lvgl_cpp/examples/anim/lv_example_anim_3.c

#include "../lv_examples.h"
#if LV_BUILD_EXAMPLES && LV_USE_SLIDER && LV_USE_CHART && LV_USE_BTN

/**
 * the example show the use of cubic-bezier3 in animation.
 * the control point P1,P2 of cubic-bezier3 can be adjusted by slider.
 * and the chart shows the cubic-bezier3 in real time. you can click
 * run button see animation in current point of cubic-bezier3.
 */

#define CHART_POINTS_NUM 256

struct {
    lv_obj_t * anim_obj;
    lv_obj_t * chart;
    lv_chart_series_t * ser1;
    lv_obj_t * p1_slider;
    lv_obj_t * p1_label;
    lv_obj_t * p2_slider;
    lv_obj_t * p2_label;
    lv_obj_t * run_btn;
    uint16_t p1;
    uint16_t p2;
    lv_anim_t a;
} ginfo;

static int32_t anim_path_bezier3_cb(const lv_anim_t * a);
static void refer_chart_cubic_bezier(void);
static void run_btn_event_handler(lv_event_t * e);
static void slider_event_cb(lv_event_t * e);
static void page_obj_init(lv_obj_t * par);
static void anim_x_cb(void * var, int32_t v);

/**
 * create an animation
 */
void lv_example_anim_3(void)
{
    static lv_coord_t col_dsc[] = {LV_GRID_FR(1), 200, LV_GRID_FR(1), LV_GRID_TEMPLATE_LAST};
    static lv_coord_t row_dsc[] = {30, 10, 10, LV_GRID_FR(1), LV_GRID_TEMPLATE_LAST};

    /*Create a container with grid*/
    lv_obj_t * cont = lv_obj_create(lv_scr_act());
    lv_obj_set_style_pad_all(cont, 2, LV_PART_MAIN);
    lv_obj_set_style_pad_column(cont, 10, LV_PART_MAIN);
    lv_obj_set_style_pad_row(cont, 10, LV_PART_MAIN);
    lv_obj_set_grid_dsc_array(cont, col_dsc, row_dsc);
    lv_obj_set_size(cont, 320, 240);
    lv_obj_center(cont);

    page_obj_init(cont);

    lv_anim_init(&ginfo.a);
    lv_anim_set_var(&ginfo.a, ginfo.anim_obj);
    int32_t end = lv_obj_get_style_width(cont, LV_PART_MAIN) -
                  lv_obj_get_style_width(ginfo.anim_obj, LV_PART_MAIN) - 10;
    lv_anim_set_values(&ginfo.a, 5, end);
    lv_anim_set_time(&ginfo.a, 2000);
    lv_anim_set_exec_cb(&ginfo.a, anim_x_cb);
    lv_anim_set_path_cb(&ginfo.a, anim_path_bezier3_cb);

    refer_chart_cubic_bezier();
}

static int32_t anim_path_bezier3_cb(const lv_anim_t * a)
{
    uint32_t t = lv_map(a->act_time, 0, a->time, 0, 1024);
    int32_t step = lv_bezier3(t, 0, ginfo.p1, ginfo.p2, 1024);
    int32_t new_value;
    new_value = step * (a->end_value - a->start_value);
    new_value = new_value >> 10;
    new_value += a->start_value;
    return new_value;
}

static void refer_chart_cubic_bezier(void)
{
    for(uint16_t i = 0; i <= CHART_POINTS_NUM; i ++) {
        uint32_t t = i * (1024 / CHART_POINTS_NUM);
        int32_t step = lv_bezier3(t, 0, ginfo.p1, ginfo.p2, 1024);
        lv_chart_set_value_by_id2(ginfo.chart, ginfo.ser1, i, t, step);
    }
    lv_chart_refresh(ginfo.chart);
}

static void anim_x_cb(void * var, int32_t v)
{
    lv_obj_set_style_translate_x(var, v, LV_PART_MAIN);
}

static void run_btn_event_handler(lv_event_t * e)
{
    lv_event_code_t code = lv_event_get_code(e);
    if(code == LV_EVENT_CLICKED) {
        lv_anim_start(&ginfo.a);
    }
}

static void slider_event_cb(lv_event_t * e)
{
    char buf[16];
    lv_obj_t * label;
    lv_obj_t * slider = lv_event_get_target(e);

