Touch

Collaboration diagram for Touch:

Modules
	Calibrate (Screen)

Data Structures
struct	TOUCH_AREA_STRUCT
struct	POINT_STRUCT

Typedefs
typedef void(*	TOUCH_CALLBACK) (void *touchArea, TOUCH_ACTION triggeredAction)

Enumerations
enum	TOUCH_STATE { TOUCH_UP, TOUCH_DOWN }
enum	TOUCH_ACTION {   NONE = 0x00, PEN_DOWN = 0x01, PEN_UP = 0x02, PEN_ENTER = 0x04,   PEN_LEAVE = 0x08, PEN_MOVE = 0x10 }

Functions
bool	touch_init ()
bool	touch_add_raw_event (uint16_t x, uint16_t y, TOUCH_STATE state)
bool	touch_have_empty (unsigned char num)
bool	touch_register_area (TOUCH_AREA_STRUCT *area)
void	touch_unregister_area (TOUCH_AREA_STRUCT *area)
POINT_STRUCT	touch_get_last_point ()
void	touch_set_calibration_values (int xs, int dx, int ys, int dy)
void	touch_set_value_convert_mode (bool use_calibration)

Detailed Description

The Touch module provides access to the touch controller, and executes a callback if a certain region is touched

Typedef Documentation

typedef void(* TOUCH_CALLBACK) (void *touchArea, TOUCH_ACTION triggeredAction)

Prototype for Event Listeners (called for every occurring, hooked action)

Note

You should NOT execute long running things in this callback nor should you update the gui. But you can call gui_screen_navigate() for instance.

Parameters

touchArea	The pointer to the TOUCH_AREA_STRUCT in which the event occurred
triggeredAction	The Action which occurred

Definition at line 67 of file touch.h.

Enumeration Type Documentation

enum TOUCH_ACTION

Enum to describe the hooked actions for which you want to receive events for. You can OR-combine them.

See also

touch_register_area

Enumerator
NONE	Do not receive any events.
PEN_DOWN	Receive an event when the pen goes down inside the region.
PEN_UP	Receive an event when the pen goes up inside the region.
PEN_ENTER	Receive an event when the pen enters the region (pen was down before)
PEN_LEAVE	Receive an event when the pen leaves the region (pen was inside region before)
PEN_MOVE	Receive an event when the pen moves inside the region (pen is down)

Definition at line 52 of file touch.h.

             {
    NONE = 0x00,    
    PEN_DOWN = 0x01, 
    PEN_UP = 0x02,  
    PEN_ENTER = 0x04, 
    PEN_LEAVE = 0x08, 
    PEN_MOVE = 0x10 
} TOUCH_ACTION;

enum TOUCH_STATE

Enum to describe the current Touch State.

See also

touch_add_raw_event

Enumerator
TOUCH_UP	The display is currently not touched.
TOUCH_DOWN	The display is currently touched at some point.

Definition at line 43 of file touch.h.

             {
    TOUCH_UP, 
    TOUCH_DOWN 
} TOUCH_STATE ;

Function Documentation

bool touch_add_raw_event	(	uint16_t	x,
		uint16_t	y,
		TOUCH_STATE	state
	)

Processes a native touch event. Call this function when the pen goes down (TOUCH_DOWN), when it moves (TOUCH_DOWN) and also when it goes up again (TOUCH_UP)! It's safe to call this function from an (SPI)-Interrupt.

Parameters

x	The x-Coordinate of the touch event
y	The y-Coordinate of the touch event
state	Whether the pen is up or down

Returns

True on success

Definition at line 72 of file touch.c.

{
    //Update current and old position/state
    bool penDown = (state == TOUCH_DOWN);
    bool oldPenDown = (oldState == TOUCH_DOWN);
    oldState = state;

    if (calibration) {  //If in Calibration mode
        if (penDown) {
            pos.x = touchX;
            pos.y = touchY;
        } else {
            if (oldPenDown) { //Run only if we got at least one pen down
                calibration = 0;    //Calibration finish (Touch X and Y are the values from the last measure, where the pen was down)
            }
        }

        return true;
    }

    //If we reach this point we're not in calibration mode and we need to process the event and call the registred handlers..

    if (use_calibration) { //the underlying touch hardware uses calibration
        //Calculate the real touch position out of the passed ones, and the calibration values
        pos.x = touchX = (((long)(DWIDTH - 2 * CCENTER) * 2 * (long)((long)touchX - cal_xs) / cal_dx + 1) >> 1) + CCENTER;
        pos.y = touchY = (((long)(DHEIGHT - 2 * CCENTER) * 2 * (long)((long)touchY - cal_ys) / cal_dy + 1) >> 1) + CCENTER;
    } else { //no conversion needed for the underlying hardware
        pos.x = touchX;
        pos.y = touchY;
    }

    if (penDown) { //pen is down now
        //tft_draw_pixel(touchX,touchY,WHITE);
        if (!oldPenDown) { //pen wasn't down before (positive edge) => First Touch
            for (int z = 0; z < NUM_AREAS; z++) { // For every touch area
                //Check if pos is inside area
                if (areas[z] != NULL  && touchX >= areas[z]->x1 && touchX <= areas[z]->x2 && touchY >= areas[z]->y1 && touchY <= areas[z]->y2) {
                    areas[z]->flags = 1; //Save PenInside=1

                    if (areas[z]->hookedActions & PEN_DOWN) { //The user wants to receive pen down events
                        areas[z]->callback(areas[z], PEN_DOWN);    //Send event to user callback
                    }
                }
            }
        } else { //Pen was down before => Second, Third event in row
            for (int z = 0; z < NUM_AREAS; z++) { // For every touch area
                if (areas[z] != NULL) {
                    //Check if pos is inside area
                    if (touchX >= areas[z]->x1 && touchX <= areas[z]->x2 && touchY >= areas[z]->y1 && touchY <= areas[z]->y2) {
                        if (areas[z]->flags == 0) { //Pen was not inside before (PenInside==0)
                            areas[z]->flags = 1; //Pen is inside now (PenInside=1)

