( 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 "simple", "flag", "diversity" or "unicode8" emoji.
+ * @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 canvas = document.createElement( 'canvas' ),
- context = canvas.getContext && canvas.getContext( '2d' ),
- stringFromCharCode = String.fromCharCode,
- flag, flag2, tonedata, tone, tone2;
+ var stringFromCharCode = String.fromCharCode,
+ flag, flag2, technologist, technologist2;
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
/*
* 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
+ * - Two squares with 'U' and 'N' in them, if the browser doesn't render flag emoji
+ * - The United Nations 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( stringFromCharCode( 55356, 56806, 55356, 56826 ), 0, 0 );
+ context.fillText( stringFromCharCode( 55356, 56826, 55356, 56819 ), 0, 0 );
if ( canvas.toDataURL().length < 3000 ) {
return false;
}
flag2 = canvas.toDataURL();
return flag !== flag2;
- case 'diversity':
- /*
- * 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( stringFromCharCode( 55356, 57221 ), 0, 0 );
- tonedata = context.getImageData( 16, 16, 1, 1 ).data;
- tone = tonedata[0] + ',' + tonedata[1] + ',' + tonedata[2] + ',' + tonedata[3];
-
- context.fillText( stringFromCharCode( 55356, 57221, 55356, 57343 ), 0, 0 );
- // Chrome has issues comparing arrays, and Safari has issues converting arrays to strings.
- // So, we create our own string and compare that, instead.
- tonedata = context.getImageData( 16, 16, 1, 1 ).data;
- tone2 = tonedata[0] + ',' + tonedata[1] + ',' + tonedata[2] + ',' + tonedata[3];
-
- return tone !== tone2;
- case 'simple':
- /*
- * 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( stringFromCharCode( 55357, 56835 ), 0, 0 );
- return context.getImageData( 16, 16, 1, 1 ).data[0] !== 0;
- case 'unicode8':
+ case 'emoji4':
/*
- * 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( stringFromCharCode( 55356, 57135 ), 0, 0 );
- return context.getImageData( 16, 16, 1, 1 ).data[0] !== 0;
- case 'unicode9':
- /*
- * Do Unicode 9 emoji render?
- * ¯\_(ツ)_/¯
+ * Emoji 4 has the best technologists. So does WordPress!
+ *
+ * To test for support, try to render a new emoji (woman technologist: medium skin tone),
+ * then compare it to how it would look if the browser doesn't render it correctly
+ * (woman technologist: medium skin tone + personal computer).
*/
- context.fillText( stringFromCharCode( 55358, 56631 ), 0, 0 );
- return context.getImageData( 16, 16, 1, 1 ).data[0] !== 0;
+ context.fillText( stringFromCharCode( 55357, 56425, 55356, 57341, 8205, 55357, 56507), 0, 0 );
+ technologist = canvas.toDataURL();
+
+ context.clearRect( 0, 0, canvas.width, canvas.height );
+
+ context.fillText( stringFromCharCode( 55357, 56425, 55356, 57341, 55357, 56507), 0, 0 );
+ technologist2 = canvas.toDataURL();
+
+ return technologist !== technologist2;
}
return false;
var script = document.createElement( 'script' );
script.src = src;
- script.type = 'text/javascript';
+ script.defer = script.type = 'text/javascript';
document.getElementsByTagName( 'head' )[0].appendChild( script );
}
- tests = Array( 'simple', 'flag', 'unicode8', 'diversity', 'unicode9' );
+ tests = Array( 'flag', 'emoji4' );
settings.supports = {
everything: true,
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