| // Copyright (c) 2010 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. |
| |
| const cr = (function() { |
| |
| /** |
| * Whether we are using a Mac or not. |
| * @type {boolean} |
| */ |
| const isMac = /Mac/.test(navigator.platform); |
| |
| /** |
| * 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 window}. |
| * @private |
| */ |
| function exportPath(name, opt_object, opt_objectToExportTo) { |
| var parts = name.split('.'); |
| var cur = opt_objectToExportTo || window /* 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) { |
| // TODO(arv): Depending on cr.Event here is a bit ugly. |
| var e = new cr.Event(propertyName + 'Change'); |
| e.propertyName = propertyName; |
| e.newValue = newValue; |
| e.oldValue = oldValue; |
| target.dispatchEvent(e); |
| } |
| |
| /** |
| * The kind of property to define in {@code defineProperty}. |
| * @enum {number} |
| */ |
| const PropertyKind = { |
| /** |
| * Plain old JS property where the backing data is stored as a "private" |
| * field on the object. |
| */ |
| JS: 'js', |
| |
| /** |
| * The property backing data is stored as an attribute on an element. |
| */ |
| 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. |
| */ |
| BOOL_ATTR: 'boolAttr' |
| }; |
| |
| /** |
| * Helper function for defineProperty that returns the getter to use for the |
| * property. |
| * @param {string} name |
| * @param {cr.PropertyKind} kind |
| * @param {*} defaultValue The default value. This is only used for the ATTR |
| * kind. |
| * @return {function():*} The getter for the property. |
| */ |
| function getGetter(name, kind, defaultValue) { |
| switch (kind) { |
| case PropertyKind.JS: |
| var privateName = name + '_'; |
| return function() { |
| return this[privateName]; |
| }; |
| case PropertyKind.ATTR: |
| // For attr with default value we return the default value if the |
| // element is missing the attribute. |
| if (defaultValue == undefined) { |
| return function() { |
| return this.getAttribute(name); |
| }; |
| } else { |
| return function() { |
| // WebKit uses null for non existant attributes. |
| var value = this.getAttribute(name); |
| return value !== null ? value : defaultValue; |
| }; |
| } |
| case PropertyKind.BOOL_ATTR: |
| // Boolean attributes don't support default values. |
| return function() { |
| return this.hasAttribute(name); |
| }; |
| } |
| } |
| |
| /** |
| * 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 {cr.PropertyKind} kind The kind of property we are getting the |
| * setter for. |
| * @return {function(*):void} The function to use as a setter. |
| */ |
| function getSetter(name, kind) { |
| switch (kind) { |
| case PropertyKind.JS: |
| var privateName = name + '_'; |
| return function(value) { |
| var oldValue = this[privateName]; |
| if (value !== oldValue) { |
| this[privateName] = value; |
| dispatchPropertyChange(this, name, value, oldValue); |
| } |
| }; |
| |
| case PropertyKind.ATTR: |
| return function(value) { |
| var oldValue = this[name]; |
| if (value !== oldValue) { |
| this.setAttribute(name, value); |
| dispatchPropertyChange(this, name, value, oldValue); |
| } |
| }; |
| |
| case PropertyKind.BOOL_ATTR: |
| return function(value) { |
| var oldValue = this[name]; |
| if (value !== oldValue) { |
| if (value) |
| this.setAttribute(name, name); |
| else |
| this.removeAttribute(name); |
| dispatchPropertyChange(this, name, value, oldValue); |
| } |
| }; |
| } |
| } |
| |
| /** |
| * 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} The object to define the property for. |
| * @param {string} The name of the property. |
| * @param {cr.PropertyKind=} opt_kind What kind of underlying storage to use. |
| * @param {*} opt_defaultValue The default value. |
| */ |
| function defineProperty(obj, name, opt_kind, opt_default) { |
| if (typeof obj == 'function') |
| obj = obj.prototype; |
| |
| var kind = opt_kind || PropertyKind.JS; |
| |
| if (!obj.__lookupGetter__(name)) { |
| // For js properties we set the default value on the prototype. |
| if (kind == PropertyKind.JS && arguments.length > 3) { |
| var privateName = name + '_'; |
| obj[privateName] = opt_default; |
| } |
| obj.__defineGetter__(name, getGetter(name, kind, opt_default)); |
| } |
| |
| if (!obj.__lookupSetter__(name)) { |
| obj.__defineSetter__(name, getSetter(name, kind)); |
| } |
| } |
| |
| /** |
| * 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(); |
| } |
| |
| /** |
| * Partially applies this function to a particular 'this object' and zero or |
| * more arguments. The result is a new function with some arguments of the |
| * first function pre-filled and the value of |this| 'pre-specified'. |
| * |
| * Remaining arguments specified at call-time are appended to the pre- |
| * specified ones. |
| * |
| * Usage: |
| * <pre>var barMethBound = bind(myFunction, myObj, 'arg1', 'arg2'); |
| * barMethBound('arg3', 'arg4');</pre> |
| * |
| * @param {Function} fn A function to partially apply. |
| * @param {Object|undefined} selfObj Specifies the object which |this| should |
| * point to when the function is run. If the value is null or undefined, |
| * it will default to the global object. |
| * @param {...*} var_args Additional arguments that are partially |
| * applied to the function. |
| * |
| * @return {!Function} A partially-applied form of the function bind() was |
| * invoked as a method of. |
| */ |
| function bind(fn, selfObj, var_args) { |
| var boundArgs = Array.prototype.slice.call(arguments, 2); |
| return function() { |
| var args = Array.prototype.slice.call(arguments); |
| args.unshift.apply(args, boundArgs); |
| return fn.apply(selfObj, args); |
| } |
| } |
| |
| /** |
| * 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. |
| * @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 cr.Event(type, opt_bubbles, opt_cancelable); |
| return target.dispatchEvent(e); |
| } |
| |
| /** |
| * @param {string} name |
| * @param {!Function} fun |
| */ |
| function define(name, fun) { |
| var obj = exportPath(name); |
| var exports = fun(); |
| for (var key in exports) { |
| obj[key] = exports[key]; |
| } |
| } |
| |
| /** |
| * Document used for various document related operations. |
| * @type {!Document} |
| */ |
| var doc = document; |
| |
| |
| /** |
| * Allows you to run func in the context of a different document. |
| * @param {!Document} document The document to use. |
| * @param {function():*} func The function to call. |
| */ |
| function withDoc(document, func) { |
| var oldDoc = doc; |
| doc = document; |
| try { |
| func(); |
| } finally { |
| doc = oldDoc; |
| } |
| } |
| |
| return { |
| isMac: isMac, |
| define: define, |
| defineProperty: defineProperty, |
| PropertyKind: PropertyKind, |
| createUid: createUid, |
| getUid: getUid, |
| bind: bind, |
| dispatchSimpleEvent: dispatchSimpleEvent, |
| dispatchPropertyChange: dispatchPropertyChange, |
| |
| /** |
| * The document that we are currently using. |
| * @type {!Document} |
| */ |
| get doc() { |
| return doc; |
| }, |
| withDoc: withDoc |
| }; |
| })(); |