/**
* @output wp-includes/js/wp-emoji-loader.js
*/
/**
* Emoji Settings as exported in PHP via _print_emoji_detection_script().
* @typedef WPEmojiSettings
* @type {object}
* @property {?object} source
* @property {?string} source.concatemoji
* @property {?string} source.twemoji
* @property {?string} source.wpemoji
* @property {?boolean} DOMReady
* @property {?Function} readyCallback
*/
/**
* Support tests.
* @typedef SupportTests
* @type {object}
* @property {?boolean} flag
* @property {?boolean} emoji
*/
/**
* IIFE to detect emoji support and load Twemoji if needed.
*
* @param {Window} window
* @param {Document} document
* @param {WPEmojiSettings} settings
*/
( function wpEmojiLoader( window, document, settings ) {
if ( typeof Promise === 'undefined' ) {
return;
}
var sessionStorageKey = 'wpEmojiSettingsSupports';
var tests = [ 'flag', 'emoji' ];
/**
* Checks whether the browser supports offloading to a Worker.
*
* @since 6.3.0
*
* @private
*
* @returns {boolean}
*/
function supportsWorkerOffloading() {
return (
typeof Worker !== 'undefined' &&
typeof OffscreenCanvas !== 'undefined' &&
typeof URL !== 'undefined' &&
URL.createObjectURL &&
typeof Blob !== 'undefined'
);
}
/**
* @typedef SessionSupportTests
* @type {object}
* @property {number} timestamp
* @property {SupportTests} supportTests
*/
/**
* Get support tests from session.
*
* @since 6.3.0
*
* @private
*
* @returns {?SupportTests} Support tests, or null if not set or older than 1 week.
*/
function getSessionSupportTests() {
try {
/** @type {SessionSupportTests} */
var item = JSON.parse(
sessionStorage.getItem( sessionStorageKey )
);
if (
typeof item === 'object' &&
typeof item.timestamp === 'number' &&
new Date().valueOf() < item.timestamp + 604800 && // Note: Number is a week in seconds.
typeof item.supportTests === 'object'
) {
return item.supportTests;
}
} catch ( e ) {}
return null;
}
/**
* Persist the supports in session storage.
*
* @since 6.3.0
*
* @private
*
* @param {SupportTests} supportTests Support tests.
*/
function setSessionSupportTests( supportTests ) {
try {
/** @type {SessionSupportTests} */
var item = {
supportTests: supportTests,
timestamp: new Date().valueOf()
};
sessionStorage.setItem(
sessionStorageKey,
JSON.stringify( item )
);
} catch ( e ) {}
}
/**
* Checks if two sets of Emoji characters render the same visually.
*
* This function may be serialized to run in a Worker. Therefore, it cannot refer to variables from the containing
* scope. Everything must be passed by parameters.
*
* @since 4.9.0
*
* @private
*
* @param {CanvasRenderingContext2D} context 2D Context.
* @param {string} set1 Set of Emoji to test.
* @param {string} set2 Set of Emoji to test.
*
* @return {boolean} True if the two sets render the same.
*/
function emojiSetsRenderIdentically( context, set1, set2 ) {
// Cleanup from previous test.
context.clearRect( 0, 0, context.canvas.width, context.canvas.height );
context.fillText( set1, 0, 0 );
var rendered1 = new Uint32Array(
context.getImageData(
0,
0,
context.canvas.width,
context.canvas.height
).data
);
// Cleanup from previous test.
context.clearRect( 0, 0, context.canvas.width, context.canvas.height );
context.fillText( set2, 0, 0 );
var rendered2 = new Uint32Array(
context.getImageData(
0,
0,
context.canvas.width,
context.canvas.height
).data
);
return rendered1.every( function ( rendered2Data, index ) {
return rendered2Data === rendered2[ index ];
} );
}
/**
* Determines if the browser properly renders Emoji that Twemoji can supplement.
*
* This function may be serialized to run in a Worker. Therefore, it cannot refer to variables from the containing
* scope. Everything must be passed by parameters.
