Description
I want a translucent rectangle to be drawn on top of all chart elements
What MCU/Processor/Board and compiler are you using?
PIC32MZ
What LVGL version are you using?
8.3
What do you want to achieve?
Overlay any drawings on the chart
What have you tried so far?
I start drawing on chart on LV_EVENT_DRAW_PART_END event.
I set transparency draw_rect_dsc.bg_opa = LV_OPA_10; But the rectangle is not at the top level and is not transparent.
Code to reproduce
static void cb_Chart(lv_event_t *e)
{
lv_obj_t *obj = lv_event_get_target(e);
lv_obj_draw_part_dsc_t *dsc = lv_event_get_draw_part_dsc(e);
lv_draw_rect_dsc_t draw_rect_dsc;
lv_draw_rect_dsc_init(&draw_rect_dsc);
draw_rect_dsc.bg_opa = LV_OPA_10;
draw_rect_dsc.bg_color = lv_color_hex(0xff0000);
lv_area_t a;
a.x1 = obj->coords.x1 + 20;
a.y1 = obj->coords.y1 + 20;
a.x2 = obj->coords.x1 + 40;
a.y2 = obj->coords.y1 + 80;
lv_draw_rect(dsc->draw_ctx, &draw_rect_dsc, &a);
}
in main code
…
lv_obj_add_event_cb(Chart, cb_Chart, LV_EVENT_DRAW_PART_END, NULL);
…
