separate offscreen proxies from backend.js

2 files changed, 221 insertions, 155 deletions

diff --git a/ext/js/background/backend.js b/ext/js/background/backend.js
index c29e5ee6..bf4841f8 100644
--- a/ext/js/background/backend.js
+++ b/ext/js/background/backend.js
@@ -35,6 +35,7 @@ import {Translator} from '../language/translator.js';
 import {AudioDownloader} from '../media/audio-downloader.js';
 import {MediaUtil} from '../media/media-util.js';
 import {yomitan} from '../yomitan.js';
+import {OffscreenProxy, DictionaryDatabaseProxy, TranslatorProxy, ClipboardReaderProxy} from './offscreen-proxy.js';
 import {ProfileConditionsUtil} from './profile-conditions-util.js';
 import {RequestBuilder} from './request-builder.js';
 import {ScriptManager} from './script-manager.js';
@@ -66,23 +67,10 @@ export class Backend {
                 richContentPasteTargetSelector: '#clipboard-rich-content-paste-target'
             });
         } else {
-            this._dictionaryDatabase = {
-                prepare: () => this._sendMessagePromise({action: 'databasePrepareOffscreen'}),
-                getDictionaryInfo: () => this._sendMessagePromise({action: 'getDictionaryInfoOffscreen'}),
-                purge: () => this._sendMessagePromise({action: 'databasePurgeOffscreen'}),
-                getMedia: this._getMediaOffscreen.bind(this)
-            };
-            this._translator = {
-                prepare: (deinflectionReasons) => this._sendMessagePromise({action: 'translatorPrepareOffscreen', params: {deinflectionReasons}}),
-                findKanji: this._findKanjiOffscreen.bind(this),
-                findTerms: this._findTermsOffscreen.bind(this),
-                getTermFrequencies: this._getTermFrequenciesOffscreen.bind(this),
-                clearDatabaseCaches: () => this._sendMessagePromise({action: 'clearDatabaseCachesOffscreen'})
-            };
-            this._clipboardReader = {
-                getText: this._getTextOffscreen.bind(this),
-                getImage: this._getImageOffscreen.bind(this)
-            };
+            this._offscreen = new OffscreenProxy();
+            this._dictionaryDatabase = new DictionaryDatabaseProxy(this._offscreen);
+            this._translator = new TranslatorProxy(this._offscreen);
+            this._clipboardReader = new ClipboardReaderProxy(this._offscreen);
         }
 
         this._clipboardMonitor = new ClipboardMonitor({
@@ -119,8 +107,6 @@ export class Backend {
         this._permissions = null;
         this._permissionsUtil = new PermissionsUtil();
 
-        this._creatingOffscreen = null;
-
         this._messageHandlers = new Map([
             ['requestBackendReadySignal',    {async: false, contentScript: true,  handler: this._onApiRequestBackendReadySignal.bind(this)}],
             ['optionsGet',                   {async: false, contentScript: true,  handler: this._onApiOptionsGet.bind(this)}],
@@ -243,7 +229,7 @@ export class Backend {
             await this._requestBuilder.prepare();
             await this._environment.prepare();
             if (chrome.offscreen) {
-                await this._setupOffscreenDocument();
+                await this._offscreen.prepare();
             }
             this._clipboardReader.browser = this._environment.getInfo().browser;
 
@@ -767,6 +753,49 @@ export class Backend {
         }
     }
 
+    _onApiOpenCrossFramePort({targetTabId, targetFrameId}, sender) {
+        const sourceTabId = (sender && sender.tab ? sender.tab.id : null);
+        if (typeof sourceTabId !== 'number') {
+            throw new Error('Port does not have an associated tab ID');
+        }
+        const sourceFrameId = sender.frameId;
+        if (typeof sourceFrameId !== 'number') {
+            throw new Error('Port does not have an associated frame ID');
+        }
+
+        const sourceDetails = {
+            name: 'cross-frame-communication-port',
+            otherTabId: targetTabId,
+            otherFrameId: targetFrameId
+        };
+        const targetDetails = {
+            name: 'cross-frame-communication-port',
+            otherTabId: sourceTabId,
+            otherFrameId: sourceFrameId
+        };
+        let sourcePort = chrome.tabs.connect(sourceTabId, {frameId: sourceFrameId, name: JSON.stringify(sourceDetails)});
+        let targetPort = chrome.tabs.connect(targetTabId, {frameId: targetFrameId, name: JSON.stringify(targetDetails)});
+
+        const cleanup = () => {
+            this._checkLastError(chrome.runtime.lastError);
+            if (targetPort !== null) {
+                targetPort.disconnect();
+                targetPort = null;
+            }
+            if (sourcePort !== null) {
+                sourcePort.disconnect();
+                sourcePort = null;
+            }
+        };
+
+        sourcePort.onMessage.addListener((message) => { targetPort.postMessage(message); });
+        targetPort.onMessage.addListener((message) => { sourcePort.postMessage(message); });
+        sourcePort.onDisconnect.addListener(cleanup);
+        targetPort.onDisconnect.addListener(cleanup);
+
+        return {targetTabId, targetFrameId};
+    }
+
     // Command handlers
 
