/**
* @output wp-includes/js/wp-emoji-loader.js
*/
( function( window, document, settings ) {
var src, ready, ii, tests;
// Create a canvas element for testing native browser support of emoji.
var canvas = document.createElement( 'canvas' );
var context = canvas.getContext && canvas.getContext( '2d' );
/**
* Checks if two sets of Emoji characters render the same visually.
*
* @since 4.9.0
*
* @private
*
* @param {number[]} set1 Set of Emoji character codes.
* @param {number[]} set2 Set of Emoji character codes.
*
* @return {boolean} True if the two sets render the same.
*/
function emojiSetsRenderIdentically( set1, set2 ) {
var stringFromCharCode = String.fromCharCode;
// Cleanup from previous test.
context.clearRect( 0, 0, canvas.width, canvas.height );
context.fillText( stringFromCharCode.apply( this, set1 ), 0, 0 );
var rendered1 = canvas.toDataURL();
// Cleanup from previous test.
context.clearRect( 0, 0, canvas.width, canvas.height );
context.fillText( stringFromCharCode.apply( this, set2 ), 0, 0 );
var rendered2 = canvas.toDataURL();
return rendered1 === rendered2;
}
/**
* Detects if the browser supports rendering emoji or flag emoji.
*
* Flag emoji are a single glyph made of two characters, so some browsers
* (notably, Firefox OS X) don't support them.
*
* @since 4.2.0
*
* @private
*
* @param {string} type Whether to test for support of "flag" or "emoji".
*
* @return {boolean} True if the browser can render emoji, false if it cannot.
*/
function browserSupportsEmoji( type ) {
var isIdentical;
if ( ! context || ! context.fillText ) {
return false;
}
/*
* 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';
switch ( type ) {
case 'flag':
/*
* Test for Transgender flag compatibility. This flag is shortlisted for the Emoji 13 spec,
* but has landed in Twemoji early, so we can add support for it, too.
*
* 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(
[ 0x1F3F3, 0xFE0F, 0x200D, 0x26A7, 0xFE0F ],
[ 0x1F3F3, 0xFE0F, 0x200B, 0x26A7, 0xFE0F ]
);
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(
[ 0xD83C, 0xDDFA, 0xD83C, 0xDDF3 ],
[ 0xD83C, 0xDDFA, 0x200B, 0xD83C, 0xDDF3 ]
);
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 an 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(
[ 0xD83C, 0xDFF4, 0xDB40, 0xDC67, 0xDB40, 0xDC62, 0xDB40, 0xDC65, 0xDB40, 0xDC6E, 0xDB40, 0xDC67, 0xDB40, 0xDC7F ],
[ 0xD83C, 0xDFF4, 0x200B, 0xDB40, 0xDC67, 0x200B, 0xDB40, 0xDC62, 0x200B, 0xDB40, 0xDC65, 0x200B, 0xDB40, 0xDC6E, 0x200B, 0xDB40, 0xDC67, 0x200B, 0xDB40, 0xDC7F ]
);
return ! isIdentical;
case 'emoji':
/*
* Burning Love: Just a hunk, a hunk of burnin' love.
*
* To test for Emoji 13.1 support, try to render a new emoji: Heart on Fire!
*
* The Heart on Fire emoji is a ZWJ sequence combining ❤️ Red Heart, a Zero Width Joiner and 🔥 Fire.
*
* 0x2764, 0xfe0f == Red Heart emoji.
* 0x200D == Zero-Width Joiner (ZWJ) that links the two code points for the new emoji or
* 0x200B == Zero-Width Space (ZWS) that is rendered for clients not supporting the new emoji.
* 0xD83D, 0xDD25 == Fire.
*
* When updating this test for future Emoji releases, ensure that individual emoji that make up the
* sequence come from older emoji standards.
*/
isIdentical = emojiSetsRenderIdentically(
[0x2764, 0xfe0f, 0x200D, 0xD83D, 0xDD25],
[0x2764, 0xfe0f, 0x200B, 0xD83D, 0xDD25]
);
return ! isIdentical;
}
return false;
}
/**
* Adds a script to the head of the document.
*
* @ignore
*
* @since 4.2.0
*
* @param {Object} src The url where the script is located.
* @return {void}
*/
function addScript( src ) {
var script = document.createElement( 'script' );
script.src = src;
script.defer = script.type = 'text/javascript';
document.getElementsByTagName( 'head' )[0].appendChild( script );
}
tests = Array( 'flag', 'emoji' );
settings.supports = {
everything: true,
everythingExceptFlag: true
};
/*
* Tests the browser support for flag emojis and other emojis, and adjusts the
* support settings accordingly.
*/
for( ii = 0; ii < tests.length; ii++ ) {
settings.supports[ tests[ ii ] ] = browserSupportsEmoji( tests[ ii ] );
settings.supports.everything = settings.supports.everything && settings.supports[ tests[ ii ] ];
if ( 'flag' !== tests[ ii ] ) {
settings.supports.everythingExceptFlag = settings.supports.everythingExceptFlag && settings.supports[ tests[ ii ] ];
}
}
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;
};
// When the browser can not render everything we need to load a polyfill.
if ( ! settings.supports.everything ) {
ready = function() {
settings.readyCallback();
};
/*
* Cross-browser version of adding a dom ready event.
*/
if ( document.addEventListener ) {
document.addEventListener( 'DOMContentLoaded', ready, false );
window.addEventListener( 'load', ready, false );
} else {
window.attachEvent( 'onload', ready );
document.attachEvent( 'onreadystatechange', function() {
if ( 'complete' === document.readyState ) {
settings.readyCallback();
}
} );
}
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 );
All system for education purposes only. For more tools: Telegram @jackleet