components/external-app-blocker.js

   1 // Bug 1506 Android P1/TBB P5: This code provides users with notification
   2 // in the event of external app launch. We want it to exist in the desktop
   3 // port, but it is probably useless for Android.
   4
   5 /*************************************************************************
   6  * External App Handler.
   7  * Handles displaying confirmation dialogs for external apps and protocols
   8  * due to Firefox Bug https://bugzilla.mozilla.org/show_bug.cgi?id=440892
   9  *
  10  * An instance of this module is created each time the browser starts to
  11  * download a file and when an external application may be invoked to
  12  * handle an URL (e.g., when the user clicks on a mailto: URL).
  13  *************************************************************************/
  14
  15 const { XPCOMUtils } = ChromeUtils.import(
  16   "resource://gre/modules/XPCOMUtils.jsm"
  17 );
  18 const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
  19 const { PromptUtils } = ChromeUtils.import(
  20   "resource://gre/modules/SharedPromptUtils.jsm"
  21 );
  22
  23 XPCOMUtils.defineLazyModuleGetters(this, {
  24   ComponentUtils: "resource://gre/modules/ComponentUtils.jsm",
  25 });
  26
  27 let { torbutton_get_property_string } = ChromeUtils.import(
  28   "resource://torbutton/modules/utils.js"
  29 );
  30
  31 // Module specific constants
  32 const kMODULE_NAME = "Torbutton External App Handler";
  33 const kCONTRACT_ID = "@torproject.org/torbutton-extAppBlocker;1";
  34 const kMODULE_CID = Components.ID("3da0269f-fc29-4e9e-a678-c3b1cafcf13f");
  35
  36 const kInterfaces = [Ci.nsIObserver, Ci.nsIClassInfo];
  37
  38 function ExternalAppBlocker() {
  39   this.logger = Cc["@torproject.org/torbutton-logger;1"].getService(
  40     Ci.nsISupports
  41   ).wrappedJSObject;
  42   this.logger.log(3, "Component Load 0: New ExternalAppBlocker.");
  43 }
  44
  45 ExternalAppBlocker.prototype = {
  46   _helperAppLauncher: undefined,
  47
  48   QueryInterface: ChromeUtils.generateQI([
  49     Ci.nsIObserver,
  50     Ci.nsIHelperAppWarningDialog,
  51   ]),
  52
  53   // make this an nsIClassInfo object
  54   flags: Ci.nsIClassInfo.DOM_OBJECT,
  55   classDescription: kMODULE_NAME,
  56   contractID: kCONTRACT_ID,
  57   classID: kMODULE_CID,
  58
  59   // method of nsIClassInfo
  60   getInterfaces(count) {
  61     count.value = kInterfaces.length;
  62     return kInterfaces;
  63   },
  64
  65   // method of nsIClassInfo
  66   getHelperForLanguage(count) {
  67     return null;
  68   },
  69
  70   // method of nsIHelperAppWarningDialog
  71   maybeShow(aLauncher, aWindowContext) {
  72     // Hold a reference to the object that called this component. This is
  73     // important not just because we need to later invoke the
  74     // continueRequest() or cancelRequest() callback on aLauncher, but also
  75     // so that the launcher object (which is a reference counted object) is
  76     // not released too soon.
  77     this._helperAppLauncher = aLauncher;
  78
  79     if (!Services.prefs.getBoolPref("extensions.torbutton.launch_warning")) {
  80       this._helperAppLauncher.continueRequest();
  81       return;
  82     }
  83
  84     this._showPrompt(aWindowContext);
  85   },
  86
  87   /*
  88    * The _showPrompt() implementation uses some XUL and JS that is part of the
  89    * browser's confirmEx() implementation. Specifically, _showPrompt() depends
  90    * on chrome://global/content/commonDialog.xhtml as well as some of the code
  91    * in resource://gre/modules/SharedPromptUtils.jsm.
  92    */
  93   _showPrompt(aWindowContext) {
  94     let parentWin;
  95     try {
  96       parentWin = aWindowContext.getInterface(Ci.nsIDOMWindow);
  97     } catch (e) {
  98       parentWin = Services.wm.getMostRecentWindow("navigator:browser");
  99     }
 100
 101     let title = torbutton_get_property_string("torbutton.popup.external.title");
 102     let app = torbutton_get_property_string("torbutton.popup.external.app");
 103     let note = torbutton_get_property_string("torbutton.popup.external.note");
 104     let suggest = torbutton_get_property_string(
 105       "torbutton.popup.external.suggest"
 106     );
 107     let launch = torbutton_get_property_string("torbutton.popup.launch");
 108     let cancel = torbutton_get_property_string("torbutton.popup.cancel");
 109     let dontask = torbutton_get_property_string("torbutton.popup.dontask");
 110
 111     let args = {
 112       promptType: "confirmEx",
 113       title,
 114       text: app + note + suggest + " ",
 115       checkLabel: dontask,
 116       checked: false,
 117       ok: false,
 118       button0Label: launch,
 119       button1Label: cancel,
 120       defaultButtonNum: 1, // Cancel
 121       buttonNumClicked: 1, // Cancel
 122       enableDelay: true,
 123     };
 124
 125     let propBag = PromptUtils.objectToPropBag(args);
 126     let uri = "chrome://global/content/commonDialog.xhtml";
 127     let promptWin = Services.ww.openWindow(
 128       parentWin,
 129       uri,
 130       "_blank",
 131       "centerscreen,chrome,titlebar",
 132       propBag
 133     );
 134     promptWin.addEventListener("load", aEvent => {
 135       promptWin.addEventListener("unload", aEvent => {
 136         PromptUtils.propBagToObject(propBag, args);
 137
 138         if (0 == args.buttonNumClicked) {
 139           // Save the checkbox value and tell the browser's external helper app
 140           // module about the user's choice.
 141           if (args.checked) {
 142             Services.prefs.setBoolPref(
 143               "extensions.torbutton.launch_warning",
 144               false
 145             );
 146           }
 147
 148           this._helperAppLauncher.continueRequest();
 149         } else {
 150           this._helperAppLauncher.cancelRequest(Cr.NS_BINDING_ABORTED);
 151         }
 152       });
 153     });
 154   },
 155 };
 156
 157 // Assign factory to global object.
 158 const NSGetFactory = XPCOMUtils.generateNSGetFactory
 159   ? XPCOMUtils.generateNSGetFactory([ExternalAppBlocker])
 160   : ComponentUtils.generateNSGetFactory([ExternalAppBlocker]);