#include "../lv_examples.h"
#if LV_BUILD_EXAMPLES && LV_USE_LABEL

#if LV_USE_DRAW_SW_COMPLEX_GRADIENTS

static void position_bullet(lv_event_t * e, lv_point_t * p)
{
    lv_indev_t * indev = lv_event_get_param(e);
    lv_indev_get_point(indev, p);

    lv_obj_t * bullet = lv_event_get_target(e);
    lv_obj_t * parent = lv_obj_get_parent(bullet);

    p->x -= lv_obj_get_x(parent);
    p->y -= lv_obj_get_y(parent);

    int32_t w = lv_obj_get_width(parent);
    int32_t h = lv_obj_get_height(parent);
    lv_obj_set_pos(bullet, LV_CLAMP(5, p->x, w - 20), LV_CLAMP(5, p->y, h - 20));
}

static void focal_event_cb(lv_event_t * e)
{
    lv_style_t * style = lv_event_get_user_data(e);
    lv_style_value_t v;
    lv_style_get_prop(style, LV_STYLE_BG_GRAD, &v);
    lv_grad_dsc_t * dsc = (lv_grad_dsc_t *)v.ptr;

    lv_point_t p;
    position_bullet(e, &p);

    dsc->params.radial.focal.x = p.x;
    dsc->params.radial.focal.y = p.y;
    dsc->params.radial.focal_extent.x = p.x + 10;
    dsc->params.radial.focal_extent.y = p.y;

    lv_obj_t * bullet = lv_event_get_target(e);
    lv_obj_t * parent = lv_obj_get_parent(bullet);
    lv_obj_invalidate(parent);
}

static void end_event_cb(lv_event_t * e)
{
    lv_style_t * style = lv_event_get_user_data(e);
    lv_style_value_t v;
    lv_style_get_prop(style, LV_STYLE_BG_GRAD, &v);
    lv_grad_dsc_t * dsc = (lv_grad_dsc_t *)v.ptr;

    lv_point_t p;
    position_bullet(e, &p);

    dsc->params.radial.end.x = p.x;
    dsc->params.radial.end.y = p.y;
    dsc->params.radial.end_extent.x = p.x + 100;
    dsc->params.radial.end_extent.y = p.y;
    lv_obj_t * bullet = lv_event_get_target(e);
    lv_obj_t * parent = lv_obj_get_parent(bullet);
    lv_obj_invalidate(parent);
}

/**
 * Play with the radial gradient
 * Adjust the end circle and focal point position.
 * The radius of the end circle and an focal point are hardcoded in the example.
 */
void lv_example_grad_3(void)
{
    static const lv_color_t grad_colors[2] = {
        LV_COLOR_MAKE(0xff, 0x00, 0x00),
        LV_COLOR_MAKE(0x00, 0xff, 0x00),
    };

    static const lv_opa_t grad_opa[2] = {
        LV_OPA_100,
        LV_OPA_0,
    };

    static lv_style_t style;
    lv_style_init(&style);

    /*First define a color gradient. In this example we use a purple to black color map.*/
    static lv_grad_dsc_t grad;

    lv_grad_init_stops(&grad, grad_colors, grad_opa, NULL, sizeof(grad_colors) / sizeof(lv_color_t));

    /*Init a radial gradient where the center is at 100;100
     *and the edge of the circle is at 200;100.
     *Try LV_GRAD_EXTEND_REFLECT and LV_GRAD_EXTEND_REPEAT too. */
    lv_grad_radial_init(&grad, 100, 100, 200, 100, LV_GRAD_EXTEND_PAD);

    /*The gradient will be calculated between the focal point's circle and the
     *edge of the circle. If the center of the focal point and the
     *center of the main circle is the same, the gradient will spread
     *evenly in all directions. The focal point should be inside the
     *main circle.*/
    lv_grad_radial_set_focal(&grad, 50, 50, 10);

    /*Set the widget containing the gradient*/
    lv_style_set_bg_grad(&style, &grad);
    lv_style_set_border_width(&style, 2);
    lv_style_set_pad_all(&style, 0);
    lv_style_set_radius(&style, 12);

    /*Create an object with the new style*/
    lv_obj_t * obj = lv_obj_create(lv_screen_active());
    lv_obj_add_style(obj, &style, 0);
    lv_obj_set_size(obj, lv_pct(80), lv_pct(80));
    lv_obj_center(obj);

    lv_obj_t * focal = lv_button_create(obj);
    lv_obj_set_size(focal, 15, 15);
    lv_obj_set_style_bg_color(focal, lv_color_hex(0x0000ff), 0);
    lv_obj_add_event_cb(focal, focal_event_cb, LV_EVENT_PRESSING, &style);
    lv_obj_set_ext_click_area(focal, 5);
    lv_obj_set_pos(focal, 50, 50);

    lv_obj_t * end = lv_button_create(obj);
    lv_obj_set_size(end, 15, 15);
    lv_obj_set_style_bg_color(end, lv_color_hex(0x00ffff), 0);
    lv_obj_add_event_cb(end, end_event_cb, LV_EVENT_PRESSING, &style);
    lv_obj_set_ext_click_area(end, 5);
    lv_obj_set_pos(end, 100, 100);
}
#else

void lv_example_grad_3(void)
{
    lv_obj_t * label = lv_label_create(lv_screen_active());
    lv_label_set_text(label, "LV_USE_DRAW_SW_COMPLEX_GRADIENTS needs to be enabled");
    lv_obj_center(label);
}

#endif /*LV_USE_DRAW_SW_COMPLEX_GRADIENTS*/

#endif