Universal Access

Chia sẻ: Nghia Tuan | Ngày: | Loại File: PDF | Số trang:6

0
56
lượt xem
6
download

Universal Access

Mô tả tài liệu
  Download Vui lòng tải xuống để xem tài liệu đầy đủ

9.27. Universal Access The Universal Access panel is designed for people who type with one hand, find it difficult to use a mouse, or have trouble seeing or hearing.

Chủ đề:
Lưu

Nội dung Text: Universal Access

  1. 9.27. Universal Access The Universal Access panel is designed for people who type with one hand, find it difficult to use a mouse, or have trouble seeing or hearing. (These features can also be handy when the mouse is broken or missing.) 9.27.1. Seeing Tab (Magnifying the Screen) If you have trouble seeing the screen, then boy, does Mac OS X have features for you (Figure 9-17). Figure 9-17. You'll be amazed at just how much you can zoom in to the Mac's screen using this Universal Access pane. In fact, there's nothing to stop you from zooming in so far that a single pixel fills the entire monitor. (That may not be especially useful for people with limited vision, but it can be handy for graphic designers learning how to reproduce a certain icon, dot by dot.) 9.27.1.1. VoiceOver One option is VoiceOver, which makes the Mac read out loud every bit of text that's on the screen. VoiceOver is described on Section 15.5.1.3. 9.27.1.2. Zoom Another quick solution is to reduce your monitor's resolution —thus magnifying the image—using the Displays panel described earlier in this chapter. If you have a 17-inch or larger monitor set to, say, 640 x 480, the result is a greatly magnified picture. That method doesn't give you much flexibility, however, and it's a hassle to adjust. If you agree, then try the Zoom feature that appears here; it lets you enlarge the area surrounding your cursor in any increment. To make it work, press Option- -8 as you're working. Or, if the Seeing panel is open, click On in the Zoom section. That's the master switch.
  2. No zooming actually takes place, however, until you press Option- -plus sign (to zoom in) or Option- -minus sign (to zoom out). With each press, the entire screen image gets larger or smaller, creating a virtual monitor that follows your cursor around the screen. Tip: If you have a laptop, just using the Control-key trackpad trick described on Section 9.14.3.1 is a far faster and easier way to magnify the screen.And if you have a mouse with a scroll wheel on top (or a scroll-BB, like Apple's standard Mighty Mouse), you can also zoom in or out by pressing Control while you scroll that. If you click Options, you'll find acres of options that control when the enlarged screen image pans (all the time, or only when the pointer hits a screen edge), the maximum or minimum degree of enlargement, and so on. 9.27.1.3. Display (inverted colors) While you're at it, pressing Control-Option- -* (asterisk), or clicking the "Switch to Black on White" button, inverts the colors of the screen, so that text appears white on black—an effect that some people find easier to read. (This option also freaks out many Mac fans who turn it on by mistake, somehow pressing Control-Option- -* by accident during everyday work. They think that the Mac's expensive monitor has just gone loco. Now you know better.) Tip: There's also a button called Use Grayscale, which banishes all color from your screen. This is another feature designed to improve text clarity, but it's also a dandy way to see how a color document will look when printed on a monochrome laser printer. No matter which color mode you choose, the "Enhance contrast" slider is another option that can help. It makes blacks blacker and whites whiter, further eliminating in-between shades and thereby making the screen easier to see. (If the Universal Access panel doesn't happen to be open, you can always use the keystrokes Control-Option -< and -> to decrease or increase contrast.) 9.27.2. Hearing Tab (Flashing the Screen)
  3. If you have trouble hearing the Mac's sounds, the obvious solution is to increase the volume, which is why this panel offers a direct link to the Sound preferences pane. (If your Mac doesn't have external speakers, consider getting some.) Fortunately, hearing your computer usually isn't critical (except when working in music and audio, of course). The only time audio is especially important is when the Mac tries to get your attention by beeping. For those situations, turn on "Flash the screen when an alert sound occurs" (an effect you can try out by clicking the Flash Screen button). Now you'll see a white flash across the entire monitor whenever the Mac would otherwise beep—not a bad idea on laptops, actually, so that you don't miss beeps when you've got the speakers muted. 