Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 461 insertions, 0 deletions

diff --git a/toolkit/modules/Preferences.sys.mjs b/toolkit/modules/Preferences.sys.mjs
new file mode 100644
index 0000000000..91aa15f245
--- /dev/null
+++ b/toolkit/modules/Preferences.sys.mjs
@@ -0,0 +1,461 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// The minimum and maximum integers that can be set as preferences.
+// The range of valid values is narrower than the range of valid JS values
+// because the native preferences code treats integers as NSPR PRInt32s,
+// which are 32-bit signed integers on all platforms.
+const MAX_INT = 0x7fffffff; // Math.pow(2, 31) - 1
+const MIN_INT = -0x80000000;
+
+export function Preferences(args) {
+  this._cachedPrefBranch = null;
+  if (isObject(args)) {
+    if (args.branch) {
+      this._branchStr = args.branch;
+    }
+    if (args.defaultBranch) {
+      this._defaultBranch = args.defaultBranch;
+    }
+    if (args.privacyContext) {
+      this._privacyContext = args.privacyContext;
+    }
+  } else if (args) {
+    this._branchStr = args;
+  }
+}
+
+/**
+ * Get the value of a pref, if any; otherwise return the default value.
+ *
+ * @param   prefName  {String|Array}
+ *          the pref to get, or an array of prefs to get
+ *
+ * @param   defaultValue
+ *          the default value, if any, for prefs that don't have one
+ *
+ * @param   valueType
+ *          the XPCOM interface of the pref's complex value type, if any
+ *
+ * @returns the value of the pref, if any; otherwise the default value
+ */
+Preferences.get = function (prefName, defaultValue, valueType = null) {
+  if (Array.isArray(prefName)) {
+    return prefName.map(v => this.get(v, defaultValue));
+  }
+
+  return this._get(prefName, defaultValue, valueType);
+};
+
+Preferences._get = function (prefName, defaultValue, valueType) {
+  switch (this._prefBranch.getPrefType(prefName)) {
+    case Ci.nsIPrefBranch.PREF_STRING:
+      if (valueType) {
+        let ifaces = ["nsIFile", "nsIPrefLocalizedString"];
+        if (ifaces.includes(valueType.name)) {
+          return this._prefBranch.getComplexValue(prefName, valueType).data;
+        }
+      }
+      return this._prefBranch.getStringPref(prefName);
+
+    case Ci.nsIPrefBranch.PREF_INT:
+      return this._prefBranch.getIntPref(prefName);
+
+    case Ci.nsIPrefBranch.PREF_BOOL:
+      return this._prefBranch.getBoolPref(prefName);
+
+    case Ci.nsIPrefBranch.PREF_INVALID:
+      return defaultValue;
+
+    default:
+      // This should never happen.
+      throw new Error(
+        `Error getting pref ${prefName}; its value's type is ` +
+          `${this._prefBranch.getPrefType(prefName)}, which I don't ` +
+          `know how to handle.`
+      );
+  }
+};
+
+/**
+ * Set a preference to a value.
+ *
+ * You can set multiple prefs by passing an object as the only parameter.
+ * In that case, this method will treat the properties of the object
+ * as preferences to set, where each property name is the name of a pref
+ * and its corresponding property value is the value of the pref.
+ *
+ * @param   prefName  {String|Object}
+ *          the name of the pref to set; or an object containing a set
+ *          of prefs to set
+ *
+ * @param   prefValue {String|Number|Boolean}
+ *          the value to which to set the pref
+ *
+ * Note: Preferences cannot store non-integer numbers or numbers outside
+ * the signed 32-bit range -(2^31-1) to 2^31-1, If you have such a number,
+ * store it as a string by calling toString() on the number before passing
+ * it to this method, i.e.:
+ *   Preferences.set("pi", 3.14159.toString())
+ *   Preferences.set("big", Math.pow(2, 31).toString()).
+ */
+Preferences.set = function (prefName, prefValue) {
+  if (isObject(prefName)) {
+    for (let [name, value] of Object.entries(prefName)) {
+      this.set(name, value);
+    }
+    return;
+  }
+
+  this._set(prefName, prefValue);
+};
+
+Preferences._set = function (prefName, prefValue) {
+  let prefType;
+  if (typeof prefValue != "undefined" && prefValue != null) {
+    prefType = prefValue.constructor.name;
+  }
+
+  switch (prefType) {
+    case "String":
+      this._prefBranch.setStringPref(prefName, prefValue);
+      break;
+
+    case "Number":
+      // We throw if the number is outside the range, since the result
+      // will never be what the consumer wanted to store, but we only warn
+      // if the number is non-integer, since the consumer might not mind
+      // the loss of precision.
+      if (prefValue > MAX_INT || prefValue < MIN_INT) {
+        throw new Error(
+          `you cannot set the ${prefName} pref to the number ` +
+            `${prefValue}, as number pref values must be in the signed ` +
+            `32-bit integer range -(2^31-1) to 2^31-1.  To store numbers ` +
+            `outside that range, store them as strings.`
+        );
+      }
+      this._prefBranch.setIntPref(prefName, prefValue);
+      if (prefValue % 1 != 0) {
+        console.error(
+          "Warning: setting the ",
+          prefName,
+          " pref to the non-integer number ",
+          prefValue,
+          " converted it " +
+            "to the integer number " +
+            this.get(prefName) +
+            "; to retain fractional precision, store non-integer " +
+            "numbers as strings."
