yomichan/ext/fg/js/source.js
toasted-nutbread e23504613f
Use DOMTextScanner (#536)
* Use DOMTextScanner instead of TextSourceRange.seek*

* Move getNodesInRange to dom.js

* Move anyNodeMatchesSelector to dom.js

* Remove unused functions

* Update tests

* Add layoutAwareScan option

* Use layoutAwareScan for source and sentence scanning

* Remove unused IGNORE_TEXT_PATTERN
2020-06-21 16:07:51 -04:00

258 lines
7.5 KiB
JavaScript

/*
* Copyright (C) 2016-2020 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
* DOMTextScanner
*/
/*
* TextSourceRange
*/
class TextSourceRange {
constructor(range, content, imposterContainer, imposterSourceElement) {
this.range = range;
this.rangeStartOffset = range.startOffset;
this.content = content;
this.imposterContainer = imposterContainer;
this.imposterSourceElement = imposterSourceElement;
}
clone() {
return new TextSourceRange(this.range.cloneRange(), this.content, this.imposterContainer, this.imposterSourceElement);
}
cleanup() {
if (this.imposterContainer !== null && this.imposterContainer.parentNode !== null) {
this.imposterContainer.parentNode.removeChild(this.imposterContainer);
}
}
text() {
return this.content;
}
setEndOffset(length, layoutAwareScan, fromEnd=false) {
const state = (
fromEnd ?
new DOMTextScanner(this.range.endContainer, this.range.endOffset, !layoutAwareScan, layoutAwareScan).seek(length) :
new DOMTextScanner(this.range.startContainer, this.range.startOffset, !layoutAwareScan, layoutAwareScan).seek(length)
);
this.range.setEnd(state.node, state.offset);
this.content = (fromEnd ? this.content + state.content : state.content);
return length - state.remainder;
}
setStartOffset(length, layoutAwareScan) {
const state = new DOMTextScanner(this.range.startContainer, this.range.startOffset, !layoutAwareScan, layoutAwareScan).seek(-length);
this.range.setStart(state.node, state.offset);
this.rangeStartOffset = this.range.startOffset;
this.content = state.content + this.content;
return length - state.remainder;
}
getRect() {
return this.range.getBoundingClientRect();
}
getWritingMode() {
return TextSourceRange.getElementWritingMode(TextSourceRange.getParentElement(this.range.startContainer));
}
select() {
const selection = window.getSelection();
selection.removeAllRanges();
selection.addRange(this.range);
}
deselect() {
const selection = window.getSelection();
selection.removeAllRanges();
}
equals(other) {
if (!(
typeof other === 'object' &&
other !== null &&
other instanceof TextSourceRange
)) {
return false;
}
if (this.imposterSourceElement !== null) {
return (
this.imposterSourceElement === other.imposterSourceElement &&
this.rangeStartOffset === other.rangeStartOffset
);
} else {
try {
return this.range.compareBoundaryPoints(Range.START_TO_START, other.range) === 0;
} catch (e) {
if (e.name === 'WrongDocumentError') {
// This can happen with shadow DOMs if the ranges are in different documents.
return false;
}
throw e;
}
}
}
static getParentElement(node) {
while (node !== null && node.nodeType !== Node.ELEMENT_NODE) {
node = node.parentNode;
}
return node;
}
static getElementWritingMode(element) {
if (element !== null) {
const style = window.getComputedStyle(element);
const writingMode = style.writingMode;
if (typeof writingMode === 'string') {
return TextSourceRange.normalizeWritingMode(writingMode);
}
}
return 'horizontal-tb';
}
static normalizeWritingMode(writingMode) {
switch (writingMode) {
case 'lr':
case 'lr-tb':
case 'rl':
return 'horizontal-tb';
case 'tb':
return 'vertical-lr';
case 'tb-rl':
return 'vertical-rl';
default:
return writingMode;
}
}
}
/*
* TextSourceElement
*/
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 element() {
return this._element;
}
get fullContent() {
return this._fullContent;
}
get startOffset() {
return this._startOffset;
}
get endOffset() {
return this._endOffset;
}
clone() {
return new TextSourceElement(this._element, this._fullContent, this._startOffset, this._endOffset);
}
cleanup() {
// NOP
}
text() {
return this._content;
}
setEndOffset(length, fromEnd=false) {
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;
}
}
setStartOffset(length) {
const delta = Math.min(this._startOffset, length);
this._startOffset -= delta;
this._content = this._fullContent.substring(this._startOffset, this._endOffset);
return delta;
}
getRect() {
return this._element.getBoundingClientRect();
}
getWritingMode() {
return 'horizontal-tb';
}
select() {
// NOP
}
deselect() {
// NOP
}
equals(other) {
return (
typeof other === 'object' &&
other !== null &&
other instanceof TextSourceElement &&
this._element === other.element &&
this._fullContent === other.fullContent &&
this._startOffset === other.startOffset &&
this._endOffset === other.endOffset
);
}
static getElementContent(element) {
let content;
switch (element.nodeName.toUpperCase()) {
case 'BUTTON':
content = element.textContent;
break;
case 'IMG':
content = element.getAttribute('alt') || '';
break;
default:
content = `${element.value}`;
break;
}
// Remove zero-width non-joiner
content = content.replace(/\u200c/g, '');
return content;
}
}