Window Controls: Mac OS vs Windows

As I observe casual users working with a Mac (my wife falls into that category) I often see them doing something that is very Windows like: trying to close an application by clicking the close button in the top of the window title. My wife also says she hates the Maximize window button because it doesn’t maximize the window like it did in Windows.

On a Mac the series of buttons in the top left corner of a window are called the Title Bar Buttons. Much like the window controls found in virtually every version of Windows, these allow the user to perform actions on the window they are attached to. In Mac OS they appear as a series of traffic lights in the top left of the window, in Windows on the top right of the window:
This is probably the one area that most people struggle with, and the underlying design philosophy is both subtle and complex, mostly because the buttons feel like they should work the same way in Mac OS and Windows but have some different behaviors.

They are named nearly the same too:

Mac OS: Close, Minimize, Zoom
Windows: Close, Minimize, Maximize

First off, the easy one. The Minimize button—yellow, center orb on Mac—works just like it does in Windows. It minimizes the window. No problem. Want it back? It’s down in the Dock. Click it to restore it.

The Close button—red, left orb on Mac—is a window close button. It closes the current window, and sometimes the application. Applications that quit when the main window is closed include Calculator, System Preferences, and Network Utility. Nearly every other application keeps running after you close the main window. Here is the fundamental difference:

Windows applications are usually completely contained within their primary window. If you want to open two WordPad documents in Windows 7 you start up two WordPad instances, each with its own window, menus, resources, etc. A Mac application that supports multiple documents (any application that has File > New in the menu) gives you an application instance and a window for each document. Closing the last window of a Mac application that supports multiple instances doesn’t mean you want to close the application as well.

This diagram may help illustrate the point:
In Windows if you close Win Doc 1, you are also closing the application associated with that document. In Mac OS closing Mac Doc 1 simply means you are closing the document window, not the application. So in Mac OS, even if you only have one document open in an application, closing that document window does not quit the application.

Side Note: If you are wondering why sometimes the Close button has a dot inside of it instead of an X (like this)

That’s because the document has changes that haven't been saved yet. Save the document and the dot becomes an X again.

Want the application to just quit? Go to the menu bar while the application has focus and select (Application Name) > Quit, or hit Command-Q. Using the keyboard shortcut for quitting applications has become my preferred method.

Finally there is the Zoom Buttongreen, right orb on Mac. Windows users expect to click the Zoom button and have the window go full screen, much like it does on Windows. It does not. First, let’s cover what it does do:

A Mac application determines the minimum and maximum size a window should be based on the resolution of the display and the user interface inside the application. That means that every time you click Zoom the results can have quite a few variables that determine what will happen. Sometimes the application will simply grow in height to the maximum size of the display area (without overlapping the Dock). Sometimes, if there were horizontal scroll bars, the width will change to eliminate them. The Zoom button is a toggle switch. Clicking it a second time will revert the window to its previous state.

Occasionally you will get an application that just maximizes right to the edges of the display (Firefox is a good example of that). The bottom line is, there is no consistency between applications on what Zoom will actually do other than likely expose a little (or a lot) more content for you.

I’ve found that nearly three years into becoming a pretty hard core Mac user I rarely ever hit the Zoom button. In fact, other than clicking it a lot to help with writing this blog post I don’t think I’ve used it in over a year. Since the impact it will have is not predictable, I just grab the window handle and resize it to what I need.

Want to learn more?
I wrote this because people often search for problems to a specific issue and I couldn't easily find something that pointed out the key differences. If you really want to understand how Mac OS applications should work, take a look a the Apple Human Interface Guidelines. Though it is written to help application developers comply with Mac OS standards, as an application user you can get a very good idea of not just how Mac applications work but also why they work that way.

Special thanks to friend and Mac expert extraordinaire Ast A. Moore for helping me put together this post.