( function( window, document, settings ) {
- var src;
+ 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
*
* @since 4.2.0
*
- * @param type {String} Whether to test for support of "simple" or "flag" 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' );
+ 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
context.textBaseline = 'top';
context.font = '600 32px Arial';
- if ( type === 'flag' ) {
- /*
- * This works because the image will be one of three things:
- * - Two empty squares, if the browser doesn't render emoji
- * - Two squares with 'G' and 'B' in them, if the browser doesn't render flag emoji
- * - The British 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, 56812, 55356, 56807 ), 0, 0 );
- return canvas.toDataURL().length > 3000;
- } else {
- /*
- * 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 );
- return context.getImageData( 16, 16, 1, 1 ).data[0] !== 0;
+ switch ( type ) {
+ case 'flag':
+ /*
+ * This works because the image will be one of three things:
+ * - Two empty squares, if the browser doesn't render emoji
+ * - 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, 56826, 55356, 56819 ), 0, 0 );
+ if ( canvas.toDataURL().length < 3000 ) {
+ return false;
+ }
+
+ context.clearRect( 0, 0, canvas.width, canvas.height );
+
+ /*
+ * Test for rainbow flag compatibility. As the rainbow flag was added out of sequence with
+ * the usual Unicode release cycle, some browsers support it, and some don't, even if their
+ * Unicode support is up to date.
+ *
+ * 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 + rainbow emoji).
+ */
+ context.fillText( stringFromCharCode( 55356, 57331, 65039, 8205, 55356, 57096 ), 0, 0 );
+ flag = canvas.toDataURL();
+
+ context.clearRect( 0, 0, canvas.width, canvas.height );
+
+ context.fillText( stringFromCharCode( 55356, 57331, 55356, 57096 ), 0, 0 );
+ flag2 = canvas.toDataURL();
+
+ return flag !== flag2;
+ case 'emoji4':
+ /*
+ * 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( 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;
}
function addScript( src ) {
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( 'flag', 'emoji4' );
+
settings.supports = {
- simple: browserSupportsEmoji( 'simple' ),
- flag: browserSupportsEmoji( 'flag' )
+ everything: true,
+ everythingExceptFlag: true
};
- if ( ! settings.supports.simple || ! settings.supports.flag ) {
+ 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 ) {
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