I’m now developing iPhone apps at work which means developing on a Mac.  It’s quite a shift from Windows, so I’ve been spending time learning the ins and outs to become comfortable with the platform.

One of the things I discovered is that the Dock doesn’t provide a way in the UI to add spacers (dividers) between application tiles.  There are two ways to do this.

Add a dummy application to the Dock

This solution is really simple. Brandon Kelly wrote a very simple application Dock Dividers.  Dock Dividers is simple a collection of do-nothing applications with an application image that looks like a divider.  All you do is simply drag an application to the place in the dock where you want a spacer.  The biggest issue is that you have to make sure you don’t drag the same application to the Dock more than once.

Use the defaults program from Terminal to add a spacer

The Dock application actually does support the concept of a spacer tile.  Apple just chose not to expose it in the UI.  To add a spacer tile, type the following sequence of commands in a Terminal window:

defaults write com.apple.dock persistent-apps -array-add '{ "tile-type" = "spacer-tile"; }
killall Dock

You can add as many spacer tiles as you want.  Once you’re done adding them, execute the killall command to restart the Dock.

To remove a spacer tile, simply drag it from the Dock, release it somewhere else, and watch it go up in a poof of smoke.

The biggest issue I see with this method is that the spacer tile is simply a space on the dock.  You don’t get to specify an image to make it look nicer.  Hmm… as I think about this, I’m sure there is a way.  Let me know if you figure it out.

Resources

• Dock Dividers by Brandon Kelly
• Real separators for the Mac OS X Leopard dock (howto)