Unicode Explained

• Character selection errors are reduced, since the user does not have to choose

between, say, ă and ǎ, as in more general methods. A particular language or other

context seldom contains both characters.

The virtual key idea is easy and quick to implement. Thus, it can be applied even on

an individual basis, to create a convenient input form for someone’s personal needs

and preferences. On the other hand, this approach is normally application dependent:

the method needs to be implemented separately for each data entry form. For imple-

mentation issues, see “Character Input and Output” in Chapter 11.

Along similar lines, we could use virtual keys that correspond to writing several char-

acters. If user input is expected to contain some fixed strings rather often, a form de-

signer can set up keys (buttons) that add those strings. This is particularly useful if the

strings contain characters that cannot be directly typed on users’ keyboards.

Program Commands

We often need program-specific ways of entering characters from a keyboard, either

because there is no key for a character we need or there is but it does not work. The

program involved might be part of system software, or it might be an application pro-

gram. We describe here some typical cases.

Copying via the Clipboard

In typical computer systems, you can copy data from one program to another through

an internal storage area called the clipboard. On Windows, you can usually highlight

text with the mouse or select a piece of text otherwise, and then press Ctrl-C to copy,

click on a location in another window, and press Ctrl-V to paste a copy of the text there.

This also works inside a program of course, so you can use it to create copies of a

character or a string.

This feature is well known by most users and often very convenient, though it cannot

be the primary method of writing text. You can however copy characters from web

pages or from text documents specifically designed for use as “cliptext.”

Often this technique has the property of copying text formatting along with the text. If

you copy bold 16-point Verdana text from Excel to Word, you get 16-point Verdana

text, not text in the normal font as defined by your Word settings or template. This

might be desirable, but more often, it is a problem. Moreover, constructs like hypertext

links may get copied along with the text. To make sure that only the plain text is in-

serted, you can first paste the text in Notepad, select it again there, press Ctrl-C, and

paste in the desired destination.

Program Commands | 83

Menu Commands

Programs

may have command menus for inserting characters, so that characters are

identified by some names or glyphs. At the simplest, you just select a command and a

subcommand from a menu. Usually it is more complicated, to allow the insertion of

more characters that can conveniently be included into a command menu.

Insertion menu in Thunderbird

In Mozilla Thunderbird, when composing an email message, you can select Insert →

Characters and symbols. This opens a small window, as in Figure 2-7. There, you can

select a class of characters by clicking on one of the radio buttons. This affects the drop-

down menu under the buttons. For example, when Common Symbols is selected, the

Character drop-down menu contains a collection of Latin 1 special characters (other

than letters), such as © and ±.

Such an input method is intuitively easy and can be found and used by a user even

without any documentation. On the other hand, it is rather clumsy, since any insertion

requires several steps.

Symbol (character) insertion menu in MS Word

In MS Word, you can use the command Insert → Symbol to invoke an auxiliary

window, which has two modes of operation. In the default mode, Symbols, you can

select a character from a table, as explained in the section “Character Maps later in this

chapter. You enter the second mode by clicking on Special Characters. There, you can

pick up a character from a short list, as shown in Figure 2-8. The list also contains

information about shortcut keys for the characters, so it can be used to check such

Figure 2-7. Character insertion window in Thunderbird

84 | Chapter 2: Writing Characters