     async _onCommandOpenSearchPage(params) {
@@ -1637,20 +1666,6 @@ export class Backend {
         return await (json ? response.json() : response.text());
     }
 
-    _sendMessagePromise(...args) {
-        return new Promise((resolve, reject) => {
-            const callback = (response) => {
-                try {
-                    resolve(this._getMessageResponseResult(response));
-                } catch (error) {
-                    reject(error);
-                }
-            };
-
-            chrome.runtime.sendMessage(...args, callback);
-        });
-    }
-
     _sendMessageIgnoreResponse(...args) {
         const callback = () => this._checkLastError(chrome.runtime.lastError);
         chrome.runtime.sendMessage(...args, callback);
@@ -2252,125 +2267,4 @@ export class Backend {
         }
         return results;
     }
-
-    async _getMediaOffscreen(targets) {
-        const serializedMedia = await this._sendMessagePromise({action: 'databaseGetMediaOffscreen', params: {targets}});
-        const media = serializedMedia.map((m) => ({...m, content: ArrayBufferUtil.base64ToArrayBuffer(m.content)}));
-        return media;
-    }
-
-    async _findKanjiOffscreen(text, findKanjiOptions) {
-        const enabledDictionaryMapList = [...findKanjiOptions.enabledDictionaryMap];
-        const modifiedKanjiOptions = {
-            ...findKanjiOptions,
-            enabledDictionaryMap: enabledDictionaryMapList
-        };
-        return this._sendMessagePromise({action: 'findKanjiOffscreen', params: {text, findKanjiOptions: modifiedKanjiOptions}});
-    }
-
-    async _findTermsOffscreen(mode, text, findTermsOptions) {
-        const {enabledDictionaryMap, excludeDictionaryDefinitions, textReplacements} = findTermsOptions;
-        const enabledDictionaryMapList = [...enabledDictionaryMap];
-        const excludeDictionaryDefinitionsList = excludeDictionaryDefinitions ? [...excludeDictionaryDefinitions] : null;
-        const textReplacementsSerialized = textReplacements.map((group) => {
-            if (!group) {
-                return group;
-            }
-            return group.map((opt) => ({...opt, pattern: opt.pattern.toString()}));
-        });
-        const modifiedFindTermsOptions = {
-            ...findTermsOptions,
-            enabledDictionaryMap: enabledDictionaryMapList,
-            excludeDictionaryDefinitions: excludeDictionaryDefinitionsList,
-            textReplacementsOptions: textReplacementsSerialized
-        };
-        return this._sendMessagePromise({action: 'findTermsOffscreen', params: {mode, text, findTermsOptions: modifiedFindTermsOptions}});
-    }
-
-    async _getTermFrequenciesOffscreen(termReadingList, dictionaries) {
-        return this._sendMessagePromise({action: 'getTermFrequenciesOffscreen', params: {termReadingList, dictionaries}});
-    }
-
-    async _getTextOffscreen(useRichText) {
-        return this._sendMessagePromise({action: 'clipboardGetTextOffscreen', params: {useRichText}});
-    }
-
-    async _getImageOffscreen() {
-        return this._sendMessagePromise({action: 'clipboardGetImageOffscreen'});
-    }
-
-    _onApiOpenCrossFramePort({targetTabId, targetFrameId}, sender) {
-        const sourceTabId = (sender && sender.tab ? sender.tab.id : null);
-        if (typeof sourceTabId !== 'number') {
-            throw new Error('Port does not have an associated tab ID');
-        }
-        const sourceFrameId = sender.frameId;
-        if (typeof sourceFrameId !== 'number') {
-            throw new Error('Port does not have an associated frame ID');
-        }
-
-        const sourceDetails = {
-            name: 'cross-frame-communication-port',
-            otherTabId: targetTabId,
-            otherFrameId: targetFrameId
-        };
-        const targetDetails = {
-            name: 'cross-frame-communication-port',
-            otherTabId: sourceTabId,
-            otherFrameId: sourceFrameId
-        };
