'blur.byteLimit'
].join( ' ' );
+ // Like String#charAt, but return the pair of UTF-16 surrogates for characters outside of BMP.
+ function codePointAt( string, offset, backwards ) {
+ // We don't need to check for offsets at the beginning or end of string,
+ // String#slice will simply return a shorter (or empty) substring.
+ var maybePair = backwards ?
+ string.slice( offset - 1, offset + 1 ) :
+ string.slice( offset, offset + 2 );
+ if ( /^[\uD800-\uDBFF][\uDC00-\uDFFF]$/.test( maybePair ) ) {
+ return maybePair;
+ } else {
+ return string.charAt( offset );
+ }
+ }
+
/**
* Utility function to trim down a string, based on byteLimit
* and given a safe start position. It supports insertion anywhere
* @return {boolean} return.trimmed
*/
$.trimByteLength = function ( safeVal, newVal, byteLimit, fn ) {
- var startMatches, endMatches, matchesLen, inpParts,
+ var startMatches, endMatches, matchesLen, inpParts, chopOff, oldChar, newChar,
oldVal = safeVal;
// Run the hook if one was provided, but only on the length
// Count same characters from the left, first.
// (if "foo" -> "foofoo", assume addition was at the end).
- while (
- startMatches < matchesLen &&
- oldVal.charAt( startMatches ) === newVal.charAt( startMatches )
- ) {
- startMatches += 1;
+ while ( startMatches < matchesLen ) {
+ oldChar = codePointAt( oldVal, startMatches, false );
+ newChar = codePointAt( newVal, startMatches, false );
+ if ( oldChar !== newChar ) {
+ break;
+ }
+ startMatches += oldChar.length;
}
- while (
- endMatches < ( matchesLen - startMatches ) &&
- oldVal.charAt( oldVal.length - 1 - endMatches ) === newVal.charAt( newVal.length - 1 - endMatches )
- ) {
- endMatches += 1;
+ while ( endMatches < ( matchesLen - startMatches ) ) {
+ oldChar = codePointAt( oldVal, oldVal.length - 1 - endMatches, true );
+ newChar = codePointAt( newVal, newVal.length - 1 - endMatches, true );
+ if ( oldChar !== newChar ) {
+ break;
+ }
+ endMatches += oldChar.length;
}
inpParts = [
if ( fn ) {
// stop, when there is nothing to slice - T43450
while ( $.byteLength( fn( inpParts.join( '' ) ) ) > byteLimit && inpParts[ 1 ].length > 0 ) {
- inpParts[ 1 ] = inpParts[ 1 ].slice( 0, -1 );
+ // Do not chop off halves of surrogate pairs
+ chopOff = /[\uD800-\uDBFF][\uDC00-\uDFFF]$/.test( inpParts[ 1 ] ) ? 2 : 1;
+ inpParts[ 1 ] = inpParts[ 1 ].slice( 0, -chopOff );
}
} else {
while ( $.byteLength( inpParts.join( '' ) ) > byteLimit ) {
- inpParts[ 1 ] = inpParts[ 1 ].slice( 0, -1 );
+ // Do not chop off halves of surrogate pairs
+ chopOff = /[\uD800-\uDBFF][\uDC00-\uDFFF]$/.test( inpParts[ 1 ] ) ? 2 : 1;
+ inpParts[ 1 ] = inpParts[ 1 ].slice( 0, -chopOff );
}
}