separate offscreen proxies from backend.js

1 files changed, 172 insertions, 0 deletions

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'});
+    }
+}