Button Interface description

A button is an instance of the more general Selector abstraction, so operations allowed on Selectors all apply to buttons. Hide this fact though at the Button abstraction level and rename the Selector operations:

button :: Picture -> a -> Component (Button a, DisplayHandle)

create button with arbitrary picture label. Each time the button is clicked, the Button will emit the value given as second argument to button.
Returns:

Button a

DisplayHandle

getButtonClick :: Button a -> IO a

get next click from the button.

setButtonLabel :: Button a -> Picture -> IO a

change the current label for the button.

combineButtons :: Button a -> IO (Button a)

merge a set of buttons together, such that button clicks that are reported to any of the combined buttons are forwarded to the combined button.

mapButton :: (a->b) -> Button a -> Button b

returns a new button which for every value output by an existing button apply a function to its output.

disableButton :: Button a -> IO ()

disable interaction with the user.

enableButton :: Button a -> IO ()

if disabled, enable interaction again.

nameButton :: SelectorName -> Button a -> Button a

return a button value with a new name.