TouchStateMachine

Class

Source: TouchStateMachine.h

Description

State machine for touch gesture detection

State transitions: Idle → Pressed (on touch down) Pressed → LongPress (after LONG_PRESS_THRESHOLD without release) Pressed → Dragging (after DRAG_THRESHOLD movement) Pressed → Idle (on touch up → generate Click/DoubleClick) LongPress → Idle (on touch up) Dragging → Idle (on touch up → generate DragEnd)

O(1) update - deterministic timing

Methods

void update(uint8_t touchId, bool pressed, int16_t x, int16_t y, uint32_t timestamp, TouchEventQueue& outputQueue)

Description:

Process a touch input update

Parameters:

• touchId: Touch identifier (0-4)
• pressed: True if touch is currently pressed
• x: Current X position
• y: Current Y position
• timestamp: Current timestamp in ms
• outputQueue: Queue to enqueue generated events

void reset(uint8_t touchId)

Description:

Reset state for a specific touch ID

Parameters:

• touchId: Touch identifier to reset

void resetAll()

Description:

Reset all touch states

TouchState getState(uint8_t touchId) const

Description:

Get current state for a touch ID

Parameters:

• touchId: Touch identifier

Returns: Current state

bool isActive() const

Description:

Check if a touch is in progress

Returns: true if any touch is active

uint32_t getPressDuration(uint8_t touchId, uint32_t currentTime) const

Description:

Get time since press for a touch

Parameters:

• touchId: Touch identifier
• currentTime: Current timestamp in ms (same source as update())

Returns: Milliseconds since press started, 0 if not pressed

static int16_t distance(int16_t x1, int16_t y1, int16_t x2, int16_t y2)

Description:

Calculate Manhattan distance between two points

void handleTouchDown(uint8_t touchId, int16_t x, int16_t y, uint32_t timestamp, TouchEventQueue& queue)

Description:

Handle touch down event

void handleTouchUp(uint8_t touchId, int16_t x, int16_t y, uint32_t timestamp, TouchEventQueue& queue)

Description:

Handle touch up event

void handleTouchMove(uint8_t touchId, int16_t x, int16_t y, uint32_t timestamp, TouchEventQueue& queue)

Description:

Handle touch move while pressed

void checkLongPress(uint8_t touchId, uint32_t timestamp, TouchEventQueue& queue)

Description:

Check and generate long press if needed