module Demo.Elevation where

import Html exposing (..)

import Material.Style as Style exposing (cs, css)
import Material.Elevation as Elevation

import Demo.Page as Page


-- VIEW


elevate : Int -> Html 
elevate k = 
  Style.div 
    [ css "height" "96px"
    , css "width"  "128px"
    , css "margin" "40px"
    , css "display" "inline-flex"
    , css "flex-flow" "row wrap" 
    , css "justify-content" "center"
    , css "align-items" "center"
    , Elevation.shadow k
    ]
    [ Style.div 
      [ cs ".mdl-typography--title-color-contrast" 
        -- TODO. Typography!
      ] 
      [ text <| toString k ]
    ]


view : Html
view =
  0 :: Elevation.validElevations
  |> List.map elevate 
  |> (::) ( p [] [ text """Below are boxes drawn at various elevations.""" ] )
  |> Page.body1 "Elevation" srcUrl intro references



intro : Html
intro =
  Page.fromMDL "https://github.com/google/material-design-lite/blob/master/src/shadow/README.md" """
  > The Material Design Lite (MDL) shadow is not a component in the same sense as
> an MDL card, menu, or textbox; it is a visual effect that can be assigned to a
> user interface element. The effect simulates a three-dimensional positioning of
> the element, as though it is slightly raised above the surface it rests upon —
> a positive z-axis value, in user interface terms. The shadow starts at the
> edges of the element and gradually fades outward, providing a realistic 3-D
> effect.
> 
> Shadows are a convenient and intuitive means of distinguishing an element from
> its surroundings. A shadow can draw the user's eye to an object and emphasize
> the object's importance, uniqueness, or immediacy.
> 
> Shadows are a well-established feature in user interfaces, and provide users
> with a visual clue to an object's intended use or value. Their design and use
> is an important factor in the overall user experience.)

The [Material Design Specification](https://www.google.com/design/spec/what-is-material/elevation-shadows.html#elevation-shadows-elevation-android-)
pre-defines appropriate elevation for most UI elements; you need to manually
assign shadows only to your own elements. 

You are encouraged to visit the
[Material Design specification](https://www.google.com/design/spec/what-is-material/elevation-shadows.html)
for details about appropriate use of shadows. 
"""


srcUrl : String
srcUrl = 
  "https://github.com/debois/elm-mdl/blob/master/examples/Demo/Elevation.elm"


references : List (String, String)
references = 
  [ Page.package "http://package.elm-lang.org/packages/debois/elm-mdl/latest/Material-Elevation"
  , Page.mds "https://www.google.com/design/spec/what-is-material/elevation-shadows.html"
  , Page.mdl "https://github.com/google/material-design-lite/blob/master/src/shadow/README.md"
  ]