Apple Newton Utilities Guide de l'utilisateur télécharger pdf (Page 385)

100

101

CHAPTER 10

Recognition: Advanced Topics

Using Advanced Topics in Recognition 10-9

Creating a recConﬁg Frame 10

For any view that is to use a recConfig frame, you must supply a recConfig

slot, usually by deﬁning it in your view’s template. The frame in your view’s

recConfig slot must be modifiable; that is, it must be RAM-based. When your

view template supplies a

recConfig frame, the view system builds a RAM-based

recConfig frame along with the view—you need not do anything more to cause

the view to use the

recConfig frame.

To create your own

recConfig frame at run time, you need to call the

PrepRecConfig function to create a RAM-based recConfig frame that the

system can use. Although you could obtain similar results by cloning a

recConfig frame that your view template defines, using the PrepRecConfig

function is more efﬁcient:

■ The PrepRecConfig function creates a smaller frame than that obtained by

cloning your view template’s

recConfig frame.

■ The frame that the PrepRecConfig function returns can be used as it is by the

recognition system. Any other frame that you place in the view’s

recConfig

slot is used by the system to create the

recConfig frame actually used by the

view, with the result being the creation of two frames in RAM rather than just one.

■ Consistent use of this function to create recConfig frames saves RAM by

permitting similar

recConfig frames to share the same frame map.

A function similar to the

PrepRecConfig function, the BuildRecConfig

function, is provided for debugging use. Do not use the

BuildRecConfig

function to create your RAM-based

recConfig frame. The argument to the

BuildRecConfig function is the view itself, rather than its recConfig frame.

This function builds an appropriate

recConfig frame for the speciﬁed view,

regardless of whether the view deﬁnes one. The system does not use the

recConfig frame that this function returns, however—as stated previously, this

frame is for debugging use only.

IMPORTANT

The contents of the inputMask slot in the view’s recConfig

frame must match the input mask (the recognition-related bits)

provided by the view’s

viewFlags slot. For more information on

this slot and others that the

recConfig frame may contain, see

“protoRecConﬁg” (page 8-36) in Newton Programmer’s

Reference.

▲

You can base your recConfig frame on one of the system-supplied recConfig

frames by simply placing the appropriate constant in your view template’s

recConfig slot. Alternatively, you can place in this slot a frame that uses its

_proto slot to reference one of the system-supplied recConfig frames. A third

way to deﬁne a

recConfig frame is to supply all necessary values yourself. The

1 2 ... 380 381 382 383 384 385 386 387 388 389 390 ... 941 942

Commentaires sur ces manuels

Pas de commentaire

Apple Newton Utilities Guide de l'utilisateur Page 385

Commentaires sur ces manuels

Produits connexes et manuels pour Logiciel Apple Newton Utilities