yomichan/ext/util.js

71 lines
2.1 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/>.
*/
function getRangeAtPoint(point, lookAhead) {
const range = document.caretRangeFromPoint(point.x, point.y);
if (range === null) {
return null;
}
const node = range.startContainer;
if (node.nodeType !== 3 /* TEXT_NODE */) {
return null;
}
const offset = range.startOffset;
const length = Math.min(node.length - offset, lookAhead);
if (length === 0) {
return null;
}
range.setEnd(node, offset + length);
return range;
}
function getRangePaddedRect(range) {
const node = range.startContainer;
const startOffset = range.startOffset;
const endOffset = range.endOffset;
range.setStart(node, Math.max(0, startOffset - 1));
range.setEnd(node, Math.min(node.length, endOffset + 1));
const rect = range.getBoundingClientRect();
range.setStart(node, startOffset);
range.setEnd(node, endOffset);
return rect;
}
function getPopupPositionForRange(popup, range, offset) {
const rangeRect = range.getBoundingClientRect();
const popupRect = popup.getBoundingClientRect();
let posX = rangeRect.left;
if (posX + popupRect.width >= window.innerWidth) {
posX = window.innerWidth - popupRect.width;
}
let posY = rangeRect.bottom + offset;
if (posY + popupRect.height >= window.innerHeight) {
posY = rangeRect.top - popupRect.height - offset;
}
return {x: posX, y: posY};
}