git.iko.soy/elk
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elk/libraries/Native/Signal/Window.js
57 lines 1.9 kB history raw
1Elm.Native.Window = {};
2Elm.Native.Window.make = function(elm) {
4 elm.Native = elm.Native || {};
5 elm.Native.Window = elm.Native.Window || {};
6 if (elm.Native.Window.values) return elm.Native.Window.values;
8 var Signal = Elm.Signal.make(elm);
9 var NS = Elm.Native.Signal.make(elm);
10 var Tuple2 = Elm.Native.Utils.make(elm).Tuple2;
12 function getWidth() { return elm.node.clientWidth; }
13 function getHeight() {
14 if (elm.display === ElmRuntime.Display.FULLSCREEN) {
15 return window.innerHeight;
16 }
17 return elm.node.clientHeight;
18 }
20 var dimensions = NS.input(Tuple2(getWidth(), getHeight()));
21 dimensions.defaultNumberOfKids = 2;
23 // Do not move width and height into Elm. By setting the default number of kids,
24 // the resize listener can be detached.
25 var width = A2(Signal.lift, function(p){return p._0;}, dimensions);
26 width.defaultNumberOfKids = 0;
28 var height = A2(Signal.lift, function(p){return p._1;}, dimensions);
29 height.defaultNumberOfKids = 0;
31 function resizeIfNeeded() {
32 // Do not trigger event if the dimensions have not changed.
33 // This should be most of the time.
34 var w = getWidth();
35 var h = getHeight();
36 if (dimensions.value._0 === w && dimensions.value._1 === h) return;
38 setTimeout(function () {
39 // Check again to see if the dimensions have changed.
40 // It is conceivable that the dimensions have changed
41 // again while some other event was being processed.
42 var w = getWidth();
43 var h = getHeight();
44 if (dimensions.value._0 === w && dimensions.value._1 === h) return;
45 elm.notify(dimensions.id, Tuple2(w,h));
46 }, 0);
47 }
48 elm.addListener([dimensions.id], window, 'resize', resizeIfNeeded);
50 return elm.Native.Window.values = {
51 dimensions:dimensions,
52 width:width,
53 height:height,
54 resizeIfNeeded:resizeIfNeeded
55 };
57};