summaryrefslogtreecommitdiff
path: root/programs/FormDemo.hs
blob: 5f5bac43cf9e61ed766c9a5d0701e113c290ebef (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
{-# LANGUAGE CPP #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE OverloadedStrings #-}
module Main where

import qualified Data.Text as T
import Lens.Micro ((^.))
import Lens.Micro.TH
#if !(MIN_VERSION_base(4,11,0))
import Data.Monoid ((<>))
#endif

import qualified Graphics.Vty as V
import Brick
import Brick.Forms
  ( Form
  , newForm
  , formState
  , formFocus
  , setFieldValid
  , renderForm
  , handleFormEvent
  , invalidFields
  , allFieldsValid
  , focusedFormInputAttr
  , invalidFormInputAttr
  , checkboxField
  , radioField
  , editShowableField
  , editTextField
  , editPasswordField
  , (@@=)
  )
import Brick.Focus
  ( focusGetCurrent
  , focusRingCursor
  )
import qualified Brick.Widgets.Edit as E
import qualified Brick.Widgets.Border as B
import qualified Brick.Widgets.Center as C

data Name = NameField
          | AgeField
          | BikeField
          | HandedField
          | PasswordField
          | LeftHandField
          | RightHandField
          | AmbiField
          | AddressField
          deriving (Eq, Ord, Show)

data Handedness = LeftHanded | RightHanded | Ambidextrous
                deriving (Show, Eq)

data UserInfo =
    UserInfo { _name      :: T.Text
             , _age       :: Int
             , _address   :: T.Text
             , _ridesBike :: Bool
             , _handed    :: Handedness
             , _password  :: T.Text
             }
             deriving (Show)

makeLenses ''UserInfo

-- This form is covered in the Brick User Guide; see the "Input Forms"
-- section.
mkForm :: UserInfo -> Form UserInfo e Name
mkForm =
    let label s w = padBottom (Pad 1) $
                    (vLimit 1 $ hLimit 15 $ str s <+> fill ' ') <+> w
    in newForm [ label "Name" @@=
                   editTextField name NameField (Just 1)
               , label "Address" @@=
                 B.borderWithLabel (str "Mailing") @@=
                   editTextField address AddressField (Just 3)
               , label "Age" @@=
                   editShowableField age AgeField
               , label "Password" @@=
                   editPasswordField password PasswordField
               , label "Dominant hand" @@=
                   radioField handed [ (LeftHanded, LeftHandField, "Left")
                                     , (RightHanded, RightHandField, "Right")
                                     , (Ambidextrous, AmbiField, "Both")
                                     ]
               , label "" @@=
                   checkboxField ridesBike BikeField "Do you ride a bicycle?"
               ]

theMap :: AttrMap
theMap = attrMap V.defAttr
  [ (E.editAttr, V.white `on` V.black)
  , (E.editFocusedAttr, V.black `on` V.yellow)
  , (invalidFormInputAttr, V.white `on` V.red)
  , (focusedFormInputAttr, V.black `on` V.yellow)
  ]

draw :: Form UserInfo e Name -> [Widget Name]
draw f = [C.vCenter $ C.hCenter form <=> C.hCenter help]
    where
        form = B.border $ padTop (Pad 1) $ hLimit 50 $ renderForm f
        help = padTop (Pad 1) $ B.borderWithLabel (str "Help") body
        body = str $ "- Name is free-form text\n" <>
                     "- Age must be an integer (try entering an\n" <>
                     "  invalid age!)\n" <>
                     "- Handedness selects from a list of options\n" <>
                     "- The last option is a checkbox\n" <>
                     "- Enter/Esc quit, mouse interacts with fields"

app :: App (Form UserInfo e Name) e Name
app =
    App { appDraw = draw
        , appHandleEvent = \s ev ->
            case ev of
                VtyEvent (V.EvResize {})     -> continue s
                VtyEvent (V.EvKey V.KEsc [])   -> halt s
                -- Enter quits only when we aren't in the multi-line editor.
                VtyEvent (V.EvKey V.KEnter [])
                    | focusGetCurrent (formFocus s) /= Just AddressField -> halt s
                _ -> do
                    s' <- handleFormEvent ev s

                    -- Example of external validation:
                    -- Require age field to contain a value that is at least 18.
                    continue $ setFieldValid ((formState s')^.age >= 18) AgeField s'

        , appChooseCursor = focusRingCursor formFocus
        , appStartEvent = return
        , appAttrMap = const theMap
        }

main :: IO ()
main = do
    let buildVty = do
          v <- V.mkVty =<< V.standardIOConfig
          V.setMode (V.outputIface v) V.Mouse True
          return v

        initialUserInfo = UserInfo { _name = ""
                                   , _address = ""
                                   , _age = 0
                                   , _handed = RightHanded
                                   , _ridesBike = False
                                   , _password = ""
                                   }
        f = setFieldValid False AgeField $
            mkForm initialUserInfo

    initialVty <- buildVty
    f' <- customMain initialVty buildVty Nothing app f

    putStrLn "The starting form state was:"
    print initialUserInfo

    putStrLn "The final form state was:"
    print $ formState f'

    if allFieldsValid f'
       then putStrLn "The final form inputs were valid."
       else putStrLn $ "The final form had invalid inputs: " <> show (invalidFields f')