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elk/libraries/Graphics/Element.elm
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2module Graphics.Element where
4import open Basics
5import Native.Utils
6import open JavaScript
7import List as List
8import open Color
9import Maybe (Maybe, Just, Nothing)
11type Properties = {
12 id : Int,
13 width : Int,
14 height : Int,
15 opacity : Float,
16 color : Maybe Color,
17 href : JSString,
18 tag : JSString,
19 hover : ()
20 }
22type Element = { props : Properties, element : ElementPrim }
24-- Get the width of an Element
25widthOf : Element -> Int
26widthOf e = e.props.width
28-- Get the height of an Element
29heightOf : Element -> Int
30heightOf e = e.props.height
32-- Get the width and height of an Element
33sizeOf : Element -> (Int,Int)
34sizeOf e = (e.props.width, e.props.height)
36-- Create an `Element` with a given width.
37width : Int -> Element -> Element
38width nw e = let p = e.props
39 props = case e.element of
40 Image _ w h _ -> {p| height <- h `div` w * nw }
41 RawHtml html -> {p| height <- let (w,h) = Native.Utils.htmlHeight nw html in h}
42 _ -> p
43 in { element=e.element, props={ props | width <- nw } }
45-- Create an `Element` with a given height.
46height : Int -> Element -> Element
47height nh e = let p = e.props
48 props = case e.element of
49 Image _ w h _ -> {p| width <- w `div` h * nh }
50 _ -> p
51 in { element=e.element, props={p| height <- nh} }
53-- Create an `Element` with a new width and height.
54size : Int -> Int -> Element -> Element
55size w h e = height h (width w e)
57-- Create an `Element` with a given opacity. Opacity is a number between 0 and 1
58-- where 0 means totally clear.
59opacity : Float -> Element -> Element
60opacity o e = let p = e.props in { element=e.element, props={p| opacity <- o} }
62-- Create an `Element` with a given background color.
63color : Color -> Element -> Element
64color c e = let p = e.props in
65 { element = e.element
66 , props = { p | color <- Just c}
67 }
69-- Create an `Element` with a tag. This lets you link directly to it.
70-- The element `(tag "all-about-badgers" thirdParagraph)` can be reached
71-- with a link lik this: `/facts-about-animals.elm#all-about-badgers`
72tag : String -> Element -> Element
73tag name e = let p = e.props in
74 { element=e.element, props={p | tag <- fromString name} }
76-- Create an `Element` that is a hyper-link.
77link : String -> Element -> Element
78link href e = let p = e.props in
79 { element=e.element, props={p | href <- fromString href} }
81emptyStr = fromString ""
82newElement w h e =
83 { props = Properties (Native.Utils.guid ()) w h 1 Nothing emptyStr emptyStr (), element = e }
85data ElementPrim
86 = Image ImageStyle Int Int JSString
87 | Container Position Element
88 | Flow Direction [Element]
89 | Spacer
90 | RawHtml JSString
91 | Custom -- for custom Elements implemented in JS, see collage for example
93data ImageStyle = Plain | Fitted | Cropped (Int,Int) | Tiled
95-- Create an image given a width, height, and image source.
96image : Int -> Int -> String -> Element
97image w h src = newElement w h (Image Plain w h (fromString src))
99-- Create a fitted image given a width, height, and image source.
100-- This will crop the picture to best fill the given dimensions.
101fittedImage : Int -> Int -> String -> Element
102fittedImage w h src = newElement w h (Image Fitted w h (fromString src))
104-- Create a cropped image. Take a rectangle out of the picture starting
105-- at the given top left coordinate. If you have a 140-by-140 image,
106-- the following will cut a 100-by-100 square out of the middle of it.
107--
108-- croppedImage (20,20) 100 100 "yogi.jpg"
109croppedImage : (Int,Int) -> Int -> Int -> String -> Element
110croppedImage pos w h src =
111 newElement w h (Image (Cropped pos) w h (fromString src))
113tiledImage : Int -> Int -> String -> Element
114tiledImage w h src =
115 newElement w h (Image Tiled w h (fromString src))
117markdown : Element
118markdown = Native.Utils.undefined
120data Three = P | Z | N
121data Pos = Absolute Int | Relative Float
122type Position = { horizontal : Three, vertical : Three, x : Pos, y : Pos }
124-- Put an element in a container. This lets you position the element really
125-- easily, and there are tons of ways to set the `Position`.
126-- To center `element` exactly in a 300-by-300 square you would say:
127--
128-- container 300 300 middle element
129--
130-- By setting the color of the container, you can create borders.
131container : Int -> Int -> Position -> Element -> Element
132container w h pos e = newElement w h (Container pos e)
134-- Create an empty box. This is useful for getting your spacing right and
135-- for making borders.
