As the sun rises and the forest mist clears, and the clouds return and the caves darken, these changes of light and shadow are the morning and evening in the mountains. Wildflowers bloom with their subtle fragrance, fine trees flourish with their dense shade, the wind and frost are pure and clean, and the water recedes to reveal the rocks—these are the four seasons in the mountains. Going out in the morning and returning in the evening, the scenery of the four seasons is different, and the joy is endless.至于负者歌于途,行者休于树,前者呼,后者应,伛偻提携,往来而不绝者,滁人游也。临溪而渔,溪深而鱼肥,酿泉为酒,泉香而酒洌,山肴野蔌,杂然而前陈者,太守宴也。宴酣之乐,非丝非竹,射者中,弈者胜,觥筹交错,起坐而喧哗者,众宾欢也。苍颜白发,颓然乎其间者,太守醉也。
/**
* @output wp-includes/js/wp-emoji-loader.js
*/
/* eslint-env es6 */
// Note: This is loaded as a script module, so there is no need for an IIFE to prevent pollution of the global scope.
/**
* 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
*/
const settings = /** @type {WPEmojiSettings} */ (
JSON.parse( document.getElementById( 'wp-emoji-settings' ).textContent )
);
// For compatibility with other scripts that read from this global, in particular wp-includes/js/wp-emoji.js (source file: js/_enqueues/wp/emoji.js).
window._wpemojiSettings = settings;
/**
* Support tests.
* @typedef SupportTests
* @type {object}
* @property {?boolean} flag
* @property {?boolean} emoji
*/
const sessionStorageKey = 'wpEmojiSettingsSupports';
const 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} */
const 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} */
const 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 is used to determine if the browser is rendering an emoji with multiple data points
* correctly. set1 is the emoji in the correct form, using a zero-width joiner. set2 is the emoji
* in the incorrect form, using a zero-width space. If the two sets render the same, then the browser
* does not support the emoji correctly.
*
* 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 );
const 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 );
const rendered2 = new Uint32Array(
context.getImageData(
0,
0,
context.canvas.width,
context.canvas.height
).data
);
return rendered1.every( ( rendered2Data, index ) => {
return rendered2Data === rendered2[ index ];
} );
}
/**
* Checks if the center point of a single emoji is empty.
*
* This is used to determine if the browser is rendering an emoji with a single data point
* correctly. The center point of an incorrectly rendered emoji will be empty. A correctly
* rendered emoji will have a non-zero value at the center point.
*
* 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 6.8.2
*
* @private
*
* @param {CanvasRenderingContext2D} context 2D Context.
* @param {string} emoji Emoji to test.
*
* @return {boolean} True if the center point is empty.
*/
function emojiRendersEmptyCenterPoint( context, emoji ) {
// Cleanup from previous test.
context.clearRect( 0, 0, context.canvas.width, context.canvas.height );
context.fillText( emoji, 0, 0 );
// Test if the center point (16, 16) is empty (0,0,0,0).
const centerPoint = context.getImageData(16, 16, 1, 1);
for ( let i = 0; i < centerPoint.data.length; i++ ) {
if ( centerPoint.data[ i ] !== 0 ) {
// Stop checking the moment it's known not to be empty.
return false;
}
}
return true;
}
/**
* 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.
* @param {Function} emojiRendersEmptyCenterPoint Reference to emojiRendersEmptyCenterPoint function, needed due to minification.
*
* @return {boolean} True if the browser can render emoji, false if it cannot.
*/
function browserSupportsEmoji( context, type, emojiSetsRenderIdentically, emojiRendersEmptyCenterPoint ) {
let 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 Sark 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 ([C] + [Q]).
*/
isIdentical = emojiSetsRenderIdentically(
context,
'\uD83C\uDDE8\uD83C\uDDF6', // as the sequence of two code points
'\uD83C\uDDE8\u200B\uD83C\uDDF6' // 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':
/*
* Is there a large, hairy, humanoid mythical creature living in the browser?
*
* To test for Emoji 17.0 support, try to render a new emoji: Hairy Creature.
*
* The hairy creature emoji is a single code point emoji. Testing for browser
* support required testing the center point of the emoji to see if it is empty.
*
* 0xD83E 0x1FAC8 (\uD83E\u1FAC8) == Hairy creature.
*
* When updating this test, please ensure that the emoji is either a single code point
* or switch to using the emojiSetsRenderIdentically function and testing with a zero-width
* joiner vs a zero-width space.
*/
const notSupported = emojiRendersEmptyCenterPoint( context, '\uD83E\u1FAC8' );
return ! notSupported;
}
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.
* @param {Function} emojiRendersEmptyCenterPoint Reference to emojiRendersEmptyCenterPoint function, needed due to minification.
*
* @return {SupportTests} Support tests.
*/
function testEmojiSupports( tests, browserSupportsEmoji, emojiSetsRenderIdentically, emojiRendersEmptyCenterPoint ) {
let canvas;
if (
typeof WorkerGlobalScope !== 'undefined' &&
self instanceof WorkerGlobalScope
) {
canvas = new OffscreenCanvas( 300, 150 ); // Dimensions are default for HTMLCanvasElement.
} else {
canvas = document.createElement( 'canvas' );
}
const 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';
const supports = {};
tests.forEach( ( test ) => {
supports[ test ] = browserSupportsEmoji( context, test, emojiSetsRenderIdentically, emojiRendersEmptyCenterPoint );
} );
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 ) {
const script = document.createElement( 'script' );
script.src = src;
script.defer = true;
document.head.appendChild( script );
}
settings.supports = {
everything: true,
everythingExceptFlag: true
};
// Obtain the emoji support from the browser, asynchronously when possible.
new Promise( ( resolve ) => {
let supportTests = getSessionSupportTests();
if ( supportTests ) {
resolve( supportTests );
return;
}
if ( supportsWorkerOffloading() ) {
try {
// Note that the functions are being passed as arguments due to minification.
const workerScript =
'postMessage(' +
testEmojiSupports.toString() +
'(' +
[
JSON.stringify( tests ),
browserSupportsEmoji.toString(),
emojiSetsRenderIdentically.toString(),
emojiRendersEmptyCenterPoint.toString()
].join( ',' ) +
'));';
const blob = new Blob( [ workerScript ], {
type: 'text/javascript'
} );
const worker = new Worker( URL.createObjectURL( blob ), { name: 'wpTestEmojiSupports' } );
worker.onmessage = ( event ) => {
supportTests = event.data;
setSessionSupportTests( supportTests );
worker.terminate();
resolve( supportTests );
};
return;
} catch ( e ) {}
}
supportTests = testEmojiSupports( tests, browserSupportsEmoji, emojiSetsRenderIdentically, emojiRendersEmptyCenterPoint );
setSessionSupportTests( supportTests );
resolve( supportTests );
} )
// Once the browser emoji support has been obtained from the session, finalize the settings.
.then( ( supportTests ) => {
/*
* Tests the browser support for flag emojis and other emojis, and adjusts the
* support settings accordingly.
*/
for ( const 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;
// When the browser can not render everything we need to load a polyfill.
if ( ! settings.supports.everything ) {
const src = settings.source || {};
if ( src.concatemoji ) {
addScript( src.concatemoji );
} else if ( src.wpemoji && src.twemoji ) {
addScript( src.twemoji );
addScript( src.wpemoji );
}
}
} );