chrome/renderer/resources/extensions/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> Experimental API is only available on canary and dev channels of
   9 // Chrome.
  10
  11 var CreateEvent = require('webView').CreateEvent;
  12 var MessagingNatives = requireNative('messaging_natives');
  13 var WebViewInternal = require('webView').WebViewInternal;
  14 var WebView = require('webView').WebView;
  15
  16 // WEB_VIEW_EXPERIMENTAL_EVENTS is a map of experimental <webview> DOM event
  17 //     names to their associated extension event descriptor objects.
  18 // An event listener will be attached to the extension event |evt| specified in
  19 //     the descriptor.
  20 // |fields| specifies the public-facing fields in the DOM event that are
  21 //     accessible to <webview> developers.
  22 // |customHandler| allows a handler function to be called each time an extension
  23 //     event is caught by its event listener. The DOM event should be dispatched
  24 //     within this handler function. With no handler function, the DOM event
  25 //     will be dispatched by default each time the extension event is caught.
  26 // |cancelable| (default: false) specifies whether the event's default
  27 //     behavior can be canceled. If the default action associated with the event
  28 //     is prevented, then its dispatch function will return false in its event
  29 //     handler. The event must have a custom handler for this to be meaningful.
  30 var WEB_VIEW_EXPERIMENTAL_EVENTS = {
  31   'dialog': {
  32     cancelable: true,
  33     customHandler: function(webViewInternal, event, webViewEvent) {
  34       webViewInternal.handleDialogEvent(event, webViewEvent);
  35     },
  36     evt: CreateEvent('webview.onDialog'),
  37     fields: ['defaultPromptText', 'messageText', 'messageType', 'url']
  38   },
  39   'zoomchange': {
  40     evt: CreateEvent('webview.onZoomChange'),
  41     fields: ['oldZoomFactor', 'newZoomFactor']
  42   }
  43 };
  44
  45 /**
  46  * @private
  47  */
  48 WebViewInternal.prototype.maybeAttachWebRequestEventToObject =
  49     function(obj, eventName, webRequestEvent) {
  50   Object.defineProperty(
  51       obj,
  52       eventName,
  53       {
  54         get: webRequestEvent,
  55         enumerable: true
  56       }
  57   );
  58 };
  59
  60 /**
  61  * @private
  62  */
  63 WebViewInternal.prototype.setZoom = function(zoomFactor) {
  64   if (!this.instanceId) {
  65     return;
  66   }
  67   WebView.setZoom(this.instanceId, zoomFactor);
  68 };
  69
  70 /**
  71  * @private
  72  */
  73 WebViewInternal.prototype.handleDialogEvent =
  74     function(event, webViewEvent) {
  75   var showWarningMessage = function(dialogType) {
  76     var VOWELS = ['a', 'e', 'i', 'o', 'u'];
  77     var WARNING_MSG_DIALOG_BLOCKED = '<webview>: %1 %2 dialog was blocked.';
  78     var article = (VOWELS.indexOf(dialogType.charAt(0)) >= 0) ? 'An' : 'A';
  79     var output = WARNING_MSG_DIALOG_BLOCKED.replace('%1', article);
  80     output = output.replace('%2', dialogType);
  81     window.console.warn(output);
  82   };
  83
  84   var self = this;
  85   var browserPluginNode = this.browserPluginNode;
  86   var webviewNode = this.webviewNode;
  87
  88   var requestId = event.requestId;
  89   var actionTaken = false;
  90
  91   var validateCall = function() {
  92     var ERROR_MSG_DIALOG_ACTION_ALREADY_TAKEN = '<webview>: ' +
  93         'An action has already been taken for this "dialog" event.';
  94
  95     if (actionTaken) {
  96       throw new Error(ERROR_MSG_DIALOG_ACTION_ALREADY_TAKEN);
  97     }
  98     actionTaken = true;
  99   };
 100
 101   var dialog = {
 102     ok: function(user_input) {
 103       validateCall();
 104       user_input = user_input || '';
 105       WebView.setPermission(self.instanceId, requestId, 'allow', user_input);
 106     },
 107     cancel: function() {
 108       validateCall();
 109       WebView.setPermission(self.instanceId, requestId, 'deny');
 110     }
 111   };
 112   webViewEvent.dialog = dialog;
 113
 114   var defaultPrevented = !webviewNode.dispatchEvent(webViewEvent);
 115   if (actionTaken) {
 116     return;
 117   }
 118
 119   if (defaultPrevented) {
 120     // Tell the JavaScript garbage collector to track lifetime of |dialog| and
 121     // call back when the dialog object has been collected.
 122     MessagingNatives.BindToGC(dialog, function() {
 123       // Avoid showing a warning message if the decision has already been made.
 124       if (actionTaken) {
 125         return;
 126       }
 127       WebView.setPermission(
 128           self.instanceId, requestId, 'default', '', function(allowed) {
 129         if (allowed) {
 130           return;
 131         }
 132         showWarningMessage(event.messageType);
 133       });
 134     });
 135   } else {
 136     actionTaken = true;
 137     // The default action is equivalent to canceling the dialog.
 138     WebView.setPermission(
 139         self.instanceId, requestId, 'default', '', function(allowed) {
 140       if (allowed) {
 141         return;
 142       }
 143       showWarningMessage(event.messageType);
 144     });
 145   }
 146 };
 147
 148 WebViewInternal.prototype.maybeGetExperimentalEvents = function() {
 149   return WEB_VIEW_EXPERIMENTAL_EVENTS;
 150 };
 151
 152 /** @private */
 153 WebViewInternal.prototype.maybeGetExperimentalPermissions = function() {
 154   return [];
 155 };
 156
 157 /** @private */
 158 WebViewInternal.prototype.maybeSetCurrentZoomFactor =
 159     function(zoomFactor) {
 160   this.currentZoomFactor = zoomFactor;
 161 };
 162
 163 /** @private */
 164 WebViewInternal.prototype.clearData = function(var_args) {
 165   if (!this.instanceId) {
 166     return;
 167   }
 168   var args = $Array.concat([this.instanceId], $Array.slice(arguments));
 169   $Function.apply(WebView.clearData, null, args);
 170 };
 171
 172 /** @private */
 173 WebViewInternal.prototype.setZoom = function(zoomFactor, callback) {
 174   if (!this.instanceId) {
 175     return;
 176   }
 177   WebView.setZoom(this.instanceId, zoomFactor, callback);
 178 };
 179
 180 WebViewInternal.prototype.getZoom = function(callback) {
 181   if (!this.instanceId) {
 182     return;
 183   }
 184   WebView.getZoom(this.instanceId, callback);
 185 };
 186
 187 /** @private */
 188 WebViewInternal.prototype.captureVisibleRegion = function(spec, callback) {
 189   WebView.captureVisibleRegion(this.instanceId, spec, callback);
 190 };
 191
 192 WebViewInternal.maybeRegisterExperimentalAPIs = function(proto) {
 193   proto.clearData = function(var_args) {
 194     var internal = privates(this).internal;
 195     $Function.apply(internal.clearData, internal, arguments);
 196   };
 197
 198   proto.setZoom = function(zoomFactor, callback) {
 199     privates(this).internal.setZoom(zoomFactor, callback);
 200   };
 201
 202   proto.getZoom = function(callback) {
 203     return privates(this).internal.getZoom(callback);
 204   };
 205
 206   proto.captureVisibleRegion = function(spec, callback) {
 207     privates(this).internal.captureVisibleRegion(spec, callback);
 208   };
 209 };