-        let sourcePort = chrome.tabs.connect(sourceTabId, {frameId: sourceFrameId, name: JSON.stringify(sourceDetails)});
-        let targetPort = chrome.tabs.connect(targetTabId, {frameId: targetFrameId, name: JSON.stringify(targetDetails)});
-
-        const cleanup = () => {
-            this._checkLastError(chrome.runtime.lastError);
-            if (targetPort !== null) {
-                targetPort.disconnect();
-                targetPort = null;
-            }
-            if (sourcePort !== null) {
-                sourcePort.disconnect();
-                sourcePort = null;
-            }
-        };
-
-        sourcePort.onMessage.addListener((message) => { targetPort.postMessage(message); });
-        targetPort.onMessage.addListener((message) => { sourcePort.postMessage(message); });
-        sourcePort.onDisconnect.addListener(cleanup);
-        targetPort.onDisconnect.addListener(cleanup);
-
-        return {targetTabId, targetFrameId};
-    }
-
-    // https://developer.chrome.com/docs/extensions/reference/offscreen/
-    async _setupOffscreenDocument() {
-        if (await this._hasOffscreenDocument()) {
-            return;
-        }
-        if (this._creatingOffscreen) {
-            await this._creatingOffscreen;
-            return;
-        }
-
-        this._creatingOffscreen = chrome.offscreen.createDocument({
-            url: 'offscreen.html',
-            reasons: ['CLIPBOARD'],
-            justification: 'Access to the clipboard'
-        });
-        await this._creatingOffscreen;
-        this._creatingOffscreen = null;
-    }
-    async _hasOffscreenDocument() {
-        const offscreenUrl = chrome.runtime.getURL('offscreen.html');
-        if (!chrome.runtime.getContexts) { // chrome version <116
-            const matchedClients = await clients.matchAll();
-            return await matchedClients.some((client) => client.url === offscreenUrl);
-        }
-
-        const contexts = await chrome.runtime.getContexts({
-            contextTypes: ['OFFSCREEN_DOCUMENT'],
-            documentUrls: [offscreenUrl]
-        });
-        return !!contexts.length;
-    }
 }
diff --git a/ext/js/background/offscreen-proxy.js b/ext/js/background/offscreen-proxy.js
new file mode 100644
index 00000000..ae414b99
--- /dev/null
+++ b/ext/js/background/offscreen-proxy.js
@@ -0,0 +1,172 @@
+/*
+ * Copyright (C) 2023  Yomitan Authors
+ * Copyright (C) 2016-2022  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/>.
+ */
+
+import {deserializeError, isObject} from '../core.js';
+import {ArrayBufferUtil} from '../data/sandbox/array-buffer-util.js';
+
+export class OffscreenProxy {
+    constructor() {
+        this._creatingOffscreen = null;
+    }
+
+    // https://developer.chrome.com/docs/extensions/reference/offscreen/
+    async prepare() {
+        if (await this._hasOffscreenDocument()) {
+            return;
+        }
+        if (this._creatingOffscreen) {
+            await this._creatingOffscreen;
+            return;
+        }
+
+        this._creatingOffscreen = chrome.offscreen.createDocument({
+            url: 'offscreen.html',
+            reasons: ['CLIPBOARD'],
+            justification: 'Access to the clipboard'
+        });
+        await this._creatingOffscreen;
+        this._creatingOffscreen = null;
+    }
+
+    async _hasOffscreenDocument() {
+        const offscreenUrl = chrome.runtime.getURL('offscreen.html');
+        if (!chrome.runtime.getContexts) { // chrome version <116
+            const matchedClients = await clients.matchAll();
+            return await matchedClients.some((client) => client.url === offscreenUrl);
+        }
+
+        const contexts = await chrome.runtime.getContexts({
+            contextTypes: ['OFFSCREEN_DOCUMENT'],
+            documentUrls: [offscreenUrl]
+        });
+        return !!contexts.length;
+    }
+
+    sendMessagePromise(...args) {
+        return new Promise((resolve, reject) => {
+            const callback = (response) => {
+                try {
