120 lines
4.1 KiB
JavaScript
120 lines
4.1 KiB
JavaScript
( function( window, document, settings ) {
|
|
var src, ready;
|
|
|
|
/**
|
|
* 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 "simple" or "flag" emoji.
|
|
* @return {Boolean} True if the browser can render emoji, false if it cannot.
|
|
*/
|
|
function browserSupportsEmoji( type ) {
|
|
var canvas = document.createElement( 'canvas' ),
|
|
context = canvas.getContext && canvas.getContext( '2d' ),
|
|
tone;
|
|
|
|
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';
|
|
|
|
if ( 'flag' === type ) {
|
|
/*
|
|
* This works because the image will be one of three things:
|
|
* - Two empty squares, if the browser doesn't render emoji
|
|
* - Two squares with 'A' and 'U' in them, if the browser doesn't render flag emoji
|
|
* - The Australian flag
|
|
*
|
|
* The first two will encode to small images (1-2KB data URLs), the third will encode
|
|
* to a larger image (4-5KB data URL).
|
|
*/
|
|
context.fillText( String.fromCharCode( 55356, 56806, 55356, 56826 ), 0, 0 );
|
|
return canvas.toDataURL().length > 3000;
|
|
} else if ( 'diversity' === type ) {
|
|
/*
|
|
* This tests if the browser supports the Emoji Diversity specification, by rendering an
|
|
* emoji with no skin tone specified (in this case, Santa). It then adds a skin tone, and
|
|
* compares if the emoji rendering has changed.
|
|
*/
|
|
context.fillText( String.fromCharCode( 55356, 57221 ), 0, 0 );
|
|
tone = context.getImageData( 16, 16, 1, 1 ).data.toString();
|
|
context.fillText( String.fromCharCode( 55356, 57221, 55356, 57343 ), 0, 0 );
|
|
// Chrome has issues comparing arrays, so we compare it as a string, instead.
|
|
return tone !== context.getImageData( 16, 16, 1, 1 ).data.toString();
|
|
} else {
|
|
if ( 'simple' === type ) {
|
|
/*
|
|
* This creates a smiling emoji, and checks to see if there is any image data in the
|
|
* center pixel. In browsers that don't support emoji, the character will be rendered
|
|
* as an empty square, so the center pixel will be blank.
|
|
*/
|
|
context.fillText( String.fromCharCode( 55357, 56835 ), 0, 0 );
|
|
} else {
|
|
/*
|
|
* To check for Unicode 8 support, let's try rendering the most important advancement
|
|
* that the Unicode Consortium have made in years: the burrito.
|
|
*/
|
|
context.fillText( String.fromCharCode( 55356, 57135 ), 0, 0 );
|
|
}
|
|
return context.getImageData( 16, 16, 1, 1 ).data[0] !== 0;
|
|
}
|
|
}
|
|
|
|
function addScript( src ) {
|
|
var script = document.createElement( 'script' );
|
|
|
|
script.src = src;
|
|
script.type = 'text/javascript';
|
|
document.getElementsByTagName( 'head' )[0].appendChild( script );
|
|
}
|
|
|
|
settings.supports = {
|
|
simple: browserSupportsEmoji( 'simple' ),
|
|
flag: browserSupportsEmoji( 'flag' ),
|
|
unicode8: browserSupportsEmoji( 'unicode8' ),
|
|
diversity: browserSupportsEmoji( 'diversity' )
|
|
};
|
|
|
|
settings.DOMReady = false;
|
|
settings.readyCallback = function() {
|
|
settings.DOMReady = true;
|
|
};
|
|
|
|
if ( ! settings.supports.simple || ! settings.supports.flag || ! settings.supports.unicode8 || ! settings.supports.diversity ) {
|
|
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 );
|