When dragging a file, all the entries on the launcher that are able to open that file stay lightened while the others fade. As far as I know, this is based on the Mime Types specified on the .desktop ...
I'm trying to create a unity launcher icon (.dekstop file) on which you can drop any (selected/highlighted) text from a web browser, google chrome in my case. I know you can use the "MimeType=" key ...
In unity, we can drag files on application's button in the launcher to open that file with that application - however, looks like its hard to change default application. I use Komodo as editor, and ...