                            if (areas[z]->hookedActions & PEN_ENTER) { //The user wants to receive pen enter events
                                areas[z]->callback(areas[z], PEN_ENTER);
                            }
                        }
                    } else if (areas[z]->flags) { //Pos not inside area, but it was before (PenInside==1)
                        areas[z]->flags = 0; //Pen is no longer inside (PenInside=0)

                        if (areas[z]->hookedActions & PEN_LEAVE) { //The user wants to receive pen leave events
                            areas[z]->callback(areas[z], PEN_LEAVE);
                        }
                    }
                }
            }
        }

        for (int z = 0; z < NUM_AREAS; z++) { // For every touch area
            if (areas[z] != NULL && (areas[z]->hookedActions & PEN_MOVE)) { //User want's to receive pen move events
                //Check if pos is inside area
                if (touchX >= areas[z]->x1 && touchX <= areas[z]->x2 && touchY >= areas[z]->y1 && touchY <= areas[z]->y2) {
                    areas[z]->callback(areas[z], PEN_MOVE);
                }
            }
        }
    } else { //pen is not down now
        if (oldPenDown) { //but it was down before (negative edge)
            for (int z = 0; z < NUM_AREAS; z++) { // For every touch area
                //Check if pos is inside area
                if (areas[z] != NULL && touchX >= areas[z]->x1 && touchX <= areas[z]->x2 && touchY >= areas[z]->y1 && touchY <= areas[z]->y2) {
                    areas[z]->flags = 0; //The pen is no longer inside (PenInside = 0);

                    if (areas[z]->hookedActions & PEN_UP) { //user want's to receive pen up events
                        areas[z]->callback(areas[z], PEN_UP);
                    }
                }
            }
        }
    }

    return true;
}

POINT_STRUCT touch_get_last_point

(

)

Gets the last touched point

Returns

The Coordinates of the last touched points

Definition at line 211 of file touch.c.

{
    return pos;
}

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bool touch_have_empty

(

unsigned char

num

)

Checks whether or not we have memory to manage and track additional num TOUCH_AREA_STRUCTs

Parameters

num	The number of touch areas you would like to allocate

Returns

True if there's enough memory to allocate num TOUCH_AREAs

Definition at line 165 of file touch.c.

{
    //go through pointer array and check for free spaces
    for (unsigned char i = 0; i < NUM_AREAS; i++) {
        if (areas[i] == NULL) {
            num--;    //a free space was found, we need one less
        }

        if (num == 0) {
            return true;    //enough free spaces found
        }
    }

    return false; //not enough free spaces found
}

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bool touch_init

(

)

Initializes the Touch Controller. Call this method before using any touch_* functions

Returns

true on success

Definition at line 61 of file touch.c.

{
    return ll_touch_init();
}

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bool touch_register_area

(

TOUCH_AREA_STRUCT *

area

)

Registers a new touch Area. You will receive events for this area from now on.

Parameters

area	A pointer to the configured TOUCH_AREA_STRUCT

Returns

True if everything was successful and the corresponding Touch Area will be monitored from now on

Definition at line 181 of file touch.c.

{
    //go through pointer array and check for free space
    for (unsigned char i = 0; i < NUM_AREAS; i++) {
        if (areas[i] == NULL) { //free space found
            area->flags = 0; //we start with empty flags (PenInside=0)
            areas[i] = area; //save pointer into list
            return true;
        }
    }

    return false; //no free space found
}

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void touch_set_calibration_values	(	int	xs,
		int	dx,
		int	ys,
		int	dy
	)

Set's the new calibration values

Parameters

xs	x offset (to calibration point 1)
dx	x difference (between calibration point 1 and 2)
ys	y offset (to calibration point 1)
dy	y difference (between calibration point 1 and 2)

Definition at line 51 of file touch.c.

{
    cal_xs = xs;
    cal_ys = ys;
    cal_dx = dx;
    cal_dy = dy;
}

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void touch_set_value_convert_mode

(

bool

use_calibration

)

Set's the new value convert mode. Per default use_calibration is false.

Parameters

use_calibration

whether or not the current platform needs display calibration

Definition at line 66 of file touch.c.

{
    use_calibration = uc;
}

void touch_unregister_area

(

TOUCH_AREA_STRUCT *

area

)

Unregisters a touch area. You will no longer receive events for this area

Parameters

area	A pointer to the TOUCH_AREA_STRUCT instance

Definition at line 195 of file touch.c.

{
    if (area == NULL) {
        return;
    }

    //go through pointer array and find the area to remove
    for (unsigned char i = 0; i < NUM_AREAS; i++) {
        if (areas[i] == area) { //area found in pointer array at pos i
            areas[i] = NULL; //set pointer in list to NULL again
            break;
        }
    }
}

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