| <!doctype html> |
| <meta charset="utf-8" /> |
| <title>Test devicePixelRatio with page zoom and iframe</title> |
| <script src="../../resources/testharness.js"></script> |
| <script src="../../resources/testharnessreport.js"></script> |
| <iframe id="frame" srcdoc="This is the iframe"></iframe> |
| <script> |
| const iframe = document.querySelector("#frame"); |
| |
| promise_test(async function (t) { |
| // Ensure page is fully loaded |
| if (document.readyState !== "complete") { |
| await new Promise((r) => |
| addEventListener("load", r, { once: true }), |
| ); |
| } |
| |
| if (!window.internals) return; |
| |
| // Initial state - should match |
| const initialMainDPR = window.devicePixelRatio; |
| const initialIframeDPR = iframe.contentWindow.devicePixelRatio; |
| assert_equals( |
| initialMainDPR, |
| initialIframeDPR, |
| "Initial DPI should match between main frame and iframe", |
| ); |
| |
| window.internals.setPageZoomFactor(2); |
| |
| // Verify both main frame and iframe have the same DPI after zoom |
| const mainDPRAfterZoom = window.devicePixelRatio; |
| const iframeDPRAfterZoom = iframe.contentWindow.devicePixelRatio; |
| assert_equals( |
| mainDPRAfterZoom, |
| initialMainDPR *2, |
| "main frame devicePixelRatio changes with zoom", |
| ); |
| assert_equals( |
| iframeDPRAfterZoom, |
| initialIframeDPR * 2, |
| "iframe devicePixelRatio changes with zoom", |
| ); |
| assert_equals( |
| iframeDPRAfterZoom, |
| mainDPRAfterZoom, |
| "Main frame and iframe devicePixelRatio should remain synchronized after page zoom", |
| ); |
| }, "devicePixelRatio remains synchronized between main frame and iframe after page zoom"); |
| </script> |
