Images mixing

[jastice]

Not sure if this is a compiler or core library issue or programming error, I haven't identified the cause yet, but it seems like it shouldn't happen due to programming error. Also I have a hard time finding a good description, but when running the example code (a simple slide-like presentation) below, this is what I observe:

• when going from the second slide (shell) to the third (book), the image dimensions get replaced with those of the third slide, but the image stays the same.
• going forward, then back again, will correctly show the book
• this happens only when an image is followed by a fittedImage, when both are regular or fitted image, they show up as expected

Also worth noting: This setup somehow breaks hot reloading in elm-reactor. When changing something, often I have to manually reload for everthing to work.

(using Elm platform 0.16)

module Bugs where

import List exposing ((::), foldr, length, drop, head)
import Signal exposing (Signal, constant, foldp, map2)
import Graphics.Element exposing (..)
import Keyboard
import Debug
import Text exposing (fromString)


slides = [
  constant <| centered <| fromString "use arrow keys to go forward/backward",
  constant <| fittedImage 100 500 "https://raw.githubusercontent.com/elm-lang/elm-lang.org/master/resources/imgs/shells.jpg",
  constant <| image 700 500 "https://raw.githubusercontent.com/elm-lang/elm-lang.org/master/resources/imgs/book.jpg",
  constant <| centered <| fromString "go back and it will be a book instead of shells"
  ]

lastSlide = length slides - 1

updateSlide {x,y} current = 
  let nextSlide = case x of
        -1 -> current - 1
        1 -> current + 1
        _ -> current
  in clamp 0 lastSlide nextSlide 

chooseSlide page = drop page >> head

safeSlide e = case e of
  Just elem -> elem
  Nothing -> centered <| fromString "…"

-- signals

currentSlide = foldp updateSlide 0 Keyboard.arrows

main = 
  let maybeSlides = applyMany (Signal.map chooseSlide currentSlide) slides
  in Signal.map safeSlide maybeSlides


-- debug
slideWatch = Signal.map (Debug.watch "slide") currentSlide


-- taken from elm-signal-extra

combine : List (Signal a) -> Signal (List a)
combine = foldr (map2 (::)) (constant [])

andMap : Signal (a -> b) -> Signal a -> Signal b
andMap = map2 (<|)

applyMany : Signal (List a -> b) -> List (Signal a) -> Signal b
applyMany fs l = andMap fs (combine l)

[jastice]

Confirmed same behavior for 0.16, and updated example code.

[jastice]

Confirmed same behavior for 0.16, and updated example code.

[evancz]

Sorry this did not get attention til now! The Graphics.* modules now live in evancz/elm-graphics so I am trying to get stuff migrated over there. I'm hoping this will make it easier to get help on stuff like this!

[evancz]

Sorry this did not get attention til now! The Graphics.* modules now live in evancz/elm-graphics so I am trying to get stuff migrated over there. I'm hoping this will make it easier to get help on stuff like this!