WordPress/wp-includes/js/wp-emoji-loader.js

162 lines
5.2 KiB
JavaScript

( 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' );
/**
* Detect 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
*
* @param type {String} Whether to test for support of "flag" or "emoji4" emoji.
* @return {Boolean} True if the browser can render emoji, false if it cannot.
*/
function browserSupportsEmoji( type ) {
var stringFromCharCode = String.fromCharCode,
flag, flag2, emoji41, emoji42;
if ( ! context || ! context.fillText ) {
return false;
}
// Cleanup from previous test.
context.clearRect( 0, 0, canvas.width, canvas.height );
/*
* 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 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]).
*/
context.fillText( stringFromCharCode( 55356, 56826, 55356, 56819 ), 0, 0 );
flag = canvas.toDataURL();
context.clearRect( 0, 0, canvas.width, canvas.height );
// Add a zero width space between the characters, to force rendering as characters.
context.fillText( stringFromCharCode( 55356, 56826, 8203, 55356, 56819 ), 0, 0 );
flag2 = canvas.toDataURL();
if ( flag !== flag2 ) {
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]).
*/
// Cleanup from previous test.
context.clearRect( 0, 0, canvas.width, canvas.height );
context.fillText( stringFromCharCode( 55356, 57332, 56128, 56423, 56128, 56418, 56128, 56421, 56128, 56430, 56128, 56423, 56128, 56447 ), 0, 0 );
flag = canvas.toDataURL();
context.clearRect( 0, 0, canvas.width, canvas.height );
context.fillText( stringFromCharCode( 55356, 57332, 8203, 56128, 56423, 8203, 56128, 56418, 8203, 56128, 56421, 8203, 56128, 56430, 8203, 56128, 56423, 8203, 56128, 56447 ), 0, 0 );
flag2 = canvas.toDataURL();
return flag !== flag2;
case 'emoji4':
/*
* Emoji 5 has faries of all genders.
*
* To test for support, try to render a new emoji (fairy, male), then compares
* it to how it would look if the browser doesn't render it correctly
* (fairy + male sign).
*/
context.fillText( stringFromCharCode( 55358, 56794, 8205, 9794, 65039 ), 0, 0 );
emoji41 = canvas.toDataURL();
context.clearRect( 0, 0, canvas.width, canvas.height );
context.fillText( stringFromCharCode( 55358, 56794, 8203, 9794, 65039 ), 0, 0 );
emoji42 = canvas.toDataURL();
return emoji41 !== emoji42;
}
return false;
}
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', 'emoji4' );
settings.supports = {
everything: true,
everythingExceptFlag: true
};
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;
settings.DOMReady = false;
settings.readyCallback = function() {
settings.DOMReady = true;
};
if ( ! settings.supports.everything ) {
ready = function() {
settings.readyCallback();
};
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 );