| # input_pipeline > Gestures > Secondary Tap Recognizer |
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| Reviewed-on: 2022-07-18 |
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| # Purpose |
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| The secondary tap recognizer detects a two-finger-tap on the touchpad, generates a mouse secondary click event, and discards all touchpad events related to the tap. |
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| A secondary tap occurs when the user puts two fingers down on the touchpad, exercises zero-to-minimal movement of both fingers, and then removes both fingers, all within a short time frame and without moving the pad. (This is distinct from a click, for which a user exerts enough force on the touchpad to move the pad itself.) |
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| Notably, this includes discarding any spurious motion that occurs during the secondary tap (when two fingers have made contact down but have not yet been raised up). |
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| # State machine |
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| The secondary tap recognizer implements the state machine below. |
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| The state machine is also available in other formats: |
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| - [state machine as graphviz source](secondary_tap_state_machine.dot) |
| - [state machine as SVG](secondary_tap_state_machine.svg) |
