Creating Simple Script Systems

You can create simple script systems-that is, script systems that contain

small character sets and are noncontextual and left to right (for example,

Greek or Cyrillic). You are only required to supply the appropriate fonts and

the following international, keyboard, and font resources: 'itlb' (with the

smsfAutoInit bit on, as described  below), 'itl0', 'itl1', 'itl2', 'itl4', 'KCHR',

and the keyboard color icon family ('kcs#', 'kcs4', and 'kcs8'). You must also

supply 'FOND' and 'NFNT' or 'sfnt' resources.

Such simple script systems can use the Roman Script System routines;

however, to operate as a script system, they need their own local variables.

Note: The capability to create simple script systems is available

beginning with system software version 6.0.7.

If the flag word in a script's 'itlb' resource in the System file has the

smsfAutoInit bit set, the Script Manager initializes the local variables for

that script and fills in the font and style information from fields in 'itlb'.

To provide built-in support for all simple script systems, the Roman

FindScriptRun function has been modified to use an optional table in the

'itl2' resource that specifies the location of Roman characters in a non-Roman

font. See The 'itl2' Resource for details.

Calling the Script Manager

The Script Manager implements several routines itself, but for many

other routines it acts as a dispatcher to the appropriate script system. For

example, each script system provides a CharType function. When a program

calls CharType, the Script Manager uses the current font script (that

is, the script that corresponds to the font of the current grafPort) to dispatch

the call to the correct script system. Your application does not need to know

whether a particular routine is implemented by the Script Manager or by a

script system.

Assembly-language note: All Script Manager routines except the

LowerText, UpperText, StripText, and StripUpperText procedures

are called via the _ScriptUtil trap.

Warning: You should always have the grafPort and A5 world set

appropriately before you call any Script Manager or

International Utilities Package routine. A5 must point to the

QuickDraw global variables, and thePort->txFont must be set

correctly.

The Figure below shows how the Script Manager calls a script system when

an application calls a Script Manager routine that is implemented by each

script system (for example, the Pixel2Char function). When your

application calls Pixel2Char, the Script Manager uses the font script to

determine which script system to call. In the example in the Figure below, the

assumption is that a Japanese font is the font of the current grafPort, so the

Script Manager dispatches to the Japanese Script System. The

Pixel2Char function in the Japanese Script System is used, and it returns

the result directly to the application that called Pixel2Char.

Calling the Script Manager routines implemented by a script system

When an application calls a Script Manager routine that is implemented

directly by the Script Manager itself (for example, the FontScript

function), the flow of control is as shown in the Figure below.

Calling the Script Manager routines

Referenced by (2):