Comment 38 for bug 49613

(In reply to comment #29)
> + exposeEvent.drawable =
> (Drawable)win->GetNativeData(NS_NATIVE_WIDGET);
>
> You want NS_NATIVE_WINDOW so that this can work in GTK1.
>
> Other than that, this looks pretty good on the painting side. But the event
> handling is missing. You need something like this:
>
> http://lxr.mozilla.org/mozilla/source/layout/generic/nsObjectFrame.cpp#3883
>
> Fix that and I think we're close to having something we can check in ... need
> testing from the Macromedia folks though, really.

a field "window" in the "NPWindow" Structure, such as In Windows Platform, just explained as a hdc.
can we add a variable in the class "ns4xPluginInstance" to hold the Drawable.
if it is windowless. then we can retrieve it. if it is windowed ,we just omit it.