+        );
+      }
+      break;
+
+    case "Boolean":
+      this._prefBranch.setBoolPref(prefName, prefValue);
+      break;
+
+    default:
+      throw new Error(
+        `can't set pref ${prefName} to value '${prefValue}'; ` +
+          `it isn't a String, Number, or Boolean`
+      );
+  }
+};
+
+/**
+ * Whether or not the given pref has a value.  This is different from isSet
+ * because it returns true whether the value of the pref is a default value
+ * or a user-set value, while isSet only returns true if the value
+ * is a user-set value.
+ *
+ * @param   prefName  {String|Array}
+ *          the pref to check, or an array of prefs to check
+ *
+ * @returns {Boolean|Array}
+ *          whether or not the pref has a value; or, if the caller provided
+ *          an array of pref names, an array of booleans indicating whether
+ *          or not the prefs have values
+ */
+Preferences.has = function (prefName) {
+  if (Array.isArray(prefName)) {
+    return prefName.map(this.has, this);
+  }
+
+  return (
+    this._prefBranch.getPrefType(prefName) != Ci.nsIPrefBranch.PREF_INVALID
+  );
+};
+
+/**
+ * Whether or not the given pref has a user-set value.  This is different
+ * from |has| because it returns true only if the value of the pref is a user-
+ * set value, while |has| returns true if the value of the pref is a default
+ * value or a user-set value.
+ *
+ * @param   prefName  {String|Array}
+ *          the pref to check, or an array of prefs to check
+ *
+ * @returns {Boolean|Array}
+ *          whether or not the pref has a user-set value; or, if the caller
+ *          provided an array of pref names, an array of booleans indicating
+ *          whether or not the prefs have user-set values
+ */
+Preferences.isSet = function (prefName) {
+  if (Array.isArray(prefName)) {
+    return prefName.map(this.isSet, this);
+  }
+
+  return this.has(prefName) && this._prefBranch.prefHasUserValue(prefName);
+};
+
+/**
+ * Whether or not the given pref has a user-set value. Use isSet instead,
+ * which is equivalent.
+ * @deprecated
+ */
+Preferences.modified = function (prefName) {
+  return this.isSet(prefName);
+};
+
+Preferences.reset = function (prefName) {
+  if (Array.isArray(prefName)) {
+    prefName.map(v => this.reset(v));
+    return;
+  }
+
+  this._prefBranch.clearUserPref(prefName);
+};
+
+/**
+ * Lock a pref so it can't be changed.
+ *
+ * @param   prefName  {String|Array}
+ *          the pref to lock, or an array of prefs to lock
+ */
+Preferences.lock = function (prefName) {
+  if (Array.isArray(prefName)) {
+    prefName.map(this.lock, this);
+  }
+
+  this._prefBranch.lockPref(prefName);
+};
+
+/**
+ * Unlock a pref so it can be changed.
+ *
+ * @param   prefName  {String|Array}
+ *          the pref to lock, or an array of prefs to lock
+ */
+Preferences.unlock = function (prefName) {
+  if (Array.isArray(prefName)) {
+    prefName.map(this.unlock, this);
+  }
+
+  this._prefBranch.unlockPref(prefName);
+};
+
+/**
+ * Whether or not the given pref is locked against changes.
+ *
+ * @param   prefName  {String|Array}
+ *          the pref to check, or an array of prefs to check
+ *
+ * @returns {Boolean|Array}
+ *          whether or not the pref has a user-set value; or, if the caller
+ *          provided an array of pref names, an array of booleans indicating
+ *          whether or not the prefs have user-set values
+ */
+Preferences.locked = function (prefName) {
+  if (Array.isArray(prefName)) {
+    return prefName.map(this.locked, this);
+  }
+
+  return this._prefBranch.prefIsLocked(prefName);
+};
+
+/**
+ * Start observing a pref.
+ *
+ * The callback can be a function or any object that implements nsIObserver.
+ * When the callback is a function and thisObject is provided, it gets called
+ * as a method of thisObject.
+ *
+ * @param   prefName    {String}
+ *          the name of the pref to observe
+ *
+ * @param   callback    {Function|Object}
+ *          the code to notify when the pref changes;
+ *
+ * @param   thisObject  {Object}  [optional]
+ *          the object to use as |this| when calling a Function callback;
+ *
+ * @returns the wrapped observer
+ */
+Preferences.observe = function (prefName, callback, thisObject) {
+  let fullPrefName = this._branchStr + (prefName || "");
+
+  let observer = new PrefObserver(fullPrefName, callback, thisObject);
+  Preferences._prefBranch.addObserver(fullPrefName, observer, true);
+  observers.push(observer);
+
+  return observer;
+};
+
+/**
+ * Stop observing a pref.
