yomichan/ext/fg/js/source-range.js
2017-05-22 21:07:25 -07:00

177 lines
5.8 KiB
JavaScript

/*
* Copyright (C) 2016 Alex Yatskov <alex@foosoft.net>
* Author: Alex Yatskov <alex@foosoft.net>
*
* 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 <http://www.gnu.org/licenses/>.
*/
class TextSourceRange {
constructor(range, content='') {
this.range = range;
this.content = content;
}
clone() {
return new TextSourceRange(this.range.cloneRange(), this.content);
}
text() {
return this.content;
}
setEndOffset(length) {
const state = TextSourceRange.seekForward(this.range.startContainer, this.range.startOffset, length);
this.range.setEnd(state.node, state.offset);
this.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.content = state.content;
return length - state.remainder;
}
containsPoint(point) {
const rect = this.getPaddedRect();
return point.x >= rect.left && point.x <= rect.right;
}
getRect() {
return this.range.getBoundingClientRect();
}
getPaddedRect() {
const range = this.range.cloneRange();
const startOffset = range.startOffset;
const endOffset = range.endOffset;
const node = range.startContainer;
range.setStart(node, Math.max(0, startOffset - 1));
range.setEnd(node, Math.min(node.length, endOffset + 1));
return range.getBoundingClientRect();
}
select() {
const selection = window.getSelection();
selection.removeAllRanges();
selection.addRange(this.range);
}
deselect() {
const selection = window.getSelection();
selection.removeAllRanges();
}
equals(other) {
return other.range && other.range.compareBoundaryPoints(Range.START_TO_START, this.range) === 0;
}
static shouldEnter(node) {
if (node.nodeType !== 1) {
return false;
}
const skip = ['RT', 'SCRIPT', 'STYLE'];
if (skip.includes(node.nodeName)) {
return false;
}
const style = window.getComputedStyle(node);
const hidden =
style.visibility === 'hidden' ||
style.display === 'none' ||
parseFloat(style.fontSize) === 0;
return !hidden;
}
static seekForward(node, offset, length) {
const state = {node, offset, remainder: length, content: ''};
if (!TextSourceRange.seekForwardHelper(node, state)) {
return state;
}
for (let current = node; current !== null; current = current.parentElement) {
for (let sibling = current.nextSibling; sibling !== null; sibling = sibling.nextSibling) {
if (!TextSourceRange.seekForwardHelper(sibling, state)) {
return state;
}
}
}
return state;
}
static seekForwardHelper(node, state) {
if (node.nodeType === 3 && node.parentElement && TextSourceRange.shouldEnter(node.parentElement)) {
const offset = state.node === node ? state.offset : 0;
const remaining = node.length - offset;
const consumed = Math.min(remaining, state.remainder);
state.content = state.content + node.nodeValue.substring(offset, offset + consumed);
state.node = node;
state.offset = offset + consumed;
state.remainder -= consumed;
} else if (TextSourceRange.shouldEnter(node)) {
for (let i = 0; i < node.childNodes.length; ++i) {
if (!TextSourceRange.seekForwardHelper(node.childNodes[i], state)) {
break;
}
}
}
return state.remainder > 0;
}
static seekBackward(node, offset, length) {
const state = {node, offset, remainder: length, content: ''};
if (!TextSourceRange.seekBackwardHelper(node, state)) {
return state;
}
for (let current = node; current !== null; current = current.parentElement) {
for (let sibling = current.previousSibling; sibling !== null; sibling = sibling.previousSibling) {
if (!TextSourceRange.seekBackwardHelper(sibling, state)) {
return state;
}
}
}
return state;
}
static seekBackwardHelper(node, state) {
if (node.nodeType === 3 && node.parentElement && TextSourceRange.shouldEnter(node.parentElement)) {
const offset = state.node === node ? state.offset : node.length;
const remaining = offset;
const consumed = Math.min(remaining, state.remainder);
state.content = node.nodeValue.substring(offset - consumed, offset) + state.content;
state.node = node;
state.offset = offset - consumed;
state.remainder -= consumed;
} else if (TextSourceRange.shouldEnter(node)) {
for (let i = node.childNodes.length - 1; i >= 0; --i) {
if (!TextSourceRange.seekBackwardHelper(node.childNodes[i], state)) {
break;
}
}
}
return state.remainder > 0;
}
}