/**
* Get the value of a needle
* @param gauge pointer to gauge object
* @param needle the id of the needle
* @return the value of the needle [min,max]
*/
int16_t lv_gauge_get_value(lv_obj_t * gauge, uint8_t needle)
{
lv_gauge_ext_t * ext = lv_obj_get_ext_attr(gauge);
int16_t min = lv_gauge_get_min_value(gauge);
if(needle >= ext->needle_count) return min;
return ext->values[needle];
}
/**
* Draw the needles of a gauge
* @param gauge pointer to gauge object
* @param mask mask of drawing
*/
static void lv_gauge_draw_needle(lv_obj_t * gauge, const lv_area_t * mask)
{
lv_style_t style_needle;
lv_gauge_ext_t * ext = lv_obj_get_ext_attr(gauge);
lv_style_t * style = lv_gauge_get_style(gauge);
lv_coord_t r = lv_obj_get_width(gauge) / 2 - style->body.padding.hor;
lv_coord_t x_ofs = lv_obj_get_width(gauge) / 2 + gauge->coords.x1;
lv_coord_t y_ofs = lv_obj_get_height(gauge) / 2 + gauge->coords.y1;
uint16_t angle = lv_lmeter_get_scale_angle(gauge);
int16_t angle_ofs = 90 + (360 - angle) / 2;
int16_t min = lv_gauge_get_min_value(gauge);
int16_t max = lv_gauge_get_max_value(gauge);
lv_point_t p_mid;
lv_point_t p_end;
uint8_t i;
lv_style_copy(&style_needle, style);
p_mid.x = x_ofs;
p_mid.y = y_ofs;
for(i = 0; i < ext->needle_count; i++) {
/*Calculate the end point of a needle*/
int16_t needle_angle = (ext->values[i] - min) * angle / (max - min) + angle_ofs;
p_end.y = (lv_trigo_sin(needle_angle) * r) / LV_TRIGO_SIN_MAX + y_ofs;
p_end.x = (lv_trigo_sin(needle_angle + 90) * r) / LV_TRIGO_SIN_MAX + x_ofs;
/*Draw the needle with the corresponding color*/
if(ext->needle_colors == NULL) style_needle.line.color = LV_GAUGE_DEF_NEEDLE_COLOR;
else style_needle.line.color = ext->needle_colors[i];
lv_draw_line(&p_mid, &p_end, mask, &style_needle);
}
/*Draw the needle middle area*/
lv_style_t style_neddle_mid;
lv_style_copy(&style_neddle_mid, &lv_style_plain);
style_neddle_mid.body.main_color = style->body.border.color;
style_neddle_mid.body.grad_color = style->body.border.color;
style_neddle_mid.body.radius = LV_RADIUS_CIRCLE;
lv_area_t nm_cord;
nm_cord.x1 = x_ofs - style->body.padding.ver;
nm_cord.y1 = y_ofs - style->body.padding.ver;
nm_cord.x2 = x_ofs + style->body.padding.ver;
nm_cord.y2 = y_ofs + style->body.padding.ver;
lv_draw_rect(&nm_cord, mask, &style_neddle_mid);
}
/**
* Set the value of a needle
* @param gauge pointer to a gauge
* @param needle_id the id of the needle
* @param value the new value
*/
void lv_gauge_set_value(lv_obj_t * gauge, uint8_t needle_id, int16_t value)
{
lv_gauge_ext_t * ext = lv_obj_get_ext_attr(gauge);
if(needle_id >= ext->needle_count) return;
int16_t min = lv_gauge_get_min_value(gauge);
int16_t max = lv_gauge_get_max_value(gauge);
if(value > max) value = max;
else if(value < min) value = min;
ext->values[needle_id] = value;
lv_obj_invalidate(gauge);
}
/**
* Draw the scale on a gauge
* @param gauge pointer to gauge object
* @param mask mask of drawing
*/
static void lv_gauge_draw_scale(lv_obj_t * gauge, const lv_area_t * mask)
{
char scale_txt[16];
lv_gauge_ext_t * ext = lv_obj_get_ext_attr(gauge);
lv_style_t * style = lv_obj_get_style(gauge);
lv_coord_t r = lv_obj_get_width(gauge) / 2 - (3 * style->body.padding.hor) - style->body.padding.inner;
lv_coord_t x_ofs = lv_obj_get_width(gauge) / 2 + gauge->coords.x1;
lv_coord_t y_ofs = lv_obj_get_height(gauge) / 2 + gauge->coords.y1;
int16_t scale_angle = lv_lmeter_get_scale_angle(gauge);
uint16_t label_num = ext->label_count;
int16_t angle_ofs = 90 + (360 - scale_angle) / 2;
int16_t min = lv_gauge_get_min_value(gauge);
int16_t max = lv_gauge_get_max_value(gauge);
uint8_t i;
for(i = 0; i < label_num; i++) {
/*Calculate the position a scale label*/
int16_t angle = (i * scale_angle) / (label_num - 1) + angle_ofs;
lv_coord_t y = (int32_t)((int32_t)lv_trigo_sin(angle) * r) / LV_TRIGO_SIN_MAX;
y += y_ofs;
lv_coord_t x = (int32_t)((int32_t)lv_trigo_sin(angle + 90) * r) / LV_TRIGO_SIN_MAX;
x += x_ofs;
int16_t scale_act = (int32_t)((int32_t)(max - min) * i) / (label_num - 1);
scale_act += min;
lv_math_num_to_str(scale_act, scale_txt);
lv_area_t label_cord;
lv_point_t label_size;
lv_txt_get_size(&label_size, scale_txt, style->text.font,
style->text.letter_space, style->text.line_space, LV_COORD_MAX, LV_TXT_FLAG_NONE);
/*Draw the label*/
label_cord.x1 = x - label_size.x / 2;
label_cord.y1 = y - label_size.y / 2;
label_cord.x2 = label_cord.x1 + label_size.x;
label_cord.y2 = label_cord.y1 + label_size.y;
lv_draw_label(&label_cord, mask, style, scale_txt, LV_TXT_FLAG_NONE, NULL);
}
}
/**
* Set the number of needles
* @param gauge pointer to gauge object
* @param needle_cnt new count of needles
* @param colors an array of colors for needles (with 'num' elements)
*/
void lv_gauge_set_needle_count(lv_obj_t * gauge, uint8_t needle_cnt, const lv_color_t * colors)
{
lv_gauge_ext_t * ext = lv_obj_get_ext_attr(gauge);
if(ext->values != NULL) {
lv_mem_free(ext->values);
ext->values = NULL;
}
ext->values = lv_mem_realloc(ext->values, needle_cnt * sizeof(int16_t));
int16_t min = lv_gauge_get_min_value(gauge);
uint8_t n;
for(n = ext->needle_count; n < needle_cnt; n++) {
ext->values[n] = min;
}
ext->needle_count = needle_cnt;
ext->needle_colors = colors;
lv_obj_invalidate(gauge);
}
