Recognition: Advanced Topics

Using Advanced Topics in Recognition

Configuring Recognizers and Dictionaries for recToggle Views

10

Regardless of whether you use a

recConfig

frame or view flags to specify your

view's recognition behavior, the view must be capable of enabling recognizers and
dictionaries appropriate for each choice in the

recToggle

picker. If your view

does not support all of the recognition settings provided by the default

recToggle

view, you need to provide a

_recogPopup

slot that restricts the choices appearing

in the picker that the

recToggle

view displays. For more information, see

"Providing the _recogPopup Slot" beginning on page 10-22.

If you are using a

recConfig

frame to specify your view's recognition behavior,

you can place the

ROM_rcPrefsConfig

constant in your

recConfig

frame's

_proto

slot to provide a general-purpose

recConfig

frame that allows

recognition of all forms of pen input. Note that you must also enable recognition
behavior and dictionaries as appropriate in order to produce useful behavior.

Creating the _recogSettings Slot

10

Applications that use a

recToggle

view must provide a

_recogSettings

slot

in a view that is a parent to both the

recToggle

view and the input view it

controls. Your view template should specify an initial value of

nil

for this slot.

Each time the user chooses an item from the

recToggle

picker, it saves a value

representing its current setting in this slot. You can preserve the user's recognition
settings by saving the contents of this slot when your application closes and
restoring this slot's value when your application reopens.

When a single

recToggle

view controls recognition for all of your application's

views, the

_recogSettings

slot can reside in the application's base view, as

shown in Figure 10-5.

This approach can be used to synchronize the recognition behavior of multiple
views; for example, the built-in Notes application uses a single

recToggle

view

to control the recognition behavior of all currently visible notes. All of the views
controlled by a single

recToggle

view must provide the same set of recognizers

and dictionaries.

When each of several

recToggle

views must control individual input views, you

must provide a

_recogSettings

slot for each

recToggle

view at an

appropriate place in the

_parent

chain of each view that performs recognition, as

shown in Figure 10-6.