How to Scroll in Mac OS X Mountain Lion
One way to see more of what’s in a Mountain Lion window or pane is to scroll through it. Scroll bars appear at the bottom and right sides of any window or pane that contains more stuff — icons, text, pixels, or whatever — than you can see in the window.
The following figure shows two instances of the same window: Dragging the scroll bar on the right side of the front window reveals the items above DVD Player and FaceTime and below iDVD and Image Capture, which you see in the expanded window in the background. Dragging the scroll bar on the bottom of the window reveals items to the left and right, such as Dictionary, iChat, GarageBand, and iPhoto.
Simply click and drag a scroll bar to move it up or down or side to side.
If your scroll bars don’t look exactly like the ones in the figure or work as described in the following list, don’t worry. These are System Preferences you can configure to your heart’s desire.
Here are some ways you can scroll in a window:
Click a scroll bar and drag. The content of the window scrolls proportionally to how far you drag the scroll bar.
Click in the scroll bar area but don’t click the scroll bar itself. The window scrolls either one page up (if you click above the scroll bar) or down (if you click below the scroll bar). You can change a setting in your General System Preferences pane to cause the window to scroll proportionally to where you click.
For what it’s worth, the Page Up and Page Down keys on your keyboard function the same way as clicking the grayish scroll bar area (the vertical scroll bar only) in the Finder and many applications. But these keys don’t work in every program; don’t become too dependent on them.
Also, if you’ve purchased a mouse, trackball, or other pointing device that has a scroll wheel, you can scroll vertically in the active (front) window with the scroll wheel or press and hold the Shift key to scroll horizontally. Alas, this horizontal scrolling-with-the-Shift-key works in Finder windows, but not in all applications. For example, it works in Apple’s TextEdit application, but not in Microsoft Word.
Use the keyboard. In the Finder, first click an icon in the window and then use the arrow keys to move up, down, left, or right. Using an arrow key selects the next icon in the direction it indicates — and automatically scrolls the window, if necessary. In other programs, you might or might not be able to use the keyboard to scroll.
Two-finger swipe (on a trackpad): If you have a notebook with a trackpad or use a Magic Trackpad or Magic Mouse, just swipe the pad with two fingers to scroll in a window.