A set of functions need to be implemented by your touch driver. These
callback functions are called into by the Input Events library to fetch
the data required to transform the device (touch controller) data into
mtouch events.
The driver will not be able to connect to the Input Events library
unless the following functions are implemented:
- get_contact_id()
-
Retrieves the contact ID for the specified digit of a
touch-related event.
- get_coords()
- Retrieves the coordinates for the specified digit of a
touch-related event.
- is_contact_down()
- Retrieves the touch status for the specified digit of a
touch-related event.
You will also need to provide implementation for the callback functions
that are related to the capabilities that are supported by your driver.
- get_down_count()
-
Retrieves the number of touchpoints currently in contact with the
screen. If you specify that your driver can track the
number of touchpoints in contact with the screen
(MTOUCH_CAPABILITIES_CONTACT_COUNT), then you
need to implement this callback function in your touch driver.
- get_touch_width()
-
Retrieves the width information of the touch area for the
specified digit of a touch-related event. If you specify that
your driver can provide the width of the touch area
(MTOUCH_CAPABILITIES_WIDTH), then you need to
implement this callback function in your touch driver.
- get_touch_height()
-
Retrieves the height information of the touch area for the
specified digit of a touch-related event. If you specify that
your driver can provide the height of the touch area
(MTOUCH_CAPABILITIES_HEIGHT), then you need to
implement this callback function in your touch driver.
- get_touch_pressure()
-
Retrieves the touch pressure information for the
specified digit of a touch-related event. If you specify that
your driver can provide the touch pressure
(MTOUCH_CAPABILITIES_PRESSURE), then you need to
implement this callback function in your touch driver.
- get_seq_id()
-
Retrieves the unique sequence ID for the specified digit of a
touch-related event. If you specify that your driver can provide
sequence IDs (MTOUCH_CAPABILITIES_SEQ_ID) associated
with a touch-related event, then you need to implement this
callback function in your touch driver.
- get_event_rate()
-
Retrieves the sampling period for the specified digit of a
touch-related event. If you specify that your driver supports
the capability of setting the event rate
(MTOUCH_CAPABILITIES_RATE_SET), then you need to
implement this callback function in your touch driver.
- get_contact_type()
-
Retrieves the contact type of a touch-related event. If you
specify that your driver can provide the type of contact
(MTOUCH_CAPABILITIES_CONTACT_TYPE), then you need
to implement this callback function in your touch driver.