yomichan/ext/fg/js/source-range.js

151 lines
4.6 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) {
this.rng = range;
}
clone() {
return new TextSourceRange(this.rng.cloneRange());
}
text() {
return this.rng.toString();
}
setEndOffset(length) {
const lengthAdj = length + this.rng.startOffset;
const state = TextSourceRange.seekForward(this.rng.startContainer, lengthAdj);
this.rng.setEnd(state.node, state.offset);
return length - state.length;
}
setStartOffset(length) {
const lengthAdj = length + (this.rng.startContainer.length - this.rng.startOffset);
const state = TextSourceRange.seekBackward(this.rng.startContainer, lengthAdj);
this.rng.setStart(state.node, state.offset);
return length - state.length;
}
containsPoint(point) {
const rect = this.getPaddedRect();
return point.x >= rect.left && point.x <= rect.right;
}
getRect() {
return this.rng.getBoundingClientRect();
}
getPaddedRect() {
const range = this.rng.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.rng);
}
deselect() {
const selection = window.getSelection();
selection.removeAllRanges();
}
equals(other) {
return other.rng && other.rng.compareBoundaryPoints(Range.START_TO_START, this.rng) === 0;
}
static seekForward(node, length) {
const state = {node, offset: 0, length};
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) {
const consumed = Math.min(node.length, state.length);
state.node = node;
state.offset = consumed;
state.length -= consumed;
} else {
for (let i = 0; i < node.childNodes.length; ++i) {
if (!TextSourceRange.seekForwardHelper(node.childNodes[i], state)) {
break;
}
}
}
return state.length > 0;
}
static seekBackward(node, length) {
const state = {node, offset: node.length, length};
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) {
const consumed = Math.min(node.length, state.length);
state.node = node;
state.offset = node.length - consumed;
state.length -= consumed;
} else {
for (let i = node.childNodes.length - 1; i >= 0; --i) {
if (!TextSourceRange.seekBackwardHelper(node.childNodes[i], state)) {
break;
}
}
}
return state.length > 0;
}
}