Using scroll bars
Scroll bars appear in program windows
whenever the window contains more information than it can fit. You may
not see any on your screen right now. But don’t worry about that. The
trick is to recognize them when you do see them, to know what they
mean, and to know how to work them. Figure 4 shows an example of a vertical scroll bar and a horizontal scroll bar.
When you see a scroll bar, it means that there’s
more to see than what’s currently visible in the window. The size of
the scroll box (the bit inside the scroll bar area that looks like a
long button) relative to the size of the scroll bar tells you roughly
how much more there is to see. For example, if the scroll bar is about
10 percent the size of the bar, it means you’re seeing only about 10
percent of all there is to see.
To see the rest, you use the scroll bar to scroll through the information. You have basically three ways to use scroll bars:
- Click a button at the end of the scroll bar to move a little bit in the direction of the arrow on the button.
- Click an empty space on the scroll bar to move the scroll box along
the bar toward the place where you clicked. That moves you farther than
clicking the buttons would.
- Drag the scroll box in the direction you want to scroll. To drag,
place the mouse pointer on the button and hold down the left mouse
button while moving the mouse in the direction you want to scroll.
If your mouse has a wheel, you can use
that to scroll as well. If the window shows a vertical scroll bar,
spinning the mouse wheel scrolls up and down. If the window shows only
a horizontal scroll bar, spinning the mouse wheel scrolls left and
right. Some mice have a horizontal scroll button (or wheel) that you
can push left or right to scroll horizontally.
You can also use the keyboard to scroll up and
down. But understand that the scroll bars work only in the active
window (the window that’s on the top of the stack). If necessary, first
click the window or press Alt+Tab to bring it to the top of the stack.
Then you can use the up and down arrow keys (? and ?) to scroll up and
down slightly. Use the Page Up (PgUp) and Page Down (PgDn) keys to
scroll up and down in larger increments. Press the Home key to scroll
all the way to the top (or all the way to the left). Press the End key
to scroll all the way to the end.
Using Back and Forward buttons
Back and Forward buttons help you
navigate through multiple pages of items. As with scroll bars, they
appear only when useful, so don’t expect to see them on your screen
right now, or all the time. At times, they may be disabled (dimmed), as at the top of Figure 5. At other times they are enabled (not dimmed). Also, you won’t find Back and Forward buttons in every program window.
A disabled button isn’t broken. When an item is
disabled, it’s just not appropriate at the moment. For example, when
you first open a window, both buttons may be disabled because you have
no page to switch to yet. When you click a link that takes you to
another page, the Back button is then enabled because now you do
have a page to go back to (the page you just left). After you go back
to the previous page, the Forward button is enabled because now you
have a page to go forward to — the page you just left.
When a button is enabled, you just click it to go back or forward. When a button is disabled, clicking it has no effect.
