yomichan/ext/fg/js/source.js
toasted-nutbread 5752b23a8e
Text source refactor (#527)
* Update TextSourceElement API to have parity with TextSourceRange

* Make fields private

* Update equality check

* Fix "this.element" being used instead of just "element"
2020-05-10 14:06:25 -04:00

466 lines
13 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/>.
*/
// \u200c (Zero-width non-joiner) appears on Google Docs from Chrome 76 onwards
const IGNORE_TEXT_PATTERN = /\u200c/;
/*
* 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, fromEnd=false) {
const state = (
fromEnd ?
TextSourceRange.seekForward(this.range.endContainer, this.range.endOffset, length) :
TextSourceRange.seekForward(this.range.startContainer, this.range.startOffset, length)
);
this.range.setEnd(state.node, state.offset);
this.content = (fromEnd ? this.content + state.content : state.content);
return length - state.remainder;
}
setStartOffset(length) {
const state = TextSourceRange.seekBackward(this.range.startContainer, this.range.startOffset, 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 shouldEnter(node) {
switch (node.nodeName.toUpperCase()) {
case 'RT':
case 'SCRIPT':
case 'STYLE':
return false;
}
const style = window.getComputedStyle(node);
return !(
style.visibility === 'hidden' ||
style.display === 'none' ||
parseFloat(style.fontSize) === 0
);
}
static getRubyElement(node) {
node = TextSourceRange.getParentElement(node);
if (node !== null && node.nodeName.toUpperCase() === 'RT') {
node = node.parentNode;
return (node !== null && node.nodeName.toUpperCase() === 'RUBY') ? node : null;
}
return null;
}
static seekForward(node, offset, length) {
const state = {node, offset, remainder: length, content: ''};
if (length <= 0) {
return state;
}
const TEXT_NODE = Node.TEXT_NODE;
const ELEMENT_NODE = Node.ELEMENT_NODE;
let resetOffset = false;
const ruby = TextSourceRange.getRubyElement(node);
if (ruby !== null) {
node = ruby;
resetOffset = true;
}
while (node !== null) {
let visitChildren = true;
const nodeType = node.nodeType;
if (nodeType === TEXT_NODE) {
state.node = node;
if (TextSourceRange.seekForwardTextNode(state, resetOffset)) {
break;
}
resetOffset = true;
} else if (nodeType === ELEMENT_NODE) {
visitChildren = TextSourceRange.shouldEnter(node);
}
node = TextSourceRange.getNextNode(node, visitChildren);
}
return state;
}
static seekForwardTextNode(state, resetOffset) {
const nodeValue = state.node.nodeValue;
const nodeValueLength = nodeValue.length;
let content = state.content;
let offset = resetOffset ? 0 : state.offset;
let remainder = state.remainder;
let result = false;
for (; offset < nodeValueLength; ++offset) {
const c = nodeValue[offset];
if (!IGNORE_TEXT_PATTERN.test(c)) {
content += c;
if (--remainder <= 0) {
result = true;
++offset;
break;
}
}
}
state.offset = offset;
state.content = content;
state.remainder = remainder;
return result;
}
static seekBackward(node, offset, length) {
const state = {node, offset, remainder: length, content: ''};
if (length <= 0) {
return state;
}
const TEXT_NODE = Node.TEXT_NODE;
const ELEMENT_NODE = Node.ELEMENT_NODE;
let resetOffset = false;
const ruby = TextSourceRange.getRubyElement(node);
if (ruby !== null) {
node = ruby;
resetOffset = true;
}
while (node !== null) {
let visitChildren = true;
const nodeType = node.nodeType;
if (nodeType === TEXT_NODE) {
state.node = node;
if (TextSourceRange.seekBackwardTextNode(state, resetOffset)) {
break;
}
resetOffset = true;
} else if (nodeType === ELEMENT_NODE) {
visitChildren = TextSourceRange.shouldEnter(node);
}
node = TextSourceRange.getPreviousNode(node, visitChildren);
}
return state;
}
static seekBackwardTextNode(state, resetOffset) {
const nodeValue = state.node.nodeValue;
let content = state.content;
let offset = resetOffset ? nodeValue.length : state.offset;
let remainder = state.remainder;
let result = false;
for (; offset > 0; --offset) {
const c = nodeValue[offset - 1];
if (!IGNORE_TEXT_PATTERN.test(c)) {
content = c + content;
if (--remainder <= 0) {
result = true;
--offset;
break;
}
}
}
state.offset = offset;
state.content = content;
state.remainder = remainder;
return result;
}
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;
}
}
static getNodesInRange(range) {
const end = range.endContainer;
const nodes = [];
for (let node = range.startContainer; node !== null; node = TextSourceRange.getNextNode(node, true)) {
nodes.push(node);
if (node === end) { break; }
}
return nodes;
}
static getNextNode(node, visitChildren) {
let next = visitChildren ? node.firstChild : null;
if (next === null) {
while (true) {
next = node.nextSibling;
if (next !== null) { break; }
next = node.parentNode;
if (next === null) { break; }
node = next;
}
}
return next;
}
static getPreviousNode(node, visitChildren) {
let next = visitChildren ? node.lastChild : null;
if (next === null) {
while (true) {
next = node.previousSibling;
if (next !== null) { break; }
next = node.parentNode;
if (next === null) { break; }
node = next;
}
}
return next;
}
static anyNodeMatchesSelector(nodeList, selector) {
for (const node of nodeList) {
if (TextSourceRange.nodeMatchesSelector(node, selector)) {
return true;
}
}
return false;
}
static nodeMatchesSelector(node, selector) {
for (; node !== null; node = node.parentNode) {
if (node.nodeType === Node.ELEMENT_NODE) {
return node.matches(selector);
}
}
return false;
}
}
/*
* 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;
}
}