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- // 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.
-
- /**
- * The global object.
- * @type {!Object}
- * @const
- */
- var global = this;
-
- /** Platform, package, object property, and Event support. **/
- var cr = function() {
- 'use strict';
-
- /**
- * Builds an object structure for the provided namespace path,
- * ensuring that names that already exist are not overwritten. For
- * example:
- * "a.b.c" -> a = {};a.b={};a.b.c={};
- * @param {string} name Name of the object that this file defines.
- * @param {*=} opt_object The object to expose at the end of the path.
- * @param {Object=} opt_objectToExportTo The object to add the path to;
- * default is {@code global}.
- * @private
- */
- function exportPath(name, opt_object, opt_objectToExportTo) {
- var parts = name.split('.');
- var cur = opt_objectToExportTo || global;
-
- for (var part; parts.length && (part = parts.shift());) {
- if (!parts.length && opt_object !== undefined) {
- // last part and we have an object; use it
- cur[part] = opt_object;
- } else if (part in cur) {
- cur = cur[part];
- } else {
- cur = cur[part] = {};
- }
- }
- return cur;
- };
-
- /**
- * Fires a property change event on the target.
- * @param {EventTarget} target The target to dispatch the event on.
- * @param {string} propertyName The name of the property that changed.
- * @param {*} newValue The new value for the property.
- * @param {*} oldValue The old value for the property.
- */
- function dispatchPropertyChange(target, propertyName, newValue, oldValue) {
- var e = new Event(propertyName + 'Change');
- e.propertyName = propertyName;
- e.newValue = newValue;
- e.oldValue = oldValue;
- target.dispatchEvent(e);
- }
-
- /**
- * Converts a camelCase javascript property name to a hyphenated-lower-case
- * attribute name.
- * @param {string} jsName The javascript camelCase property name.
- * @return {string} The equivalent hyphenated-lower-case attribute name.
- */
- function getAttributeName(jsName) {
- return jsName.replace(/([A-Z])/g, '-$1').toLowerCase();
- }
-
- /**
- * The kind of property to define in {@code defineProperty}.
- * @enum {string}
- * @const
- */
- var PropertyKind = {
- /**
- * Plain old JS property where the backing data is stored as a "private"
- * field on the object.
- * Use for properties of any type. Type will not be checked.
- */
- JS: 'js',
-
- /**
- * The property backing data is stored as an attribute on an element.
- * Use only for properties of type {string}.
- */
- ATTR: 'attr',
-
- /**
- * The property backing data is stored as an attribute on an element. If the
- * element has the attribute then the value is true.
- * Use only for properties of type {boolean}.
- */
- BOOL_ATTR: 'boolAttr'
- };
-
- /**
- * Helper function for defineProperty that returns the getter to use for the
- * property.
- * @param {string} name The name of the property.
- * @param {PropertyKind} kind The kind of the property.
- * @return {function():*} The getter for the property.
- */
- function getGetter(name, kind) {
- switch (kind) {
- case PropertyKind.JS:
- var privateName = name + '_';
- return function() {
- return this[privateName];
- };
- case PropertyKind.ATTR:
- var attributeName = getAttributeName(name);
- return function() {
- return this.getAttribute(attributeName);
- };
- case PropertyKind.BOOL_ATTR:
- var attributeName = getAttributeName(name);
- return function() {
- return this.hasAttribute(attributeName);
- };
- }
-
- // TODO(dbeam): replace with assertNotReached() in assert.js when I can coax
- // the browser/unit tests to preprocess this file through grit.
- throw 'not reached';
- }
-
- /**
- * Helper function for defineProperty that returns the setter of the right
- * kind.
- * @param {string} name The name of the property we are defining the setter
- * for.
- * @param {PropertyKind} kind The kind of property we are getting the
- * setter for.
- * @param {function(*, *):void=} opt_setHook A function to run after the
- * property is set, but before the propertyChange event is fired.
- * @return {function(*):void} The function to use as a setter.
- */
- function getSetter(name, kind, opt_setHook) {
- switch (kind) {
- case PropertyKind.JS:
- var privateName = name + '_';
- return function(value) {
- var oldValue = this[name];
- if (value !== oldValue) {
- this[privateName] = value;
- if (opt_setHook)
- opt_setHook.call(this, value, oldValue);
- dispatchPropertyChange(this, name, value, oldValue);
- }
- };
-
- case PropertyKind.ATTR:
- var attributeName = getAttributeName(name);
- return function(value) {
- var oldValue = this[name];
- if (value !== oldValue) {
- if (value == undefined)
- this.removeAttribute(attributeName);
- else
- this.setAttribute(attributeName, value);
- if (opt_setHook)
- opt_setHook.call(this, value, oldValue);
- dispatchPropertyChange(this, name, value, oldValue);
- }
- };
-
- case PropertyKind.BOOL_ATTR:
- var attributeName = getAttributeName(name);
- return function(value) {
- var oldValue = this[name];
- if (value !== oldValue) {
- if (value)
- this.setAttribute(attributeName, name);
- else
- this.removeAttribute(attributeName);
- if (opt_setHook)
- opt_setHook.call(this, value, oldValue);
- dispatchPropertyChange(this, name, value, oldValue);
- }
- };
- }
-
- // TODO(dbeam): replace with assertNotReached() in assert.js when I can coax
- // the browser/unit tests to preprocess this file through grit.