+ *
+ * You must call this method with the same prefName, callback, and thisObject
+ * with which you originally registered the observer.  However, you don't have
+ * to call this method on the same exact instance of Preferences; you can call
+ * it on any instance.  For example, the following code first starts and then
+ * stops observing the "foo.bar.baz" preference:
+ *
+ *   let observer = function() {...};
+ *   Preferences.observe("foo.bar.baz", observer);
+ *   new Preferences("foo.bar.").ignore("baz", observer);
+ *
+ * @param   prefName    {String}
+ *          the name of the pref being observed
+ *
+ * @param   callback    {Function|Object}
+ *          the code being notified when the pref changes
+ *
+ * @param   thisObject  {Object}  [optional]
+ *          the object being used as |this| when calling a Function callback
+ */
+Preferences.ignore = function (prefName, callback, thisObject) {
+  let fullPrefName = this._branchStr + (prefName || "");
+
+  // This seems fairly inefficient, but I'm not sure how much better we can
+  // make it.  We could index by fullBranch, but we can't index by callback
+  // or thisObject, as far as I know, since the keys to JavaScript hashes
+  // (a.k.a. objects) can apparently only be primitive values.
+  let [observer] = observers.filter(
+    v =>
+      v.prefName == fullPrefName &&
+      v.callback == callback &&
+      v.thisObject == thisObject
+  );
+
+  if (observer) {
+    Preferences._prefBranch.removeObserver(fullPrefName, observer);
+    observers.splice(observers.indexOf(observer), 1);
+  } else {
+    console.error(
+      `Attempt to stop observing a preference "${prefName}" that's not being observed`
+    );
+  }
+};
+
+Preferences.resetBranch = function (prefBranch = "") {
+  try {
+    this._prefBranch.resetBranch(prefBranch);
+  } catch (ex) {
+    // The current implementation of nsIPrefBranch in Mozilla
+    // doesn't implement resetBranch, so we do it ourselves.
+    if (ex.result == Cr.NS_ERROR_NOT_IMPLEMENTED) {
+      this.reset(this._prefBranch.getChildList(prefBranch));
+    } else {
+      throw ex;
+    }
+  }
+};
+
+/**
+ * A string identifying the branch of the preferences tree to which this
+ * instance provides access.
+ * @private
+ */
+Preferences._branchStr = "";
+
+/**
+ * The cached preferences branch object this instance encapsulates, or null.
+ * Do not use!  Use _prefBranch below instead.
+ * @private
+ */
+Preferences._cachedPrefBranch = null;
+
+/**
+ * The preferences branch object for this instance.
+ * @private
+ */
+Object.defineProperty(Preferences, "_prefBranch", {
+  get: function _prefBranch() {
+    if (!this._cachedPrefBranch) {
+      let prefSvc = Services.prefs;
+      this._cachedPrefBranch = this._defaultBranch
+        ? prefSvc.getDefaultBranch(this._branchStr)
+        : prefSvc.getBranch(this._branchStr);
+    }
+    return this._cachedPrefBranch;
+  },
+  enumerable: true,
+  configurable: true,
+});
+
+// Constructor-based access (Preferences.get(...) and set) is preferred over
+// instance-based access (new Preferences().get(...) and set) and when using the
+// root preferences branch, as it's desirable not to allocate the extra object.
+// But both forms are acceptable.
+Preferences.prototype = Preferences;
+
+/**
+ * A cache of pref observers.
+ *
+ * We use this to remove observers when a caller calls Preferences::ignore.
+ *
+ * All Preferences instances share this object, because we want callers to be
+ * able to remove an observer using a different Preferences object than the one
+ * with which they added it.  That means we have to identify the observers
+ * in this object by their complete pref name, not just their name relative to
+ * the root branch of the Preferences object with which they were created.
+ */
+var observers = [];
+
+function PrefObserver(prefName, callback, thisObject) {
+  this.prefName = prefName;
+  this.callback = callback;
+  this.thisObject = thisObject;
+}
+
+PrefObserver.prototype = {
+  QueryInterface: ChromeUtils.generateQI([
+    "nsIObserver",
+    "nsISupportsWeakReference",
+  ]),
+
+  observe(subject, topic, data) {
+    // The pref service only observes whole branches, but we only observe
+    // individual preferences, so we check here that the pref that changed
+    // is the exact one we're observing (and not some sub-pref on the branch).
+    if (data != this.prefName) {
+      return;
+    }
+
+    if (typeof this.callback == "function") {
+      let prefValue = Preferences.get(this.prefName);
+
+      if (this.thisObject) {
+        this.callback.call(this.thisObject, prefValue);
+      } else {
+        this.callback(prefValue);
+      }
+    } else {
+      // typeof this.callback == "object" (nsIObserver)
+      this.callback.observe(subject, topic, data);
+    }
+  },
+};
+
+function isObject(val) {
+  // We can't check for |val.constructor == Object| here, since the value
+  // might be from a different context whose Object constructor is not the same
+  // as ours, so instead we match based on the name of the constructor.
+  return (
+    typeof val != "undefined" &&
+    val != null &&
+    typeof val == "object" &&
+    val.constructor.name == "Object"
+  );
+}