Issue 5587, 5748 - Use mobile options page on Firefox for Android

ext/background.js

Index: ext/background.js
===================================================================
--- a/ext/background.js
+++ b/ext/background.js
@@ -312,26 +312,16 @@
   chrome.tabs.onActivated.addListener(details =>
   {
     ext.pages.onActivated._dispatch(new Page({id: details.tabId}));
   });
 
 
   /* Browser actions */
 
-  // On Firefox for Android, open the options page directly when the browser
-  // action is clicked.
-  if (!("getPopup" in chrome.browserAction))
-  {
-    chrome.browserAction.onClicked.addListener(() =>
-    {
-      ext.showOptions();
-    });
-  }
-
   let BrowserAction = function(tabId)
   {
     this._tabId = tabId;
     this._changes = null;
   };
   BrowserAction.prototype = {
     _applyChanges()
     {
@@ -727,55 +717,58 @@
                 callback(new Page(tabs[0]));
               else
                 afterTabLoaded(callback)(tabs[0]);
             }
           });
         });
       }
     }
-    else if ("windows" in chrome)
+    else
     {
       // Edge does not yet support runtime.openOptionsPage (tested version 38)
-      // and so this workaround needs to stay for now.
-      // We are not using extension.getURL to get the absolute path here
-      // because of the Edge issue:
-      // https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/10276332/
-      let optionsUrl = "options.html";
-      let fullOptionsUrl = ext.getURL(optionsUrl);
-
       chrome.tabs.query({}, tabs =>
       {
         // We find a tab ourselves because Edge has a bug when quering tabs
         // with extension URL protocol:
         // https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/8094141/ 
         // https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/8604703/
+        // Firefox won't let us query for moz-extension:// pages either, though
+        // starting with Firefox 56 an extension can query for its own URLs:
+        // https://bugzilla.mozilla.org/show_bug.cgi?id=1271354
+        let optionsUrl = "options.html";
+        let fullOptionsUrl = ext.getURL(optionsUrl);
         let tab = tabs.find(element => element.url == fullOptionsUrl);
         if (tab)
         {
-          chrome.windows.update(tab.windowId, {focused: true});
+          // Firefox for Android before version 57 does not support
+          // runtime.openOptionsPage, nor does it support the windows API.
+          // Since there is effectively only one window on the mobile browser,
+          // there's no need to bring it into focus.
+          if ("windows" in chrome)
+            chrome.windows.update(tab.windowId, {focused: true});
+
           chrome.tabs.update(tab.id, {active: true});
 
           if (callback)
-            callback(new Page(tab));
+          {
+            if (tab.status == "complete")
+              callback(new Page(tab));
+            else
+              afterTabLoaded(callback)(tab);
+          }
         }
         else
         {
+          // We don't use fullOptionsUrl here because of this Edge issue:
+          // https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/10276332
           ext.pages.open(optionsUrl, callback);
         }
       });
     }
-    else
-    {
-      // Firefox for Android before version 57 does not support
-      // runtime.openOptionsPage, nor does it support the windows API. Since
-      // there is effectively only one window on the mobile browser, there's no
-      // need to bring it into focus.
-      ext.pages.open("options.html", callback);
-    }
   };
 
   /* Windows */
   ext.windows = {
     create(createData, callback)
     {
       chrome.windows.create(createData, createdWindow =>
       {