Judson Valeski wrote:
> Judson Valeski wrote:
>> nsresult rv = NS_OK;
>> mChrome = do_QueryInterface(browserImpl, rv);
>> if (NS_FAILED(rv)) return rv;
>
> Apologies. The above QI will not compile. do_QueryInterface()
> (http://lxr.mozilla.org/mozilla/source/xpcom/base/nsCOMPtr.h#344) requires an
>nsISupports
> derrived pointer chain (base class nsISupports). You'll have to do a cast
> (NS_STATIC_CAST). That sticks the cast back in, but maintains the ownership model we
>want.
How about:
rv = browserImpl->QueryInterface(NS_GET_IID(what you want mChrome to
be),(void**)&mChrome);
or if mChrome is nsCOMPtr replace (void**)&mChrome with
getter_AddRefs(mChrome).
Also, scc has mentioned that:
nsCOMPtr<nsIFoo> foo = do_QueryInterface(someObject, rv);
can be made more efficient by:
nsCOMPtr<nsIFoo> foo(do_QueryInterface(someObject, rv));
i.e. replace the assignment with constructor. Results in fewer
instructions. Works with other "do_" things as well.
--
Heikki Toivonen
