| <!DOCTYPE html> | 
 | <title>CSS Anchor Positioning: position-area with writing-mode and direction</title> | 
 | <link rel="help" href="https://drafts.csswg.org/css-anchor-position/#position-area"> | 
 | <script src="/resources/testharness.js"></script> | 
 | <script src="/resources/testharnessreport.js"></script> | 
 | <!-- The grid: | 
 |  | 
 |           100      150      150 | 
 |       +--------+--------+--------+ | 
 |       |        |        |        | | 
 |   150 |        |        |        | | 
 |       |        |        |        | | 
 |       +--------+--------+--------+ | 
 |       |        |        |        | | 
 |    75 |        |        |        | | 
 |       |        |        |        | | 
 |       +--------+--------+--------+ | 
 |       |        |        |        | | 
 |   175 |        |        |        | | 
 |       |        |        |        | | 
 |       +--------+--------+--------+ | 
 |  | 
 |   --> | 
 | <style> | 
 |   #container { | 
 |     position: absolute; | 
 |     width: 400px; | 
 |     height: 400px; | 
 |   } | 
 |   #anchored { | 
 |     position: absolute; | 
 |     align-self: stretch; | 
 |     justify-self: stretch; | 
 |     position-anchor: --anchor; | 
 |   } | 
 |   #anchor { | 
 |     margin-top: 150px; | 
 |     margin-bottom: 175px; | 
 |     margin-left: 100px; | 
 |     margin-right: 150px; | 
 |     width: 150px; | 
 |     height: 75px; | 
 |     anchor-name: --anchor; | 
 |   } | 
 | </style> | 
 | <div id="container"> | 
 |   <div id="anchored"></div> | 
 |   <div id="anchor"></div> | 
 | </div> | 
 | <script> | 
 |   function test_position_area(writing_direction, position_area, expected_offsets) { | 
 |     anchored.style.positionArea = position_area; | 
 |     test(() => { | 
 |       assert_equals(anchored.offsetLeft, expected_offsets.left, "Checking offsetLeft"); | 
 |       assert_equals(anchored.offsetTop, expected_offsets.top, "Checking offsetTop"); | 
 |       assert_equals(anchored.offsetWidth, expected_offsets.width, "Checking offsetWidth"); | 
 |       assert_equals(anchored.offsetHeight, expected_offsets.height, "Checking offsetHeight"); | 
 |     }, "Offsets for: " + position_area + " with writing-mode / direction: " + writing_direction); | 
 |   } | 
 |  | 
 |   const top_left = {left:0, top:0, width:100, height:150}; | 
 |   const top_right = {left:250, top:0, width:150, height:150}; | 
 |   const bottom_left = {left:0, top:225, width:100, height:175}; | 
 |   const bottom_right = {left:250, top:225, width:150, height:175}; | 
 |  | 
 |   anchored.style.writingMode = "horizontal-tb"; | 
 |   anchored.style.direction = "ltr"; | 
 |  | 
 |   // Writing-mode and direction on container | 
 |   let writing_direction = "containing-block: horizontal-tb / rtl"; | 
 |   container.style.writingMode = "horizontal-tb"; | 
 |   container.style.direction = "rtl"; | 
 |   test_position_area(writing_direction, "start start", top_right); | 
 |   test_position_area(writing_direction, "self-start self-start", top_left); | 
 |   test_position_area(writing_direction, "x-start y-start", top_right); | 
 |   test_position_area(writing_direction, "self-x-start self-y-start", top_left); | 
 |   test_position_area(writing_direction, "inline-start block-end", bottom_right); | 
 |   test_position_area(writing_direction, "self-inline-start self-block-end", bottom_left); | 
 |  | 
 |   // containing-block: vertical-lr / ltr | 
 |   // self: horizontal-tb / ltr | 
 |   writing_direction = "containing-block: vertical-lr / ltr"; | 
 |   container.style.writingMode = "vertical-lr"; | 
 |   container.style.direction = "ltr"; | 
 |   test_position_area(writing_direction, "start start", top_left); | 
 |   test_position_area(writing_direction, "self-start self-start", top_left); | 
 |   test_position_area(writing_direction, "x-start y-start", top_left); | 
 |   test_position_area(writing_direction, "self-x-start self-y-start", top_left); | 
 |   test_position_area(writing_direction, "inline-start block-end", top_right); | 
 |   test_position_area(writing_direction, "self-inline-start self-block-end", bottom_left); | 
 |  | 
 |   // containing-block: vertical-lr / rtl | 
 |   // self: horizontal-tb / ltr | 
 |   writing_direction = "containing-block: vertical-lr / rtl"; | 
 |   container.style.writingMode = "vertical-lr"; | 
 |   container.style.direction = "rtl"; | 
