auto_tests/tests/hidpi.js

   1 /**
   2  * @fileoverview Tests for window.devicePixelRatio > 1.
   3  *
   4  * @author danvdk@gmail.com (Dan Vanderkam)
   5  */
   6 var hidpiTestCase = TestCase("hidpi");
   7
   8 var savePixelRatio;
   9 hidpiTestCase.prototype.setUp = function() {
  10   savePixelRatio = window.devicePixelRatio;
  11   window.devicePixelRatio = 2;
  12
  13   document.body.innerHTML = "<div id='graph'></div>";
  14 };
  15
  16 hidpiTestCase.prototype.tearDown = function() {
  17   window.devicePixelRatio = savePixelRatio;
  18 };
  19
  20 hidpiTestCase.prototype.testDoesntCreateScrollbars = function() {
  21   var sw = document.body.scrollWidth;
  22   var cw = document.body.clientWidth;
  23
  24   var graph = document.getElementById("graph");
  25   graph.style.width = "70%";  // more than half.
  26   graph.style.height = "200px";
  27
  28   var opts = {};
  29   var data = "X,Y\n" +
  30       "0,-1\n" +
  31       "1,0\n" +
  32       "2,1\n" +
  33       "3,0\n"
  34   ;
  35
  36   var g = new Dygraph(graph, data, opts);
  37
  38   // Adding the graph shouldn't cause the width of the page to change.
  39   // (essentially, we're checking that we don't end up with a scrollbar)
  40   // See http://stackoverflow.com/a/2146905/388951
  41   assertEquals(cw, document.body.clientWidth);
  42   assertEquals(sw, document.body.scrollWidth);
  43 };
  44