// 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. **/
this.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 {number}
* @const
*/
var 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 The name of the property.
* @param {cr.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);
};
}
}
/**
* 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.
* @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);
}
};
}
}
/**
* 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 {cr.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 = 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());
};
}
/**
* Initialization which must be deferred until run-time.
*/
function initialize() {
// If 'document' isn't defined, then we must be being pre-compiled,
// so set a trap so that we're initialized on first access at run-time.
if (!global.document) {
var originalCr = cr;
Object.defineProperty(global, 'cr', {
get: function() {
Object.defineProperty(global, 'cr', {value: originalCr});
originalCr.initialize();
return originalCr;
},
configurable: true
});
return;
}
cr.doc = document;
/**
* Whether we are using a Mac or not.
*/
cr.isMac = /Mac/.test(navigator.platform);
/**
* Whether this is on the Windows platform or not.
*/
cr.isWindows = /Win/.test(navigator.platform);
/**
* Whether this is on chromeOS or not.
*/
cr.isChromeOS = /CrOS/.test(navigator.userAgent);
/**
* Whether this is on vanilla Linux (not chromeOS).
*/
cr.isLinux = /Linux/.test(navigator.userAgent);
/**
* Whether this uses GTK or not.
*/
cr.isGTK = typeof chrome.getVariableValue == 'function' &&
/GTK/.test(chrome.getVariableValue('toolkit'));
/**
* Whether this uses the views toolkit or not.
*/
cr.isViews = typeof chrome.getVariableValue == 'function' &&
/views/.test(chrome.getVariableValue('toolkit'));
}
return {
addSingletonGetter: addSingletonGetter,
createUid: createUid,
define: define,
defineProperty: defineProperty,
dispatchPropertyChange: dispatchPropertyChange,
dispatchSimpleEvent: dispatchSimpleEvent,
getUid: getUid,
initialize: initialize,
PropertyKind: PropertyKind
};
})();
/**
* TODO(kgr): Move this to another file which is to be loaded last.
* This will be done as part of future work to make this code pre-compilable.
*/
cr.initialize();