136spacer : Int -> Int -> Element
137spacer w h = newElement w h Spacer
139data Direction = DUp | DDown | DLeft | DRight | DIn | DOut
141-- Have a list of elements flow in a particular direction.
142-- The `Direction` starts from the first element in the list.
143--
144-- flow right [a,b,c]
145--
146-- +---+---+---+
147-- | a | b | c |
148-- +---+---+---+
149flow : Direction -> [Element] -> Element
150flow dir es =
151 let ws = List.map widthOf es
152 hs = List.map heightOf es
153 newFlow w h = newElement w h (Flow dir es)
154 in
155 if es == [] then spacer 0 0 else
156 case dir of
157 DUp -> newFlow (List.maximum ws) (List.sum hs)
158 DDown -> newFlow (List.maximum ws) (List.sum hs)
159 DLeft -> newFlow (List.sum ws) (List.maximum hs)
160 DRight -> newFlow (List.sum ws) (List.maximum hs)
161 DIn -> newFlow (List.maximum ws) (List.maximum hs)
162 DOut -> newFlow (List.maximum ws) (List.maximum hs)
164-- Stack elements vertically. To put `a` above `b` you would say:
165--
166-- a `above` b
167above : Element -> Element -> Element
168above hi lo =
169 newElement (max (widthOf hi) (widthOf lo))
170 (heightOf hi + heightOf lo)
171 (Flow DDown [hi,lo])
173-- Stack elements vertically. To put `a` below `b` you would say:
174--
175-- a `below` b
176below : Element -> Element -> Element
177below lo hi =
178 newElement (max (widthOf hi) (widthOf lo))
179 (heightOf hi + heightOf lo)
180 (Flow DDown [hi,lo])
182-- Put elements beside each other horizontally.
183beside : Element -> Element -> Element
184beside lft rht =
185 newElement (widthOf lft + widthOf rht)
186 (max (heightOf lft) (heightOf rht))
187 (Flow right [lft,rht])
189-- Layer elements on top of each other, starting from the bottom.
190-- `(layers == flow outward)`
191layers : [Element] -> Element
192layers es =
193 let ws = List.map widthOf es
194 hs = List.map heightOf es
195 in newElement (List.maximum ws) (List.maximum hs) (Flow DOut es)
198-- Repetitive things --
200absolute : Int -> Pos
201absolute = Absolute
202relative : Float -> Pos
203relative = Relative
205middle : Position
206middle = { horizontal=Z, vertical=Z, x=Relative 0.5, y=Relative 0.5 }
207topLeft : Position
208topLeft = { horizontal=N, vertical=P, x=Absolute 0, y=Absolute 0 }
209topRight : Position
210topRight = { topLeft | horizontal <- P }
211bottomLeft : Position
212bottomLeft = { topLeft | vertical <- N }
213bottomRight : Position
214bottomRight = { bottomLeft | horizontal <- P }
215midLeft : Position
216midLeft = { middle | horizontal <- N, x <- Absolute 0 }
217midRight : Position
218midRight = { midLeft | horizontal <- P }
219midTop : Position
220midTop = { middle | vertical <- P, y <- Absolute 0 }
221midBottom : Position
222midBottom = { midTop | vertical <- N }
224middleAt : Pos -> Pos -> Position
225middleAt x y = { horizontal = Z, vertical = Z, x = x, y = y }
226topLeftAt : Pos -> Pos -> Position
227topLeftAt x y = { horizontal = N, vertical = P, x = x, y = y }
228topRightAt : Pos -> Pos -> Position
229topRightAt x y = { horizontal = P, vertical = P, x = x, y = y }
230bottomLeftAt : Pos -> Pos -> Position
231bottomLeftAt x y = { horizontal = N, vertical = N, x = x, y = y }
232bottomRightAt : Pos -> Pos -> Position
233bottomRightAt x y = { horizontal = P, vertical = N, x = x, y = y }
234midLeftAt : Pos -> Pos -> Position
235midLeftAt x y = { horizontal = N, vertical = Z, x = x, y = y }
236midRightAt : Pos -> Pos -> Position
237midRightAt x y = { horizontal = P, vertical = Z, x = x, y = y }
238midTopAt : Pos -> Pos -> Position
239midTopAt x y = { horizontal = Z, vertical = P, x = x, y = y }
240midBottomAt : Pos -> Pos -> Position
241midBottomAt x y = { horizontal = Z, vertical = N, x = x, y = y }
243up : Direction
244up = DUp
246down : Direction
247down = DDown
249left : Direction
250left = DLeft
252right : Direction
253right = DRight
255inward : Direction
256inward = DIn
258outward : Direction
259outward = DOut