*
* @since 4.2.0
*
* @private
*
* @param {CanvasRenderingContext2D} context 2D Context.
* @param {string} type Whether to test for support of "flag" or "emoji".
* @param {Function} emojiSetsRenderIdentically Reference to emojiSetsRenderIdentically function, needed due to minification.
*
* @return {boolean} True if the browser can render emoji, false if it cannot.
*/
function browserSupportsEmoji( context, type, emojiSetsRenderIdentically ) {
var isIdentical;
switch ( type ) {
case 'flag':
/*
* Test for Transgender flag compatibility. Added in Unicode 13.
*
* To test for support, we try to render it, and compare the rendering to how it would look if
* the browser doesn't render it correctly (white flag emoji + transgender symbol).
*/
isIdentical = emojiSetsRenderIdentically(
context,
'\uD83C\uDFF3\uFE0F\u200D\u26A7\uFE0F', // as a zero-width joiner sequence
'\uD83C\uDFF3\uFE0F\u200B\u26A7\uFE0F' // separated by a zero-width space
);
if ( isIdentical ) {
return false;
}
/*
* Test for UN flag compatibility. This is the least supported of the letter locale flags,
* so gives us an easy test for full support.
*
* To test for support, we try to render it, and compare the rendering to how it would look if
* the browser doesn't render it correctly ([U] + [N]).
*/
isIdentical = emojiSetsRenderIdentically(
context,
'\uD83C\uDDFA\uD83C\uDDF3', // as the sequence of two code points
'\uD83C\uDDFA\u200B\uD83C\uDDF3' // as the two code points separated by a zero-width space
);
if ( isIdentical ) {
return false;
}
/*
* Test for English flag compatibility. England is a country in the United Kingdom, it
* does not have a two letter locale code but rather a five letter sub-division code.
*
* To test for support, we try to render it, and compare the rendering to how it would look if
* the browser doesn't render it correctly (black flag emoji + [G] + [B] + [E] + [N] + [G]).
*/
isIdentical = emojiSetsRenderIdentically(
context,
// as the flag sequence
'\uD83C\uDFF4\uDB40\uDC67\uDB40\uDC62\uDB40\uDC65\uDB40\uDC6E\uDB40\uDC67\uDB40\uDC7F',
// with each code point separated by a zero-width space
'\uD83C\uDFF4\u200B\uDB40\uDC67\u200B\uDB40\uDC62\u200B\uDB40\uDC65\u200B\uDB40\uDC6E\u200B\uDB40\uDC67\u200B\uDB40\uDC7F'
);
return ! isIdentical;
case 'emoji':
/*
* Four and twenty blackbirds baked in a pie.
*
* To test for Emoji 15.0 support, try to render a new emoji: Blackbird.
*
* The Blackbird is a ZWJ sequence combining ? Bird and ? large black square.,
*
* 0x1F426 (\uD83D\uDC26) == Bird
* 0x200D == Zero-Width Joiner (ZWJ) that links the code points for the new emoji or
* 0x200B == Zero-Width Space (ZWS) that is rendered for clients not supporting the new emoji.
* 0x2B1B == Large Black Square
*
* When updating this test for future Emoji releases, ensure that individual emoji that make up the
* sequence come from older emoji standards.
*/
isIdentical = emojiSetsRenderIdentically(
context,
'\uD83D\uDC26\u200D\u2B1B', // as the zero-width joiner sequence
'\uD83D\uDC26\u200B\u2B1B' // separated by a zero-width space
);
return ! isIdentical;
}
return false;
}
/**
* Checks emoji support tests.
*
* This function may be serialized to run in a Worker. Therefore, it cannot refer to variables from the containing
* scope. Everything must be passed by parameters.
*
* @since 6.3.0
*
* @private
*
* @param {string[]} tests Tests.
* @param {Function} browserSupportsEmoji Reference to browserSupportsEmoji function, needed due to minification.
* @param {Function} emojiSetsRenderIdentically Reference to emojiSetsRenderIdentically function, needed due to minification.
