prefers-contrast.html (1774B)
1 <!DOCTYPE html> 2 <link rel="help" href="https://drafts.csswg.org/mediaqueries-5/#prefers-contrast" /> 3 <script type="text/javascript" src="/resources/testharness.js"></script> 4 <script type="text/javascript" src="/resources/testharnessreport.js"></script> 5 6 <script type="text/javascript" src="resources/matchmedia-utils.js"></script> 7 <script> 8 query_should_be_known("(prefers-contrast)"); 9 query_should_be_known("(prefers-contrast: no-preference)"); 10 query_should_be_known("(prefers-contrast: more)"); 11 query_should_be_known("(prefers-contrast: less)"); 12 query_should_be_known("(prefers-contrast: custom)"); 13 14 query_should_be_unknown("(prefers-contrast: increase)"); 15 query_should_be_unknown("(prefers-contrast: none)"); 16 query_should_be_unknown("(prefers-contrast: forced high)"); 17 query_should_be_unknown("(prefers-contrast: forced low)"); 18 query_should_be_unknown("(prefers-contrast > increase)"); 19 query_should_be_unknown("(prefers-increased-contrast)"); 20 query_should_be_unknown("(prefers-decreased-contrast)"); 21 query_should_be_unknown("(prefers-contrast: high)"); 22 query_should_be_unknown("(prefers-contrast: low)"); 23 query_should_be_unknown("(prefers-contrast: forced)"); 24 25 test(() => { 26 // no-preference is the default and all other values evaluate to 27 // true in the boolean context. If no-preference matches, then 28 // boolean context should be false. If no-preference does not match 29 // then boolean context should be true. Therefore, these two values 30 // should always be each others inverse irrespective of OS level 31 // settings. 32 let booleanContext = window.matchMedia("(prefers-contrast)"); 33 let noPref = window.matchMedia("(prefers-contrast: no-preference)"); 34 assert_equals(noPref.matches, !booleanContext.matches); 35 }, "Check boolean context evaluation."); 36 </script>