| "use strict"; |
| |
| { |
| // private variables are defined with `const` so they don't leak outside this block statement |
| const IFRAME_DEFAULT_SIZE = "200"; |
| const iframes = new WeakMap(); |
| |
| // helpers are defined with `var` so they are globally accessible |
| var createMQL = async t => { |
| const iframe = await createIFrame(t); |
| const mql = iframe.contentWindow.matchMedia(`(max-width: ${IFRAME_DEFAULT_SIZE}px)`); |
| assert_true(mql.matches, "MQL should match on newly created <iframe>"); |
| iframes.set(mql, iframe); |
| return mql; |
| }; |
| |
| var createIFrame = (t, width = IFRAME_DEFAULT_SIZE, height = width) => { |
| assert_not_equals(document.body, null, "<body> element is missing"); |
| |
| const iframe = document.createElement("iframe"); |
| iframe.srcdoc = ""; |
| iframe.width = String(width); |
| iframe.height = String(height); |
| iframe.style.border = "none"; |
| |
| t.add_cleanup(() => { |
| document.body.removeChild(iframe); |
| }); |
| |
| return new Promise(resolve => { |
| iframe.addEventListener("load", () => { |
| iframe.contentDocument.body.offsetWidth; // reflow |
| resolve(iframe); |
| }); |
| |
| document.body.appendChild(iframe); |
| }); |
| }; |
| |
| var triggerMQLEvent = mql => { |
| const iframe = iframes.get(mql); |
| assert_not_equals(iframe, undefined, "Passed MQL instance was not created with createMQL"); |
| iframe.width = iframe.width === IFRAME_DEFAULT_SIZE ? "250" : IFRAME_DEFAULT_SIZE; |
| }; |
| |
| var getWindow = mql => { |
| const iframe = iframes.get(mql); |
| assert_not_equals(iframe, undefined, "Passed MQL instance was not created with createMQL"); |
| return iframe.contentWindow; |
| }; |
| |
| var waitForChangesReported = () => { |
| return new Promise(resolve => { |
| requestAnimationFrame(() => { |
| requestAnimationFrame(resolve); |
| }); |
| }); |
| }; |
| |
| } |
