src/lv_objx/lv_lmeter.c

/**
 * @file lv_lmeter.c
 *
 */

/*********************
 *      INCLUDES
 *********************/
#include "lv_lmeter.h"
#if LV_USE_LMETER != 0

#include "../lv_draw/lv_draw.h"
#include "../lv_themes/lv_theme.h"
#include "../lv_core/lv_group.h"
#include "../lv_misc/lv_math.h"

/*********************
 *      DEFINES
 *********************/
#define LV_LMETER_LINE_UPSCALE 5 /*2^x upscale of line to make rounding*/
#define LV_LMETER_LINE_UPSCALE_MASK ((1 << LV_LMETER_LINE_UPSCALE) - 1)

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

/**********************
 *  STATIC PROTOTYPES
 **********************/
static bool lv_lmeter_design(lv_obj_t * lmeter, const lv_area_t * mask, lv_design_mode_t mode);
static lv_res_t lv_lmeter_signal(lv_obj_t * lmeter, lv_signal_t sign, void * param);
static lv_coord_t lv_lmeter_coord_round(int32_t x);

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

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

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

/**
 * Create a line meter objects
 * @param par pointer to an object, it will be the parent of the new line meter
 * @param copy pointer to a line meter object, if not NULL then the new object will be copied from
 * it
 * @return pointer to the created line meter
 */
lv_obj_t * lv_lmeter_create(lv_obj_t * par, const lv_obj_t * copy)
{
    LV_LOG_TRACE("line meter create started");

    /*Create the ancestor of line meter*/
    lv_obj_t * new_lmeter = lv_obj_create(par, copy);
    lv_mem_assert(new_lmeter);
    if(new_lmeter == NULL) return NULL;

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

    /*Allocate the line meter type specific extended data*/
    lv_lmeter_ext_t * ext = lv_obj_allocate_ext_attr(new_lmeter, sizeof(lv_lmeter_ext_t));
    lv_mem_assert(ext);
    if(ext == NULL) return NULL;

    /*Initialize the allocated 'ext' */
    ext->min_value   = 0;
    ext->max_value   = 100;
    ext->cur_value   = 0;
    ext->line_cnt    = 21;  /*Odd scale number looks better*/
    ext->scale_angle = 240; /*(scale_num - 1) * N looks better */

    /*The signal and design functions are not copied so set them here*/
    lv_obj_set_signal_cb(new_lmeter, lv_lmeter_signal);
    lv_obj_set_design_cb(new_lmeter, lv_lmeter_design);

    /*Init the new line meter line meter*/
    if(copy == NULL) {
        lv_obj_set_size(new_lmeter, LV_DPI, LV_DPI);

        /*Set the default styles*/
        lv_theme_t * th = lv_theme_get_current();
        if(th) {
            lv_lmeter_set_style(new_lmeter, LV_LMETER_STYLE_MAIN, th->style.lmeter);
        } else {
            lv_lmeter_set_style(new_lmeter, LV_LMETER_STYLE_MAIN, &lv_style_pretty_color);
        }
    }
    /*Copy an existing line meter*/
    else {
        lv_lmeter_ext_t * copy_ext = lv_obj_get_ext_attr(copy);
        ext->scale_angle           = copy_ext->scale_angle;
        ext->line_cnt              = copy_ext->line_cnt;
        ext->min_value             = copy_ext->min_value;
        ext->max_value             = copy_ext->max_value;
        ext->cur_value             = copy_ext->cur_value;

        /*Refresh the style with new signal function*/
        lv_obj_refresh_style(new_lmeter);
    }

    LV_LOG_INFO("line meter created");

    return new_lmeter;
}

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

/**
 * Set a new value on the line meter
 * @param lmeter pointer to a line meter object
 * @param value new value
 */
void lv_lmeter_set_value(lv_obj_t * lmeter, int16_t value)
{
    lv_lmeter_ext_t * ext = lv_obj_get_ext_attr(lmeter);
    if(ext->cur_value == value) return;

    ext->cur_value = value > ext->max_value ? ext->max_value : value;
    ext->cur_value = ext->cur_value < ext->min_value ? ext->min_value : ext->cur_value;
    lv_obj_invalidate(lmeter);
}

