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
|
{-# LANGUAGE ExistentialQuantification, TypeFamilies #-}
module Phi.Widget ( Widget(..)
, WidgetClass(..)
, WidgetState(..)
, separator
, createWidgetState
, layoutWidgets
, renderWidgets
) where
import Control.Monad
import Graphics.Rendering.Cairo
class WidgetClass a where
type WidgetData a :: *
initialState :: a -> WidgetData a
minSize :: a -> Int
weight :: a -> Float
weight _ = 0
layout :: a -> Int -> Int -> WidgetData a
layout widget _ _ = initialState widget
render :: a -> WidgetData a -> Int -> Int -> Render ()
data Widget = forall a. WidgetClass a => Widget a
data WidgetState = forall a. WidgetClass a => WidgetState { stateWidget :: a
, stateWidth :: Int
, stateHeight :: Int
, statePrivateData :: WidgetData a
}
createWidgetState :: Widget -> WidgetState
createWidgetState (Widget w) = WidgetState { stateWidget = w
, stateWidth = 0
, stateHeight = 0
, statePrivateData = initialState w
}
layoutWidgets :: [WidgetState] -> Int -> Int -> [WidgetState]
layoutWidgets widgets w h = map layoutWidget widgets
where
layoutWidget state = state { stateWidth = w, stateHeight = h }
renderWidgets :: [WidgetState] -> Render ()
renderWidgets widgets = forM_ widgets $ \WidgetState { stateWidget = widget, stateWidth = w, stateHeight = h, statePrivateData = priv } -> render widget priv w h
data Separator = Separator Int Float
instance WidgetClass Separator where
type WidgetData Separator = ()
initialState _ = ()
minSize (Separator s _) = s
weight (Separator _ w) = w
render _ _ _ _ = return ()
separator :: Int -> Float -> Widget
separator s w = Widget $ Separator s w
|
