From e7944d29b0380d46e44cc316e10a3088e9da3a8c Mon Sep 17 00:00:00 2001
From: toasted-nutbread <toasted-nutbread@users.noreply.github.com>
Date: Sat, 20 Aug 2022 14:32:34 -0400
Subject: TextSourceElement surrogate pair support (#2217)
* Update StringUtil
* Refactor
* Handle UTF-16 surrogate pairs
---
ext/js/data/sandbox/string-util.js | 15 ++++++++++-----
ext/js/dom/text-source-element.js | 30 +++++++++++++++++-------------
2 files changed, 27 insertions(+), 18 deletions(-)
(limited to 'ext')
diff --git a/ext/js/data/sandbox/string-util.js b/ext/js/data/sandbox/string-util.js
index 65d73eef..72b8fc7f 100644
--- a/ext/js/data/sandbox/string-util.js
+++ b/ext/js/data/sandbox/string-util.js
@@ -27,16 +27,19 @@ class StringUtil {
* @returns {string} The code points from the string.
*/
static readCodePointsForward(text, position, count) {
+ const textLength = text.length;
let result = '';
for (; count > 0; --count) {
const char = text[position];
- const charCode = char.charCodeAt(0);
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 charCode2 = char2.charCodeAt(0);
if (charCode2 >= 0xdc00 && charCode2 < 0xe000) {
result += char2;
+ if (++position >= textLength) { break; }
}
}
}
@@ -54,13 +57,15 @@ class StringUtil {
let result = '';
for (; count > 0; --count) {
const char = text[position];
- const charCode = char.charCodeAt(0);
result = char + result;
- if (charCode >= 0xdc00 && charCode < 0xe000 && position > 0) {
- const char2 = text[position - 1];
+ if (--position < 0) { break; }
+ const charCode = char.charCodeAt(0);
+ if (charCode >= 0xdc00 && charCode < 0xe000) {
+ const char2 = text[position];
const charCode2 = char2.charCodeAt(0);
if (charCode2 >= 0xd800 && charCode2 < 0xdc00) {
result = char2 + result;
+ if (--position < 0) { break; }
}
}
}
diff --git a/ext/js/dom/text-source-element.js b/ext/js/dom/text-source-element.js
index 257b9df4..fe3fe083 100644
--- a/ext/js/dom/text-source-element.js
+++ b/ext/js/dom/text-source-element.js
@@ -15,6 +15,10 @@
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
+/* global
+ * StringUtil
+ */
+
class TextSourceElement {
constructor(element, fullContent=null, startOffset=0, endOffset=0) {
this._element = element;
@@ -61,24 +65,24 @@ class TextSourceElement {
}
setEndOffset(length, _layoutAwareScan, fromEnd) {
- if (fromEnd) {
- const delta = Math.min(this._fullContent.length - this._endOffset, length);
- this._endOffset += delta;
- this._content = this._fullContent.substring(this._startOffset, this._endOffset);
- 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;
+ const offset = fromEnd ? this._endOffset : this._startOffset;
+ length = Math.min(this._fullContent.length - offset, length);
+ if (length > 0) {
+ length = StringUtil.readCodePointsForward(this._fullContent, offset, length).length;
}
+ this._endOffset = offset + length;
+ this._content = this._fullContent.substring(this._startOffset, this._endOffset);
+ return length;
}
setStartOffset(length) {
- const delta = Math.min(this._startOffset, length);
- this._startOffset -= delta;
+ length = Math.min(this._startOffset, length);
+ 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);
- return delta;
+ return length;
}
collapse(toStart) {
--
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