/**
 * Set minimum and the maximum values of a line meter
 * @param lmeter pointer to he line meter object
 * @param min minimum value
 * @param max maximum value
 */
void lv_lmeter_set_range(lv_obj_t * lmeter, int16_t min, int16_t max)
{
    lv_lmeter_ext_t * ext = lv_obj_get_ext_attr(lmeter);
    if(ext->min_value == min && ext->max_value == max) return;

    ext->max_value = max;
    ext->min_value = min;
    if(ext->cur_value > max) {
        ext->cur_value = max;
        lv_lmeter_set_value(lmeter, ext->cur_value);
    }
    if(ext->cur_value < min) {
        ext->cur_value = min;
        lv_lmeter_set_value(lmeter, ext->cur_value);
    }
    lv_obj_invalidate(lmeter);
}

/**
 * Set the scale settings of a line meter
 * @param lmeter pointer to a line meter object
 * @param angle angle of the scale (0..360)
 * @param line_cnt number of lines
 */
void lv_lmeter_set_scale(lv_obj_t * lmeter, uint16_t angle, uint8_t line_cnt)
{
    lv_lmeter_ext_t * ext = lv_obj_get_ext_attr(lmeter);
    if(ext->scale_angle == angle && ext->line_cnt == line_cnt) return;

    ext->scale_angle = angle;
    ext->line_cnt    = line_cnt;

    lv_obj_invalidate(lmeter);
}

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

/**
 * Get the value of a line meter
 * @param lmeter pointer to a line meter object
 * @return the value of the line meter
 */
int16_t lv_lmeter_get_value(const lv_obj_t * lmeter)
{
    lv_lmeter_ext_t * ext = lv_obj_get_ext_attr(lmeter);
    return ext->cur_value;
}

/**
 * Get the minimum value of a line meter
 * @param lmeter pointer to a line meter object
 * @return the minimum value of the line meter
 */
int16_t lv_lmeter_get_min_value(const lv_obj_t * lmeter)
{
    lv_lmeter_ext_t * ext = lv_obj_get_ext_attr(lmeter);
    return ext->min_value;
}

/**
 * Get the maximum value of a line meter
 * @param lmeter pointer to a line meter object
 * @return the maximum value of the line meter
 */
int16_t lv_lmeter_get_max_value(const lv_obj_t * lmeter)
{
    lv_lmeter_ext_t * ext = lv_obj_get_ext_attr(lmeter);
    return ext->max_value;
}

/**
 * Get the scale number of a line meter
 * @param lmeter pointer to a line meter object
 * @return number of the scale units
 */
uint8_t lv_lmeter_get_line_count(const lv_obj_t * lmeter)
{
    lv_lmeter_ext_t * ext = lv_obj_get_ext_attr(lmeter);
    return ext->line_cnt;
}

/**
 * Get the scale angle of a line meter
 * @param lmeter pointer to a line meter object
 * @return angle of the scale
 */
uint16_t lv_lmeter_get_scale_angle(const lv_obj_t * lmeter)
{
    lv_lmeter_ext_t * ext = lv_obj_get_ext_attr(lmeter);
    return ext->scale_angle;
}

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

/**
 * Handle the drawing related tasks of the line meters
 * @param lmeter pointer to an object
 * @param mask 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 true/false, depends on 'mode'
 */
static bool lv_lmeter_design(lv_obj_t * lmeter, const lv_area_t * mask, lv_design_mode_t mode)
{
    /*Return false if the object is not covers the mask_p area*/
    if(mode == LV_DESIGN_COVER_CHK) {
        return false;
    }
    /*Draw the object*/
    else if(mode == LV_DESIGN_DRAW_MAIN) {
        lv_lmeter_ext_t * ext    = lv_obj_get_ext_attr(lmeter);
        const lv_style_t * style = lv_obj_get_style(lmeter);
        lv_opa_t opa_scale       = lv_obj_get_opa_scale(lmeter);
        lv_style_t style_tmp;
        lv_style_copy(&style_tmp, style);

