One of the new features of Mac OS 10.5, a.k.a. Leopard, is .Mac’s Back to My Mac, a way to connect to your computer at home remotely. Back to My Mac allows a user log into another Mac remotely via internet. This is a great feature but it is only available if you are a .Mac subscriber. However, the new iChat supports Screen Sharing, so the only thing to figure out is how to auto-accept a Screen Share invitation and how to do it securely. This quick tutorial will show you how set up iChat to do just that.

Requirements:

This set up requires that both computers run Leopard. If you don’t have it yet, here’s the Amazon link to buy it. It is well worth the price. You also need two separate iChat supported IM accounts, one for each computer. This could be AIM, .Mac or Jabber accounts.

Step 1: Limit Users

It is very important this step is not skipped. Not limiting the users will open up to anyone taking over your computer.

From your Mac at home, launch iChat and from the top menu select iChat > Preferences and from the Accounts tab select your account from the Accounts list on the left panel.

From the Security tab, select Allow Specific People and add the username of the ichat account you would like to allow to auto-connect.

Step 2: Set Up Auto Accept Screen Sharing

From the Alerts tab in the ‘iChat > Preferences’, select Audio Invitation from the Event pull down menu. Then check-mark Run AppleScript and select Auto Accept.applescript from the pulldown menu. You can close the Preferences window now.

Now, we’ll need to edit the Auto Accept script we selected in the previous step. Click on the desktop to go to the Finder and from a new Finder window, navigate to ‘Your Hard Disk/Library/Scripts/iChat/’. This is the folder that contains the iChat AppleScripts provided by Apple in Leopard. Double click the file Auto Accept.applescript to open in AppleScript Utility.

A Screen Sharing invitation is sent to iChat as an Audio chat with a Screen Sharing flag. We will need to locate the audio invitation section and comment out the screen sharing if statement by enclosing the lines with (* and *). See example bellow. Additions are marked in red.


on received audio invitation theText from theBuddy for theChat
   (* if (screen sharing of theChat is none) then *)
    accept theChat
  (* end if *)
end received audio invitation


Save the document and quit AppleScript Utility.

Step 3: Set Home Computer To Stay Awake

Next, we need to set the home computer to stay stay awake, otherwise it will automatically go to sleep when not in use. From the top menu bar, select ‘Apple > System Preferences’ and click on the Energy Saver Preference Pane. From the Sleep tab, set the Computer sleep mode to never and check-mark the Put the hard disk to sleep option then quit System Preferences.

Step 4: Connect Remotely

Now we’re going to connect to our home Mac. From the other computer, add the username to the buddy list, select it and click the ‘Start Screen Sharing’ button on the bottom right of the buddy list window.

From the ‘Start Screen Sharing’ pull down menu, select ‘Ask to Share Username’s Screen…’ to begin the process.

iChat will ask permission on the Home account, but it will be automatically approved by our script there.

iChat will do it’s magic and your screen will shrink down to the corner as the remote Mac at home will go full screen.

Conclusion

I thought ‘Back to My Mac’ was going to be the .Mac feature that will make me renew my .Mac subscription, but the new iChat has proven more capable than the demo Steve made in his keynote.