The nsIWebNavigationInfo interface exposes a way to get information
 on the capabilities of Gecko webnavigation objects.

 @status UNDER_REVIEW
[scriptable, uuid(62a93afb-93a1-465c-84c8-0432264229de)]
interface nsIWebNavigationInfo : nsISupports

Constants

 Returned by isTypeSupported to indicate lack of support for a type.
 @note this is guaranteed not to change, so that boolean tests can be done
 on the return value if isTypeSupported to detect whether a type is
 supported at all.
const unsigned long UNSUPPORTED = 0
 Returned by isTypeSupported to indicate that a type is supported as an
 image.
const unsigned long IMAGE = 1
 Returned by isTypeSupported to indicate that a type is supported via an
 NPAPI ("Netscape 4 API") plug-in.  This is not the value returned for
 "XPCOM plug-ins".
const unsigned long PLUGIN = 2
 @note Other return types may be added here in the future as they become
 relevant.


 Returned by isTypeSupported to indicate that a type is supported via some
 other means.
const unsigned long OTHER = 32768

Methods

 Query whether aType is supported.
 @param aType the MIME type in question.
 @param aWebNav the nsIWebNavigation object for which the request
        is being made.  This is allowed to be null.  If it is non-null,
        the return value of this method may depend on the exact state of
        aWebNav and the values set through nsIWebBrowserSetup; otherwise
        the method will assume that the caller is interested in information
        about nsIWebNavigation objects in their default state.
 @return an enum value indicating whether and how aType is supported.
 @note This method may rescan plugins to ensure that they're properly
       registered for the types they support.
unsigned long isTypeSupported(in ACString aType, in nsIWebNavigation aWebNav)