9.27.3. Keyboard Tab (Typing Assistance) This panel offers two clever features designed to help people who have trouble using the keyboard. • Sticky Keys lets you press multiple-key shortcuts (involving keys like Shift, Option, Control, and ) one at a time instead of all together. To make Sticky Keys work, first turn on the master switch at the top of the dialog box. Then go to work on the Mac, triggering keyboard commands as shown in Figure 9-18. Figure 9-18. Whenever you want to press a multiple-key keystroke like Shift- -D, press them one at a time. You'll see ghost images of these keys superimposed on your screen, as though to show you which keystrokes you've added to your temporary collection. To "un-press" a key you've already pressed, press it again twice. If you press a modifier key twice, meanwhile, you lock it down. (Its onscreen symbol gets brighter to let you know.) When a key is locked, you can use it for several commands in a row. For example, if a folder icon is highlighted, you could double-press to lock it down—and then type O (to open the folder), look around, and then press W (to close the window). Press the key a third time to "un-press" it.
  4. Tip: The checkbox called "Press the Shift key five times to turn Sticky Keys on or off" gives you the flexibility of turning Sticky Keys on and off at will, without even taking a trip to System Preferences. Whenever you want to turn on Sticky Keys, press the Shift key five times in succession. You'll hear a special clacking sound effect alerting you that you just turned on Sticky Keys. (Repeat the five presses to turn Sticky Keys off again.) • Slow Keys, on the other hand, doesn't register a key press at all until you've held down the key for more than a second or so—a feature designed to screen out accidental key presses. If "Use click key sounds" is turned on, you'll hear a little typing sound each time you press a key—but none of these key presses registers unless you hold the key down for a moment. (Use the Acceptance Delay slider to govern this threshold.) GEM IN THE ROUGH Direct System Preferences Access from the Dock As noted earlier in this chapter, Mac OS X offers a tidy pop-up menu of System Preferences panels right there in your Dock. That's a great feature, one that saves you several steps on the way to System Preferences—but it works only when System Preferences is already running. Wouldn't it be cool if your favorite preference panels could pop up from the Dock anytime, whether System Preferences was running or not? Here's how you do it. Make a new folder (in your Home folder, for example). Name it whatever you'll want the Dock icon to say—SysPrefs or Control Panels, for example. Stick it into your Sidebar for a moment. Now open your System Library PreferencePanes folder, which contains the icons for the various System Preferences panes. Select all of them—or only the ones you actually use. Drag them into the SysPrefs folder on your Sidebar, taking care to press Option- as you release the mouse. (Option- -dragging makes aliases of them.) If the .prefPane suffix on the aliases bugs you, select all of the aliases, press Option- -I, open the Name & Extension panel in the Info window, and then
  5. turn on "Hide extension." Finally, drag the SysPrefs folder onto the right side of your Dock. Now, whenever you want to open a particular panel, just click this SysPrefs Dock icon. You get a handy pop-up stack, as shown here; one more click opens the panel you want. You hear a different sound when the Mac actually accepts the key press—and, of course, you'll see the letter you typed appear onscreen. 9.27.4. Mouse & Trackpad Tab (Cursor Control from the Keyboard) Mouse Keys is designed to help people who can't use the mouse—or who want more precision when working in graphics programs. It lets you click, drag, and otherwise manipulate the cursor by pressing the keys on your numeric keypad. (It's not very useful on keyboards that don't have separate numeric keypads, including laptops.) When Mouse Keys is turned on, the 5 key acts as the clicker—hold it down for a moment to "click the mouse," do that twice to double-click, and so on. Hold down the 0 key to lock down the mouse button, and the period key to unlock it. (The amount of time you have to hold them down depends on how you've set the Initial Delay slider.) Move the cursor around the screen by pressing the eight keys that surround the 5 key. (For example, hold down the 9 key to move the cursor diagonally up and to the right.) If you hold one of these keys down continuously, the cursor, after a pause, begins to move smoothly in that direction—according to the way you have adjusted the sliders called Initial Delay and Maximum Speed. Tip: The checkbox called "Press the Option key five times to turn Mouse Keys on or off" saves you the trouble of opening System Preferences. At the bottom of this window, you'll find the Cursor Size slider. It's a godsend not only to people with failing vision, but also to anyone using one of Apple's large, super-high- resolution screens; as the pixel density increases, the arrow cursor gets smaller and smaller. This slider lets you make the arrow cursor larger—much larger, if you like— making it much easier to see.
Đồng bộ tài khoản