Changeset 41669

Timestamp:

10/02/2017 03:59:50 AM (8 years ago)

Author:

peterwilsoncc

Message:

Emoji: Refactor browser support tests.

Moves the repeated code in the emoji browser support test to a function to reduced the potential for errors and follow DRY principles.

Renames the "emoji4" test "emoji" as unicode version specific tests were removed in [38869].

Props peterwilsoncc, pento for code review.
Fixes #41156.

File:

• trunk/src/wp-includes/js/wp-emoji-loader.js (modified) (6 diffs)

trunk/src/wp-includes/js/wp-emoji-loader.js

@@ -10 +10 @@
 
     /**
+     * Check if two sets of Emoji characters render the same.
+     *
+     * @param set1 array Set of Emoji characters.
+     * @param set2 array Set of Emoji characters.
+     * @returns {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;
+    }
+
+    /**
      * 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.
@@ -15 +38 @@
      * @since 4.2.0
      *
-     * @param type {String} Whether to test for support of "flag" or "emoji4" emoji.
+     * @param type {String} 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 stringFromCharCode = String.fromCharCode,
-            flag, flag2, emoji41, emoji42;
+        var isIdentical;
 
         if ( ! context || ! context.fillText ) {
             return false;
         }
-
-        // Cleanup from previous test.
-        context.clearRect( 0, 0, canvas.width, canvas.height );
 
         /*
@@ -46 +65 @@
                  * the browser doesn't render it correctly ([U] + [N]).
                  */
-                context.fillText( stringFromCharCode( 55356, 56826, 55356, 56819 ), 0, 0 );
-                flag = canvas.toDataURL();
+                isIdentical = emojiSetsRenderIdentically(
+                    [ 55356, 56826, 55356, 56819 ],
+                    [ 55356, 56826, 8203, 55356, 56819 ]
+                );
 
-                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 ) {
+                if ( isIdentical ) {
                     return false;
                 }
@@ -66 +81 @@
                  * 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 );
+                isIdentical = emojiSetsRenderIdentically(
+                    [ 55356, 57332, 56128, 56423, 56128, 56418, 56128, 56421, 56128, 56430, 56128, 56423, 56128, 56447 ],
+                    [ 55356, 57332, 8203, 56128, 56423, 8203, 56128, 56418, 8203, 56128, 56421, 8203, 56128, 56430, 8203, 56128, 56423, 8203, 56128, 56447 ]
+                );
 
-                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':
+                return ! isIdentical;
+            case 'emoji':
                 /*
                  * Emoji 5 has fairies of all genders.
@@ -86 +95 @@
                  * (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;
+                isIdentical = emojiSetsRenderIdentically(
+                    [ 55358, 56794, 8205, 9794, 65039 ],
+                    [ 55358, 56794, 8203, 9794, 65039 ]
+                );
+                return ! isIdentical;
         }
 
@@ -108 +113 @@
     }
 
-    tests = Array( 'flag', 'emoji4' );
+    tests = Array( 'flag', 'emoji' );
 
     settings.supports = {