Adding OmniWeb the Internet Control Panel by Rick Roe

I prefer to use OmniWeb as my web browser (no surprise), but I still use Entourage in Classic because Apple Mail doesn't do multiple outgoing accounts (yet, I hope). Unfortunately, it's not possible to set up the Internet Control panel to use OmniWeb as a helper app, because it doesn't recognize Cocoa applications (or some types of Carbon apps) in its app-choosing dialog.

However, with a resource editor anything is possible... :)

I set out trying to find and edit whatever resource specifies the content of the "Default Web Browser" pop-up menu in the Internet control panel.

While I did find and successfully edit this resource, it didn't solve my problem. It appears that the Internet control panel does some searching to make sure that only applications that exist on disk will show up in that menu -- and said searching doesn't find Mac OS X apps. (If you're interested in editing it anyway, you'll find info at the end of this tutorial.)

So instead I directly edited the Internet Preferences file to make OmniWeb the helper app for http and https. Open it with your favorite resource editor (I use Resorcerer), and look at the "ICRP" resource list. The numbering of these resources seems to be dynamic, so look for the "Helper*http" resource by name. Open it up, and it should look something like this:

It should be pretty obvious where to put the name and signature (creator code) of whatever app you're wanting to use. (Signatures for Mac OS X apps can be found in their Info.plist files. OmniWeb's is "OWEB".) Note the ninth byte (highlighted in green); its hex value should be the length of the name string that follows it. For example: "Internet Explorer" is 17 characters long, or 11 in hexadecimal. Following the name string is what appears to be an arbitrary amount of "padding" (highlighted in blue). It appears to be safe to have pretty much any number of zeros here.

Save your edited resource, close the Internet Preferences file, and open the Internet control panel. You should see your browser of choice on the Web pane now, and any http URLs you click should be directed to it. This same technique works for other protocols, so it's probably a good idea to also do https and file if you're trying to set your default web browser. Or you can use it to set helper apps for other protocols, like mail and news/nntp.

Now, for editing the popup list. It's the "HelperList*http" resource, and it looks like this:

The format for each application in the list is the same as for the "Helper*http" resource, but with a couple of differences. First, the fifth and sixth bytes from the beginning of the resource (highlighted in green) should indicate the number of entries in the list. The default is 0003; be sure to increment it if you add more. Second, it looks like the amount of "padding" actually matters in this resource: you have to make it so that the combined length of the name and the string of zeros following it (highlighted in blue) is 3F bytes. In decimal terms, that's 63 characters long.

You can also edit the "HelperList*mailto" and "HelperList*news" resources in this fashion. This only works for Classic (and some Carbon) apps, but it can be useful for, say, permanently adding PowerMail to your list of mailers.

Also, you can edit Helper* and HelperList* resources in the Internet Config Extension to set the defaults that get used when no Internet Preferences file exists. In that file, they're "Pref" resources, but otherwise they're pretty similar.