Prior to Yosemite, the familiar green “stoplight” button at the upper-left corner of windows was meant to toggle between the maximized size of the window and whatever user-defined size was currently configured.
So for example, if you resized Mail to be teeny-tiny by dragging the edge of its window, clicking the green button once would maximize it; clicking it again would return it to its tiny self. In Yosemite, however, that behavior is different in some programs (but not all of them—some, like Contacts, TextEdit, and Reminders, still do what I described above). When you hover over the green button in the changed applications, you’ll see arrows instead of a plus sign.
Or would you just call those triangles? I’m not sure. APPLE, WHY ARE YOU MAKING THIS SO HARD ON ME?!
Ahem. Anyway, clicking that button will now take you into full-screen mode. This replaces the functionality of the “arrows” icon that used to appear at the upper-right corner of our windows in earlier versions of the operating system.
I do think this is a nice way to consolidate window controls, so I’m a happy camper, right? Well, sorta. I see why Apple made this change, but heck, what if I want that green button to do what it did under Mavericks? The workarounds are pretty simple, but they’re really, truly not obvious.
First, you could Option-click that green button to force it to perform exactly the way it used to. In fact, when you hold down Option and hover your cursor over an arrow-triangle green button, you’ll see the icon switch to the old “plus” one, giving you a hint about what will happen when you click.
Alternatively, you could double-click anywhere in the grey area of a program’s title bar.
Interestingly, this will now maximize and de-maximize the window, just like the green button used to! Totally intuitive, right?
Keep in mind, though, that whether or not you can do that double-clicking stuff is dependent on what you’ve got set in System Preferences> Dock; if you have “Double-click a window’s title bar to minimize” turned on, then that will happen instead of the window changing size.
As I said, completely intuitive. Oh, Apple, sometimes you really [CONTENT REDACTED] me in the [CONTENT REDACTED], you know?
This tip was suggested by the excellent Benjamin Everson. Thank you, Ben!