1 #include "../../lv_examples.h"
2 #if LV_USE_CHART && LV_BUILD_EXAMPLES
3
event_cb(lv_event_t * e)4 static void event_cb(lv_event_t * e)
5 {
6 lv_event_code_t code = lv_event_get_code(e);
7 lv_obj_t * chart = lv_event_get_target(e);
8
9 if(code == LV_EVENT_VALUE_CHANGED) {
10 lv_obj_invalidate(chart);
11 }
12 if(code == LV_EVENT_REFR_EXT_DRAW_SIZE) {
13 int32_t * s = lv_event_get_param(e);
14 *s = LV_MAX(*s, 20);
15 }
16 else if(code == LV_EVENT_DRAW_POST_END) {
17 int32_t id = lv_chart_get_pressed_point(chart);
18 if(id == LV_CHART_POINT_NONE) return;
19
20 LV_LOG_USER("Selected point %d", (int)id);
21
22 lv_chart_series_t * ser = lv_chart_get_series_next(chart, NULL);
23 while(ser) {
24 lv_point_t p;
25 lv_chart_get_point_pos_by_id(chart, ser, id, &p);
26
27 int32_t * y_array = lv_chart_get_y_array(chart, ser);
28 int32_t value = y_array[id];
29
30 /*Draw a rectangle above the clicked point*/
31 lv_layer_t * layer = lv_event_get_layer(e);
32 lv_draw_rect_dsc_t draw_rect_dsc;
33 lv_draw_rect_dsc_init(&draw_rect_dsc);
34 draw_rect_dsc.bg_color = lv_color_black();
35 draw_rect_dsc.bg_opa = LV_OPA_50;
36 draw_rect_dsc.radius = 3;
37
38 lv_area_t chart_obj_coords;
39 lv_obj_get_coords(chart, &chart_obj_coords);
40 lv_area_t rect_area;
41 rect_area.x1 = chart_obj_coords.x1 + p.x - 20;
42 rect_area.x2 = chart_obj_coords.x1 + p.x + 20;
43 rect_area.y1 = chart_obj_coords.y1 + p.y - 30;
44 rect_area.y2 = chart_obj_coords.y1 + p.y - 10;
45 lv_draw_rect(layer, &draw_rect_dsc, &rect_area);
46
47 /*Draw the value as label to the center of the rectangle*/
48 char buf[16];
49 lv_snprintf(buf, sizeof(buf), LV_SYMBOL_DUMMY"$%d", value);
50
51 lv_draw_label_dsc_t draw_label_dsc;
52 lv_draw_label_dsc_init(&draw_label_dsc);
53 draw_label_dsc.color = lv_color_white();
54 draw_label_dsc.text = buf;
55 draw_label_dsc.text_local = 1;
56 draw_label_dsc.align = LV_TEXT_ALIGN_CENTER;
57 lv_area_t label_area = rect_area;
58 lv_area_set_height(&label_area, lv_font_get_line_height(draw_label_dsc.font));
59 lv_area_align(&rect_area, &label_area, LV_ALIGN_CENTER, 0, 0);
60 lv_draw_label(layer, &draw_label_dsc, &label_area);
61
62 ser = lv_chart_get_series_next(chart, ser);
63 }
64 }
65 else if(code == LV_EVENT_RELEASED) {
66 lv_obj_invalidate(chart);
67 }
68 }
69
70 /**
71 * Show the value of the pressed points
72 */
lv_example_chart_3(void)73 void lv_example_chart_3(void)
74 {
75 /*Create a chart*/
76 lv_obj_t * chart;
77 chart = lv_chart_create(lv_screen_active());
78 lv_obj_set_size(chart, 200, 150);
79 lv_obj_center(chart);
80
81 lv_obj_add_event_cb(chart, event_cb, LV_EVENT_ALL, NULL);
82 lv_obj_refresh_ext_draw_size(chart);
83
84 /*Zoom in a little in X*/
85 // lv_chart_set_scale_x(chart, 800);
86
87 /*Add two data series*/
88 lv_chart_series_t * ser1 = lv_chart_add_series(chart, lv_palette_main(LV_PALETTE_RED), LV_CHART_AXIS_PRIMARY_Y);
89 lv_chart_series_t * ser2 = lv_chart_add_series(chart, lv_palette_main(LV_PALETTE_GREEN), LV_CHART_AXIS_PRIMARY_Y);
90 uint32_t i;
91 for(i = 0; i < 10; i++) {
92 lv_chart_set_next_value(chart, ser1, lv_rand(60, 90));
93 lv_chart_set_next_value(chart, ser2, lv_rand(10, 40));
94 }
95 }
96
97 #endif
98
