TextSourceElement surrogate pair support (#2217)

* Update StringUtil

* Refactor

* Handle UTF-16 surrogate pairs
This commit is contained in:
toasted-nutbread 2022-08-20 14:32:34 -04:00 committed by GitHub
parent 4194252fe3
commit e7944d29b0
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 27 additions and 18 deletions

View File

@ -27,16 +27,19 @@ class StringUtil {
* @returns {string} The code points from the string. * @returns {string} The code points from the string.
*/ */
static readCodePointsForward(text, position, count) { static readCodePointsForward(text, position, count) {
const textLength = text.length;
let result = ''; let result = '';
for (; count > 0; --count) { for (; count > 0; --count) {
const char = text[position]; const char = text[position];
const charCode = char.charCodeAt(0);
result += char; result += char;
if (charCode >= 0xd800 && charCode < 0xdc00 && ++position < text.length) { if (++position >= textLength) { break; }
const charCode = char.charCodeAt(0);
if (charCode >= 0xd800 && charCode < 0xdc00) {
const char2 = text[position]; const char2 = text[position];
const charCode2 = char2.charCodeAt(0); const charCode2 = char2.charCodeAt(0);
if (charCode2 >= 0xdc00 && charCode2 < 0xe000) { if (charCode2 >= 0xdc00 && charCode2 < 0xe000) {
result += char2; result += char2;
if (++position >= textLength) { break; }
} }
} }
} }
@ -54,13 +57,15 @@ class StringUtil {
let result = ''; let result = '';
for (; count > 0; --count) { for (; count > 0; --count) {
const char = text[position]; const char = text[position];
const charCode = char.charCodeAt(0);
result = char + result; result = char + result;
if (charCode >= 0xdc00 && charCode < 0xe000 && position > 0) { if (--position < 0) { break; }
const char2 = text[position - 1]; const charCode = char.charCodeAt(0);
if (charCode >= 0xdc00 && charCode < 0xe000) {
const char2 = text[position];
const charCode2 = char2.charCodeAt(0); const charCode2 = char2.charCodeAt(0);
if (charCode2 >= 0xd800 && charCode2 < 0xdc00) { if (charCode2 >= 0xd800 && charCode2 < 0xdc00) {
result = char2 + result; result = char2 + result;
if (--position < 0) { break; }
} }
} }
} }

View File

@ -15,6 +15,10 @@
* along with this program. If not, see <https://www.gnu.org/licenses/>. * along with this program. If not, see <https://www.gnu.org/licenses/>.
*/ */
/* global
* StringUtil
*/
class TextSourceElement { class TextSourceElement {
constructor(element, fullContent=null, startOffset=0, endOffset=0) { constructor(element, fullContent=null, startOffset=0, endOffset=0) {
this._element = element; this._element = element;
@ -61,24 +65,24 @@ class TextSourceElement {
} }
setEndOffset(length, _layoutAwareScan, fromEnd) { setEndOffset(length, _layoutAwareScan, fromEnd) {
if (fromEnd) { const offset = fromEnd ? this._endOffset : this._startOffset;
const delta = Math.min(this._fullContent.length - this._endOffset, length); length = Math.min(this._fullContent.length - offset, length);
this._endOffset += delta; if (length > 0) {
this._content = this._fullContent.substring(this._startOffset, this._endOffset); length = StringUtil.readCodePointsForward(this._fullContent, offset, length).length;
return delta;
} else {
const delta = Math.min(this._fullContent.length - this._startOffset, length);
this._endOffset = this._startOffset + delta;
this._content = this._fullContent.substring(this._startOffset, this._endOffset);
return delta;
} }
this._endOffset = offset + length;
this._content = this._fullContent.substring(this._startOffset, this._endOffset);
return length;
} }
setStartOffset(length) { setStartOffset(length) {
const delta = Math.min(this._startOffset, length); length = Math.min(this._startOffset, length);
this._startOffset -= delta; if (length > 0) {
length = StringUtil.readCodePointsBackward(this._fullContent, this._startOffset - 1, length).length;
}
this._startOffset -= length;
this._content = this._fullContent.substring(this._startOffset, this._endOffset); this._content = this._fullContent.substring(this._startOffset, this._endOffset);
return delta; return length;
} }
collapse(toStart) { collapse(toStart) {