yomichan/ext/js/dom/text-source-element.js
toasted-nutbread e7944d29b0
TextSourceElement surrogate pair support (#2217)
* Update StringUtil

* Refactor

* Handle UTF-16 surrogate pairs
2022-08-20 14:32:34 -04:00

159 lines
4.3 KiB
JavaScript

/*
* Copyright (C) 2016-2022 Yomichan Authors
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* 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;
this._fullContent = (typeof fullContent === 'string' ? fullContent : TextSourceElement.getElementContent(element));
this._startOffset = startOffset;
this._endOffset = endOffset;
this._content = this._fullContent.substring(this._startOffset, this._endOffset);
}
get type() {
return 'element';
}
get element() {
return this._element;
}
get fullContent() {
return this._fullContent;
}
get startOffset() {
return this._startOffset;
}
get endOffset() {
return this._endOffset;
}
get isConnected() {
return this._element.isConnected;
}
clone() {
return new TextSourceElement(this._element, this._fullContent, this._startOffset, this._endOffset);
}
cleanup() {
// NOP
}
text() {
return this._content;
}
setEndOffset(length, _layoutAwareScan, fromEnd) {
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) {
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 length;
}
collapse(toStart) {
if (toStart) {
this._endOffset = this._startOffset;
} else {
this._startOffset = this._endOffset;
}
this._content = '';
}
getRect() {
return this._element.getBoundingClientRect();
}
getRects() {
return this._element.getClientRects();
}
getWritingMode() {
return 'horizontal-tb';
}
select() {
// NOP
}
deselect() {
// NOP
}
hasSameStart(other) {
return (
typeof other === 'object' &&
other !== null &&
other instanceof TextSourceElement &&
this._element === other.element &&
this._fullContent === other.fullContent &&
this._startOffset === other.startOffset
);
}
getNodesInRange() {
return [this._element];
}
static getElementContent(element) {
let content;
switch (element.nodeName.toUpperCase()) {
case 'BUTTON':
content = element.textContent;
break;
case 'IMG':
content = element.getAttribute('alt') || '';
break;
case 'SELECT':
{
const {selectedIndex, options} = element;
const option = (selectedIndex >= 0 && selectedIndex < options.length ? options[selectedIndex] : null);
content = (option !== null ? option.textContent : '');
}
break;
default:
content = `${element.value}`;
break;
}
// Remove zero-width space and zero-width non-joiner
content = content.replace(/[\u200b\u200c]/g, '');
return content;
}
}