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web/preferences.js

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+/* Copyright 2013 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { AppOptions, OptionKind } from "./app_options.js";
+
+/**
+ * BasePreferences - Abstract base class for storing persistent settings.
+ *   Used for settings that should be applied to all opened documents,
+ *   or every time the viewer is loaded.
+ */
+class BasePreferences {
+  #defaults = Object.freeze(
+    typeof PDFJSDev === "undefined"
+      ? AppOptions.getAll(OptionKind.PREFERENCE, /* defaultOnly = */ true)
+      : PDFJSDev.eval("DEFAULT_PREFERENCES")
+  );
+
+  #initializedPromise = null;
+
+  constructor() {
+    if (
+      (typeof PDFJSDev === "undefined" || PDFJSDev.test("TESTING")) &&
+      this.constructor === BasePreferences
+    ) {
+      throw new Error("Cannot initialize BasePreferences.");
+    }
+
+    if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("CHROME")) {
+      Object.defineProperty(this, "defaults", {
+        get() {
+          return this.#defaults;
+        },
+      });
+    }
+
+    this.#initializedPromise = this._readFromStorage(this.#defaults).then(
+      ({ browserPrefs, prefs }) => {
+        if (
+          (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) &&
+          AppOptions._checkDisablePreferences()
+        ) {
+          return;
+        }
+        AppOptions.setAll({ ...browserPrefs, ...prefs }, /* prefs = */ true);
+      }
+    );
+
+    if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
+      window.addEventListener(
+        "updatedPreference",
+        async ({ detail: { name, value } }) => {
+          await this.#initializedPromise;
+          AppOptions.setAll({ [name]: value }, /* prefs = */ true);
+        }
+      );
+    }
+  }
+
+  /**
+   * Stub function for writing preferences to storage.
+   * @param {Object} prefObj The preferences that should be written to storage.
+   * @returns {Promise} A promise that is resolved when the preference values
+   *                    have been written.
+   */
+  async _writeToStorage(prefObj) {
+    throw new Error("Not implemented: _writeToStorage");
+  }
+
+  /**
+   * Stub function for reading preferences from storage.
+   * @param {Object} prefObj The preferences that should be read from storage.
+   * @returns {Promise} A promise that is resolved with an {Object} containing
+   *                    the preferences that have been read.
+   */
+  async _readFromStorage(prefObj) {
+    throw new Error("Not implemented: _readFromStorage");
+  }
+
+  /**
+   * Reset the preferences to their default values and update storage.
+   * @returns {Promise} A promise that is resolved when the preference values
+   *                    have been reset.
+   */
+  async reset() {
+    if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
+      throw new Error("Please use `about:config` to change preferences.");
+    }
+    await this.#initializedPromise;
+    AppOptions.setAll(this.#defaults, /* prefs = */ true);
+
+    await this._writeToStorage(this.#defaults);
+  }
+
+  /**
+   * Set the value of a preference.
+   * @param {string} name The name of the preference that should be changed.
+   * @param {boolean|number|string} value The new value of the preference.
+   * @returns {Promise} A promise that is resolved when the value has been set,
+   *                    provided that the preference exists and the types match.
+   */
+  async set(name, value) {
+    await this.#initializedPromise;
+    AppOptions.setAll({ [name]: value }, /* prefs = */ true);
+
+    await this._writeToStorage(
+      typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")
+        ? { [name]: AppOptions.get(name) }
+        : AppOptions.getAll(OptionKind.PREFERENCE)
+    );
+  }
+
+  /**
+   * Get the value of a preference.
+   * @param {string} name The name of the preference whose value is requested.
+   * @returns {Promise} A promise resolved with a {boolean|number|string}
+   *                    containing the value of the preference.
+   */
+  async get(name) {
+    if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
+      throw new Error("Not implemented: get");
+    }
+    await this.#initializedPromise;
+    return AppOptions.get(name);
+  }
+
+  get initializedPromise() {
+    return this.#initializedPromise;
+  }
+}
+
+export { BasePreferences };