lvgl_cpp/examples/event/lv_example_event_4.c

67 lines
1.7 KiB
C

#include "../lv_examples.h"
#if LV_BUILD_EXAMPLES
static int n = 3;
static lv_obj_t * label = NULL;
static void timer_cb(lv_timer_t * timer)
{
if(n < 3 || n > 32) {
n = 3;
}
else {
static uint32_t old_tick = 0;
uint32_t tick = lv_tick_get();
if(!old_tick) {
old_tick = tick;
}
if(tick - old_tick > 3000) {
n++;
lv_label_set_text_fmt(label, "%d sides", n);
old_tick = tick;
}
}
lv_obj_invalidate(timer->user_data);
}
static void event_cb(lv_event_t * e)
{
/*The original target of the event. Can be the buttons or the container*/
lv_draw_ctx_t * draw_ctx = lv_event_get_draw_ctx(e);
lv_draw_rect_dsc_t draw_dsc;
lv_draw_rect_dsc_init(&draw_dsc);
draw_dsc.bg_color = lv_palette_main(LV_PALETTE_LIGHT_GREEN);
draw_dsc.bg_opa = LV_OPA_COVER;
lv_point_t points[32];
int i, r = 150;
uint32_t tick = lv_tick_get();
for(i = 0; i < n; i++) {
int angle = i * 360 / n + ((tick % 36000) / 100);
lv_coord_t x = 150 + (r * lv_trigo_cos(angle) >> LV_TRIGO_SHIFT), y =
150 + (r * lv_trigo_sin(angle) >> LV_TRIGO_SHIFT);
points[i].x = x;
points[i].y = y;
}
lv_draw_polygon(draw_ctx, &draw_dsc, points, n);
}
/**
* Demonstrate event bubbling
*/
void lv_example_event_4(void)
{
lv_obj_t * cont = lv_obj_create(lv_scr_act());
lv_obj_remove_style_all(cont);
lv_obj_set_size(cont, 300, 300);
label = lv_label_create(cont);
lv_label_set_text_fmt(label, "%d sides", n);
lv_obj_center(label);
lv_obj_add_event_cb(cont, event_cb, LV_EVENT_DRAW_MAIN, NULL);
lv_timer_create(timer_cb, 17, cont);
}
#endif