Touch device generic API

Define the generic API of a touch device. More...

Detailed Description

Define the generic API of a touch device.

Warning

This feature is experimental!
This API is experimental and in an early state - expect changes!

Author

Alexandre Abadie alexa.nosp@m.ndre.nosp@m..abad.nosp@m.ie@i.nosp@m.nria..nosp@m.fr

Data Structures
struct	touch_t
	Touch coordinates. More...
struct	touch_dev_driver_t
	Generic type for a touch driver. More...
struct	touch_dev
	Generic type for a touch device. More...
struct	touch_dev_reg
	Touch dev registry entry. More...

Macros
#define	TOUCH_DEV_VALUE_INVALID   ((touch_t){ UINT16_MAX, UINT16_MAX })
	Invalid touch value.

Typedefs
typedef struct touch_dev	touch_dev_t
	Forward declaration for touch device struct.
typedef void(*	touch_event_cb_t) (void *arg)
	Signature of touch event callback triggered from interrupt.
typedef struct touch_dev_reg	touch_dev_reg_t
	Touch dev registry entry.

Functions
int	touch_dev_reg_add (touch_dev_reg_t *dev)
	Add pointer to a touch device item to the list of touch items.
touch_dev_reg_t *	touch_dev_reg_find_screen (uint8_t screen_id)
	Find the touch device that is attached to a given screen.
uint16_t	touch_dev_height (const touch_dev_t *dev)
	Get the height of the touch device.
uint16_t	touch_dev_width (const touch_dev_t *dev)
	Get the width of the touch device.
static uint8_t	touch_dev_max_numof (const touch_dev_t *dev)
	Get the maximum number of touches the touch device supports.
uint8_t	touch_dev_touches (const touch_dev_t *dev, touch_t *touches, size_t len)
	Get the current touches on the touch device.
void	touch_dev_set_touch_event_callback (const touch_dev_t *dev, touch_event_cb_t cb, void *arg)
	Set and configure the touch event callback.

Variables
touch_dev_reg_t *	touch_dev_reg
	Export the touch device registry as global variable.

Macro Definition Documentation

TOUCH_DEV_VALUE_INVALID

#define TOUCH_DEV_VALUE_INVALID   ((touch_t){ UINT16_MAX, UINT16_MAX })

Invalid touch value.

Definition at line 34 of file touch_dev.h.

Typedef Documentation

touch_dev_t

typedef struct touch_dev touch_dev_t

Forward declaration for touch device struct.

Definition at line 39 of file touch_dev.h.

touch_event_cb_t

typedef void(* touch_event_cb_t) (void *arg)

Signature of touch event callback triggered from interrupt.

Parameters

[in]

arg

optional context for the callback

Definition at line 54 of file touch_dev.h.

Function Documentation

touch_dev_height()

uint16_t touch_dev_height

(

const touch_dev_t *

dev

)

Get the height of the touch device.

Parameters

[in]

dev

Pointer to the touch device

Returns

Height in points

touch_dev_max_numof()

static uint8_t touch_dev_max_numof ( const touch_dev_t *  dev )

inlinestatic

Get the maximum number of touches the touch device supports.

Parameters

[in]

dev

Pointer to the touch device

Returns

number of touches

Definition at line 179 of file touch_dev.h.

touch_dev_reg_add()

int touch_dev_reg_add

(

touch_dev_reg_t *

dev

)

Add pointer to a touch device item to the list of touch items.

Parameters

[in]

dev

Pointer to the touch device

Returns

0 on success

-ENODEV on invalid entry

touch_dev_reg_find_screen()

touch_dev_reg_t * touch_dev_reg_find_screen

(

uint8_t

screen_id

)

Find the touch device that is attached to a given screen.

Parameters

[in]

screen_id

Identifier (number) of the screen

Returns

pointer to the touch device in the registry

NULL if there's no match

touch_dev_set_touch_event_callback()

void touch_dev_set_touch_event_callback	(	const touch_dev_t *	dev,
		touch_event_cb_t	cb,
		void *	arg
	)

Set and configure the touch event callback.

Parameters

[in]	dev	Pointer to the touch device
[in]	cb	The callback function
[in]	arg	Context argument

touch_dev_touches()

uint8_t touch_dev_touches	(	const touch_dev_t *	dev,
		touch_t *	touches,
		size_t	len
	)

Get the current touches on the touch device.

If touches is NULL, this function only returns the number of touches.

Touch position coordinates use the top left corner as origin.

Parameters

[in]	dev	Pointer to the touch device
[out]	touches	The array of touches
[in]	len	The touches array len

Returns

number of touch positions, 0 means no touch

touch_dev_width()

uint16_t touch_dev_width

(

const touch_dev_t *

dev

)

Get the width of the touch device.

Parameters

[in]

dev

Pointer to the touch device

Returns

Width in points