lvgl/src/lv_objx/lv_line.c

/**
 * @file lv_line.c
 *
 */

/*********************
 *      INCLUDES
 *********************/
#include "lv_line.h"

#if LV_USE_LINE != 0
#include "../lv_core/lv_debug.h"
#include "../lv_draw/lv_draw.h"
#include "../lv_misc/lv_math.h"
#include <stdbool.h>
#include <stdint.h>
#include <string.h>

/*********************
 *      DEFINES
 *********************/
#define LV_OBJX_NAME "lv_line"

/**********************
 *      TYPEDEFS
 **********************/

/**********************
 *  STATIC PROTOTYPES
 **********************/
static lv_design_res_t lv_line_design(lv_obj_t * line, const lv_area_t * clip_area, lv_design_mode_t mode);
static lv_res_t lv_line_signal(lv_obj_t * line, lv_signal_t sign, void * param);

/**********************
 *  STATIC VARIABLES
 **********************/
static lv_signal_cb_t ancestor_signal;

/**********************
 *      MACROS
 **********************/

/**********************
 *   GLOBAL FUNCTIONS
 **********************/

/**
 * Create a line objects
 * @param par pointer to an object, it will be the parent of the new line
 * @return pointer to the created line
 */
lv_obj_t * lv_line_create(lv_obj_t * par, const lv_obj_t * copy)
{
    LV_LOG_TRACE("line create started");

    /*Create a basic object*/
    lv_obj_t * new_line = lv_obj_create(par, copy);
    LV_ASSERT_MEM(new_line);
    if(new_line == NULL) return NULL;

    if(ancestor_signal == NULL) ancestor_signal = lv_obj_get_signal_cb(new_line);

    /*Extend the basic object to line object*/
    lv_line_ext_t * ext = lv_obj_allocate_ext_attr(new_line, sizeof(lv_line_ext_t));
    LV_ASSERT_MEM(ext);
    if(ext == NULL) {
        lv_obj_del(new_line);
        return NULL;
    }

    ext->point_num   = 0;
    ext->point_array = NULL;
    ext->auto_size   = 1;
    ext->y_inv       = 0;

    lv_obj_set_design_cb(new_line, lv_line_design);
    lv_obj_set_signal_cb(new_line, lv_line_signal);

    /*Init the new line*/
    if(copy == NULL) {
        lv_obj_set_size(new_line, LV_DPI,
                        LV_DPI);          /*Auto size is enables, but set default size until no points are added*/

        lv_obj_set_click(new_line, false);
    }
    /*Copy an existing object*/
    else {
        lv_line_ext_t * copy_ext = lv_obj_get_ext_attr(copy);
        lv_line_set_auto_size(new_line, lv_line_get_auto_size(copy));
        lv_line_set_y_invert(new_line, lv_line_get_y_invert(copy));
        lv_line_set_auto_size(new_line, lv_line_get_auto_size(copy));
        lv_line_set_points(new_line, copy_ext->point_array, copy_ext->point_num);
        /*Refresh the style with new signal function*/
//        lv_obj_refresh_style(new_line);
    }

    LV_LOG_INFO("line created");

    return new_line;
}

/*=====================
 * Setter functions
 *====================*/

/**
 * Set an array of points. The line object will connect these points.
 * @param line pointer to a line object
 * @param point_a an array of points. Only the address is saved,
 * so the array can NOT be a local variable which will be destroyed
 * @param point_num number of points in 'point_a'
 */
void lv_line_set_points(lv_obj_t * line, const lv_point_t point_a[], uint16_t point_num)
{
    LV_ASSERT_OBJ(line, LV_OBJX_NAME);

    lv_line_ext_t * ext = lv_obj_get_ext_attr(line);
    ext->point_array    = point_a;
    ext->point_num      = point_num;

    if(point_num > 0 && ext->auto_size != 0) {
        uint16_t i;
        lv_coord_t xmax = LV_COORD_MIN;
        lv_coord_t ymax = LV_COORD_MIN;
        for(i = 0; i < point_num; i++) {
            xmax = LV_MATH_MAX(point_a[i].x, xmax);
            ymax = LV_MATH_MAX(point_a[i].y, ymax);
        }

        lv_style_int_t line_width = lv_obj_get_style_int(line, LV_LINE_PART_MAIN, LV_STYLE_LINE_WIDTH);
        lv_obj_set_size(line, xmax + line_width, ymax + line_width);
    }

    lv_obj_invalidate(line);
}

/**
 * Enable (or disable) the auto-size option. The size of the object will fit to its points.
 * (set width to x max and height to y max)
 * @param line pointer to a line object
 * @param en true: auto size is enabled, false: auto size is disabled
 */
void lv_line_set_auto_size(lv_obj_t * line, bool en)
{
    LV_ASSERT_OBJ(line, LV_OBJX_NAME);

    lv_line_ext_t * ext = lv_obj_get_ext_attr(line);
    if(ext->auto_size == en) return;

    ext->auto_size = en == false ? 0 : 1;

