editable widget
+***************** -}
+
+type EditableField = MenuField
+
+createEditableInput :: (Ord n, Show n) => n -> (T.Text -> Either ErrorMessage a) -> FieldInput a (Edit.Editor T.Text n) n
+createEditableInput name validator = FieldInput initEdit validateEditContent "" drawEdit Edit.handleEditorEvent
+  where
+    drawEdit focus errMsg help edi amp =
+      let 
+        borderBox = amp . Border.border . Brick.padRight Brick.Max
+        editorRender = Edit.renderEditor (Brick.txt . T.unlines) focus edi
+      in case errMsg of
+           Valid ->
+              if Edit.getEditContents edi == [mempty] 
+                then borderBox $ renderAsHelpMsg help 
+                else borderBox editorRender
+           Invalid msg ->
+              if focus
+                then borderBox editorRender
+                else borderBox $ renderAsErrMsg msg
+    validateEditContent = validator . T.unlines . Edit.getEditContents
+    initEdit = Edit.editorText name (Just 1) ""
+
+createEditableField :: (Eq n, Ord n, Show n) => n -> (T.Text -> Either ErrorMessage a) -> Lens' s a  -> EditableField s n
+createEditableField name validator access = MenuField access input "" Valid name
+  where
+    input = createEditableInput name validator
+
+{- *****************
+  Button widget
+***************** -}
+
+type Button = MenuField
+
+createButtonInput :: FieldInput () () n
+createButtonInput = FieldInput () Right "" drawButton (const $ pure ())
+  where drawButton _ _ help _ amp = amp . centerV . renderAsHelpMsg $ help
+
+createButtonField :: n -> Button s n
+createButtonField = MenuField emptyLens createButtonInput "" Valid
+
+{- *****************
+  Utilities
+***************** -}
+
+-- | highlights a widget (using List.listSelectedFocusedAttr)
+highlighted :: Widget n -> Widget n
+highlighted = Brick.withAttr L.listSelectedFocusedAttr
+
+-- | Given a text, crates a highlighted label on focus. An amplifier can be passed
+renderAslabel :: T.Text -> Bool -> Widget n
+renderAslabel t focus =
+  if focus
+    then highlighted $ Brick.txt t
+    else Brick.txt t
+
+-- | Creates a left align column. 
+-- Example:       |- col2 is align dispite the length of col1
+--   row1_col1         row1_col2
+--   row2_col1_large   row2_col2
+leftify :: Int -> Brick.Widget n -> Brick.Widget n
+leftify i = Brick.hLimit i . Brick.padRight Brick.Max
+
+-- | center a line in three rows. 
+centerV :: Widget n -> Widget n
+centerV = Brick.padTopBottom 1
+
+-- | render some Text using helpMsgAttr
+renderAsHelpMsg :: T.Text -> Widget n
+renderAsHelpMsg = Brick.withAttr Attributes.helpMsgAttr . Brick.txt
+
+-- | render some Text using errMsgAttr
+renderAsErrMsg :: T.Text -> Widget n
+renderAsErrMsg = Brick.withAttr Attributes.errMsgAttr . Brick.txt
+
+{- *****************
+  Menu widget
+***************** -}
+
+-- | A menu is a list of Fields and a state. Informally we can think about s in terms of the record type returned by 
+-- a form. 
+data Menu s n
+    = Menu
+    { menuFields    :: [MenuField s n]   -- ^ The datatype representing the list of entries. Precisely, any array-like data type is highly unconvinient.
+    , menuState     :: s
+    , menuButtons   :: [Button s n]      -- ^ The buttons. Commonly, the handlers for buttons are defined outside the menu handler.
+    , menuFocusRing :: FocusRing n       -- ^ The focus ring with the resource name for each entry and each button, in the order you want to loop them.
+    , menuExitKey   :: KeyCombination    -- ^ The key to exit the Menu
+    , menuName      :: n                 -- ^ The resource Name.
