contextual menus not working in the webapp container

I did a bit of preliminary investigation, and I’m not even seeing the contextmenu event being emitted when using the webapp (as noted in the bug’s description, it works in the browser app).

On desktop, right click on a link on twitter.com in the container brings up the contextual menu, so the issue seems to be touch-specific.

It might be that twitter on touch inhibits the contextmenu event, in which case there wouldn’t be much we can do about it.

Scratch the previous comment, if it was the case then it wouldn’t work in the plain webbrowser-app, but it does.

Note that the gmail webapp is affected too, so it looks like the issue might be in the webapp-container.

I can confirm that the issue is not specific to a given webapp, it seems to be in the container itself.
Tested by launching webapp-container directly on the device with any URL as a parameter, and verified that no contextual menu ever shows.

The contextmenu event is received on the javascript side, but the message it sends to the webview (using oxide.sendMessage(…)) doesn’t seem to get through.

The scroll event (confirmed to be received on the JS side) that also triggers a call to oxide.sendMessage(…) doesn’t get through either, so there is a condition that makes oxide.sendMessage() fail when ran in the context of webapp-container.

Also tested with a sample QML app (confined) that instantiates a WebView and defines custom contextualActions, and the context menu shows up as expected, so the issue seems restricted to webapp-container only.

I found the culprit: UnityWebAppsUtils.js (from the unity-webapps-qml package) does this:

        var script = 'import com.canonical.Oxide 1.0 as Oxide; ' +
                ' Oxide.ScriptMessageHandler { msgId: "UnityWebappApi-Message"; contexts: ["' +
                this._WEBAPPS_USER_SCRIPT_CONTEXT +
                '"]; ' +
                '}';
        var messageHandler = Qt.createQmlObject(script, this.webview);
        messageHandler.callback = handler;
        this.webview.messageHandlers = [ messageHandler ];

So it effectively overrides the webview’s existing message handlers.

This bug was fixed in the package unity-webapps-qml - 0.1+14.10.20140620-0ubuntu1

---------------
unity-webapps-qml (0.1+14.10.20140620-0ubuntu1) utopic; urgency=low

  [ Ubuntu daily release ]
  * New rebuild forced

  [ Olivier Tilloy ]
  * Do not override existing message handlers. Oxide has this nice
    feature that it automatically attaches the instantiated message
    handler to the webview anyway, so this line was useless. (LP:
    #1323735)
 -- Ubuntu daily release <email address hidden> Fri, 20 Jun 2014 09:37:13 +0000