elm/core/Native/Keyboard.js
2013-02-21 09:40:41 +01:00

94 lines
2.5 KiB
JavaScript

Elm.Keyboard = { Raw : function() {
var keysDown = Elm.Signal.constant(["Nil"]);
var charPressed = Elm.Signal.constant(["Nothing"]);
function remove(x,xs) {
if (xs[0] === "Nil") return xs;
if (xs[1] === x) return xs[2];
return ["Cons", xs[1], remove(x,xs[2])];
}
function has(x,xs) {
while (xs[0] !== "Nil") {
if (xs[1] === x) return true;
xs = xs[2];
}
return false;
}
Value.addListener(document, 'keydown', function(e) {
if (has(e.keyCode, keysDown.value)) return;
var hasListener = Dispatcher.notify(keysDown.id, ["Cons", e.keyCode, keysDown.value]);
if (!hasListener)
this.removeEventListener('keydown',arguments.callee,false);
});
Value.addListener(document, 'keyup', function(e) {
var codes = remove(e.keyCode, keysDown.value);
var hasListener = Dispatcher.notify(keysDown.id, codes);
if (!hasListener)
this.removeEventListener('keyup',arguments.callee,false);
});
Value.addListener(window, 'blur', function(e) {
var hasListener = Dispatcher.notify(keysDown.id, ["Nil"]);
if (!hasListener)
this.removeEventListener('blur',arguments.callee,false);
});
Value.addListener(document, 'keypress', function(e) {
var hasListener = Dispatcher.notify(charPressed.id, ["Just",e.charCode || e.keyCode]);
Dispatcher.notify(charPressed.id, ["Nothing"]);
if (!hasListener)
this.removeEventListener('keypress',arguments.callee,false);
});
return {keysDown:keysDown,
charPressed:charPressed};
}()
};
/*! Keyboard
These are nicely curated inputs from the keyboard. See the
[Keyboard.Raw library](/docs/Signal/KeyboardRaw.elm) for a
lower-level interface that will let you define more complicated behavior.
!*/
function nativeKeyboard(elm) {
'use strict';
function keySignal(f) {
var signal = Elm.Signal.lift(f)(Elm.Keyboard.Raw.keysDown);
Elm.Keyboard.Raw.keysDown.defaultNumberOfKids += 1;
signal.defaultNumberOfKids = 0;
return signal;
}
function dir(up) { return function(down) {
return function(left) { return function(right) {
function f(ks) {
var x = 0, y = 0;
while (ks.ctor == "Cons") {
switch (ks._0) {
case left : --x; break;
case right: ++x; break;
case up : ++y; break;
case down : --y; break;
}
ks = ks._1;
}
return { _:{}, x:x, y:y };
}
return keySignal(f);
}}}
}
function is(key) {
function f(ks) {
while (ks.ctor == "Cons") {
if (key == ks._0) return true;
ks = ks._1;
}
return false;
}
return keySignal(f);
}
elm.Native.Keyboard = { isDown:is, dir:dir };
}