Apple Newton Utilities Guide de l'utilisateur télécharger pdf (Page 417)

100

101

CHAPTER 10

Recognition: Advanced Topics

Using Advanced Topics in Recognition 10-41

Customized Processing of Double Taps 10

To process double taps reliably, your view’s ViewGestureScript method can

test for the presence of the

aeDoubleTap gesture. The gesture recognizer

measures time between pen events reliably even when the main NewtonScript

thread is busy.

The recognition system considers a second tap to be part of a double tap when it

occurs within a speciﬁed amount of time and distance relative to the ﬁrst tap.

The second tap must be within 6 pixels of the ﬁrst to be considered part of a double

tap. Any stroke longer than 6 pixels is not recognized as a tap (or as the second

tap). Measurement of the distance between taps is based on the midpoint of the

start and end points of the stroke.

The amount of time that determines whether a second tap is considered part of a

double tap is speciﬁed by the value of the

timeoutCursiveOption slot in the

system’s user conﬁguration data. This value ranges between 15 and 60 ticks, with a

default value of 45 ticks. The user sets the value of this slot by moving the

“Transform my handwriting” slider in the Fine Tuning slip. The Fine Tuning slip is

available from the picker displayed by the Options button in the Handwriting

Recognition preferences slip.

Your

ViewGestureScript method is called only if the view does not handle the

gesture automatically. Your

ViewGestureScript method should return the

value

true to avoid passing the gesture unit to other ViewGestureScript

methods, such as those supplied by views in the

_parent chain. If you do want to

pass the gesture unit to other views, your method should return the value

nil.

Changing User Preferences for Recognition 10

When you must make system-wide changes in recognition behavior, you can set

the values of slots in the system’s user conﬁguration data to do so. However, in

most cases it is more appropriate to change the behavior of individual views, rather

than system-wide settings. For information on using

recConfig frames to specify

the recognition behavior of individual views, see “Using recConﬁg Frames”

beginning on page 10-8.

Take the following steps to change recognition settings used by all views:

1. Call the

SetUserConfig function to set the values of one or more slots in the

system’s user conﬁguration data. For a complete listing of the recognition-

related slots, see “System-Wide Settings” (page 8-2) in Newton Programmer’s

Reference.

2. Call the

ReadCursiveOptions function to cause the system to use the

new settings.

1 2 ... 412 413 414 415 416 417 418 419 420 421 422 ... 941 942

Commentaires sur ces manuels

Pas de commentaire

Apple Newton Utilities Guide de l'utilisateur Page 417

Commentaires sur ces manuels

Produits connexes et manuels pour Logiciel Apple Newton Utilities