Implement extension specific events

chrome/test/data/extensions/samples/subscribe_page_action/background.html

Index: chrome/test/data/extensions/samples/subscribe_page_action/background.html
===================================================================
--- chrome/test/data/extensions/samples/subscribe_page_action/background.html	(revision 20629)
+++ chrome/test/data/extensions/samples/subscribe_page_action/background.html	(working copy)
@@ -4,53 +4,14 @@
   // The Page Action ID.
   var pageActionId = "RssPageAction";
 
-  // The icons to use. These correspond to the icons listed in the manifest.
+  // The icon to use. This corresponds to the icon listed in the manifest.
   var subscribeId = 0;
-  var alreadySubscribedId = 1;
 
-  // The window this Page Action is associated with.
-  var windowId = -1;
+  // A dictionary keyed off of tabId that keeps track of data per tab (for
+  // example what feedUrl was detected in the tab).
+  var feedData = {};
 
-  // The TabId this Page Action is associated with.
-  var tabId = -1;
-
-  // The URL of the page that contains the feed.
-  var pageUrl = "";
-
-  // The feed URL found on the page.
-  var feedUrl = "";
-
-  // The URL to use to check if user is subscribed already.
-  var subscribedUrl = "http://www.google.com/reader/api/0/subscribed?s=feed%2F";
-
-  // The XMLHttpRequest object that checks if you are already subscribed.
-  var req;
-
-  // The status of whether you have already subscribed to this feed or not.
-  var alreadySubscribed = false;
-
-  function EnableIcon(subscribed) {
-    alreadySubscribed = subscribed;
-    if (!alreadySubscribed) {
-      chrome.pageActions.enableForTab(
-        pageActionId, {tabId: tabId,
-                       url: pageUrl,
-                       title: "Click to subscribe...",
-                       iconId: subscribeId});
-    } else {
-      chrome.pageActions.enableForTab(
-        pageActionId, {tabId: tabId,
-                       url: pageUrl,
-                       title: "You are already subscribed to this feed",
-                       iconId: alreadySubscribedId});
-    }
-  }
-
   chrome.self.onConnect.addListener(function(port) {
-    windowId = port.tab.windowId;
-    tabId = port.tab.id;
-    pageUrl = port.tab.url;
-
     // This will get called from the content script using PostMessage.
     // |feedUrls| is a list of URL feeds found on the page. We only need 1 to
     // enable the PageAction icon in the Omnibox.
@@ -59,49 +20,39 @@
       // Let Chrome know that the PageAction needs to be enabled for this tabId
       // and for the url of this page.
       if (feedUrl) {
-        EnableIcon(false);  // Not subscribed (as far as we know, might change).
+        feedData[port.tab.id] = {pageUrl: port.tab.url,
+                                 feedUrl: feedUrl};
 
-        // But also check the server to see if we have already subscribed so
-        // that we can update the status.
-        feedUrl = encodeURIComponent(feedUrl);
-        req = new XMLHttpRequest();
-        req.onload = handleResponse;
-        req.open("GET", subscribedUrl + feedUrl, false);
-        req.send(null);
+        chrome.pageActions.enableForTab(
+            pageActionId, {tabId: port.tab.id,
+                           url: port.tab.url,
+                           title: "Click to subscribe...",
+                           iconId: subscribeId});
       }
     });
   });
 
-  function handleResponse() {
-    if (req.responseText == "true")
-      EnableIcon(true);  // true == Already suscribed.
-  }
-
   // Chrome will call into us when the user clicks on the icon in the OmniBox.
-  chrome.pageActions.onExecute.addListener(function(reply) {
+  chrome.pageActions["RssPageAction"].addListener(function(reply) {
     chrome.windows.getCurrent(function(window) {
       chrome.tabs.get(reply.data.tabId, function(tab) {
-        if (!alreadySubscribed && window.focused) {
-          // We need to know if we are the active window, because the tab may
-          // have moved to another window and we don't want to execute this
-          // action multiple times.
-          if (reply.pageActionId == pageActionId &&
-              reply.data.tabUrl == pageUrl) {
-            // Create a new tab showing the subscription page with the right
-            // feed URL.
-            chrome.tabs.create({url: "subscribe.html?" + feedUrl,
-                               windowId: windowId});
-          } else {
-            console.log("Ignoring execute event.");
-            console.log("PageActionId: " + reply.pageActionId + " == " +
-                                           pageActionId);
-            console.log("TabUrl      : " + reply.data.tabUrl + " == " +
-                                           pageUrl);
-          }
+        // We need to know if we are the active window, because the tab may
+        // have moved to another window and we don't want to execute this
+        // action multiple times.
+        if (window.focused) {
+          // Create a new tab showing the subscription page with the right
+          // feed URL.
+          chrome.tabs.create({url: "subscribe.html?" +
+                                       feedData[reply.data.tabId].feedUrl,
+                             windowId: window.windowId});
         }
       });
     });
   });
+
+  chrome.tabs.onRemoved.addListener(function(reply) {
+    feedData[reply.tabId] = null;
+  });
 </script>
 </head>
 </html>