    /*Refresh the object*/
    if(en) lv_line_set_points(line, ext->point_array, ext->point_num);
}

/**
 * Enable (or disable) the y coordinate inversion.
 * If enabled then y will be subtracted from the height of the object,
 * therefore the y=0 coordinate will be on the bottom.
 * @param line pointer to a line object
 * @param en true: enable the y inversion, false:disable the y inversion
 */
void lv_line_set_y_invert(lv_obj_t * line, bool en)
{
    LV_ASSERT_OBJ(line, LV_OBJX_NAME);

    lv_line_ext_t * ext = lv_obj_get_ext_attr(line);
    if(ext->y_inv == en) return;

    ext->y_inv = en == false ? 0 : 1;

    lv_obj_invalidate(line);
}

/*=====================
 * Getter functions
 *====================*/

/**
 * Get the auto size attribute
 * @param line pointer to a line object
 * @return true: auto size is enabled, false: disabled
 */
bool lv_line_get_auto_size(const lv_obj_t * line)
{
    LV_ASSERT_OBJ(line, LV_OBJX_NAME);

    lv_line_ext_t * ext = lv_obj_get_ext_attr(line);

    return ext->auto_size == 0 ? false : true;
}

/**
 * Get the y inversion attribute
 * @param line pointer to a line object
 * @return true: y inversion is enabled, false: disabled
 */
bool lv_line_get_y_invert(const lv_obj_t * line)
{
    LV_ASSERT_OBJ(line, LV_OBJX_NAME);

    lv_line_ext_t * ext = lv_obj_get_ext_attr(line);

    return ext->y_inv == 0 ? false : true;
}

/**********************
 *   STATIC FUNCTIONS
 **********************/

/**
 * Handle the drawing related tasks of the lines
 * @param line pointer to an object
 * @param clip_area the object will be drawn only in this area
 * @param mode LV_DESIGN_COVER_CHK: only check if the object fully covers the 'mask_p' area
 *                                  (return 'true' if yes)
 *             LV_DESIGN_DRAW: draw the object (always return 'true')
 *             LV_DESIGN_DRAW_POST: drawing after every children are drawn
 * @param return an element of `lv_design_res_t`
 */
static lv_design_res_t lv_line_design(lv_obj_t * line, const lv_area_t * clip_area, lv_design_mode_t mode)
{
    /*A line never covers an area*/
    if(mode == LV_DESIGN_COVER_CHK)
        return LV_DESIGN_RES_NOT_COVER;
    else if(mode == LV_DESIGN_DRAW_MAIN) {
        lv_line_ext_t * ext = lv_obj_get_ext_attr(line);

        if(ext->point_num == 0 || ext->point_array == NULL) return false;

        lv_area_t area;
        lv_obj_get_coords(line, &area);
        lv_coord_t x_ofs = area.x1;
        lv_coord_t y_ofs = area.y1;
        lv_point_t p1;
        lv_point_t p2;
        lv_coord_t h = lv_obj_get_height(line);
        uint16_t i;

        lv_draw_line_dsc_t line_dsc;
        lv_draw_line_dsc_init(&line_dsc);
        lv_obj_init_draw_line_dsc(line, LV_LINE_PART_MAIN, &line_dsc);
        line_dsc.round_end = 1;
        line_dsc.round_start = 1;

        /*Read all points and draw the lines*/
        for(i = 0; i < ext->point_num - 1; i++) {

            p1.x = ext->point_array[i].x + x_ofs;
            p2.x = ext->point_array[i + 1].x + x_ofs;

            if(ext->y_inv == 0) {
                p1.y = ext->point_array[i].y + y_ofs;
                p2.y = ext->point_array[i + 1].y + y_ofs;
            } else {
                p1.y = h - ext->point_array[i].y + y_ofs;
                p2.y = h - ext->point_array[i + 1].y + y_ofs;
            }
            lv_draw_line(&p1, &p2, clip_area, &line_dsc);
            line_dsc.round_start = 0;
        }

    }
    return LV_DESIGN_RES_OK;
}

/**
 * Signal function of the line
 * @param line pointer to a line object
 * @param sign a signal type from lv_signal_t enum
 * @return LV_RES_OK: the object is not deleted in the function; LV_RES_INV: the object is deleted
 */
static lv_res_t lv_line_signal(lv_obj_t * line, lv_signal_t sign, void * param)
{
    lv_res_t res;

    /* Include the ancient signal function */
    res = ancestor_signal(line, sign, param);
    if(res != LV_RES_OK) return res;
    if(sign == LV_SIGNAL_GET_TYPE) return lv_obj_handle_get_type_signal(param, LV_OBJX_NAME);

   if(sign == LV_SIGNAL_REFR_EXT_DRAW_PAD) {
       /*The corner of the skew lines is out of the intended area*/
       lv_style_int_t line_width = lv_obj_get_style_int(line, LV_LINE_PART_MAIN, LV_STYLE_LINE_WIDTH);
        if(line->ext_draw_pad < line_width) line->ext_draw_pad = line_width;
    }

    return res;
}
#endif