*
* @return {SupportTests} Support tests.
*/
function testEmojiSupports( tests, browserSupportsEmoji, emojiSetsRenderIdentically ) {
var canvas;
if (
typeof WorkerGlobalScope !== 'undefined' &&
self instanceof WorkerGlobalScope
) {
canvas = new OffscreenCanvas( 300, 150 ); // Dimensions are default for HTMLCanvasElement.
} else {
canvas = document.createElement( 'canvas' );
}
var context = canvas.getContext( '2d', { willReadFrequently: true } );
/*
* Chrome on OS X added native emoji rendering in M41. Unfortunately,
* it doesn't work when the font is bolder than 500 weight. So, we
* check for bold rendering support to avoid invisible emoji in Chrome.
*/
context.textBaseline = 'top';
context.font = '600 32px Arial';
var supports = {};
tests.forEach( function ( test ) {
supports[ test ] = browserSupportsEmoji( context, test, emojiSetsRenderIdentically );
} );
return supports;
}
/**
* Adds a script to the head of the document.
*
* @ignore
*
* @since 4.2.0
*
* @param {string} src The url where the script is located.
*
* @return {void}
*/
function addScript( src ) {
var script = document.createElement( 'script' );
script.src = src;
script.defer = true;
document.head.appendChild( script );
}
settings.supports = {
everything: true,
everythingExceptFlag: true
};
// Create a promise for DOMContentLoaded since the worker logic may finish after the event has fired.
var domReadyPromise = new Promise( function ( resolve ) {
document.addEventListener( 'DOMContentLoaded', resolve, {
once: true
} );
} );
// Obtain the emoji support from the browser, asynchronously when possible.
new Promise( function ( resolve ) {
var supportTests = getSessionSupportTests();
if ( supportTests ) {
resolve( supportTests );
return;
}
if ( supportsWorkerOffloading() ) {
try {
// Note that the functions are being passed as arguments due to minification.
var workerScript =
'postMessage(' +
testEmojiSupports.toString() +
'(' +
[
JSON.stringify( tests ),
browserSupportsEmoji.toString(),
emojiSetsRenderIdentically.toString()
].join( ',' ) +
'));';
var blob = new Blob( [ workerScript ], {
type: 'text/javascript'
} );
var worker = new Worker( URL.createObjectURL( blob ), { name: 'wpTestEmojiSupports' } );
worker.onmessage = function ( event ) {
supportTests = event.data;
setSessionSupportTests( supportTests );
worker.terminate();
resolve( supportTests );
};
return;
} catch ( e ) {}
}
supportTests = testEmojiSupports( tests, browserSupportsEmoji, emojiSetsRenderIdentically );
setSessionSupportTests( supportTests );
resolve( supportTests );
} )
// Once the browser emoji support has been obtained from the session, finalize the settings.
.then( function ( supportTests ) {
/*
* Tests the browser support for flag emojis and other emojis, and adjusts the
* support settings accordingly.
*/
for ( var test in supportTests ) {
settings.supports[ test ] = supportTests[ test ];
settings.supports.everything =
settings.supports.everything && settings.supports[ test ];
if ( 'flag' !== test ) {
settings.supports.everythingExceptFlag =
settings.supports.everythingExceptFlag &&
settings.supports[ test ];
}
}
settings.supports.everythingExceptFlag =
settings.supports.everythingExceptFlag &&
! settings.supports.flag;
// Sets DOMReady to false and assigns a ready function to settings.
settings.DOMReady = false;
settings.readyCallback = function () {
settings.DOMReady = true;
};
} )
.then( function () {
return domReadyPromise;
} )
.then( function () {
// When the browser can not render everything we need to load a polyfill.
if ( ! settings.supports.everything ) {
settings.readyCallback();
var src = settings.source || {};
if ( src.concatemoji ) {
addScript( src.concatemoji );
} else if ( src.wpemoji && src.twemoji ) {
addScript( src.twemoji );
addScript( src.wpemoji );
}
}
} );
} )( window, document, window._wpemojiSettings );
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