chrome/test/data/prerender/prerender_visibility_shared.js

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // Code shared by some of the visibility tests.  Maintains a list of
   6 // visibility states, starting with the state when this file was loaded.
   7 // New states are added on each visibility change event.
   8
   9 // Array of previously observed visibility states.
  10 var visibilityStates = [document.visibilityState];
  11
  12 // Array of previously observed hidden values.
  13 var hiddenValues = [document.hidden];
  14
  15 // Record all visibility changes in corresponding arrays.
  16 function onVisibilityChange(event) {
  17   visibilityStates.push(document.visibilityState);
  18   hiddenValues.push(document.hidden);
  19 }
  20
  21 document.addEventListener("visibilitychange",
  22                           onVisibilityChange,
  23                           false);
  24