chrome/browser/resources/shared/js/cr.js - platform/external/chromium - Git at Google

 // 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);

   /**
    * Whether this is on the Windows platform or not.
    * @type {boolean}
    */
   const isWindows = /Win/.test(navigator.platform);

   /**
    * Whether this is on chromeOS or not.
    * @type {boolean}
    */
   const isChromeOS = /CrOS/.test(navigator.userAgent);

   /**
    * Whether this is on vanilla Linux (not chromeOS).
    * @type {boolean}
    */
   const isLinux = /Linux/.test(navigator.userAgent);

   /**
    * Whether this uses the views toolkit or not.
    * @type {boolean}
    */
   const isViews = isWindows || isChromeOS;

   /**
    * 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;
   };

   // cr.Event is called CrEvent in here to prevent naming conflicts. We also
   // store the original Event in case someone does a global alias of cr.Event.
   const DomEvent = Event;

   /**
    * Creates a new event to be used with cr.EventTarget or DOM EventTarget
    * objects.
    * @param {string} type The name of the event.
    * @param {boolean=} opt_bubbles Whether the event bubbles. Default is false.
    * @param {boolean=} opt_preventable Whether the default action of the event
    *     can be prevented.
    * @constructor
    * @extends {DomEvent}
    */
   function CrEvent(type, opt_bubbles, opt_preventable) {
     var e = cr.doc.createEvent('Event');
     e.initEvent(type, !!opt_bubbles, !!opt_preventable);
     e.__proto__ = CrEvent.prototype;
     return e;
   }

   CrEvent.prototype = {
     __proto__: DomEvent.prototype
   };

   /**
    * 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 CrEvent(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
    * @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:
         return function() {
           return this.getAttribute(name);
         };
       case PropertyKind.BOOL_ATTR:
         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.
    * @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[privateName];
           if (value !== oldValue) {
             this[privateName] = value;
             if (opt_setHook)
               opt_setHook.call(this, value, oldValue);
             dispatchPropertyChange(this, name, value, oldValue);
           }
         };

       case PropertyKind.ATTR:
         return function(value) {
           var oldValue = this[name];
           if (value !== oldValue) {
             this.setAttribute(name, value);
             if (opt_setHook)
               opt_setHook.call(this, value, oldValue);
             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);
             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.
    * @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 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);
     }
   }

   /**
    * 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;
     }
   }

   /**
    * 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());
     };
   }

   return {
     addSingletonGetter: addSingletonGetter,
     isChromeOS: isChromeOS,
     isMac: isMac,
     isWindows: isWindows,
     isLinux: isLinux,
     isViews: isViews,
     define: define,
     defineProperty: defineProperty,
     PropertyKind: PropertyKind,
     createUid: createUid,
     getUid: getUid,
     dispatchSimpleEvent: dispatchSimpleEvent,
     dispatchPropertyChange: dispatchPropertyChange,

     /**
      * The document that we are currently using.
      * @type {!Document}
      */
     get doc() {
       return doc;
     },
     withDoc: withDoc,
     Event: CrEvent
   };
 })();
	// 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);

	/**
	* Whether this is on the Windows platform or not.
	* @type {boolean}
	*/
	const isWindows = /Win/.test(navigator.platform);

	/**
	* Whether this is on chromeOS or not.
	* @type {boolean}
	*/
	const isChromeOS = /CrOS/.test(navigator.userAgent);

	/**
	* Whether this is on vanilla Linux (not chromeOS).
	* @type {boolean}
	*/
	const isLinux = /Linux/.test(navigator.userAgent);

	/**
	* Whether this uses the views toolkit or not.
	* @type {boolean}
	*/
	const isViews = isWindows \|\| isChromeOS;

	/**
	* 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;
	};

	// cr.Event is called CrEvent in here to prevent naming conflicts. We also
	// store the original Event in case someone does a global alias of cr.Event.
	const DomEvent = Event;

	/**
	* Creates a new event to be used with cr.EventTarget or DOM EventTarget
	* objects.
	* @param {string} type The name of the event.
	* @param {boolean=} opt_bubbles Whether the event bubbles. Default is false.
	* @param {boolean=} opt_preventable Whether the default action of the event
	* can be prevented.
	* @constructor
	* @extends {DomEvent}
	*/
	function CrEvent(type, opt_bubbles, opt_preventable) {
	var e = cr.doc.createEvent('Event');
	e.initEvent(type, !!opt_bubbles, !!opt_preventable);
	e.__proto__ = CrEvent.prototype;
	return e;
	}

	CrEvent.prototype = {
	__proto__: DomEvent.prototype
	};

	/**
	* 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 CrEvent(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
	* @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:
	return function() {
	return this.getAttribute(name);
	};
	case PropertyKind.BOOL_ATTR:
	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.
	* @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[privateName];
	if (value !== oldValue) {
	this[privateName] = value;
	if (opt_setHook)
	opt_setHook.call(this, value, oldValue);
	dispatchPropertyChange(this, name, value, oldValue);
	}
	};

	case PropertyKind.ATTR:
	return function(value) {
	var oldValue = this[name];
	if (value !== oldValue) {
	this.setAttribute(name, value);
	if (opt_setHook)
	opt_setHook.call(this, value, oldValue);
	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);
	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.
	* @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 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);
	}
	}

	/**
	* 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;
	}
	}

	/**
	* 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());
	};
	}

	return {
	addSingletonGetter: addSingletonGetter,
	isChromeOS: isChromeOS,
	isMac: isMac,
	isWindows: isWindows,
	isLinux: isLinux,
	isViews: isViews,
	define: define,
	defineProperty: defineProperty,
	PropertyKind: PropertyKind,
	createUid: createUid,
	getUid: getUid,
	dispatchSimpleEvent: dispatchSimpleEvent,
	dispatchPropertyChange: dispatchPropertyChange,

	/**
	* The document that we are currently using.
	* @type {!Document}
	*/
	get doc() {
	return doc;
	},
	withDoc: withDoc,
	Event: CrEvent
	};
	})();