Add message query method

webext/background.js

@@ -1 +1,54 @@
-console.log("Hello world!");
+console.log("Starting background.js");
+
+var SysTrayX = {};
+
+SysTrayX.Messaging = {
+
+  initialized: false,
+  
+  unreadFilter: { unread: true },
+  
+  init: function() {
+    if (this.initialized) {
+      console.log("Messaging already initialized");
+      return;
+    }
+    console.log("Enabling Messaging");
+
+    this.unReadMessages(this.unreadFilter).then(this.unreadCb);
+
+    this.initialized = true;
+  },
+  
+  /*
+   * Use the messages API to get the unread messages (Promise)
+   * Be aware that the data is only avaiable inside the callback
+   */
+  unReadMessages: async function(filter) {
+    let page = await browser.messages.query(filter);
+    
+    let unread = page.messages.length;
+    
+    while (page.id) {
+      page = await browser.messages.continueList(page.id);
+
+      unread = unread + page.messages.length
+    }
+
+    return unread;
+  },
+  
+  /*
+   * Callback for unReadMessages
+   */
+  unreadCb: function(count) {
+    console.log("SysTrayX unread "+count);
+  }
+  
+};
+
+console.log("Starting SysTray-X");
+
+SysTrayX.Messaging.init();
+
+console.log("Done");

webext/manifest.json

@@ -17,11 +17,11 @@
     "48": "icons/message.svg"
   },
 
+  "permissions": [
+    "messagesRead"
+  ],
+  
   "background": {
     "scripts": ["background.js"]
-  },
-
-  "browser_action": {
-    "default_icon": "icons/message.svg"
   }
 }