input_pipeline > Gestures > Two finger Button Recognizer
Reviewed-on: 2022-11-08
Purpose
The two finger button recognizer detects a two finger click or a click-drag on the touchpad.
A click occurs when the user exerts enough force on the touchpad to move the button under the pad with 2 finger, then release the button. (This is distinct from a tap, which does not move the pad.)
A two finger drag occurs when the user exerts enough force on the touchpad to move the pad itself without releasing the button then move the finger more than threshold.
Notably, this includes discarding any spurious motion that occurs during the click (when a button has been pressed but not yet released).
State machine
The two finger button recognizer implements the state machine below.
The state machine is also available in other formats:
