BMessaging files from BMenu like Tracker does

[zuMi]

You know, every Tracker window has a dragable icon in the upper right corner that bmessage the opened folder to any other application, I'm just wondering how the system usability could be enhanced if that feature will be available in every application, i.e. you listen a media file on MediaPlayer and just drop its icon from the BMenu to ArmyKnife to modify its tags, or to MediaConverter to change its format; read a mail from Mail and drop it to the Trash or to a mime_parser to purge its enclosures, etc.

[axeld]

While I'm general in favour of that icon, I wouldn't mind a more usable solution, for example by adding that feature to BMenuBar directly.

We could also think about moving this into the title bar of the window, although I have no idea on how to make that actually usable for the user (I haven't seen anything convincing elsewhere yet).

[axeld]

Possible API extension for BMenuBar:

void SetIcon(entry_ref* ref, BMessage* message = NULL);
void SetIcon(BBitmap* bitmap, BMessage* message = NULL);

[pulkomandy]

Moving out of R1 milestone, but that would be a great feature to have anyway.