    if(slider == ginfo.p1_slider) {
        label = ginfo.p1_label;
        ginfo.p1 = lv_slider_get_value(slider);
        lv_snprintf(buf, sizeof(buf), "p1:%d", ginfo.p1);
    }
    else {
        label = ginfo.p2_label;
        ginfo.p2 = lv_slider_get_value(slider);
        lv_snprintf(buf, sizeof(buf), "p2:%d", ginfo.p2);
    }

    lv_label_set_text(label, buf);
    refer_chart_cubic_bezier();
}

static void page_obj_init(lv_obj_t * par)
{
    ginfo.anim_obj = lv_obj_create(par);
    lv_obj_set_size(ginfo.anim_obj, 30, 30);
    lv_obj_set_align(ginfo.anim_obj, LV_ALIGN_TOP_LEFT);
    lv_obj_clear_flag(ginfo.anim_obj, LV_OBJ_FLAG_SCROLLABLE);
    lv_obj_set_style_bg_color(ginfo.anim_obj, lv_palette_main(LV_PALETTE_RED), LV_PART_MAIN);
    lv_obj_set_grid_cell(ginfo.anim_obj, LV_GRID_ALIGN_START, 0, 1, LV_GRID_ALIGN_START, 0, 1);

    ginfo.p1_label = lv_label_create(par);
    ginfo.p2_label = lv_label_create(par);
    lv_label_set_text(ginfo.p1_label, "p1:0");
    lv_label_set_text(ginfo.p2_label, "p2:0");
    lv_obj_set_grid_cell(ginfo.p1_label, LV_GRID_ALIGN_START, 0, 1, LV_GRID_ALIGN_START, 1, 1);
    lv_obj_set_grid_cell(ginfo.p2_label, LV_GRID_ALIGN_START, 0, 1, LV_GRID_ALIGN_START, 2, 1);

    ginfo.p1_slider = lv_slider_create(par);
    ginfo.p2_slider = lv_slider_create(par);
    lv_slider_set_range(ginfo.p1_slider, 0, 1024);
    lv_slider_set_range(ginfo.p2_slider, 0, 1024);
    lv_obj_set_style_pad_all(ginfo.p1_slider, 2, LV_PART_KNOB);
    lv_obj_set_style_pad_all(ginfo.p2_slider, 2, LV_PART_KNOB);
    lv_obj_add_event_cb(ginfo.p1_slider, slider_event_cb, LV_EVENT_VALUE_CHANGED, NULL);
    lv_obj_add_event_cb(ginfo.p2_slider, slider_event_cb, LV_EVENT_VALUE_CHANGED, NULL);
    lv_obj_set_grid_cell(ginfo.p1_slider, LV_GRID_ALIGN_STRETCH, 1, 1, LV_GRID_ALIGN_START, 1, 1);
    lv_obj_set_grid_cell(ginfo.p2_slider, LV_GRID_ALIGN_STRETCH, 1, 1, LV_GRID_ALIGN_START, 2, 1);

    ginfo.run_btn = lv_btn_create(par);
    lv_obj_add_event_cb(ginfo.run_btn, run_btn_event_handler, LV_EVENT_CLICKED, NULL);
    lv_obj_t * btn_label = lv_label_create(ginfo.run_btn);
    lv_label_set_text(btn_label, LV_SYMBOL_PLAY);
    lv_obj_center(btn_label);
    lv_obj_set_grid_cell(ginfo.run_btn, LV_GRID_ALIGN_STRETCH, 2, 1, LV_GRID_ALIGN_STRETCH, 1, 2);

    ginfo.chart = lv_chart_create(par);
    lv_obj_set_style_pad_all(ginfo.chart, 0, LV_PART_MAIN);
    lv_obj_set_style_size(ginfo.chart, 0, LV_PART_INDICATOR);
    lv_chart_set_type(ginfo.chart, LV_CHART_TYPE_SCATTER);
    ginfo.ser1 = lv_chart_add_series(ginfo.chart, lv_palette_main(LV_PALETTE_RED), LV_CHART_AXIS_PRIMARY_Y);
    lv_chart_set_range(ginfo.chart, LV_CHART_AXIS_PRIMARY_Y, 0, 1024);
    lv_chart_set_range(ginfo.chart, LV_CHART_AXIS_PRIMARY_X, 0, 1024);
    lv_chart_set_point_count(ginfo.chart, CHART_POINTS_NUM);
    lv_obj_set_grid_cell(ginfo.chart, LV_GRID_ALIGN_STRETCH, 0, 3, LV_GRID_ALIGN_STRETCH, 3, 1);
}

#endif