GUI not automatically updated after model change

[smarwei]

I Maybe I've misunderstood something, but it seems like the GUI is sometimes not automatically updated after the model was changed.
Only after I move the mouse over the elements, the interface is updated.

Simplified code:

{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE ConstrainedClassMethods #-}

module Main where

import Control.Lens
import Data.Text (pack, toLower)
import qualified Monomer as M
import Monomer hiding (width)


data Box = Box {
    _width :: Int
} deriving (Eq, Show)

newtype BoxRow = BoxRow {
    _boxRowContent :: [Box]
} deriving (Eq, Show)

data Resolution = XL | LG | MD
    deriving (Eq, Show)

resolutionSize :: Num p => Resolution -> p
resolutionSize XL = 190
resolutionSize LG = 126
resolutionSize MD = 50

data AppModel = AppModel {
    _selectedResolution :: Resolution,
    _boxes :: [Box]
} deriving (Eq, Show)

data ElementLocation = ElementLocation BoxRowIdx BoxIdx RowIdx ElementIdx deriving (Eq, Show)
type BoxRowIdx = Int
type BoxIdx = Int
type RowIdx = Int
type ElementIdx = Int

data AppEvent
    = AppInit
    deriving (Eq, Show)

makeLenses 'AppModel
makeLenses 'Box


buildUI
  :: WidgetEnv AppModel AppEvent
  -> AppModel
  -> WidgetNode AppModel AppEvent
buildUI wenv model = widgetTree where
    widgetTree = vstack [
        hstack [
            label "Resolution: ",
            dropdown selectedResolution [XL, LG, MD] (label . toLower . pack . show) (label . toLower . pack . show)
        ],
        spacer,
        box ( hstack_ [childSpacing] $
            fmap (buildBox model) (model ^. boxes) )
            `styleBasic` [padding 8, border 2 red]
        ] `styleBasic` [padding 10]


buildBox :: AppModel -> Box -> WidgetNode AppModel AppEvent
buildBox model b =
    box ( label "Some content" )
        `styleBasic` [M.width boxWidth, padding 8, border 2 blueViolet, borderL 12 blueViolet]
  where
    resWidth = resolutionSize $ model ^. selectedResolution
    boxWidth = fromIntegral (b ^. width) * resWidth / 12


handleEvent
    :: WidgetEnv AppModel AppEvent
    -> WidgetNode AppModel AppEvent
    -> AppModel
    -> AppEvent
    -> [AppEventResponse AppModel AppEvent]
handleEvent wenv node model evt = case evt of
    AppInit -> []

main :: IO ()
main = do
    startApp model handleEvent buildUI config
    where
        config = [
            appTheme darkTheme,
            appFontDef "Regular" "./assets/fonts/Roboto-Regular.ttf",
            appInitEvent AppInit
            ]
        model = AppModel LG
            [ Box 12
            , Box 10
            , Box 3
            ]

[fjvallarino]

This is indeed a bug! You can test the fix by modifying your stack.yaml to point to:

- git: https://github.com/fjvallarino/monomer.git
  commit: 20332c4aca0e5d362ad5209e95040dd786df2c97

This commit hash will only be valid until the fix is merged to main.

Thanks for reporting!

[smarwei]

that fixes the problem, thank you very much!

[fjvallarino]

Nice! I just merged the fix to main, so the previous commit hash is no longer valid. The new one, which will not be removed, is: 908de6f48eb91d3a7a0405737de30b1ddc3338a2.

I'll close the issue now. Thanks for reporting!