- throw 'not reached';
- }
-
- /**
- * Defines a property on an object. When the setter changes the value a
- * property change event with the type {@code name + 'Change'} is fired.
- * @param {!Object} obj The object to define the property for.
- * @param {string} name The name of the property.
- * @param {PropertyKind=} opt_kind What kind of underlying storage to use.
- * @param {function(*, *):void=} opt_setHook A function to run after the
- * property is set, but before the propertyChange event is fired.
- */
- function defineProperty(obj, name, opt_kind, opt_setHook) {
- if (typeof obj == 'function')
- obj = obj.prototype;
-
- var kind = /** @type {PropertyKind} */ (opt_kind || PropertyKind.JS);
-
- if (!obj.__lookupGetter__(name))
- obj.__defineGetter__(name, getGetter(name, kind));
-
- if (!obj.__lookupSetter__(name))
- obj.__defineSetter__(name, getSetter(name, kind, opt_setHook));
- }
-
- /**
- * Counter for use with createUid
- */
- var uidCounter = 1;
-
- /**
- * @return {number} A new unique ID.
- */
- function createUid() {
- return uidCounter++;
- }
-
- /**
- * Returns a unique ID for the item. This mutates the item so it needs to be
- * an object
- * @param {!Object} item The item to get the unique ID for.
- * @return {number} The unique ID for the item.
- */
- function getUid(item) {
- if (item.hasOwnProperty('uid'))
- return item.uid;
- return item.uid = createUid();
- }
-
- /**
- * Dispatches a simple event on an event target.
- * @param {!EventTarget} target The event target to dispatch the event on.
- * @param {string} type The type of the event.
- * @param {boolean=} opt_bubbles Whether the event bubbles or not.
- * @param {boolean=} opt_cancelable Whether the default action of the event
- * can be prevented. Default is true.
- * @return {boolean} If any of the listeners called {@code preventDefault}
- * during the dispatch this will return false.
- */
- function dispatchSimpleEvent(target, type, opt_bubbles, opt_cancelable) {
- var e = new Event(type, {
- bubbles: opt_bubbles,
- cancelable: opt_cancelable === undefined || opt_cancelable
- });
- return target.dispatchEvent(e);
- }
-
- /**
- * Calls |fun| and adds all the fields of the returned object to the object
- * named by |name|. For example, cr.define('cr.ui', function() {
- * function List() {
- * ...
- * }
- * function ListItem() {
- * ...
- * }
- * return {
- * List: List,
- * ListItem: ListItem,
- * };
- * });
- * defines the functions cr.ui.List and cr.ui.ListItem.
- * @param {string} name The name of the object that we are adding fields to.
- * @param {!Function} fun The function that will return an object containing
- * the names and values of the new fields.
- */
- function define(name, fun) {
- var obj = exportPath(name);
- var exports = fun();
- for (var propertyName in exports) {
- // Maybe we should check the prototype chain here? The current usage
- // pattern is always using an object literal so we only care about own
- // properties.
- var propertyDescriptor = Object.getOwnPropertyDescriptor(exports,
- propertyName);
- if (propertyDescriptor)
- Object.defineProperty(obj, propertyName, propertyDescriptor);
- }
- }
-
- /**
- * Adds a {@code getInstance} static method that always return the same
- * instance object.
- * @param {!Function} ctor The constructor for the class to add the static
- * method to.
- */
- function addSingletonGetter(ctor) {
- ctor.getInstance = function() {
- return ctor.instance_ || (ctor.instance_ = new ctor());
- };
- }
-
- /**
- * Forwards public APIs to private implementations.
- * @param {Function} ctor Constructor that have private implementations in its
- * prototype.
- * @param {Array.<string>} methods List of public method names that have their
- * underscored counterparts in constructor's prototype.
- * @param {string=} opt_target Selector for target node.
- */
- function makePublic(ctor, methods, opt_target) {
- methods.forEach(function(method) {
- ctor[method] = function() {
- var target = opt_target ? document.getElementById(opt_target) :
- ctor.getInstance();
- return target[method + '_'].apply(target, arguments);
- };
- });
- }
-
- return {
- addSingletonGetter: addSingletonGetter,
- createUid: createUid,
- define: define,
- defineProperty: defineProperty,
- dispatchPropertyChange: dispatchPropertyChange,
- dispatchSimpleEvent: dispatchSimpleEvent,
- exportPath: exportPath,
- getUid: getUid,
- makePublic: makePublic,
- PropertyKind: PropertyKind,
-
- get doc() {
- return document;
- },
-
- /** Whether we are using a Mac or not. */
- get isMac() {
- return /Mac/.test(navigator.platform);
- },
-
- /** Whether this is on the Windows platform or not. */
- get isWindows() {
- return /Win/.test(navigator.platform);
- },
-
- /** Whether this is on chromeOS or not. */
- get isChromeOS() {
- return /CrOS/.test(navigator.userAgent);
- },
-
- /** Whether this is on vanilla Linux (not chromeOS). */
- get isLinux() {
- return /Linux/.test(navigator.userAgent);
- },
-
- /** Whether this uses the views toolkit or not. */
- get isViews() {
- return typeof chrome.getVariableValue == 'function' &&
- /views/.test(chrome.getVariableValue('toolkit'));
- },
- };
- }();
-