Clean up copy&paste in confirmation dialogs for prefs

chrome/browser/resources/options/confirm_dialog.js

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+cr.define('options', function() {
+  /** @const */ var OptionsPage = options.OptionsPage;
+
+  /**
+   * A dialog that will pop up when the user attempts to set the value of the
+   * Boolean |pref| to |true|, asking for confirmation. If the user clicks OK,
+   * the new value is committed to Chrome. If the user clicks Cancel or leaves
+   * the settings page, the new value is discarded.
+   * @constructor
+   * @param {string} name See OptionsPage constructor.
+   * @param {string} title See OptionsPage constructor.
+   * @param {string} pageDivName See OptionsPage constructor.
+   * @param {HTMLInputElement} okButton The confirmation button element.
+   * @param {HTMLInputElement} cancelButton The cancellation button element.
+   * @param {string} pref The pref that requires confirmation.
+   * @param {string} metric User metrics identifier.
+   * @param {string} confirmed_pref A pref used to remember whether the user has
+   *     confirmed the dialog before. This ensures that the user is presented
+   *     with the dialog only once. If left |undefined| or |null|, the dialog
+   *     will pop up every time the user attempts to set |pref| to |true|.
+   * @extends {OptionsPage}
+   */
+  function ConfirmDialog(name, title, pageDivName, okButton, cancelButton, pref,
+                         metric, confirmed_pref) {
+    OptionsPage.call(this, name, title, pageDivName);
+    this.okButton = okButton;
+    this.cancelButton = cancelButton;
+    this.pref = pref;
+    this.metric = metric;
+    this.confirmed_pref = confirmed_pref;
+    this.confirmed_ = false;
+  }
+
+  ConfirmDialog.prototype = {
+    // Set up the prototype chain
+    __proto__: OptionsPage.prototype,
+
+    /**
+     * Handle changes to |pref|. Only uncommitted changes are relevant as these
+     * originate from user and need to be explicitly committed to take effect.
+     * Pop up the dialog or commit the change, depending on whether confirmation
+     * is needed.
+     * @param {Event} event Change event.
+     * @private
+     */
+    onPrefChanged_: function(event) {
+      if (!event.value.uncommitted)
+        return;
+
+      if (event.value.value && !this.confirmed_)
+        OptionsPage.showPageByName(this.name, false);
+      else
+        Preferences.getInstance().commitPref(this.pref, this.metric);
+    },
+
+    /**
+     * Handle changes to |confirmed_pref| by caching them.
+     * @param {Event} event Change event.
+     * @private
+     */
+    onConfirmedChanged_: function(event) {
+      this.confirmed_ = event.value.value;
+    },
+
+    /**
+     * @inheritDoc
+     */
+    initializePage: function() {
+      this.okButton.onclick = this.handleConfirm.bind(this);
+      this.cancelButton.onclick = this.handleCancel.bind(this);
+      Preferences.getInstance().addEventListener(
+          this.pref, this.onPrefChanged_.bind(this));
+      if (this.confirmed_pref) {
+        Preferences.getInstance().addEventListener(
+            this.confirmed_pref, this.onConfirmedChanged_.bind(this));
+      }
+    },
+
+    /**
+     * Handle the confirm button by committing the |pref| change. If
+     * |confirmed_pref| has been specified, also remember that the dialog has
+     * been confirmed to avoid bringing it up in the future.
+     */
+    handleConfirm: function() {
+      OptionsPage.closeOverlay();
+
+      Preferences.getInstance().commitPref(this.pref, this.metric);
+      if (this.confirmed_pref)
+        Preferences.setBooleanPref(this.confirmed_pref, true, true);
+    },
+
+    /**
+     * Handle the cancel button by rolling back the |pref| change without it
+     * ever taking effect.
+     */
+    handleCancel: function() {
+      OptionsPage.closeOverlay();
+
+      Preferences.getInstance().rollbackPref(this.pref);
+    },
+  };
+
+  return {
+    ConfirmDialog: ConfirmDialog
+  };
+});