Issue 5347 - Check for windows API support

ext/background.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 470 matching lines @@
         {
           items.splice(index, 1);
           updateContextMenu();
         }
       }
     }
   };
 
   chrome.tabs.onActivated.addListener(updateContextMenu);
 
-  chrome.windows.onFocusChanged.addListener(windowId =>
+  if ("windows" in chrome)
   {
-    if (windowId != chrome.windows.WINDOW_ID_NONE)
-      updateContextMenu();
-  });
+    chrome.windows.onFocusChanged.addListener(windowId =>
+    {
+      if (windowId != chrome.windows.WINDOW_ID_NONE)
+        updateContextMenu();
+    });
+  }
 
 
   /* Web requests */
 
   let framesOfTabs = new Map();
 
   ext.getFrame = (tabId, frameId) =>
   {
     let frames = framesOfTabs.get(tabId);
     return frames && frames.get(frameId);
@@ skipping 183 matching lines @@
               else
                 afterTabLoaded(callback)(tabs[0]);
             }
           });
         });
       }
     };
   }
   else
   {
     // Edge does not yet support runtime.openOptionsPage (tested version 38)

[Sebastian Noack, 2017/08/15 14:40:19]

This comment should be updated, also mentioning Firefox on Android, in addition
to Microsoft Edge.

[Manish Jethani, 2017/08/15 16:24:12]

I'm going to make another change for runtime.openOptionsPage, because even
though Firefox for Android has this function, it does nothing. We have to use
the info module here.

I'll update the comment as part of that change.

     // 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/
     ext.showOptions = callback =>
     {
-      chrome.windows.getLastFocused(win =>
+      let optionsUrl = "options.html";
+      let queryInfo = {url: optionsUrl};
+
+      let open = win =>
       {
-        let optionsUrl = "options.html";
-        let queryInfo = {url: optionsUrl};
-
         // extension pages can't be accessed in incognito windows. In order to
         // correctly mimic the way in which Chrome opens extension options,
         // we have to focus the options page in any other window.
-        if (!win.incognito)
+        if (win && !win.incognito)
           queryInfo.windowId = win.id;
 
         chrome.tabs.query(queryInfo, tabs =>
         {
           if (tabs.length > 0)
           {
             let tab = tabs[0];
 
-            chrome.windows.update(tab.windowId, {focused: true});
+            if ("windows" in chrome)
+              chrome.windows.update(tab.windowId, {focused: true});
+
             chrome.tabs.update(tab.id, {active: true});
 
             if (callback)
               callback(new Page(tab));
           }
           else
           {
             ext.pages.open(optionsUrl, callback);
           }
         });
-      });
+      };
+
+      if ("windows" in chrome)
+        chrome.windows.getLastFocused(open);
+      else
+        open();
     };
   }
 
   /* Windows */
-  ext.windows = {
-    create(createData, callback)
-    {
-      chrome.windows.create(createData, createdWindow =>
+  if ("windows" in chrome)
+  {
+    ext.windows = {

[Sebastian Noack, 2017/08/15 14:40:19]

What is about the code using ext.windows? I suppose it will just fail with a
different error now?

[Manish Jethani, 2017/08/15 16:24:12]

ext.windows is only used from lib/filterComposer.js. Since we're going to
disable the composer on mobile, this shouldn't be a problem.

If any other code wants to use ext.windows in the future, it should check if it
is supported and do the right thing accordingly.

[Sebastian Noack, 2017/08/18 10:25:21]

I guess we can just leave the code here unchanged then, and just disable the
calling code on Android, as we have to anyway. And if ext.windows is used there
it shouldn't matter whether it fails because it doesn't exist or because the
underlying API it wraps doesn't exist.

[Manish Jethani, 2017/08/18 14:09:58]

I just checked and the only way ext.windows can be called on Android is if the
context menu item is actually displayed. We're not going to display it, so I
think it's OK to just remove this check here.

+      create(createData, callback)
       {
-        afterTabLoaded(callback)(createdWindow.tabs[0]);
-      });
-    }
-  };
+        chrome.windows.create(createData, createdWindow =>
+        {
+          afterTabLoaded(callback)(createdWindow.tabs[0]);
+        });
+      }
+    };
+  }
 }());