+                    resolve(this._getMessageResponseResult(response));
+                } catch (error) {
+                    reject(error);
+                }
+            };
+
+            chrome.runtime.sendMessage(...args, callback);
+        });
+    }
+
+    _getMessageResponseResult(response) {
+        let error = chrome.runtime.lastError;
+        if (error) {
+            throw new Error(error.message);
+        }
+        if (!isObject(response)) {
+            throw new Error('Offscreen document did not respond');
+        }
+        error = response.error;
+        if (error) {
+            throw deserializeError(error);
+        }
+        return response.result;
+    }
+}
+
+export class DictionaryDatabaseProxy {
+    constructor(offscreen) {
+        this._offscreen = offscreen;
+    }
+
+    prepare() {
+        return this._offscreen.sendMessagePromise({action: 'databasePrepareOffscreen'});
+    }
+
+    getDictionaryInfo() {
+        return this._offscreen.sendMessagePromise({action: 'getDictionaryInfoOffscreen'});
+    }
+
+    purge() {
+        return this._offscreen.sendMessagePromise({action: 'databasePurgeOffscreen'});
+    }
+
+    async getMedia(targets) {
+        const serializedMedia = await this._offscreen.sendMessagePromise({action: 'databaseGetMediaOffscreen', params: {targets}});
+        const media = serializedMedia.map((m) => ({...m, content: ArrayBufferUtil.base64ToArrayBuffer(m.content)}));
+        return media;
+    }
+}
+
+export class TranslatorProxy {
+    constructor(offscreen) {
+        this._offscreen = offscreen;
+    }
+
+    prepare(deinflectionReasons) {
+        return this._offscreen.sendMessagePromise({action: 'translatorPrepareOffscreen', params: {deinflectionReasons}});
+    }
+
+    async findKanji(text, findKanjiOptions) {
+        const enabledDictionaryMapList = [...findKanjiOptions.enabledDictionaryMap];
+        const modifiedKanjiOptions = {
+            ...findKanjiOptions,
+            enabledDictionaryMap: enabledDictionaryMapList
+        };
+        return this._offscreen.sendMessagePromise({action: 'findKanjiOffscreen', params: {text, findKanjiOptions: modifiedKanjiOptions}});
+    }
+
+    async findTerms(mode, text, findTermsOptions) {
+        const {enabledDictionaryMap, excludeDictionaryDefinitions, textReplacements} = findTermsOptions;
+        const enabledDictionaryMapList = [...enabledDictionaryMap];
+        const excludeDictionaryDefinitionsList = excludeDictionaryDefinitions ? [...excludeDictionaryDefinitions] : null;
+        const textReplacementsSerialized = textReplacements.map((group) => {
+            if (!group) {
+                return group;
+            }
+            return group.map((opt) => ({...opt, pattern: opt.pattern.toString()}));
+        });
+        const modifiedFindTermsOptions = {
+            ...findTermsOptions,
+            enabledDictionaryMap: enabledDictionaryMapList,
+            excludeDictionaryDefinitions: excludeDictionaryDefinitionsList,
+            textReplacementsOptions: textReplacementsSerialized
+        };
+        return this._offscreen.sendMessagePromise({action: 'findTermsOffscreen', params: {mode, text, findTermsOptions: modifiedFindTermsOptions}});
+    }
+
+    async getTermFrequencies(termReadingList, dictionaries) {
+        return this._offscreen.sendMessagePromise({action: 'getTermFrequenciesOffscreen', params: {termReadingList, dictionaries}});
+    }
+
+    clearDatabaseCaches() {
+        return this._offscreen.sendMessagePromise({action: 'clearDatabaseCachesOffscreen'});
+    }
+}
+
+export class ClipboardReaderProxy {
+    constructor(offscreen) {
+        this._offscreen = offscreen;
+    }
+
+    async getText(useRichText) {
+        return this._offscreen.sendMessagePromise({action: 'clipboardGetTextOffscreen', params: {useRichText}});
+    }
+
+    async getImage() {
+        return this._offscreen.sendMessagePromise({action: 'clipboardGetImageOffscreen'});
+    }
+}