#if LV_USE_GROUP
        lv_group_t * g = lv_obj_get_group(lmeter);
        if(lv_group_get_focused(g) == lmeter) {
            style_tmp.line.width += 1;
        }
#endif

        lv_coord_t r_out = lv_obj_get_width(lmeter) / 2;
        lv_coord_t r_in  = r_out - style->body.padding.left;
        if(r_in < 1) r_in = 1;

        lv_coord_t x_ofs  = lv_obj_get_width(lmeter) / 2 + lmeter->coords.x1;
        lv_coord_t y_ofs  = lv_obj_get_height(lmeter) / 2 + lmeter->coords.y1;
        int16_t angle_ofs = 90 + (360 - ext->scale_angle) / 2;
        int16_t level =
            (int32_t)((int32_t)(ext->cur_value - ext->min_value) * ext->line_cnt) / (ext->max_value - ext->min_value);
        uint8_t i;

        style_tmp.line.color = style->body.main_color;

        /*Calculate every coordinate in a bigger size to make rounding later*/
        r_out = r_out << LV_LMETER_LINE_UPSCALE;
        r_in  = r_in << LV_LMETER_LINE_UPSCALE;

        for(i = 0; i < ext->line_cnt; i++) {
            /*Calculate the position a scale label*/
            int16_t angle = (i * ext->scale_angle) / (ext->line_cnt - 1) + angle_ofs;

            lv_coord_t y_out = (int32_t)((int32_t)lv_trigo_sin(angle) * r_out) >> LV_TRIGO_SHIFT;
            lv_coord_t x_out = (int32_t)((int32_t)lv_trigo_sin(angle + 90) * r_out) >> LV_TRIGO_SHIFT;
            lv_coord_t y_in  = (int32_t)((int32_t)lv_trigo_sin(angle) * r_in) >> LV_TRIGO_SHIFT;
            lv_coord_t x_in  = (int32_t)((int32_t)lv_trigo_sin(angle + 90) * r_in) >> LV_TRIGO_SHIFT;

            /*Rounding*/
            x_out = lv_lmeter_coord_round(x_out);
            x_in  = lv_lmeter_coord_round(x_in);
            y_out = lv_lmeter_coord_round(y_out);
            y_in  = lv_lmeter_coord_round(y_in);

            lv_point_t p1;
            lv_point_t p2;

            p2.x = x_in + x_ofs;
            p2.y = y_in + y_ofs;

            p1.x = x_out + x_ofs;
            p1.y = y_out + y_ofs;

            if(i >= level)
                style_tmp.line.color = style->line.color;
            else {
                style_tmp.line.color =
                    lv_color_mix(style->body.grad_color, style->body.main_color, (255 * i) / ext->line_cnt);
            }

            lv_draw_line(&p1, &p2, mask, &style_tmp, opa_scale);
        }

    }
    /*Post draw when the children are drawn*/
    else if(mode == LV_DESIGN_DRAW_POST) {
    }

    return true;
}

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

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

    if(sign == LV_SIGNAL_CLEANUP) {
        /*Nothing to cleanup. (No dynamically allocated memory in 'ext')*/
    } else if(sign == LV_SIGNAL_STYLE_CHG) {
        lv_obj_refresh_ext_draw_pad(lmeter);
    } else if(sign == LV_SIGNAL_REFR_EXT_DRAW_PAD) {
        const lv_style_t * style = lv_lmeter_get_style(lmeter, LV_LMETER_STYLE_MAIN);
        lmeter->ext_draw_pad     = LV_MATH_MAX(lmeter->ext_draw_pad, style->line.width);
    } else if(sign == LV_SIGNAL_GET_TYPE) {
        lv_obj_type_t * buf = param;
        uint8_t i;
        for(i = 0; i < LV_MAX_ANCESTOR_NUM - 1; i++) { /*Find the last set data*/
            if(buf->type[i] == NULL) break;
        }
        buf->type[i] = "lv_lmeter";
    }

    return res;
}

/**
 * Round a coordinate which is upscaled  (>=x.5 -> x + 1;   <x.5 -> x)
 * @param x a coordinate which is greater then it should be
 * @return the downscaled and rounded coordinate  (+-1)
 */
static lv_coord_t lv_lmeter_coord_round(int32_t x)
{
#if LV_LMETER_LINE_UPSCALE > 0
    bool was_negative = false;
    if(x < 0) {
        was_negative = true;
        x            = -x;
    }

    x = (x >> LV_LMETER_LINE_UPSCALE) + ((x & LV_LMETER_LINE_UPSCALE_MASK) >> (LV_LMETER_LINE_UPSCALE - 1));

    if(was_negative) x = -x;

    return x;
#else
    return x;
#endif
}

#endif