Recognition: Advanced Topics

Using Advanced Topics in Recognition

You may also need to know the boundaries of the word in the

text

slot when

working with certain

protoCharEdit

methods and functions. The

protoCharEdit

view's

wordLeft

and

wordRight

slots provide indexes into

the

text

string that you can use to determine the boundaries of a substring suitable

for external display or for use as an argument to these routines. The

wordLeft

slot contains the index of the first externally-displayed character in the

text

slot.

The

wordRight

slot contains the index of the position immediately following the

last externally-displayed character in the

text

slot. For example, when the

text

slot holds the

"one "

string, 1 is the value of the

wordLeft

slot and 4 is the value

of the

wordRight

slot. The

dispLeft

slot contains the index of the first

character in the

text

slot that is displayed--this character occupies the leftmost

position in the comb view. The

dispLeft

slot normally has the value 0, but after

scrolling it may have values greater than 0. The

dispIndent

slot is the offset

from the leftmost edge of the view to the leftmost edge of the first character displayed.

For more information, see "protoCharEdit Functions and Methods" (page 8-47) in
Newton Programmer's Reference.

Restricting Characters Returned by protoCharEdit Views

10

This section provides code examples illustrating the use of templates to restrict the
set of characters that may appear in a comb view. Note that templates post-process
the characters returned by the recognition system before the view displays them,
rather than limiting the set of characters that the view can recognize.

The templates defined by the following code fragments are intended to serve as
examples only. The system provides templates that handle formatting conventions
for dates, times, phone numbers, and numeric values properly according to the
user's locale. For complete descriptions of these templates, see "System-Supplied
protoCharEdit Templates" (page 8-46) in Newton Programmer's Reference.

The following code example defines a template for a date field:

digits :=

"0123456789";// filters[0]

digits1 := "01";

// filters[1]

digits3 := "0123";

// filters[2]

dateTemplate := {

string:" / / ",// slashes locked by "_" in format
format:"10_20_00",// indexes into filters array
filters:[digits, digits1, digits3],
};

This example template is used in a

protoCharEdit

view that specifies a value of

8

or more for its

maxChars

slot; hence, the eight-character strings in the

format

and

string

slots.