PHONEBUTTONSTATE_ Constants

The PHONEBUTTONSTATE_ bit-flag constants describe the button's positions.

PHONEBUTTONSTATE_UP
The button is in the "up" state.
PHONEBUTTONSTATE_DOWN
The button is in the "down" state (pressed down).
PHONEBUTTONSTATE_UNKNOWN
Indicates that the up or down state of the button is not known at this time, but may become known at a future time.
PHONEBUTTONSTATE_UNAVAIL
Indicates that the up or down state of the button is not known to the service provider, and will not become known at a future time.

No extensibility. All 32 bits are reserved.

For backward compatibility, it is the responsibility of the service provider to examine the negotiated API version on the phone, and to not use these PHONEBUTTONSTATE_ values if not supported on the negotiated version.