1class ExampleChart_6():
2
3    def __init__(self):
4        self.last_id = -1
5        #
6        # Show cursor on the clicked point
7        #
8
9        chart = lv.chart(lv.scr_act())
10        chart.set_size(200, 150)
11        chart.align(lv.ALIGN.CENTER, 0, -10)
12
13        chart.set_axis_tick(lv.chart.AXIS.PRIMARY_Y, 10, 5, 6, 5, True, 40)
14        chart.set_axis_tick(lv.chart.AXIS.PRIMARY_X, 10, 5, 10, 1, True, 30)
15
16        chart.add_event_cb(self.event_cb, lv.EVENT.ALL, None)
17        chart.refresh_ext_draw_size()
18
19        self.cursor = chart.add_cursor(lv.palette_main(lv.PALETTE.BLUE), lv.DIR.LEFT | lv.DIR.BOTTOM)
20
21        self.ser = chart.add_series(lv.palette_main(lv.PALETTE.RED), lv.chart.AXIS.PRIMARY_Y)
22
23        self.ser_p = []
24        for i in range(10):
25            self.ser_p.append(lv.rand(10,90))
26        self.ser.y_points = self.ser_p
27
28        newser = chart.get_series_next(None)
29        # print("length of data points: ",len(newser.points))
30        chart.set_zoom_x(500)
31
32        label = lv.label(lv.scr_act())
33        label.set_text("Click on a point")
34        label.align_to(chart, lv.ALIGN.OUT_TOP_MID, 0, -5)
35
36
37    def event_cb(self,e):
38
39        code = e.get_code()
40        chart = e.get_target()
41
42        if code == lv.EVENT.VALUE_CHANGED:
43            # print("last_id: ",self.last_id)
44            self.last_id = chart.get_pressed_point()
45            if self.last_id != lv.CHART_POINT.NONE:
46                p = lv.point_t()
47                chart.get_point_pos_by_id(self.ser, self.last_id, p)
48                chart.set_cursor_point(self.cursor, None, self.last_id)
49
50        elif code == lv.EVENT.DRAW_PART_END:
51            # print("EVENT.DRAW_PART_END")
52            dsc = lv.obj_draw_part_dsc_t.__cast__(e.get_param())
53            # if dsc.p1 and dsc.p2:
54                # print("p1, p2", dsc.p1,dsc.p2)
55                # print("p1.y, p2.y", dsc.p1.y, dsc.p2.y)
56                # print("last_id: ",self.last_id)
57            if dsc.part == lv.PART.CURSOR and dsc.p1 and dsc.p2 and dsc.p1.y == dsc.p2.y and self.last_id >= 0:
58
59                v = self.ser_p[self.last_id]
60
61                # print("value: ",v)
62                value_txt = str(v)
63                size = lv.point_t()
64                lv.txt_get_size(size, value_txt, lv.font_default(), 0, 0, lv.COORD.MAX, lv.TEXT_FLAG.NONE)
65
66                a = lv.area_t()
67                a.y2 = dsc.p1.y - 5
68                a.y1 = a.y2 - size.y - 10
69                a.x1 = dsc.p1.x + 10
70                a.x2 = a.x1 + size.x + 10
71
72                draw_rect_dsc = lv.draw_rect_dsc_t()
73                draw_rect_dsc.init()
74                draw_rect_dsc.bg_color = lv.palette_main(lv.PALETTE.BLUE)
75                draw_rect_dsc.radius = 3
76
77                lv.draw_rect(a, dsc.clip_area, draw_rect_dsc)
78
79                draw_label_dsc = lv.draw_label_dsc_t()
80                draw_label_dsc.init()
81                draw_label_dsc.color = lv.color_white()
82                a.x1 += 5
83                a.x2 -= 5
84                a.y1 += 5
85                a.y2 -= 5
86                lv.draw_label(a, dsc.clip_area, draw_label_dsc, value_txt, None)
87
88example_chart_6 = ExampleChart_6()
89