26 lines
594 B
HTML
26 lines
594 B
HTML
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<script>
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'use strict';
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var vis = (function() {
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var stateKey,
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eventKey,
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keys = {
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hidden: "visibilitychange",
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webkitHidden: "webkitvisibilitychange",
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mozHidden: "mozvisibilitychange",
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msHidden: "msvisibilitychange"
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};
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for (stateKey in keys) {
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if (stateKey in document) {
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eventKey = keys[stateKey];
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break;
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}
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}
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return function(c) {
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if (c) {
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document.addEventListener(eventKey, c);
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}
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return !document[stateKey];
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};
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})();
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</script>
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