/* * Copyright (C) 2020-2021 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 * FrameAncestryHandler * api */ class FrameOffsetForwarder { constructor(frameId) { this._frameId = frameId; this._frameAncestryHandler = new FrameAncestryHandler(frameId); } prepare() { this._frameAncestryHandler.prepare(); api.crossFrame.registerHandlers([ ['FrameOffsetForwarder.getChildFrameRect', {async: false, handler: this._onMessageGetChildFrameRect.bind(this)}] ]); } async getOffset() { if (this._frameAncestryHandler.isRootFrame()) { return [0, 0]; } const ancestorFrameIds = await this._frameAncestryHandler.getFrameAncestryInfo(); let childFrameId = this._frameId; const promises = []; for (const frameId of ancestorFrameIds) { promises.push(api.crossFrame.invoke(frameId, 'FrameOffsetForwarder.getChildFrameRect', {frameId: childFrameId})); childFrameId = frameId; } const results = await Promise.all(promises); let xOffset = 0; let yOffset = 0; for (const {x, y} of results) { xOffset += x; yOffset += y; } return [xOffset, yOffset]; } // Private _onMessageGetChildFrameRect({frameId}) { const frameElement = this._frameAncestryHandler.getChildFrameElement(frameId); if (frameElement === null) { return null; } const {x, y, width, height} = frameElement.getBoundingClientRect(); return {x, y, width, height}; } }