check.jcarr.wit.com/chrome/cr.js

490 lines
16 KiB
JavaScript

// 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;
/** @typedef {{eventName: string, uid: number}} */
var WebUIListener;
/** Platform, package, object property, and Event support. **/
var cr = 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}.
* @return {!Object} The last object exported (i.e. exportPath('cr.ui')
* returns a reference to the ui property of window.cr).
* @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 ?
// Disable document.getElementById restriction since cr.js should
// not depend on util.js.
// eslint-disable-next-line no-restricted-properties
document.getElementById(opt_target) :
ctor.getInstance();
return target[method + '_'].apply(target, arguments);
};
});
}
/**
* The mapping used by the sendWithPromise mechanism to tie the Promise
* returned to callers with the corresponding WebUI response. The mapping is
* from ID to the PromiseResolver helper; the ID is generated by
* sendWithPromise and is unique across all invocations of said method.
* @type {!Object<!PromiseResolver>}
*/
var chromeSendResolverMap = {};
/**
* The named method the WebUI handler calls directly in response to a
* chrome.send call that expects a response. The handler requires no knowledge
* of the specific name of this method, as the name is passed to the handler
* as the first argument in the arguments list of chrome.send. The handler
* must pass the ID, also sent via the chrome.send arguments list, as the
* first argument of the JS invocation; additionally, the handler may
* supply any number of other arguments that will be included in the response.
* @param {string} id The unique ID identifying the Promise this response is
* tied to.
* @param {boolean} isSuccess Whether the request was successful.
* @param {*} response The response as sent from C++.
*/
function webUIResponse(id, isSuccess, response) {
var resolver = chromeSendResolverMap[id];
delete chromeSendResolverMap[id];
if (isSuccess)
resolver.resolve(response);
else
resolver.reject(response);
}
/**
* A variation of chrome.send, suitable for messages that expect a single
* response from C++.
* @param {string} methodName The name of the WebUI handler API.
* @param {...*} var_args Variable number of arguments to be forwarded to the
* C++ call.
* @return {!Promise}
*/
function sendWithPromise(methodName, var_args) {
var args = Array.prototype.slice.call(arguments, 1);
var promiseResolver = new PromiseResolver();
var id = methodName + '_' + createUid();
chromeSendResolverMap[id] = promiseResolver;
chrome.send(methodName, [id].concat(args));
return promiseResolver.promise;
}
/**
* A map of maps associating event names with listeners. The 2nd level map
* associates a listener ID with the callback function, such that individual
* listeners can be removed from an event without affecting other listeners of
* the same event.
* @type {!Object<!Object<!Function>>}
*/
var webUIListenerMap = {};
/**
* The named method the WebUI handler calls directly when an event occurs.
* The WebUI handler must supply the name of the event as the first argument
* of the JS invocation; additionally, the handler may supply any number of
* other arguments that will be forwarded to the listener callbacks.
* @param {string} event The name of the event that has occurred.
* @param {...*} var_args Additional arguments passed from C++.
*/
function webUIListenerCallback(event, var_args) {
var eventListenersMap = webUIListenerMap[event];
if (!eventListenersMap) {
// C++ event sent for an event that has no listeners.
// TODO(dpapad): Should a warning be displayed here?
return;
}
var args = Array.prototype.slice.call(arguments, 1);
for (var listenerId in eventListenersMap) {
eventListenersMap[listenerId].apply(null, args);
}
}
/**
* Registers a listener for an event fired from WebUI handlers. Any number of
* listeners may register for a single event.
* @param {string} eventName The event to listen to.
* @param {!Function} callback The callback run when the event is fired.
* @return {!WebUIListener} An object to be used for removing a listener via
* cr.removeWebUIListener. Should be treated as read-only.
*/
function addWebUIListener(eventName, callback) {
webUIListenerMap[eventName] = webUIListenerMap[eventName] || {};
var uid = createUid();
webUIListenerMap[eventName][uid] = callback;
return {eventName: eventName, uid: uid};
}
/**
* Removes a listener. Does nothing if the specified listener is not found.
* @param {!WebUIListener} listener The listener to be removed (as returned by
* addWebUIListener).
* @return {boolean} Whether the given listener was found and actually
* removed.
*/
function removeWebUIListener(listener) {
var listenerExists = webUIListenerMap[listener.eventName] &&
webUIListenerMap[listener.eventName][listener.uid];
if (listenerExists) {
delete webUIListenerMap[listener.eventName][listener.uid];
return true;
}
return false;
}
return {
addSingletonGetter: addSingletonGetter,
createUid: createUid,
define: define,
defineProperty: defineProperty,
dispatchPropertyChange: dispatchPropertyChange,
dispatchSimpleEvent: dispatchSimpleEvent,
exportPath: exportPath,
getUid: getUid,
makePublic: makePublic,
PropertyKind: PropertyKind,
// C++ <-> JS communication related methods.
addWebUIListener: addWebUIListener,
removeWebUIListener: removeWebUIListener,
sendWithPromise: sendWithPromise,
webUIListenerCallback: webUIListenerCallback,
webUIResponse: webUIResponse,
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 is on Android. */
get isAndroid() {
return /Android/.test(navigator.userAgent);
},
/** Whether this is on iOS. */
get isIOS() {
return /iPad|iPhone|iPod/.test(navigator.platform);
}
};
}();