Provide the callback functions

Updated: May 06, 2022

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.