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-rw-r--r--ext/fg/js/frame-ancestry-handler.js196
1 files changed, 196 insertions, 0 deletions
diff --git a/ext/fg/js/frame-ancestry-handler.js b/ext/fg/js/frame-ancestry-handler.js
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+/*
+ * Copyright (C) 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
+ * api
+ */
+
+/**
+ * This class is used to return the ancestor frame IDs for the current frame.
+ * This is a workaround to using the `webNavigation.getAllFrames` API, which
+ * would require an additional permission that is otherwise unnecessary.
+ */
+class FrameAncestryHandler {
+ /**
+ * Creates a new instance.
+ * @param frameId The frame ID of the current frame the instance is instantiated in.
+ */
+ constructor(frameId) {
+ this._frameId = frameId;
+ this._isPrepared = false;
+ this._requestMessageId = 'FrameAncestryHandler.requestFrameInfo';
+ this._responseMessageId = `${this._requestMessageId}.response`;
+ }
+
+ /**
+ * Gets the frame ID that the instance is instantiated in.
+ */
+ get frameId() {
+ return this._frameId;
+ }
+
+ /**
+ * Initializes event event listening.
+ */
+ prepare() {
+ if (this._isPrepared) { return; }
+ window.addEventListener('message', this._onWindowMessage.bind(this), false);
+ this._isPrepared = true;
+ }
+
+ /**
+ * Gets the frame ancestry information for the current frame. If the frame is the
+ * root frame, an empty array is returned. Otherwise, an array of frame IDs is returned,
+ * starting from the nearest ancestor.
+ * @param timeout The maximum time to wait to receive a response to frame information requests.
+ * @returns An array of frame IDs corresponding to the ancestors of the current frame.
+ */
+ getFrameAncestryInfo(timeout=5000) {
+ return new Promise((resolve, reject) => {
+ const targetWindow = window.parent;
+ if (window === targetWindow) {
+ resolve([]);
+ return;
+ }
+
+ const uniqueId = generateId(16);
+ const responseMessageId = this._responseMessageId;
+ const results = [];
+ let resultsExpectedCount = null;
+ let resultsCount = 0;
+ let timer = null;
+
+ const cleanup = () => {
+ if (timer !== null) {
+ clearTimeout(timer);
+ timer = null;
+ }
+ chrome.runtime.onMessage.removeListener(onMessage);
+ };
+ const onMessage = (message, sender, sendResponse) => {
+ // Validate message
+ if (
+ typeof message !== 'object' ||
+ message === null ||
+ message.action !== responseMessageId
+ ) {
+ return;
+ }
+
+ const {params} = message;
+ if (params.uniqueId !== uniqueId) { return; } // Wrong ID
+
+ const {frameId, index, more} = params;
+ console.log({frameId, index, more});
+ if (typeof results[index] !== 'undefined') { return; } // Invalid repeat
+
+ // Add result
+ results[index] = frameId;
+ ++resultsCount;
+ if (!more) {
+ resultsExpectedCount = index + 1;
+ }
+
+ if (resultsExpectedCount !== null && resultsCount >= resultsExpectedCount) {
+ // Cleanup
+ cleanup();
+ sendResponse();
+
+ // Finish
+ resolve(results);
+ } else {
+ resetTimeout();
+ }
+ };
+ const onTimeout = () => {
+ timer = null;
+ cleanup();
+ reject(new Error(`Request for parent frame ID timed out after ${timeout}ms`));
+ };
+ const resetTimeout = () => {
+ if (timer !== null) { clearTimeout(timer); }
+ timer = setTimeout(onTimeout, timeout);
+ };
+
+ // Start
+ chrome.runtime.onMessage.addListener(onMessage);
+ resetTimeout();
+ this._requestFrameInfo(targetWindow, uniqueId, this._frameId, 0);
+ });
+ }
+
+ // Private
+
+ _onWindowMessage(event) {
+ const {data} = event;
+ if (
+ typeof data === 'object' &&
+ data !== null &&
+ data.action === this._requestMessageId
+ ) {
+ try {
+ this._onRequestFrameInfo(data.params);
+ } catch (e) {
+ // NOP
+ }
+ }
+ }
+
+ _onRequestFrameInfo({uniqueId, originFrameId, index}) {
+ if (
+ typeof uniqueId !== 'string' ||
+ typeof originFrameId !== 'number' ||
+ !this._isNonNegativeInteger(index)
+ ) {
+ return;
+ }
+
+ const {parent} = window;
+ const more = (window !== parent);
+
+ const responseParams = {uniqueId, frameId: this._frameId, index, more};
+ this._safeSendMessageToFrame(originFrameId, this._responseMessageId, responseParams);
+
+ if (more) {
+ this._requestFrameInfo(parent, uniqueId, originFrameId, index + 1);
+ }
+ }
+
+ async _safeSendMessageToFrame(frameId, action, params) {
+ try {
+ await api.sendMessageToFrame(frameId, action, params);
+ } catch (e) {
+ // NOP
+ }
+ }
+
+ _requestFrameInfo(targetWindow, uniqueId, originFrameId, index) {
+ targetWindow.postMessage({
+ action: this._requestMessageId,
+ params: {uniqueId, originFrameId, index}
+ }, '*');
+ }
+
+ _isNonNegativeInteger(value) {
+ return (
+ typeof value === 'number' &&
+ Number.isFinite(value) &&
+ value >= 0 &&
+ Math.floor(value) === value
+ );
+ }
+}