 |   test_position_area(writing_direction, "start start", bottom_left); | 
 |   test_position_area(writing_direction, "self-start self-start", top_left); | 
 |   test_position_area(writing_direction, "x-start y-start", bottom_left); | 
 |   test_position_area(writing_direction, "self-x-start self-y-start", top_left); | 
 |  | 
 |   // containing-block: vertical-rl / ltr | 
 |   // self: horizontal-tb / ltr | 
 |   writing_direction = "containing-block: vertical-rl / ltr"; | 
 |   container.style.writingMode = "vertical-rl"; | 
 |   container.style.direction = "ltr"; | 
 |   test_position_area(writing_direction, "start start", top_right); | 
 |   test_position_area(writing_direction, "self-start self-start", top_left); | 
 |   test_position_area(writing_direction, "x-start y-start", top_right); | 
 |   test_position_area(writing_direction, "self-x-start self-y-start", top_left); | 
 |  | 
 |   // containing-block: vertical-rl / rtl | 
 |   // self: horizontal-tb / ltr | 
 |   writing_direction = "containing-block: vertical-rl / rtl"; | 
 |   container.style.writingMode = "vertical-rl"; | 
 |   container.style.direction = "rtl"; | 
 |   test_position_area(writing_direction, "start start", bottom_right); | 
 |   test_position_area(writing_direction, "self-start self-start", top_left); | 
 |   test_position_area(writing_direction, "x-start y-start", bottom_right); | 
 |   test_position_area(writing_direction, "self-x-start self-y-start", top_left); | 
 |  | 
 |   // Writing-mode and direction on self | 
 |   container.style.writingMode = "horizontal-tb"; | 
 |   container.style.direction = "ltr"; | 
 |  | 
 |   // containing-block: horizontal-tb / ltr | 
 |   // self: horizontal-tb / rtl | 
 |   writing_direction = "self: horizontal-tb / rtl"; | 
 |   anchored.style.writingMode = "horizontal-tb"; | 
 |   anchored.style.direction = "rtl"; | 
 |   test_position_area(writing_direction, "start start", top_left); | 
 |   test_position_area(writing_direction, "self-start self-start", top_right); | 
 |   test_position_area(writing_direction, "x-start y-start", top_left); | 
 |   test_position_area(writing_direction, "self-x-start self-y-start", top_right); | 
 |  | 
 |   // containing-block: horizontal-tb / ltr | 
 |   // self: vertical-lr / ltr | 
 |   writing_direction = "self: vertical-lr / ltr"; | 
 |   anchored.style.writingMode = "vertical-lr"; | 
 |   anchored.style.direction = "ltr"; | 
 |   test_position_area(writing_direction, "start start", top_left); | 
 |   test_position_area(writing_direction, "self-start self-start", top_left); | 
 |   test_position_area(writing_direction, "x-start y-start", top_left); | 
 |   test_position_area(writing_direction, "self-x-start self-y-start", top_left); | 
 |  | 
 |   // containing-block: horizontal-tb / ltr | 
 |   // self: vertical-lr / rtl | 
 |   writing_direction = "self: vertical-lr / rtl"; | 
 |   anchored.style.writingMode = "vertical-lr"; | 
 |   anchored.style.direction = "rtl"; | 
 |   test_position_area(writing_direction, "start start", top_left); | 
 |   test_position_area(writing_direction, "self-start self-start", bottom_left); | 
 |   test_position_area(writing_direction, "x-start y-start", top_left); | 
 |   test_position_area(writing_direction, "self-x-start self-y-start", bottom_left); | 
 |  | 
 |   // containing-block: horizontal-tb / ltr | 
 |   // self: vertical-rl / ltr | 
 |   writing_direction = "self: vertical-rl / ltr"; | 
 |   anchored.style.writingMode = "vertical-rl"; | 
 |   anchored.style.direction = "ltr"; | 
 |   test_position_area(writing_direction, "start start", top_left); | 
 |   test_position_area(writing_direction, "self-start self-start", top_right); | 
 |   test_position_area(writing_direction, "x-start y-start", top_left); | 
 |   test_position_area(writing_direction, "self-x-start self-y-start", top_right); | 
 |  | 
 |   // containing-block: horizontal-tb / ltr | 
 |   // self: vertical-rl / rtl | 
 |   writing_direction = "self: vertical-rl / rtl"; | 
 |   anchored.style.writingMode = "vertical-rl"; | 
 |   anchored.style.direction = "rtl"; | 
 |   test_position_area(writing_direction, "start start", top_left); | 
 |   test_position_area(writing_direction, "self-start self-start", bottom_right); | 
 |   test_position_area(writing_direction, "x-start y-start", top_left); | 
 |   test_position_area(writing_direction, "self-x-start self-y-start", bottom_right); | 
 |  | 
 | </script> |