77 lines
2.3 KiB
Python
77 lines
2.3 KiB
Python
def draw_event_cb(e):
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obj = e.get_target()
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# Add the faded area before the lines are drawn
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dsc = lv.obj_draw_part_dsc_t.__cast__(e.get_param())
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if dsc.part != lv.PART.ITEMS:
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return
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if not dsc.p1 or not dsc.p2:
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return
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# Add a line mask that keeps the area below the line
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line_mask_param = lv.draw_mask_line_param_t()
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line_mask_param.points_init(dsc.p1.x, dsc.p1.y, dsc.p2.x, dsc.p2.y, lv.DRAW_MASK_LINE_SIDE.BOTTOM)
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# line_mask_id = line_mask_param.draw_mask_add(None)
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line_mask_id = lv.draw_mask_add(line_mask_param, None)
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# Add a fade effect: transparent bottom covering top
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h = obj.get_height()
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fade_mask_param = lv.draw_mask_fade_param_t()
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coords = lv.area_t()
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obj.get_coords(coords)
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fade_mask_param.init(coords, lv.OPA.COVER, coords.y1 + h // 8, lv.OPA.TRANSP,coords.y2)
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fade_mask_id = lv.draw_mask_add(fade_mask_param,None)
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# Draw a rectangle that will be affected by the mask
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draw_rect_dsc = lv.draw_rect_dsc_t()
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draw_rect_dsc.init()
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draw_rect_dsc.bg_opa = lv.OPA._20
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draw_rect_dsc.bg_color = dsc.line_dsc.color
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a = lv.area_t()
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a.x1 = dsc.p1.x
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a.x2 = dsc.p2.x - 1
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a.y1 = min(dsc.p1.y, dsc.p2.y)
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coords = lv.area_t()
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obj.get_coords(coords)
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a.y2 = coords.y2
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dsc.draw_ctx.rect(draw_rect_dsc, a)
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# Remove the masks
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lv.draw_mask_remove_id(line_mask_id)
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lv.draw_mask_remove_id(fade_mask_id)
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def add_data(timer):
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# LV_UNUSED(timer);
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cnt = 0
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chart1.set_next_value(ser1, lv.rand(20, 90))
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if cnt % 4 == 0:
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chart1.set_next_value(ser2, lv.rand(40, 60))
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cnt +=1
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#
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# Add a faded area effect to the line chart
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#
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# Create a chart1
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chart1 = lv.chart(lv.scr_act())
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chart1.set_size(200, 150)
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chart1.center()
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chart1.set_type(lv.chart.TYPE.LINE) # Show lines and points too
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chart1.add_event_cb(draw_event_cb, lv.EVENT.DRAW_PART_BEGIN, None)
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chart1.set_update_mode(lv.chart.UPDATE_MODE.CIRCULAR)
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# Add two data series
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ser1 = chart1.add_series(lv.palette_main(lv.PALETTE.RED), lv.chart.AXIS.PRIMARY_Y)
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ser2 = chart1.add_series(lv.palette_main(lv.PALETTE.BLUE), lv.chart.AXIS.SECONDARY_Y)
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for i in range(10):
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chart1.set_next_value(ser1, lv.rand(20, 90))
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chart1.set_next_value(ser2, lv.rand(30, 70))
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timer = lv.timer_create(add_data, 200, None)
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