Tech Tip Tuesday - Docked Mac Icons

I know that my blog posts are heavily weighted to Windows machines. Believe me when I say that this is not because of preference. I much prefer Linux over OS X and OS X over Windows. It's just that most of my readers run Windows machines and even most of my Mac users have at least one Windows machine or run Windows in Bootcamp. Therefore, I am more or less forced to post more Windows-centric posts. However, occasionally I like to throw my Mac users a bone. This is one of those days.

Even if you have only been using a Mac for a short period, you may have noticed that some of the dock icons change. These are known as dynamic icons as opposed to static icons which do not change. A perfect example of a dynamic icon is the icon for the calendar app iCal. You will surely have noticed that the icon for iCal shows the current date:

Another, yet more subtle example for dynamic icons are ones that are update-aware such as the AppStore, Yammer, and Facebook apps:

As you can see these icons display a number in a red circle to let you know there are new updates for that app. So what am I getting at you may ask?

What I'm getting at is that certain docked app icons can display useful information. This information can be useful without even opening the app as in the iCal example. You do not have to open iCal to see that the date is August 20^th. It's like having a mini stripped-down version of the app always there for handy reference. Well, now I want to show you one of the most useful dynamic icons I have discovered so far. It is the icon for the Activity Monitor.

Activity Monitor in OS X is very similar to the task manager in Windows, showing running apps and how much resources they consume. What is neat about it's icon is that when docked it can show various information such as CPU usage all at your command. Here are some of the icons that can be displayed with the activity monitor:

CPU Usage Icon

As you can see my iMac has dual processors and a realtime graphical representation of each is shown on the icon.

CPU History Icon

This icon shows CPU usage over time in realtime.

Network Usage Icon

This one shows traffic over the network, in realtime.

Disk Activity Icon

This one shows the activity of the hard drive over time, in realtime.

Memory Usage Icon

This one shows a pie chart representing the usage of the RAM. Red is wired usage, otherwise known as system usage (i.e. the operating system). Yellow is active programs. Blue is inactive programs. Green is free memory. Did I mention that this pie chart changes in realtime? Yes. All these icons display their information in realtime.

So here is how you do it:

1. Click the Applications icon
2. Click the Utilities icon
3. Click the Activity Monitor icon

At this point the Activity Monitor should be running and visible on the desktop, but more importantly the Activity Monitor icon should be in the dock. However, if you quit the activity monitor or if you log out or restart the computer the icon disappears and you have to repeat the above process to get it back. To prevent this:

1. Right-click (control-click) the Activity Monitor icon
2. Under options select Keep in Dock and Open at Login

Keep in Dock will keep the Activity Monitor on the dock, but if you quit the app or log out the icon reverts to the default Activity Monitor icon, which looks like this:

This icon is static. So to keep your dynamic icon displayed just check Open at Login and Activity Monitor will launch at startup so that your dynamic monitor icon will always be displayed. If you have been following along, you probably have noticed that you can change which icon is displayed by selecting it under the Dock Icon submenu after control-clicking.

Now that you know about the dynamic icons in OS X have fun with the activity Monitor and see if you can find some other cool dynamic icons that display useful information. If you find any, please share them in the comments so that the rest of us can enjoy them.