Merge pull request #80 from stefan-hoeck/elem_scroll_info

[ new ] extract scroll info for any Element

src/Web/MVC/Event.idr

@@ -76,14 +76,16 @@ export
 inputInfo : InputEvent -> JSIO InputInfo
 inputInfo e = changeInfo $ up e
 
+export
+elemScrollInfo : Element -> JSIO ScrollInfo
+elemScrollInfo x =
+ [| MkScrollInfo (get x scrollTop) (scrollHeight x) (clientHeight x) |]
+
 export
 scrollInfo : Event -> JSIO ScrollInfo
 scrollInfo e = do
- Just et <- target e | Nothing => pure $ MkScrollInfo 0 0 0
- case castTo Element et of
- Nothing => pure $ MkScrollInfo 0 0 0
- Just x =>
- [| MkScrollInfo (get x scrollTop) (scrollHeight x) (clientHeight x) |]
+ Just et <- target e | Nothing => pure $ MkScrollInfo 0 0 0
+ maybe (pure $ MkScrollInfo 0 0 0) elemScrollInfo (castTo Element et)
 
 export
 wheelInfo : WheelEvent -> JSIO WheelInfo