+    }
+
+
+makeLensesFor
+  [ ("menuFields", "menuFieldsL"), ("menuState", "menuStateL")
+  , ("menuButtons", "menuButtonsL"), ("menuFocusRing", "menuFocusRingL")
+  , ("menuExitKey", "menuExitKeyL"), ("menuName", "menuNameL")
+  ]
+  ''Menu
+
+createMenu :: n -> s -> KeyCombination -> [Button s n] -> [MenuField s n] -> Menu s n
+createMenu n initial exitK buttons fields = Menu fields initial buttons ring exitK n
+  where ring = F.focusRing $ [field & fieldName | field <- fields] ++ [button & fieldName | button <- buttons]
+
+handlerMenu :: forall n e s. Eq n => BrickEvent n e -> EventM n (Menu s n) ()
+handlerMenu ev =
+  case ev of
+    VtyEvent (Vty.EvKey (Vty.KChar '\t') [])  -> menuFocusRingL %= F.focusNext
+    VtyEvent (Vty.EvKey Vty.KBackTab [])      -> menuFocusRingL %= F.focusPrev
+    VtyEvent (Vty.EvKey Vty.KDown [])         -> menuFocusRingL %= F.focusNext
+    VtyEvent (Vty.EvKey Vty.KUp [])           -> menuFocusRingL %= F.focusPrev
+    VtyEvent e -> do
+      focused <- use $ menuFocusRingL % to F.focusGetCurrent
+      fields  <- use menuFieldsL
+      case focused of
+        Nothing -> pure ()
+        Just n  -> do 
+          updated_fields <- updateFields n (VtyEvent e) fields
+          menuFieldsL .= updated_fields
+    _ -> pure ()
+ where
+  updateFields :: n -> BrickEvent n () -> [MenuField s n] -> EventM n (Menu s n) [MenuField s n]
+  updateFields n e [] = pure []
+  updateFields n e (x@(MenuField {fieldInput = i@(FieldInput {..}) , ..}):xs) =
+    if Brick.getName x == n
+      then do
+       newb <- Brick.nestEventM' inputState (inputHandler e)
+       let newField = MenuField {fieldInput = (FieldInput {inputState=newb, ..}) , ..}
+       case inputValidator newb of
+        Left errmsg -> pure $ (newField & fieldStatusL .~ Invalid errmsg):xs
+        Right a     -> menuStateL % fieldAccesor .= a >> pure ((newField & fieldStatusL .~ Valid):xs)
+      else fmap (x:) (updateFields n e xs)
+
+
+drawMenu :: (Eq n, Ord n, Show n, Brick.Named (MenuField s n) n) => Menu s n -> Widget n
+drawMenu menu = 
+  Brick.vBox
+      [ Brick.vBox buttonWidgets
+      , Common.separator
+      , Brick.withVScrollBars Brick.OnRight
+          $ Brick.viewport (menu ^. menuNameL) Brick.Vertical
+          $ Brick.vBox fieldWidgets
+      , Brick.txt " "
+      , Brick.padRight Brick.Max $ 
+          Brick.txt "Press " 
+          <+> Common.keyToWidget (menu ^. menuExitKeyL)
+          <+> Brick.txt " to go back"
+      ]
+  where
+    drawField amp focus (MenuField { fieldInput = FieldInput {..}, ..}) =
+      let input = inputRender focus fieldStatus inputHelp inputState (amp focus)
+       in if focus
+            then Brick.visible input
+            else input
+    
+    fieldLabels  = [field & fieldLabel | field <- menu ^. menuFieldsL]
+    buttonLabels = [button & fieldLabel | button <- menu ^. menuButtonsL]
+    allLabels    = fieldLabels ++ buttonLabels
+
+    maxWidth = foldl' max 5 (fmap Brick.textWidth allLabels)
+
+    -- A list of functions which draw a highlighted label with right padding at the left of a widget. 
+    amplifiers =
+      let labelsWidgets = fmap (\b -> renderAslabel b) fieldLabels
+       in fmap (\f b -> ((centerV . leftify (maxWidth + 10) $ f b) <+>) ) labelsWidgets
+    drawFields = fmap drawField amplifiers
+    fieldWidgets = zipWith (F.withFocusRing (menu ^. menuFocusRingL)) drawFields (menu ^. menuFieldsL)
+
+    buttonAmplifiers =
+      let buttonAsWidgets = fmap (\b -> renderAslabel b) buttonLabels
+       in fmap (\f b -> ((leftify (maxWidth + 10) . Border.border $ f b) <+>) ) buttonAsWidgets
+    drawButtons = fmap drawField buttonAmplifiers
+    buttonWidgets = zipWith (F.withFocusRing (menu ^. menuFocusRingL)) drawButtons (menu ^. menuButtonsL)
+
+