chrome/renderer/resources/extensions/chrome_web_view_experimental.js

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // This module implements experimental API for <webview>.
   6 // See web_view.js for details.
   7 //
   8 // <webview> Chrome Experimental API is only available on canary and dev
   9 // channels of Chrome.
  10
  11 var ChromeWebView = require('chromeWebViewInternal').ChromeWebView;
  12 var ChromeWebViewSchema =
  13     requireNative('schema_registry').GetSchema('chromeWebViewInternal');
  14 var ContextMenusSchema =
  15     requireNative('schema_registry').GetSchema('contextMenus');
  16 var CreateEvent = require('webViewEvents').CreateEvent;
  17 var EventBindings = require('event_bindings');
  18 var idGeneratorNatives = requireNative('id_generator');
  19 var MessagingNatives = requireNative('messaging_natives');
  20 var utils = require('utils');
  21 var WebViewImpl = require('webView').WebViewImpl;
  22
  23 function GetUniqueSubEventName(eventName) {
  24   return eventName + '/' + idGeneratorNatives.GetNextId();
  25 }
  26
  27 // This is the only "webViewInternal.onClicked" named event for this renderer.
  28 //
  29 // Since we need an event per <webview>, we define events with suffix
  30 // (subEventName) in each of the <webview>. Behind the scenes, this event is
  31 // registered as a ContextMenusEvent, with filter set to the webview's
  32 // |viewInstanceId|. Any time a ContextMenusEvent is dispatched, we re-dispatch
  33 // it to the subEvent's listeners. This way
  34 // <webview>.contextMenus.onClicked behave as a regular chrome Event type.
  35 var ContextMenusEvent = CreateEvent('chromeWebViewInternal.onClicked');
  36
  37 /**
  38  * This event is exposed as <webview>.contextMenus.onClicked.
  39  *
  40  * @constructor
  41  */
  42 function ContextMenusOnClickedEvent(opt_eventName,
  43                                     opt_argSchemas,
  44                                     opt_eventOptions,
  45                                     opt_webViewInstanceId) {
  46   var subEventName = GetUniqueSubEventName(opt_eventName);
  47   EventBindings.Event.call(this,
  48                            subEventName,
  49                            opt_argSchemas,
  50                            opt_eventOptions,
  51                            opt_webViewInstanceId);
  52
  53   // TODO(lazyboy): When do we dispose this listener?
  54   ContextMenusEvent.addListener(function() {
  55     // Re-dispatch to subEvent's listeners.
  56     $Function.apply(this.dispatch, this, $Array.slice(arguments));
  57   }.bind(this), {instanceId: opt_webViewInstanceId || 0});
  58 }
  59
  60 ContextMenusOnClickedEvent.prototype = {
  61   __proto__: EventBindings.Event.prototype
  62 };
  63
  64 /**
  65  * An instance of this class is exposed as <webview>.contextMenus.
  66  * @constructor
  67  */
  68 function WebViewContextMenusImpl(viewInstanceId) {
  69   this.viewInstanceId_ = viewInstanceId;
  70 }
  71
  72 WebViewContextMenusImpl.prototype.create = function() {
  73   var args = $Array.concat([this.viewInstanceId_], $Array.slice(arguments));
  74   return $Function.apply(ChromeWebView.contextMenusCreate, null, args);
  75 };
  76
  77 WebViewContextMenusImpl.prototype.remove = function() {
  78   var args = $Array.concat([this.viewInstanceId_], $Array.slice(arguments));
  79   return $Function.apply(ChromeWebView.contextMenusRemove, null, args);
  80 };
  81
  82 WebViewContextMenusImpl.prototype.removeAll = function() {
  83   var args = $Array.concat([this.viewInstanceId_], $Array.slice(arguments));
  84   return $Function.apply(ChromeWebView.contextMenusRemoveAll, null, args);
  85 };
  86
  87 WebViewContextMenusImpl.prototype.update = function() {
  88   var args = $Array.concat([this.viewInstanceId_], $Array.slice(arguments));
  89   return $Function.apply(ChromeWebView.contextMenusUpdate, null, args);
  90 };
  91
  92 var WebViewContextMenus = utils.expose(
  93     'WebViewContextMenus', WebViewContextMenusImpl,
  94     { functions: ['create', 'remove', 'removeAll', 'update'] });
  95
  96 /** @private */
  97 WebViewImpl.prototype.maybeHandleContextMenu = function(e, webViewEvent) {
  98   var requestId = e.requestId;
  99   // Construct the event.menu object.
 100   var actionTaken = false;
 101   var validateCall = function() {
 102     var ERROR_MSG_CONTEXT_MENU_ACTION_ALREADY_TAKEN = '<webview>: ' +
 103         'An action has already been taken for this "contextmenu" event.';
 104
 105     if (actionTaken) {
 106       throw new Error(ERROR_MSG_CONTEXT_MENU_ACTION_ALREADY_TAKEN);
 107     }
 108     actionTaken = true;
 109   };
 110   var menu = {
 111     show: function(items) {
 112       validateCall();
 113       // TODO(lazyboy): WebViewShowContextFunction doesn't do anything useful
 114       // with |items|, implement.
 115       ChromeWebView.showContextMenu(this.guestInstanceId, requestId, items);
 116     }.bind(this)
 117   };
 118   webViewEvent.menu = menu;
 119   var webviewNode = this.webviewNode;
 120   var defaultPrevented = !webviewNode.dispatchEvent(webViewEvent);
 121   if (actionTaken) {
 122     return;
 123   }
 124   if (!defaultPrevented) {
 125     actionTaken = true;
 126     // The default action is equivalent to just showing the context menu as is.
 127     ChromeWebView.showContextMenu(this.guestInstanceId, requestId, undefined);
 128
 129     // TODO(lazyboy): Figure out a way to show warning message only when
 130     // listeners are registered for this event.
 131   } //  else we will ignore showing the context menu completely.
 132 };
 133
 134 /** @private */
 135 WebViewImpl.prototype.setupExperimentalContextMenus = function() {
 136   var createContextMenus = function() {
 137     return function() {
 138       if (this.contextMenus_) {
 139         return this.contextMenus_;
 140       }
 141
 142       this.contextMenus_ = new WebViewContextMenus(this.viewInstanceId);
 143
 144       // Define 'onClicked' event property on |this.contextMenus_|.
 145       var getOnClickedEvent = function() {
 146         return function() {
 147           if (!this.contextMenusOnClickedEvent_) {
 148             var eventName = 'chromeWebViewInternal.onClicked';
 149             // TODO(lazyboy): Find event by name instead of events[0].
 150             var eventSchema = ChromeWebViewSchema.events[0];
 151             var eventOptions = {supportsListeners: true};
 152             var onClickedEvent = new ContextMenusOnClickedEvent(
 153                 eventName, eventSchema, eventOptions, this.viewInstanceId);
 154             this.contextMenusOnClickedEvent_ = onClickedEvent;
 155             return onClickedEvent;
 156           }
 157           return this.contextMenusOnClickedEvent_;
 158         }.bind(this);
 159       }.bind(this);
 160       Object.defineProperty(
 161           this.contextMenus_,
 162           'onClicked',
 163           {get: getOnClickedEvent(), enumerable: true});
 164
 165       return this.contextMenus_;
 166     }.bind(this);
 167   }.bind(this);
 168
 169   // Expose <webview>.contextMenus object.
 170   Object.defineProperty(
 171       this.webviewNode,
 172       'contextMenus',
 173       {
 174         get: createContextMenus(),
 175         enumerable: true
 176       });
 177 };