So I was reading Usenet one morning in March, 2005, and saw someone ask if anyone knew of a program that would display the cover art for the current iTunes track in the dock. He had looked at a couple of things that were close to what he wanted, but they all fell short in some way. I thought it might be a fun project. Here's the result. It's fairly small and very focussed.
Copy DockArtPlugin.bundle to ~/Library/iTunes/iTunes Plug-Ins or /Library/iTunes/iTunes Plug-Ins. If iTunes is running, stop and restart it. You'll see an entry named DockArt added to iTunes' Visualizer menu, but you don't have to select it. Any time you play a song that has cover art, it will replace the iTunes icon in your dock. When nothing is playing, or whatever is playing has no art, the normal iTunes icon will appear.
DockArt has a settings dialog that will be displayed if you select DockArt as your active visualizer and then choose the Options... command. As of this writing (iTunes 10.4 is current) this is in the Visualizer submenu of the View menu. Once DockArt is configured, you can go back to setting a different plugin as the active one.
Skew Art In Dock
Check this box to tilt the dock tile a bit so it fits in more with the feel of many other application icons.
Show Unread Podcasts
Check this box to display a badge in the upper-right corner showing the number of podcasts that have not been played.
Show iTunes Badge
Check this box to use the original iTunes icon as a badge on the dock image to help remind you what that picture actually is. You can use the slider to adjust the size of the badge. I think it looks best in conjunction with the skewing option.
Show All Attached Art
Check this box to let DockArt cycle through all the images attached to the current track instead of just the first one.
If DockArt does not find artwork embedded in the current music file, it will look for an image file with this name in the folder that contains that music file. If you have opted to keep, for example, a single JPEG file in the directory iTunes maintains for each album to reduce space consumption, just enter the name you use for that artwork here. At the moment, this function only supports a single file name.
DockArt 2 requires iTunes 10.4 or higher. If you're still using an older a version of iTunes and installed this prematurely, you can get the previous build of DockArt here.
DockArt 2.2 was released specifically to address an issue introduced in iTunes 11.0.3 and is Intel-only. The most recent build supporting PowerPC is here.
The DockArt package was released as freeware and remains so. It was a quick, fun project that someone else inspired. That said, its development has consumed some significant time and, as those who've contacted me know, it's well supported. If you use DockArt - and possibly even find it useful - please consider making a charitable donation to Fidelco.
Someone who feels compelled to give me money might want to check out my trash automation utility, Compost.