billstclair/elm-svg-button package at elm-lang.org
Html.Button is a nice thing, but it is often very small on the small screen. For interactive games, I prefer to draw my own buttons with SVG.
This library automates the button part of an SVG button, so you can focus on its size and appearance. It works in standard computer browsers, with a mouse, or portable browsers, with touch. It supports buttons that auto-repeat as long as the mouse or finger is held down, and buttons that fire once each time they're clicked/tapped.
example directory contains a working, elm-reactor-friendly, example.
The library makes it easy to render rectangular and triangular buttons, and allows you to replace those renderers with your own custom code.
A button has user state, which you usually use to encode what it does (for repeating buttons, it also needs to encode the button's identity). But you can put anything you need there, and read and update it as necesssary (with
type Operation = Increment | Decrement
As one of your
Msg options, you need a wrapper for the button messages:
type Msg = ... | ButtonMsg Svg.Button.Msg Operation ...
Your model needs to store repeating buttons, but not simple buttons, and your update function needs to update the model when it receives messages containing them. See the example for how to code a repeating button. This README documents only simple buttons.
case msg of ... ButtonMsg m operation -> let button = getButton operation model ( isClick, btn, _ ) = Svg.Button.update (\bm -> ButtonMsg bm operation) m button in operate isClick operation mdl ...
getButton is a function to lookup the button corresponding to the given operation and
operate actually does the operation.
Svg.Button.Content to define the button's appearance:
pressMeContent : Svg.Button.Content pressMeContent = Svg.Button.TextContent "Press Me"
Define a simple increment button:
incrementButton : Svg.Button.Button () incrementButton = Svg.Button.simpleButton (100, 50) ()
Svg [...] [ ... , Svg.Button.render (x, y) pressMeContent (\m -> ButtonMsg m Increment) incrementButton ... ]
Bill St. Clair, 20 March, 2018