Touch Interface

The touch component provides the shared TouchPoint, TouchState, TouchpadData, and ITouchDevice types used by ESPP touch controller drivers and BSPs.

It also provides the type-erasure helpers used to store any touch driver behind a single runtime handle:

• espp::TouchDriverConcept — C++23 concept satisfied by any touch driver exposing update(), get_touch_point(), and get_home_button_state().

• espp::ITouchDriver — abstract type-erased interface backed by the concept.

• espp::TouchDriverAdapter<T> — concept-constrained adapter wrapping any concrete driver (e.g. Gt911 or St7123Touch) behind ITouchDriver.

• espp::make_touch_driver(driver) — convenience factory returning a std::shared_ptr<ITouchDriver>.

• Touch Interface Example
  • How to use example
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API Reference

Header File

• components/touch/include/touch.hpp

Classes

class ITouchDevice

Runtime interface implemented by touch controller drivers.

Subclassed by espp::Chsc6x, espp::Cst816, espp::Ft5x06, espp::Gt911, espp::Tt21100

Public Functions

virtual bool update(std::error_code &ec) = 0

Update the cached touch state from the hardware.

Parameters:

ec – Error code to set if an error occurs.

Returns:

True if the device reported new data, false otherwise.

virtual TouchState touch_state() const = 0

Get the cached touch state.

Returns:

The cached touch state.

inline virtual bool has_home_button() const

Whether the controller exposes a touch-adjacent home button.

Returns:

True if the controller exposes a home button, false otherwise.

inline uint8_t get_num_touch_points() const

Get the number of cached touch points.

Returns:

The number of cached touch points.

inline void get_touch_point(uint8_t *num_touch_points, uint16_t *x, uint16_t *y) const

Get the primary cached touch point.

Parameters:

• num_touch_points – The number of touch points as of the last update.

• x – The x coordinate of the primary touch point.

• y – The y coordinate of the primary touch point.

inline uint8_t get_home_button_state() const

Get the cached home button state.

Returns:

The cached home button state.

inline TouchpadData touchpad_data() const

Get the cached single-point touchpad view.

Returns:

The primary touchpad view of the cached state.