Bug 1165841 - Part 5: remove listener when window is destroyed. r=dimi

dom/nfc/NfcContentHelper.js

@@ -194,6 +194,12 @@ NfcContentHelper.prototype = {
     cpmm.sendAsyncMessage("NFC:AddEventListener", { tabId: tabId });
   },
 
+  removeEventListener: function removeEventListener(tabId) {
+    delete this.eventListeners[tabId];
+
+    cpmm.sendAsyncMessage("NFC:RemoveEventListener", { tabId: tabId });
+  },
+
   registerTargetForPeerReady: function registerTargetForPeerReady(appId) {
     cpmm.sendAsyncMessage("NFC:RegisterPeerReadyTarget", { appId: appId });
   },

dom/nfc/gonk/Nfc.js

@@ -57,6 +57,7 @@ const NFC_CID =
 const NFC_IPC_MSG_ENTRIES = [
   { permission: null,
     messages: ["NFC:AddEventListener",
+               "NFC:RemoveEventListener",
                "NFC:QueryInfo",
                "NFC:CallDefaultFoundHandler",
                "NFC:CallDefaultLostHandler"] },
@@ -256,12 +257,16 @@ XPCOMUtils.defineLazyGetter(this, "gMessageManager", function () {
     removeEventListener: function removeEventListener(target) {
       for (let id in this.eventListeners) {
         if (target == this.eventListeners[id]) {
-          delete this.eventListeners[id];
+          this.removeEventListenerById(id);
           break;
         }
       }
     },
 
+    removeEventListenerById: function removeEventListenerById(id) {
+      delete this.eventListeners[id];
+    },
+
     checkP2PRegistration: function checkP2PRegistration(message) {
       let target = this.peerTargets[message.data.appId];
       let sessionToken = SessionHelper.getCurrentP2PToken();
@@ -385,6 +390,9 @@ XPCOMUtils.defineLazyGetter(this, "gMessageManager", function () {
         case "NFC:AddEventListener":
           this.addEventListener(message.target, message.data.tabId);
           return null;
+        case "NFC:RemoveEventListener":
+          this.removeEventListenerById(message.data.tabId);
+          return null;
         case "NFC:RegisterPeerReadyTarget":
           this.registerPeerReadyTarget(message.target, message.data.appId);
           return null;

dom/nfc/nsINfcContentHelper.idl

@@ -124,7 +124,7 @@ interface nsINfcBrowserAPI : nsISupports
                    in boolean isFocus);
 };
 
-[scriptable, uuid(f098c114-b21f-43f5-9f53-0c22b4f194eb)]
+[scriptable, uuid(75f0c8c0-2e5a-491f-a75d-4f3849c4feec)]
 interface nsINfcContentHelper : nsISupports
 {
   /**
@@ -236,6 +236,14 @@ interface nsINfcContentHelper : nsISupports
    */
   void addEventListener(in nsINfcEventListener listener, in uint64_t tabId);
 
+  /**
+   * Remove event listener.
+   *
+   * @param tabId
+   *        The tabId provided in addEventListener.
+   */
+  void removeEventListener(in uint64_t tabId);
+
   /**
    * Register the given application id with parent process
    *

dom/nfc/nsNfc.js

@@ -345,6 +345,7 @@ MozNFCImpl.prototype = {
   _nfcContentHelper: null,
   window: null,
   _tabId: null,
+  _innerWindowId: null,
   _rfState: null,
   _contentObj: null,
   nfcPeer: null,
@@ -354,12 +355,19 @@ MozNFCImpl.prototype = {
   init: function init(aWindow) {
     debug("MozNFCImpl init called");
     this.window = aWindow;
+    let util = aWindow.QueryInterface(Ci.nsIInterfaceRequestor)
+                      .getInterface(Ci.nsIDOMWindowUtils);
+    this._innerWindowId = util.currentInnerWindowID;
+
     this.defineEventHandlerGetterSetter("ontagfound");
     this.defineEventHandlerGetterSetter("ontaglost");
     this.defineEventHandlerGetterSetter("onpeerready");
     this.defineEventHandlerGetterSetter("onpeerfound");
     this.defineEventHandlerGetterSetter("onpeerlost");
 
+    Services.obs.addObserver(this, "inner-window-destroyed",
+                             /* weak-ref */ false);
+
     if (this._nfcContentHelper) {
       this._tabId = this.getTabId(aWindow);
       this._nfcContentHelper.addEventListener(this, this._tabId);
@@ -441,6 +449,19 @@ MozNFCImpl.prototype = {
     return this._rfState != RFState.IDLE;
   },
 
+  observe: function observe(subject, topic, data) {
+    if (topic !== "inner-window-destroyed") {
+      return;
+    }
+
+    let wId = subject.QueryInterface(Ci.nsISupportsPRUint64).data;
+    if (wId != this._innerWindowId) {
+      return;
+    }
+
+    this._nfcContentHelper.removeEventListener(this._tabId);
+  },
+
   defineEventHandlerGetterSetter: function defineEventHandlerGetterSetter(name) {
     Object.defineProperty(this, name, {
       get: function get() {
@@ -699,7 +720,8 @@ MozNFCImpl.prototype = {
   contractID: "@mozilla.org/nfc/manager;1",
   QueryInterface: XPCOMUtils.generateQI([Ci.nsISupports,
                                          Ci.nsIDOMGlobalPropertyInitializer,
-                                         Ci.nsINfcEventListener]),
+                                         Ci.nsINfcEventListener,
+                                         Ci.nsIObserver]),
 };
 
 function NFCSendFileWrapper() {